test fixes

Reviewed-on: #114

.github/workflows/ci.yml

@@ -1,42 +1,39 @@
-on: [push]
-
 name: ci
+on: [push, pull_request]
 
 jobs:
   check:
-    name: Check
+    name: Check build
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.os }}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@stable
-        with:
+      - run: cargo check --release
-          profile: minimal
-          toolchain: stable
-      - uses: actions-rs/cargo@v1
-        with:
-          command: check
-          args: --release
 
-  msrv:
+  test:
-    name: Check with MSRV
+    name: Run Tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@stable
-        with:
+      - name: Install nextest
-          toolchain: 1.61.0
+        uses: taiki-e/install-action@nextest
-          override: true
+      - run: cargo nextest run --all-features
-          profile: minimal
+      - run: cargo test --doc
-      - uses: actions-rs/cargo@v1
+
-        with:
+  msrv:
-          command: check
+    name: Check MSRV
-          args: --release
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@1.81.0
+      - run: cargo check --release
 
   cross-check:
-    name: Check Cross
+    name: Check Cross-Compilation
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -44,70 +41,32 @@ jobs:
           - armv7-unknown-linux-gnueabihf
           - thumbv7em-none-eabihf
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@stable
         with:
-          profile: minimal
+          targets: "armv7-unknown-linux-gnueabihf, thumbv7em-none-eabihf"
-          toolchain: stable
+      - run: cargo check --release --target=${{matrix.target}} --no-default-features
-          target: ${{ matrix.target }}
-          override: true
-      - uses: actions-rs/cargo@v1
-        with:
-          use-cross: true
-          command: check
-          args: --release --target=${{ matrix.target }} --no-default-features
 
   fmt:
-    name: Rustfmt
+    name: Check formatting
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@stable
-        with:
+      - run: cargo fmt --all -- --check
-          profile: minimal
-          toolchain: stable
-          override: true
-      - run: rustup component add rustfmt
-      - uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: --all -- --check
 
-  check-doc:
+  docs:
     name: Check Documentation Build
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@nightly
-        with:
+      - run: RUSTDOCFLAGS="--cfg docsrs --generate-link-to-definition -Z unstable-options" cargo +nightly doc --all-features
-          toolchain: nightly
-          override: true
-          profile: minimal
-      - uses: actions-rs/cargo@v1
-        with:
-          command: doc
-          args: --all-features
 
   clippy:
     name: Clippy
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
-      - uses: actions-rs/toolchain@v1
+      - uses: dtolnay/rust-toolchain@stable
-        with:
+      - run: cargo clippy -- -D warnings
-          profile: minimal
-          toolchain: stable
-      - run: rustup component add clippy
-      - uses: actions-rs/cargo@v1
-        with:
-          command: clippy
-          args: -- -D warnings
-
-  ci:
-      if: ${{ success() }}
-      # all new jobs must be added to this list
-      needs: [check, fmt, clippy]
-      runs-on: ubuntu-latest
-      steps:
-        - name: CI succeeded
-          run: exit 0

CHANGELOG.md

@@ -8,6 +8,93 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 # [unreleased]
 
+- Bumped MSRV to 1.81.0
+- Bump `zerocopy` to v0.8.0
+- Bump `thiserror` to v2.0.0
+
+# [v0.12.0] 2024-09-10
+
+- Bumped MSRV to 1.70.0
+
+## Added
+
+- Added new `cfdp::tlv::TlvOwned` type which erases the lifetime and is clonable.
+- Dedicated `cfdp::tlv::TlvLvDataTooLarge` error struct for APIs where this is the only possible
+  API error.
+- Added File Data PDU API which expects the expected file data size and then exposes the unwritten
+  file data field as a mutable slice. This allows to read data from the virtual file system
+  API to the file data buffer without an intermediate buffer.
+- Generic `EofPdu::new` constructor.
+- Added generic sequence counter module.
+- Added `MsgToUserTlv::to_tlv` converter which reduced the type and converts
+  it to a generic `Tlv`.
+- Implemented `From<MsgToUserTlv> for Tlv` converter trait.
+- Added CFDP maximum file segment length calculator method `calculate_max_file_seg_len_for_max_packet_len_and_pdu_header`
+
+## Added and Changed
+
+- Added new `ReadableTlv` to avoid some boilerplate code and have a common abstraction implemented
+  for both `Tlv` and `TlvOwned` to read the raw TLV data field and its length.
+- Replaced `cfdp::tlv::TlvLvError` by `cfdp::tlv::TlvLvDataTooLarge` where applicable.
+
+## Fixed
+
+- Fixed an error in the EOF writer which wrote the fault location to the wrong buffer position.
+- cfdp `ConditionCode::CheckLimitReached` previous had the wrong numerical value of `0b1001` (9)
+  and now has the correct value of `0b1010` (10).
+
+## Changed
+
+- Minor documentation build updates.
+- Increased delegate version range to v0.13
+
+# [v0.11.2] 2024-05-19
+
+- Bumped MSRV to 1.68.2
+
+## Fixed
+
+- Removed `defmt::Format` impl for `MetadataPduCreator` which seems to be problematic.
+
+# [v0.11.1] 2024-04-22
+
+## Fixed
+
+- The default data length for for `SpHeader` constructors where the data field length is not
+  specified is now 0.
+- The `SpHeader::new_from_fields` is public now.
+
+## Added
+
+- `SpHeader::to_vec` method.
+
+# [v0.11.0] 2024-04-16
+
+## Changed
+
+- Moved `CCSDS_HEADER_LEN` constant to the crate root.
+
+## Added
+
+- Added `SpacePacketHeader` type alias for `SpHeader` type.
+
+# [v0.11.0-rc.2] 2024-04-04
+
+## Changed
+
+- Renamed `PacketId` and `PacketSequenceCtrl` `new` method to `new_checked` and former
+  `new_const` method to `new`.
+- Renamed `tc`, `tm`, `tc_unseg` and `tm_unseg` variants for `PacketId` and `SpHeader`
+  to `new_for_tc_checked`, `new_for_tm_checked`, `new_for_unseg_tc_checked` and
+  `new_for_unseg_tm_checked`.
+- `PusTmCreator` and `PusTcCreator` now expect a regular instance of `SpHeader` instead of
+  a mutable reference.
+
+## Added
+
+- `SpHeader::new_from_apid` and `SpHeader::new_from_apid_checked` constructor.
+- `#[inline]` attribute for a lot of small functions.
+
 # [v0.11.0-rc.1] 2024-04-03
 
 Major API changes for the time API. If you are using the time API, it is strongly recommended

Cargo.toml

@@ -1,8 +1,8 @@
 [package]
 name = "spacepackets"
-version = "0.11.0-rc.1"
+version = "0.12.0"
 edition = "2021"
-rust-version = "1.61"
+rust-version = "1.81.0"
 authors = ["Robin Mueller <muellerr@irs.uni-stuttgart.de>"]
 description = "Generic implementations for various CCSDS and ECSS packet standards"
 homepage = "https://egit.irs.uni-stuttgart.de/rust/spacepackets"
@@ -14,15 +14,16 @@ categories = ["aerospace", "aerospace::space-protocols", "no-std", "hardware-sup
 
 [dependencies]
 crc = "3"
-delegate = ">=0.8, <0.11"
+delegate = ">=0.8, <=0.13"
+paste = "1"
 
 [dependencies.zerocopy]
-version = "0.7"
+version = "0.8"
 features = ["derive"]
 
 [dependencies.thiserror]
-version = "1"
+version = "2"
-optional = true
+default-features = false
 
 [dependencies.num_enum]
 version = ">0.5, <=0.7"
@@ -52,19 +53,17 @@ default-features = false
 version = "0.3"
 optional = true
 
-[dev-dependencies]
-postcard = "1"
-chrono = "0.4"
-
 [features]
 default = ["std"]
-std = ["chrono/std", "chrono/clock", "alloc", "thiserror"]
+std = ["alloc", "chrono/std", "chrono/clock", "thiserror/std"]
-serde = ["dep:serde", "chrono/serde"]
+serde = ["dep:serde", "chrono?/serde"]
-alloc = ["postcard/alloc", "chrono/alloc"]
+alloc = ["chrono?/alloc", "defmt?/alloc", "serde?/alloc"]
-chrono = ["dep:chrono"]
 timelib = ["dep:time"]
-defmt = ["dep:defmt"]
+
+[dev-dependencies]
+postcard = { version = "1", features = ["alloc"] }
+chrono = "0.4"
 
 [package.metadata.docs.rs]
 all-features = true
-rustdoc-args = ["--cfg", "docs_rs", "--generate-link-to-definition"]
+rustdoc-args = ["--generate-link-to-definition"]

README.md

@@ -29,10 +29,6 @@ Currently, this includes the following components:
 
 `spacepackets` supports various runtime environments and is also suitable for `no_std` environments.
 
-It also offers optional support for [`serde`](https://serde.rs/). This allows serializing and
-deserializing them with an appropriate `serde` provider like
-[`postcard`](https://github.com/jamesmunns/postcard).
-
 ## Default features
 
  - [`std`](https://doc.rust-lang.org/std/): Enables functionality relying on the standard library.
@@ -65,3 +61,13 @@ cargo install grcov --locked
 
 After that, you can simply run `coverage.py` to test the project with coverage. You can optionally
 supply the `--open` flag to open the coverage report in your webbrowser.
+
+# Miri
+
+You can run the [`miri`](https://github.com/rust-lang/miri) tool on this library to check for
+undefined behaviour (UB). This library does not use use any `unsafe` code blocks, but `miri` could
+still catch UB from used libraries.
+
+```sh
+cargo +nightly miri nextest run --all-features
+```

automation/Dockerfile

@@ -15,7 +15,10 @@ RUN rustup install nightly && \
     rustup target add thumbv7em-none-eabihf armv7-unknown-linux-gnueabihf && \
     rustup component add rustfmt clippy llvm-tools-preview
 
+# Get grcov
 RUN curl -sSL https://github.com/mozilla/grcov/releases/download/v0.8.19/grcov-x86_64-unknown-linux-gnu.tar.bz2 | tar -xj --directory /usr/local/bin
+# Get nextest
+RUN curl -LsSf https://get.nexte.st/latest/linux | tar zxf - -C ${CARGO_HOME:-~/.cargo}/bin
 
 # SSH stuff to allow deployment to doc server
 RUN adduser --uid 114 jenkins

automation/Jenkinsfile

@@ -21,7 +21,9 @@ pipeline {
     }
     stage('Docs') {
         steps {
-          sh 'cargo +nightly doc --all-features'
+          sh """
+            RUSTDOCFLAGS="--cfg docsrs --generate-link-to-definition -Z unstable-options" cargo +nightly doc --all-features
+          """
         }
     }
     stage('Rustfmt') {
@@ -31,7 +33,8 @@ pipeline {
     }
     stage('Test') {
       steps {
-        sh 'cargo test --all-features'
+        sh 'cargo nextest r --all-features'
+        sh 'cargo test --doc'
       }
     }
     stage('Check with all features') {

docs.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+export RUSTDOCFLAGS="--cfg docsrs --generate-link-to-definition -Z unstable-options"
+cargo +nightly doc --all-features --open

release-checklist.md

@@ -4,11 +4,14 @@ Checklist for new releases
 # Pre-Release
 
 1. Make sure any new modules are documented sufficiently enough and check docs with
-   `cargo +nightly doc --all-features --config 'build.rustdocflags=["--cfg", "docs_rs"]' --open`.
+   `RUSTDOCFLAGS="--cfg docsrs --generate-link-to-definition -Z unstable-options" cargo +nightly doc --all-features --open`
+   or `cargo +nightly doc --all-features --config 'build.rustdocflags=["--cfg", "docsrs" --generate-link-to-definition"]' --open`
+   (was problematic on more recent nightly versions).
 2. Bump version specifier in `Cargo.toml`.
 3. Update `CHANGELOG.md`: Convert `unreleased` section into version section with date and add new
    `unreleased` section.
-4. Run `cargo test --all-features` or `cargo nextest r --all-features`.
+4. Run `cargo test --all-features` or `cargo nextest r --all-features` together with
+   `cargo test --doc`.
 5. Run `cargo fmt` and `cargo clippy`. Check `cargo msrv` against MSRV in `Cargo.toml`.
 6. Wait for CI/CD results for EGit and Github. These also check cross-compilation for bare-metal
    targets.

src/cfdp/lv.rs

@@ -1,5 +1,4 @@
 //! Generic CFDP length-value (LV) abstraction as specified in CFDP 5.1.8.
-use crate::cfdp::TlvLvError;
 use crate::ByteConversionError;
 use core::str::Utf8Error;
 #[cfg(feature = "serde")]
@@ -7,6 +6,8 @@ use serde::{Deserialize, Serialize};
 #[cfg(feature = "std")]
 use std::string::String;
 
+use super::TlvLvDataTooLargeError;
+
 pub const MIN_LV_LEN: usize = 1;
 
 /// Generic CFDP length-value (LV) abstraction as specified in CFDP 5.1.8.
@@ -62,9 +63,10 @@ pub(crate) fn generic_len_check_deserialization(
 }
 
 impl<'data> Lv<'data> {
-    pub fn new(data: &[u8]) -> Result<Lv, TlvLvError> {
+    #[inline]
+    pub fn new(data: &[u8]) -> Result<Lv, TlvLvDataTooLargeError> {
         if data.len() > u8::MAX as usize {
-            return Err(TlvLvError::DataTooLarge(data.len()));
+            return Err(TlvLvDataTooLargeError(data.len()));
         }
         Ok(Lv {
             data,
@@ -73,6 +75,7 @@ impl<'data> Lv<'data> {
     }
 
     /// Creates a LV with an empty value field.
+    #[inline]
     pub fn new_empty() -> Lv<'data> {
         Lv {
             data: &[],
@@ -82,44 +85,52 @@ impl<'data> Lv<'data> {
 
     /// Helper function to build a string LV. This is especially useful for the file or directory
     /// path LVs
-    pub fn new_from_str(str_slice: &str) -> Result<Lv, TlvLvError> {
+    #[inline]
+    pub fn new_from_str(str_slice: &str) -> Result<Lv, TlvLvDataTooLargeError> {
         Self::new(str_slice.as_bytes())
     }
 
     /// Helper function to build a string LV. This is especially useful for the file or directory
     /// path LVs
     #[cfg(feature = "std")]
-    pub fn new_from_string(string: &'data String) -> Result<Lv<'data>, TlvLvError> {
+    #[inline]
+    pub fn new_from_string(string: &'data String) -> Result<Lv<'data>, TlvLvDataTooLargeError> {
         Self::new(string.as_bytes())
     }
 
     /// Returns the length of the value part, not including the length byte.
+    #[inline]
     pub fn len_value(&self) -> usize {
         self.data.len()
     }
 
     /// Returns the full raw length, including the length byte.
+    #[inline]
     pub fn len_full(&self) -> usize {
         self.len_value() + 1
     }
 
     /// Checks whether the value field is empty.
+    #[inline]
     pub fn is_empty(&self) -> bool {
         self.data.len() == 0
     }
 
+    #[inline]
     pub fn value(&self) -> &[u8] {
         self.data
     }
 
     /// If the LV was generated from a raw bytestream using [Self::from_bytes], the raw start
     /// of the LV can be retrieved with this method.
+    #[inline]
     pub fn raw_data(&self) -> Option<&[u8]> {
         self.raw_data
     }
 
     /// Convenience function to extract the value as a [str]. This is useful if the LV is
     /// known to contain a [str], for example being a file name.
+    #[inline]
     pub fn value_as_str(&self) -> Option<Result<&'data str, Utf8Error>> {
         if self.is_empty() {
             return None;
@@ -135,6 +146,7 @@ impl<'data> Lv<'data> {
     }
 
     /// Reads a LV  from a raw buffer.
+    #[inline]
     pub fn from_bytes(buf: &'data [u8]) -> Result<Lv<'data>, ByteConversionError> {
         generic_len_check_deserialization(buf, MIN_LV_LEN)?;
         Self::from_be_bytes_no_len_check(buf)
@@ -151,6 +163,7 @@ impl<'data> Lv<'data> {
         MIN_LV_LEN + self.data.len()
     }
 
+    #[inline]
     pub(crate) fn from_be_bytes_no_len_check(
         buf: &'data [u8],
     ) -> Result<Lv<'data>, ByteConversionError> {
@@ -165,10 +178,10 @@ impl<'data> Lv<'data> {
 
 #[cfg(test)]
 pub mod tests {
-    use super::*;
     use alloc::string::ToString;
 
-    use crate::cfdp::TlvLvError;
+    use super::*;
+
     use crate::ByteConversionError;
     use std::string::String;
 
@@ -259,15 +272,11 @@ pub mod tests {
         let lv = Lv::new(&data_big);
         assert!(lv.is_err());
         let error = lv.unwrap_err();
-        if let TlvLvError::DataTooLarge(size) = error {
+        assert_eq!(error.0, u8::MAX as usize + 1);
-            assert_eq!(size, u8::MAX as usize + 1);
+        assert_eq!(
-            assert_eq!(
+            error.to_string(),
-                error.to_string(),
+            "data with size 256 larger than allowed 255 bytes"
-                "data with size 256 larger than allowed 255 bytes"
+        );
-            );
-        } else {
-            panic!("invalid exception {:?}", error)
-        }
     }
 
     #[test]

src/cfdp/mod.rs

@@ -1,11 +1,8 @@
 //! Low-level CCSDS File Delivery Protocol (CFDP) support according to [CCSDS 727.0-B-5](https://public.ccsds.org/Pubs/727x0b5.pdf).
 use crate::ByteConversionError;
-use core::fmt::{Display, Formatter};
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-#[cfg(feature = "std")]
-use std::error::Error;
 
 pub mod lv;
 pub mod pdu;
@@ -116,7 +113,7 @@ pub enum ConditionCode {
     FileSizeError = 0b0110,
     NakLimitReached = 0b0111,
     InactivityDetected = 0b1000,
-    CheckLimitReached = 0b1001,
+    CheckLimitReached = 0b1010,
     UnsupportedChecksumType = 0b1011,
     /// Not an actual fault condition for which fault handler overrides can be specified
     SuspendRequestReceived = 0b1110,
@@ -176,76 +173,43 @@ impl Default for ChecksumType {
 
 pub const NULL_CHECKSUM_U32: [u8; 4] = [0; 4];
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[error("data with size {0} larger than allowed {max} bytes", max = u8::MAX)]
+pub struct TlvLvDataTooLargeError(pub usize);
+
+/// First value: Found value. Second value: Expected value if there is one.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[error("invalid TLV type field, found {found}, expected {expected:?}")]
+pub struct InvalidTlvTypeFieldError {
+    found: u8,
+    expected: Option<u8>,
+}
+
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum TlvLvError {
-    DataTooLarge(usize),
+    #[error("{0}")]
-    ByteConversion(ByteConversionError),
+    DataTooLarge(#[from] TlvLvDataTooLargeError),
-    /// First value: Found value. Second value: Expected value if there is one.
+    #[error("byte conversion error: {0}")]
-    InvalidTlvTypeField {
+    ByteConversion(#[from] ByteConversionError),
-        found: u8,
+    #[error("{0}")]
-        expected: Option<u8>,
+    InvalidTlvTypeField(#[from] InvalidTlvTypeFieldError),
-    },
+    #[error("invalid value length {0}")]
-    /// Logically invalid value length detected. The value length may not exceed 255 bytes.
-    /// Depending on the concrete TLV type, the value length may also be logically invalid.
     InvalidValueLength(usize),
     /// Only applies to filestore requests and responses. Second name was missing where one is
     /// expected.
+    #[error("second name missing for filestore request or response")]
     SecondNameMissing,
     /// Invalid action code for filestore requests or responses.
+    #[error("invalid action code {0}")]
     InvalidFilestoreActionCode(u8),
 }
 
-impl From<ByteConversionError> for TlvLvError {
-    fn from(value: ByteConversionError) -> Self {
-        Self::ByteConversion(value)
-    }
-}
-
-impl Display for TlvLvError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            TlvLvError::DataTooLarge(data_len) => {
-                write!(
-                    f,
-                    "data with size {} larger than allowed {} bytes",
-                    data_len,
-                    u8::MAX
-                )
-            }
-            TlvLvError::ByteConversion(e) => {
-                write!(f, "tlv or lv byte conversion: {}", e)
-            }
-            TlvLvError::InvalidTlvTypeField { found, expected } => {
-                write!(
-                    f,
-                    "invalid TLV type field, found {found}, expected {expected:?}"
-                )
-            }
-            TlvLvError::InvalidValueLength(len) => {
-                write!(f, "invalid value length {len}")
-            }
-            TlvLvError::SecondNameMissing => {
-                write!(f, "second name missing for filestore request or response")
-            }
-            TlvLvError::InvalidFilestoreActionCode(raw) => {
-                write!(f, "invalid filestore action code with raw value {raw}")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for TlvLvError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        match self {
-            TlvLvError::ByteConversion(e) => Some(e),
-            _ => None,
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

src/cfdp/pdu/eof.rs

@@ -25,20 +25,36 @@ pub struct EofPdu {
 }
 
 impl EofPdu {
-    pub fn new_no_error(mut pdu_header: PduHeader, file_checksum: u32, file_size: u64) -> Self {
+    pub fn new(
+        mut pdu_header: PduHeader,
+        condition_code: ConditionCode,
+        file_checksum: u32,
+        file_size: u64,
+        fault_location: Option<EntityIdTlv>,
+    ) -> Self {
         // Force correct direction flag.
         pdu_header.pdu_conf.direction = Direction::TowardsReceiver;
         let mut eof_pdu = Self {
             pdu_header,
-            condition_code: ConditionCode::NoError,
+            condition_code,
             file_checksum,
             file_size,
-            fault_location: None,
+            fault_location,
         };
         eof_pdu.pdu_header.pdu_datafield_len = eof_pdu.calc_pdu_datafield_len() as u16;
         eof_pdu
     }
 
+    pub fn new_no_error(pdu_header: PduHeader, file_checksum: u32, file_size: u64) -> Self {
+        Self::new(
+            pdu_header,
+            ConditionCode::NoError,
+            file_checksum,
+            file_size,
+            None,
+        )
+    }
+
     pub fn pdu_header(&self) -> &PduHeader {
         &self.pdu_header
     }
@@ -148,7 +164,7 @@ impl WritablePduPacket for EofPdu {
             &mut buf[current_idx..],
         )?;
         if let Some(fault_location) = self.fault_location {
-            current_idx += fault_location.write_to_bytes(buf)?;
+            current_idx += fault_location.write_to_bytes(&mut buf[current_idx..])?;
         }
         if self.crc_flag() == CrcFlag::WithCrc {
             current_idx = add_pdu_crc(buf, current_idx);
@@ -171,13 +187,23 @@ mod tests {
     use crate::cfdp::{ConditionCode, CrcFlag, LargeFileFlag, PduType, TransmissionMode};
     #[cfg(feature = "serde")]
     use crate::tests::generic_serde_test;
+    use crate::util::{UnsignedByteFieldU16, UnsignedEnum};
 
-    fn verify_state(&eof_pdu: &EofPdu, file_flag: LargeFileFlag) {
+    fn verify_state_no_error_no_crc(eof_pdu: &EofPdu, file_flag: LargeFileFlag) {
+        verify_state(eof_pdu, CrcFlag::NoCrc, file_flag, ConditionCode::NoError);
+    }
+
+    fn verify_state(
+        eof_pdu: &EofPdu,
+        crc_flag: CrcFlag,
+        file_flag: LargeFileFlag,
+        cond_code: ConditionCode,
+    ) {
         assert_eq!(eof_pdu.file_checksum(), 0x01020304);
         assert_eq!(eof_pdu.file_size(), 12);
-        assert_eq!(eof_pdu.condition_code(), ConditionCode::NoError);
+        assert_eq!(eof_pdu.condition_code(), cond_code);
 
-        assert_eq!(eof_pdu.crc_flag(), CrcFlag::NoCrc);
+        assert_eq!(eof_pdu.crc_flag(), crc_flag);
         assert_eq!(eof_pdu.file_flag(), file_flag);
         assert_eq!(eof_pdu.pdu_type(), PduType::FileDirective);
         assert_eq!(
@@ -197,7 +223,7 @@ mod tests {
         let pdu_header = PduHeader::new_no_file_data(pdu_conf, 0);
         let eof_pdu = EofPdu::new_no_error(pdu_header, 0x01020304, 12);
         assert_eq!(eof_pdu.len_written(), pdu_header.header_len() + 2 + 4 + 4);
-        verify_state(&eof_pdu, LargeFileFlag::Normal);
+        verify_state_no_error_no_crc(&eof_pdu, LargeFileFlag::Normal);
     }
 
     #[test]
@@ -271,7 +297,7 @@ mod tests {
         buf[written - 1] -= 1;
         let crc: u16 = ((buf[written - 2] as u16) << 8) as u16 | buf[written - 1] as u16;
         let error = EofPdu::from_bytes(&buf).unwrap_err();
-        if let PduError::ChecksumError(e) = error {
+        if let PduError::Checksum(e) = error {
             assert_eq!(e, crc);
         } else {
             panic!("expected crc error");
@@ -283,7 +309,7 @@ mod tests {
         let pdu_conf = common_pdu_conf(CrcFlag::NoCrc, LargeFileFlag::Large);
         let pdu_header = PduHeader::new_no_file_data(pdu_conf, 0);
         let eof_pdu = EofPdu::new_no_error(pdu_header, 0x01020304, 12);
-        verify_state(&eof_pdu, LargeFileFlag::Large);
+        verify_state_no_error_no_crc(&eof_pdu, LargeFileFlag::Large);
         assert_eq!(eof_pdu.len_written(), pdu_header.header_len() + 2 + 8 + 4);
     }
 
@@ -295,4 +321,48 @@ mod tests {
         let eof_pdu = EofPdu::new_no_error(pdu_header, 0x01020304, 12);
         generic_serde_test(eof_pdu);
     }
+
+    fn generic_test_with_fault_location_and_error(crc: CrcFlag) {
+        let pdu_conf = common_pdu_conf(crc, LargeFileFlag::Normal);
+        let pdu_header = PduHeader::new_no_file_data(pdu_conf, 0);
+        let eof_pdu = EofPdu::new(
+            pdu_header,
+            ConditionCode::FileChecksumFailure,
+            0x01020304,
+            12,
+            Some(EntityIdTlv::new(UnsignedByteFieldU16::new(5).into())),
+        );
+        let mut expected_len = pdu_header.header_len() + 2 + 4 + 4 + 4;
+        if crc == CrcFlag::WithCrc {
+            expected_len += 2;
+        }
+        // Entity ID TLV increaes length by 4.
+        assert_eq!(eof_pdu.len_written(), expected_len);
+        verify_state(
+            &eof_pdu,
+            crc,
+            LargeFileFlag::Normal,
+            ConditionCode::FileChecksumFailure,
+        );
+        let eof_vec = eof_pdu.to_vec().unwrap();
+        let eof_read_back = EofPdu::from_bytes(&eof_vec);
+        if let Err(e) = eof_read_back {
+            panic!("deserialization failed with: {e}")
+        }
+        let eof_read_back = eof_read_back.unwrap();
+        assert_eq!(eof_read_back, eof_pdu);
+        assert!(eof_read_back.fault_location.is_some());
+        assert_eq!(eof_read_back.fault_location.unwrap().entity_id().value(), 5);
+        assert_eq!(eof_read_back.fault_location.unwrap().entity_id().size(), 2);
+    }
+
+    #[test]
+    fn test_with_fault_location_and_error() {
+        generic_test_with_fault_location_and_error(CrcFlag::NoCrc);
+    }
+
+    #[test]
+    fn test_with_fault_location_and_error_and_crc() {
+        generic_test_with_fault_location_and_error(CrcFlag::WithCrc);
+    }
 }

src/cfdp/pdu/file_data.rs

@@ -92,16 +92,67 @@ impl<'seg_meta> SegmentMetadata<'seg_meta> {
     }
 }
 
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+struct FdPduBase<'seg_meta> {
+    pdu_header: PduHeader,
+    #[cfg_attr(feature = "serde", serde(borrow))]
+    segment_metadata: Option<SegmentMetadata<'seg_meta>>,
+    offset: u64,
+}
+
+impl CfdpPdu for FdPduBase<'_> {
+    fn pdu_header(&self) -> &PduHeader {
+        &self.pdu_header
+    }
+
+    fn file_directive_type(&self) -> Option<FileDirectiveType> {
+        None
+    }
+}
+
+impl FdPduBase<'_> {
+    fn calc_pdu_datafield_len(&self, file_data_len: u64) -> usize {
+        let mut len = core::mem::size_of::<u32>();
+        if self.pdu_header.pdu_conf.file_flag == LargeFileFlag::Large {
+            len += 4;
+        }
+        if self.segment_metadata.is_some() {
+            len += self.segment_metadata.as_ref().unwrap().written_len()
+        }
+        len += file_data_len as usize;
+        if self.crc_flag() == CrcFlag::WithCrc {
+            len += 2;
+        }
+        len
+    }
+
+    fn write_common_fields_to_bytes(&self, buf: &mut [u8]) -> Result<usize, PduError> {
+        let mut current_idx = self.pdu_header.write_to_bytes(buf)?;
+        if self.segment_metadata.is_some() {
+            current_idx += self
+                .segment_metadata
+                .as_ref()
+                .unwrap()
+                .write_to_bytes(&mut buf[current_idx..])?;
+        }
+        current_idx += write_fss_field(
+            self.pdu_header.common_pdu_conf().file_flag,
+            self.offset,
+            &mut buf[current_idx..],
+        )?;
+        Ok(current_idx)
+    }
+}
+
 /// File Data PDU abstraction.
 ///
 /// For more information, refer to CFDP chapter 5.3.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct FileDataPdu<'seg_meta, 'file_data> {
-    pdu_header: PduHeader,
     #[cfg_attr(feature = "serde", serde(borrow))]
-    segment_metadata: Option<SegmentMetadata<'seg_meta>>,
+    common: FdPduBase<'seg_meta>,
-    offset: u64,
     file_data: &'file_data [u8],
 }
 
@@ -134,42 +185,34 @@ impl<'seg_meta, 'file_data> FileDataPdu<'seg_meta, 'file_data> {
             pdu_header.seg_metadata_flag = SegmentMetadataFlag::Present;
         }
         let mut pdu = Self {
-            pdu_header,
+            common: FdPduBase {
-            segment_metadata,
+                pdu_header,
-            offset,
+                segment_metadata,
+                offset,
+            },
             file_data,
         };
-        pdu.pdu_header.pdu_datafield_len = pdu.calc_pdu_datafield_len() as u16;
+        pdu.common.pdu_header.pdu_datafield_len = pdu.calc_pdu_datafield_len() as u16;
         pdu
     }
 
     fn calc_pdu_datafield_len(&self) -> usize {
-        let mut len = core::mem::size_of::<u32>();
+        self.common
-        if self.pdu_header.pdu_conf.file_flag == LargeFileFlag::Large {
+            .calc_pdu_datafield_len(self.file_data.len() as u64)
-            len += 4;
+    }
-        }
+
-        if self.segment_metadata.is_some() {
+    pub fn segment_metadata(&self) -> Option<&SegmentMetadata> {
-            len += self.segment_metadata.as_ref().unwrap().written_len()
+        self.common.segment_metadata.as_ref()
-        }
-        len += self.file_data.len();
-        if self.crc_flag() == CrcFlag::WithCrc {
-            len += 2;
-        }
-        len
     }
 
     pub fn offset(&self) -> u64 {
-        self.offset
+        self.common.offset
     }
 
     pub fn file_data(&self) -> &'file_data [u8] {
         self.file_data
     }
 
-    pub fn segment_metadata(&self) -> Option<&SegmentMetadata> {
-        self.segment_metadata.as_ref()
-    }
-
     pub fn from_bytes<'buf: 'seg_meta + 'file_data>(buf: &'buf [u8]) -> Result<Self, PduError> {
         let (pdu_header, mut current_idx) = PduHeader::from_bytes(buf)?;
         let full_len_without_crc = pdu_header.verify_length_and_checksum(buf)?;
@@ -190,16 +233,18 @@ impl<'seg_meta, 'file_data> FileDataPdu<'seg_meta, 'file_data> {
             .into());
         }
         Ok(Self {
-            pdu_header,
+            common: FdPduBase {
-            segment_metadata,
+                pdu_header,
-            offset,
+                segment_metadata,
+                offset,
+            },
             file_data: &buf[current_idx..full_len_without_crc],
         })
     }
 }
 impl CfdpPdu for FileDataPdu<'_, '_> {
     fn pdu_header(&self) -> &PduHeader {
-        &self.pdu_header
+        &self.common.pdu_header
     }
 
     fn file_directive_type(&self) -> Option<FileDirectiveType> {
@@ -216,19 +261,8 @@ impl WritablePduPacket for FileDataPdu<'_, '_> {
             }
             .into());
         }
-        let mut current_idx = self.pdu_header.write_to_bytes(buf)?;
+
-        if self.segment_metadata.is_some() {
+        let mut current_idx = self.common.write_common_fields_to_bytes(buf)?;
-            current_idx += self
-                .segment_metadata
-                .as_ref()
-                .unwrap()
-                .write_to_bytes(&mut buf[current_idx..])?;
-        }
-        current_idx += write_fss_field(
-            self.pdu_header.common_pdu_conf().file_flag,
-            self.offset,
-            &mut buf[current_idx..],
-        )?;
         buf[current_idx..current_idx + self.file_data.len()].copy_from_slice(self.file_data);
         current_idx += self.file_data.len();
         if self.crc_flag() == CrcFlag::WithCrc {
@@ -238,10 +272,167 @@ impl WritablePduPacket for FileDataPdu<'_, '_> {
     }
 
     fn len_written(&self) -> usize {
-        self.pdu_header.header_len() + self.calc_pdu_datafield_len()
+        self.common.pdu_header.header_len() + self.calc_pdu_datafield_len()
     }
 }
 
+/// File Data PDU creator abstraction.
+///
+/// This special creator object allows to read into the file data buffer directly. This avoids
+/// the need of an additional buffer to create a file data PDU. This structure therefore
+/// does not implement the regular [WritablePduPacket] trait.
+///
+/// For more information, refer to CFDP chapter 5.3.
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct FileDataPduCreatorWithReservedDatafield<'seg_meta> {
+    #[cfg_attr(feature = "serde", serde(borrow))]
+    common: FdPduBase<'seg_meta>,
+    file_data_len: u64,
+}
+
+impl<'seg_meta> FileDataPduCreatorWithReservedDatafield<'seg_meta> {
+    pub fn new_with_seg_metadata(
+        pdu_header: PduHeader,
+        segment_metadata: SegmentMetadata<'seg_meta>,
+        offset: u64,
+        file_data_len: u64,
+    ) -> Self {
+        Self::new_generic(pdu_header, Some(segment_metadata), offset, file_data_len)
+    }
+
+    pub fn new_no_seg_metadata(pdu_header: PduHeader, offset: u64, file_data_len: u64) -> Self {
+        Self::new_generic(pdu_header, None, offset, file_data_len)
+    }
+
+    pub fn new_generic(
+        mut pdu_header: PduHeader,
+        segment_metadata: Option<SegmentMetadata<'seg_meta>>,
+        offset: u64,
+        file_data_len: u64,
+    ) -> Self {
+        pdu_header.pdu_type = PduType::FileData;
+        if segment_metadata.is_some() {
+            pdu_header.seg_metadata_flag = SegmentMetadataFlag::Present;
+        }
+        let mut pdu = Self {
+            common: FdPduBase {
+                pdu_header,
+                segment_metadata,
+                offset,
+            },
+            file_data_len,
+        };
+        pdu.common.pdu_header.pdu_datafield_len = pdu.calc_pdu_datafield_len() as u16;
+        pdu
+    }
+
+    fn calc_pdu_datafield_len(&self) -> usize {
+        self.common.calc_pdu_datafield_len(self.file_data_len)
+    }
+
+    pub fn len_written(&self) -> usize {
+        self.common.pdu_header.header_len() + self.calc_pdu_datafield_len()
+    }
+
+    /// This function performs a partial write by writing all data except the file data
+    /// and the CRC.
+    ///
+    /// It returns a [FileDataPduCreatorWithUnwrittenData] which provides a mutable slice to
+    /// the reserved file data field. The user can read file data into this field directly and
+    /// then finish the PDU creation using the [FileDataPduCreatorWithUnwrittenData::finish] call.
+    pub fn write_to_bytes_partially<'buf>(
+        &self,
+        buf: &'buf mut [u8],
+    ) -> Result<FileDataPduCreatorWithUnwrittenData<'buf>, PduError> {
+        if buf.len() < self.len_written() {
+            return Err(ByteConversionError::ToSliceTooSmall {
+                found: buf.len(),
+                expected: self.len_written(),
+            }
+            .into());
+        }
+        let mut current_idx = self.common.write_common_fields_to_bytes(buf)?;
+        let file_data_offset = current_idx as u64;
+        current_idx += self.file_data_len as usize;
+        if self.crc_flag() == CrcFlag::WithCrc {
+            current_idx += 2;
+        }
+        Ok(FileDataPduCreatorWithUnwrittenData {
+            write_buf: &mut buf[0..current_idx],
+            file_data_offset,
+            file_data_len: self.file_data_len,
+            needs_crc: self.crc_flag() == CrcFlag::WithCrc,
+        })
+    }
+}
+
+impl CfdpPdu for FileDataPduCreatorWithReservedDatafield<'_> {
+    fn pdu_header(&self) -> &PduHeader {
+        &self.common.pdu_header
+    }
+
+    fn file_directive_type(&self) -> Option<FileDirectiveType> {
+        None
+    }
+}
+
+/// This structure is created with [FileDataPduCreatorWithReservedDatafield::write_to_bytes_partially]
+/// and provides an API to read file data from the virtual filesystem into the file data PDU buffer
+/// directly.
+///
+/// This structure provides a mutable slice to the reserved file data field. The user can read
+/// file data into this field directly and then finish the PDU creation using the
+/// [FileDataPduCreatorWithUnwrittenData::finish] call.
+pub struct FileDataPduCreatorWithUnwrittenData<'buf> {
+    write_buf: &'buf mut [u8],
+    file_data_offset: u64,
+    file_data_len: u64,
+    needs_crc: bool,
+}
+
+impl FileDataPduCreatorWithUnwrittenData<'_> {
+    pub fn file_data_field_mut(&mut self) -> &mut [u8] {
+        &mut self.write_buf[self.file_data_offset as usize
+            ..self.file_data_offset as usize + self.file_data_len as usize]
+    }
+
+    /// This functio needs to be called to add a CRC to the file data PDU where applicable.
+    ///
+    /// It returns the full written size of the PDU.
+    pub fn finish(self) -> usize {
+        if self.needs_crc {
+            add_pdu_crc(
+                self.write_buf,
+                self.file_data_offset as usize + self.file_data_len as usize,
+            );
+        }
+        self.write_buf.len()
+    }
+}
+
+/// This function can be used to calculate the maximum allowed file segment size for
+/// a given maximum packet length and the segment metadata if there is any.
+pub fn calculate_max_file_seg_len_for_max_packet_len_and_pdu_header(
+    pdu_header: &PduHeader,
+    max_packet_len: usize,
+    segment_metadata: Option<&SegmentMetadata>,
+) -> usize {
+    let mut subtract = pdu_header.header_len();
+    if segment_metadata.is_some() {
+        subtract += 1 + segment_metadata.as_ref().unwrap().metadata().unwrap().len();
+    }
+    if pdu_header.common_pdu_conf().file_flag == LargeFileFlag::Large {
+        subtract += 8;
+    } else {
+        subtract += 4;
+    }
+    if pdu_header.common_pdu_conf().crc_flag == CrcFlag::WithCrc {
+        subtract += 2;
+    }
+    max_packet_len.saturating_sub(subtract)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -263,7 +454,7 @@ mod tests {
         assert!(fd_pdu.segment_metadata().is_none());
         assert_eq!(
             fd_pdu.len_written(),
-            fd_pdu.pdu_header.header_len() + core::mem::size_of::<u32>() + 4
+            fd_pdu.pdu_header().header_len() + core::mem::size_of::<u32>() + 4
         );
 
         assert_eq!(fd_pdu.crc_flag(), CrcFlag::NoCrc);
@@ -290,11 +481,11 @@ mod tests {
         let written = res.unwrap();
         assert_eq!(
             written,
-            fd_pdu.pdu_header.header_len() + core::mem::size_of::<u32>() + 4
+            fd_pdu.pdu_header().header_len() + core::mem::size_of::<u32>() + 4
         );
-        let mut current_idx = fd_pdu.pdu_header.header_len();
+        let mut current_idx = fd_pdu.pdu_header().header_len();
         let file_size = u32::from_be_bytes(
-            buf[fd_pdu.pdu_header.header_len()..fd_pdu.pdu_header.header_len() + 4]
+            buf[fd_pdu.pdu_header().header_len()..fd_pdu.pdu_header().header_len() + 4]
                 .try_into()
                 .unwrap(),
         );
@@ -353,7 +544,7 @@ mod tests {
         buf[written - 1] -= 1;
         let crc: u16 = ((buf[written - 2] as u16) << 8) | buf[written - 1] as u16;
         let error = FileDataPdu::from_bytes(&buf).unwrap_err();
-        if let PduError::ChecksumError(e) = error {
+        if let PduError::Checksum(e) = error {
             assert_eq!(e, crc);
         } else {
             panic!("expected crc error");
@@ -380,7 +571,7 @@ mod tests {
         assert_eq!(*fd_pdu.segment_metadata().unwrap(), segment_meta);
         assert_eq!(
             fd_pdu.len_written(),
-            fd_pdu.pdu_header.header_len()
+            fd_pdu.pdu_header().header_len()
                 + 1
                 + seg_metadata.len()
                 + core::mem::size_of::<u32>()
@@ -390,7 +581,7 @@ mod tests {
         fd_pdu
             .write_to_bytes(&mut buf)
             .expect("writing FD PDU failed");
-        let mut current_idx = fd_pdu.pdu_header.header_len();
+        let mut current_idx = fd_pdu.pdu_header().header_len();
         assert_eq!(
             RecordContinuationState::try_from((buf[current_idx] >> 6) & 0b11).unwrap(),
             RecordContinuationState::StartAndEnd
@@ -482,4 +673,142 @@ mod tests {
         let output_converted_back: FileDataPdu = from_bytes(&output).unwrap();
         assert_eq!(output_converted_back, fd_pdu);
     }
+
+    #[test]
+    fn test_fd_pdu_creator_with_reserved_field_no_crc() {
+        let common_conf =
+            CommonPduConfig::new_with_byte_fields(TEST_SRC_ID, TEST_DEST_ID, TEST_SEQ_NUM).unwrap();
+        let pdu_header = PduHeader::new_for_file_data_default(common_conf, 0);
+        let test_str = "hello world!";
+        let fd_pdu = FileDataPduCreatorWithReservedDatafield::new_no_seg_metadata(
+            pdu_header,
+            10,
+            test_str.len() as u64,
+        );
+        let mut write_buf: [u8; 64] = [0; 64];
+        let mut pdu_unwritten = fd_pdu
+            .write_to_bytes_partially(&mut write_buf)
+            .expect("partial write failed");
+        pdu_unwritten
+            .file_data_field_mut()
+            .copy_from_slice(test_str.as_bytes());
+        pdu_unwritten.finish();
+
+        let pdu_reader = FileDataPdu::from_bytes(&write_buf).expect("reading file data PDU failed");
+        assert_eq!(
+            core::str::from_utf8(pdu_reader.file_data()).expect("reading utf8 string failed"),
+            "hello world!"
+        );
+    }
+
+    #[test]
+    fn test_fd_pdu_creator_with_reserved_field_with_crc() {
+        let mut common_conf =
+            CommonPduConfig::new_with_byte_fields(TEST_SRC_ID, TEST_DEST_ID, TEST_SEQ_NUM).unwrap();
+        common_conf.crc_flag = true.into();
+        let pdu_header = PduHeader::new_for_file_data_default(common_conf, 0);
+        let test_str = "hello world!";
+        let fd_pdu = FileDataPduCreatorWithReservedDatafield::new_no_seg_metadata(
+            pdu_header,
+            10,
+            test_str.len() as u64,
+        );
+        let mut write_buf: [u8; 64] = [0; 64];
+        let mut pdu_unwritten = fd_pdu
+            .write_to_bytes_partially(&mut write_buf)
+            .expect("partial write failed");
+        pdu_unwritten
+            .file_data_field_mut()
+            .copy_from_slice(test_str.as_bytes());
+        pdu_unwritten.finish();
+
+        let pdu_reader = FileDataPdu::from_bytes(&write_buf).expect("reading file data PDU failed");
+        assert_eq!(
+            core::str::from_utf8(pdu_reader.file_data()).expect("reading utf8 string failed"),
+            "hello world!"
+        );
+    }
+
+    #[test]
+    fn test_fd_pdu_creator_with_reserved_field_with_crc_without_finish_fails() {
+        let mut common_conf =
+            CommonPduConfig::new_with_byte_fields(TEST_SRC_ID, TEST_DEST_ID, TEST_SEQ_NUM).unwrap();
+        common_conf.crc_flag = true.into();
+        let pdu_header = PduHeader::new_for_file_data_default(common_conf, 0);
+        let test_str = "hello world!";
+        let fd_pdu = FileDataPduCreatorWithReservedDatafield::new_no_seg_metadata(
+            pdu_header,
+            10,
+            test_str.len() as u64,
+        );
+        let mut write_buf: [u8; 64] = [0; 64];
+        let mut pdu_unwritten = fd_pdu
+            .write_to_bytes_partially(&mut write_buf)
+            .expect("partial write failed");
+        pdu_unwritten
+            .file_data_field_mut()
+            .copy_from_slice(test_str.as_bytes());
+
+        let pdu_reader_error = FileDataPdu::from_bytes(&write_buf);
+        assert!(pdu_reader_error.is_err());
+        let error = pdu_reader_error.unwrap_err();
+        match error {
+            PduError::Checksum(_) => (),
+            _ => {
+                panic!("unexpected PDU error {}", error)
+            }
+        }
+    }
+
+    #[test]
+    fn test_max_file_seg_calculator_0() {
+        let pdu_header = PduHeader::new_for_file_data_default(CommonPduConfig::default(), 0);
+        assert_eq!(
+            calculate_max_file_seg_len_for_max_packet_len_and_pdu_header(&pdu_header, 64, None),
+            53
+        );
+    }
+
+    #[test]
+    fn test_max_file_seg_calculator_1() {
+        let common_conf = CommonPduConfig {
+            crc_flag: CrcFlag::WithCrc,
+            ..Default::default()
+        };
+        let pdu_header = PduHeader::new_for_file_data_default(common_conf, 0);
+        assert_eq!(
+            calculate_max_file_seg_len_for_max_packet_len_and_pdu_header(&pdu_header, 64, None),
+            51
+        );
+    }
+
+    #[test]
+    fn test_max_file_seg_calculator_2() {
+        let common_conf = CommonPduConfig {
+            file_flag: LargeFileFlag::Large,
+            ..Default::default()
+        };
+        let pdu_header = PduHeader::new_for_file_data_default(common_conf, 0);
+        assert_eq!(
+            calculate_max_file_seg_len_for_max_packet_len_and_pdu_header(&pdu_header, 64, None),
+            49
+        );
+    }
+
+    #[test]
+    fn test_max_file_seg_calculator_saturating_sub() {
+        let common_conf = CommonPduConfig {
+            file_flag: LargeFileFlag::Large,
+            ..Default::default()
+        };
+        let pdu_header = PduHeader::new_for_file_data_default(common_conf, 0);
+        assert_eq!(
+            calculate_max_file_seg_len_for_max_packet_len_and_pdu_header(&pdu_header, 15, None),
+            0
+        );
+        assert_eq!(
+            calculate_max_file_seg_len_for_max_packet_len_and_pdu_header(&pdu_header, 14, None),
+            0
+        );
+    }
 }

src/cfdp/pdu/finished.rs

@@ -4,13 +4,14 @@ use crate::cfdp::pdu::{
 use crate::cfdp::tlv::{
     EntityIdTlv, FilestoreResponseTlv, GenericTlv, Tlv, TlvType, TlvTypeField, WritableTlv,
 };
-use crate::cfdp::{ConditionCode, CrcFlag, Direction, PduType, TlvLvError};
+use crate::cfdp::{ConditionCode, CrcFlag, Direction, PduType};
 use crate::ByteConversionError;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
-use super::{CfdpPdu, WritablePduPacket};
+use super::tlv::ReadableTlv;
+use super::{CfdpPdu, InvalidTlvTypeFieldError, WritablePduPacket};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, TryFromPrimitive, IntoPrimitive)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -331,22 +332,26 @@ impl<'buf> FinishedPduReader<'buf> {
                         // last TLV, everything else would break the whole handling of the packet
                         // TLVs.
                         if current_idx != full_len_without_crc {
-                            return Err(PduError::FormatError);
+                            return Err(PduError::Format);
                         }
                     } else {
-                        return Err(TlvLvError::InvalidTlvTypeField {
+                        return Err(PduError::TlvLv(
-                            found: tlv_type.into(),
+                            InvalidTlvTypeFieldError {
-                            expected: Some(TlvType::FilestoreResponse.into()),
+                                found: tlv_type.into(),
-                        }
+                                expected: Some(TlvType::FilestoreResponse.into()),
-                        .into());
+                            }
+                            .into(),
+                        ));
                     }
                 }
                 TlvTypeField::Custom(raw) => {
-                    return Err(TlvLvError::InvalidTlvTypeField {
+                    return Err(PduError::TlvLv(
-                        found: raw,
+                        InvalidTlvTypeFieldError {
-                        expected: None,
+                            found: raw,
-                    }
+                            expected: None,
-                    .into());
+                        }
+                        .into(),
+                    ));
                 }
             }
         }
@@ -563,7 +568,7 @@ mod tests {
         buf[written - 1] -= 1;
         let crc: u16 = ((buf[written - 2] as u16) << 8) as u16 | buf[written - 1] as u16;
         let error = FinishedPduReader::new(&buf).unwrap_err();
-        if let PduError::ChecksumError(e) = error {
+        if let PduError::Checksum(e) = error {
             assert_eq!(e, crc);
         } else {
             panic!("expected crc error");

src/cfdp/pdu/metadata.rs

@@ -1,3 +1,5 @@
+#[cfg(feature = "alloc")]
+use super::tlv::TlvOwned;
 use crate::cfdp::lv::Lv;
 use crate::cfdp::pdu::{
     add_pdu_crc, generic_length_checks_pdu_deserialization, read_fss_field, write_fss_field,
@@ -11,6 +13,7 @@ use alloc::vec::Vec;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
+use super::tlv::ReadableTlv;
 use super::{CfdpPdu, WritablePduPacket};
 
 #[derive(Default, Debug, Copy, Clone, PartialEq, Eq)]
@@ -51,18 +54,26 @@ pub fn build_metadata_opts_from_vec(
     build_metadata_opts_from_slice(buf, tlvs.as_slice())
 }
 
+#[cfg(feature = "alloc")]
+pub fn build_metadata_opts_from_owned_slice(tlvs: &[TlvOwned]) -> Vec<u8> {
+    let mut sum_vec = Vec::new();
+    for tlv in tlvs {
+        sum_vec.extend(tlv.to_vec());
+    }
+    sum_vec
+}
+
 /// Metadata PDU creator abstraction.
 ///
 /// This abstraction exposes a specialized API for creating metadata PDUs as specified in
 /// CFDP chapter 5.2.5.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct MetadataPduCreator<'src_name, 'dest_name, 'opts> {
     pdu_header: PduHeader,
     metadata_params: MetadataGenericParams,
     src_file_name: Lv<'src_name>,
     dest_file_name: Lv<'dest_name>,
-    options: &'opts [Tlv<'opts>],
+    options: &'opts [u8],
 }
 
 impl<'src_name, 'dest_name, 'opts> MetadataPduCreator<'src_name, 'dest_name, 'opts> {
@@ -86,7 +97,7 @@ impl<'src_name, 'dest_name, 'opts> MetadataPduCreator<'src_name, 'dest_name, 'op
         metadata_params: MetadataGenericParams,
         src_file_name: Lv<'src_name>,
         dest_file_name: Lv<'dest_name>,
-        options: &'opts [Tlv<'opts>],
+        options: &'opts [u8],
     ) -> Self {
         Self::new(
             pdu_header,
@@ -102,7 +113,7 @@ impl<'src_name, 'dest_name, 'opts> MetadataPduCreator<'src_name, 'dest_name, 'op
         metadata_params: MetadataGenericParams,
         src_file_name: Lv<'src_name>,
         dest_file_name: Lv<'dest_name>,
-        options: &'opts [Tlv<'opts>],
+        options: &'opts [u8],
     ) -> Self {
         pdu_header.pdu_type = PduType::FileDirective;
         pdu_header.pdu_conf.direction = Direction::TowardsReceiver;
@@ -129,10 +140,19 @@ impl<'src_name, 'dest_name, 'opts> MetadataPduCreator<'src_name, 'dest_name, 'op
         self.dest_file_name
     }
 
-    pub fn options(&self) -> &'opts [Tlv<'opts>] {
+    pub fn options(&self) -> &'opts [u8] {
         self.options
     }
 
+    /// Yield an iterator which can be used to loop through all options. Returns [None] if the
+    /// options field is empty.
+    pub fn options_iter(&self) -> OptionsIter<'_> {
+        OptionsIter {
+            opt_buf: self.options,
+            current_idx: 0,
+        }
+    }
+
     fn calc_pdu_datafield_len(&self) -> usize {
         // One directve type octet and one byte of the directive parameter field.
         let mut len = 2;
@@ -143,9 +163,7 @@ impl<'src_name, 'dest_name, 'opts> MetadataPduCreator<'src_name, 'dest_name, 'op
         }
         len += self.src_file_name.len_full();
         len += self.dest_file_name.len_full();
-        for tlv in self.options() {
+        len += self.options().len();
-            len += tlv.len_full()
-        }
         if self.crc_flag() == CrcFlag::WithCrc {
             len += 2;
         }
@@ -191,10 +209,8 @@ impl WritablePduPacket for MetadataPduCreator<'_, '_, '_> {
         current_idx += self
             .dest_file_name
             .write_to_be_bytes(&mut buf[current_idx..])?;
-        for opt in self.options() {
+        buf[current_idx..current_idx + self.options.len()].copy_from_slice(self.options);
-            opt.write_to_bytes(&mut buf[current_idx..current_idx + opt.len_full()])?;
+        current_idx += self.options.len();
-            current_idx += opt.len_full();
-        }
         if self.crc_flag() == CrcFlag::WithCrc {
             current_idx = add_pdu_crc(buf, current_idx);
         }
@@ -355,7 +371,7 @@ pub mod tests {
     };
     use crate::cfdp::pdu::{CfdpPdu, PduError, WritablePduPacket};
     use crate::cfdp::pdu::{FileDirectiveType, PduHeader};
-    use crate::cfdp::tlv::{Tlv, TlvType};
+    use crate::cfdp::tlv::{ReadableTlv, Tlv, TlvOwned, TlvType, WritableTlv};
     use crate::cfdp::{
         ChecksumType, CrcFlag, Direction, LargeFileFlag, PduType, SegmentMetadataFlag,
         SegmentationControl, TransmissionMode,
@@ -365,16 +381,16 @@ pub mod tests {
     const SRC_FILENAME: &str = "hello-world.txt";
     const DEST_FILENAME: &str = "hello-world2.txt";
 
-    fn generic_metadata_pdu<'opts>(
+    fn generic_metadata_pdu(
         crc_flag: CrcFlag,
         checksum_type: ChecksumType,
         closure_requested: bool,
         fss: LargeFileFlag,
-        opts: &'opts [Tlv],
+        opts: &[u8],
     ) -> (
         Lv<'static>,
         Lv<'static>,
-        MetadataPduCreator<'static, 'static, 'opts>,
+        MetadataPduCreator<'static, 'static, '_>,
     ) {
         let pdu_header = PduHeader::new_no_file_data(common_pdu_conf(crc_flag, fss), 0);
         let metadata_params = MetadataGenericParams::new(closure_requested, checksum_type, 0x1010);
@@ -544,9 +560,9 @@ pub mod tests {
         assert_eq!(written.metadata_params(), read.metadata_params());
         assert_eq!(written.src_file_name(), read.src_file_name());
         assert_eq!(written.dest_file_name(), read.dest_file_name());
-        let opts = written.options();
+        let opts = written.options_iter();
-        for (tlv_written, tlv_read) in opts.iter().zip(read.options_iter().unwrap()) {
+        for (tlv_written, tlv_read) in opts.zip(read.options_iter().unwrap()) {
-            assert_eq!(tlv_written, &tlv_read);
+            assert_eq!(&tlv_written, &tlv_read);
         }
     }
 
@@ -661,14 +677,14 @@ pub mod tests {
         let tlv1 = Tlv::new_empty(TlvType::FlowLabel);
         let msg_to_user: [u8; 4] = [1, 2, 3, 4];
         let tlv2 = Tlv::new(TlvType::MsgToUser, &msg_to_user).unwrap();
-        let tlv_vec = vec![tlv1, tlv2];
+        let mut tlv_buf: [u8; 64] = [0; 64];
-        let opts_len = tlv1.len_full() + tlv2.len_full();
+        let opts_len = build_metadata_opts_from_slice(&mut tlv_buf, &[tlv1, tlv2]).unwrap();
         let (src_filename, dest_filename, metadata_pdu) = generic_metadata_pdu(
             CrcFlag::NoCrc,
             ChecksumType::Crc32,
             false,
             LargeFileFlag::Normal,
-            &tlv_vec,
+            &tlv_buf[0..opts_len],
         );
         let mut buf: [u8; 128] = [0; 128];
         let write_res = metadata_pdu.write_to_bytes(&mut buf);
@@ -691,7 +707,55 @@ pub mod tests {
         let opts_iter = opts_iter.unwrap();
         let mut accumulated_len = 0;
         for (idx, opt) in opts_iter.enumerate() {
-            assert_eq!(tlv_vec[idx], opt);
+            if idx == 0 {
+                assert_eq!(tlv1, opt);
+            } else if idx == 1 {
+                assert_eq!(tlv2, opt);
+            }
+            accumulated_len += opt.len_full();
+        }
+        assert_eq!(accumulated_len, pdu_read_back.options().len());
+    }
+    #[test]
+    fn test_with_owned_opts() {
+        let tlv1 = TlvOwned::new_empty(TlvType::FlowLabel);
+        let msg_to_user: [u8; 4] = [1, 2, 3, 4];
+        let tlv2 = TlvOwned::new(TlvType::MsgToUser, &msg_to_user);
+        let mut all_tlvs = tlv1.to_vec();
+        all_tlvs.extend(tlv2.to_vec());
+        let (src_filename, dest_filename, metadata_pdu) = generic_metadata_pdu(
+            CrcFlag::NoCrc,
+            ChecksumType::Crc32,
+            false,
+            LargeFileFlag::Normal,
+            &all_tlvs,
+        );
+        let mut buf: [u8; 128] = [0; 128];
+        let write_res = metadata_pdu.write_to_bytes(&mut buf);
+        assert!(write_res.is_ok());
+        let written = write_res.unwrap();
+        assert_eq!(
+            written,
+            metadata_pdu.pdu_header.header_len()
+                + 1
+                + 1
+                + 4
+                + src_filename.len_full()
+                + dest_filename.len_full()
+                + all_tlvs.len()
+        );
+        let pdu_read_back = MetadataPduReader::from_bytes(&buf).unwrap();
+        compare_read_pdu_to_written_pdu(&metadata_pdu, &pdu_read_back);
+        let opts_iter = pdu_read_back.options_iter();
+        assert!(opts_iter.is_some());
+        let opts_iter = opts_iter.unwrap();
+        let mut accumulated_len = 0;
+        for (idx, opt) in opts_iter.enumerate() {
+            if idx == 0 {
+                assert_eq!(tlv1, opt);
+            } else if idx == 1 {
+                assert_eq!(tlv2, opt);
+            }
             accumulated_len += opt.len_full();
         }
         assert_eq!(accumulated_len, pdu_read_back.options().len());
@@ -716,7 +780,7 @@ pub mod tests {
             assert_eq!(expected, Some(FileDirectiveType::MetadataPdu));
             assert_eq!(
                 error.to_string(),
-                "invalid directive type value 255, expected Some(MetadataPdu)"
+                "invalid directive type, found 255, expected Some(MetadataPdu)"
             );
         } else {
             panic!("Expected InvalidDirectiveType error, got {:?}", error);
@@ -742,7 +806,7 @@ pub mod tests {
             assert_eq!(expected, FileDirectiveType::MetadataPdu);
             assert_eq!(
                 error.to_string(),
-                "found directive type EofPdu, expected MetadataPdu"
+                "wrong directive type, found EofPdu, expected MetadataPdu"
             );
         } else {
             panic!("Expected InvalidDirectiveType error, got {:?}", error);

src/cfdp/pdu/mod.rs

@@ -5,9 +5,6 @@ use crate::ByteConversionError;
 use crate::CRC_CCITT_FALSE;
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
-use core::fmt::{Display, Formatter};
-#[cfg(feature = "std")]
-use std::error::Error;
 
 pub mod ack;
 pub mod eof;
@@ -30,135 +27,60 @@ pub enum FileDirectiveType {
     KeepAlivePdu = 0x0c,
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum PduError {
-    ByteConversion(ByteConversionError),
+    #[error("byte conversion error: {0}")]
-    /// Found version ID invalid, not equal to [CFDP_VERSION_2].
+    ByteConversion(#[from] ByteConversionError),
+    /// Found version ID invalid, not equal to [super::CFDP_VERSION_2].
+    #[error("CFDP version missmatch, found {0}, expected {ver}", ver = super::CFDP_VERSION_2)]
     CfdpVersionMissmatch(u8),
     /// Invalid length for the entity ID detected. Only the values 1, 2, 4 and 8 are supported.
+    #[error("invalid PDU entity ID length {0}, only [1, 2, 4, 8] are allowed")]
     InvalidEntityLen(u8),
     /// Invalid length for the entity ID detected. Only the values 1, 2, 4 and 8 are supported.
+    #[error("invalid transaction ID length {0}")]
     InvalidTransactionSeqNumLen(u8),
+    #[error("missmatch of PDU source ID length {src_id_len} and destination ID length {dest_id_len}")]
     SourceDestIdLenMissmatch {
         src_id_len: usize,
         dest_id_len: usize,
     },
     /// Wrong directive type, for example when parsing the directive field for a file directive
     /// PDU.
+    #[error("wrong directive type, found {found:?}, expected {expected:?}")]
     WrongDirectiveType {
         found: FileDirectiveType,
         expected: FileDirectiveType,
     },
     /// The directive type field contained a value not in the range of permitted values. This can
     /// also happen if an invalid value is passed to the ACK PDU constructor.
+    #[error("invalid directive type, found {found:?}, expected {expected:?}")]
     InvalidDirectiveType {
         found: u8,
         expected: Option<FileDirectiveType>,
     },
+    #[error("invalid start or end of scope value for NAK PDU")]
     InvalidStartOrEndOfScopeValue,
     /// Invalid condition code. Contains the raw detected value.
+    #[error("invalid condition code {0}")]
     InvalidConditionCode(u8),
     /// Invalid checksum type which is not part of the checksums listed in the
     /// [SANA Checksum Types registry](https://sanaregistry.org/r/checksum_identifiers/).
+    #[error("invalid checksum type {0}")]
     InvalidChecksumType(u8),
+    #[error("file size {0} too large")]
     FileSizeTooLarge(u64),
     /// If the CRC flag for a PDU is enabled and the checksum check fails. Contains raw 16-bit CRC.
-    ChecksumError(u16),
+    #[error("checksum error for checksum {0}")]
+    Checksum(u16),
     /// Generic error for invalid PDU formats.
-    FormatError,
+    #[error("generic PDU format error")]
+    Format,
     /// Error handling a TLV field.
-    TlvLvError(TlvLvError),
+    #[error("PDU error: {0}")]
-}
+    TlvLv(#[from] TlvLvError),
-
-impl Display for PduError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            PduError::InvalidEntityLen(raw_id) => {
-                write!(
-                    f,
-                    "invalid PDU entity ID length {raw_id}, only [1, 2, 4, 8] are allowed"
-                )
-            }
-            PduError::InvalidStartOrEndOfScopeValue => {
-                write!(f, "invalid start or end of scope for NAK PDU")
-            }
-            PduError::InvalidTransactionSeqNumLen(raw_id) => {
-                write!(
-                    f,
-                    "invalid PDUtransaction seq num length {raw_id}, only [1, 2, 4, 8] are allowed"
-                )
-            }
-            PduError::CfdpVersionMissmatch(raw) => {
-                write!(
-                    f,
-                    "cfdp version missmatch, found {raw}, expected {CFDP_VERSION_2}"
-                )
-            }
-            PduError::SourceDestIdLenMissmatch {
-                src_id_len,
-                dest_id_len,
-            } => {
-                write!(
-                    f,
-                    "missmatch of PDU source length {src_id_len} and destination length {dest_id_len}"
-                )
-            }
-            PduError::ByteConversion(e) => {
-                write!(f, "{}", e)
-            }
-            PduError::FileSizeTooLarge(value) => {
-                write!(f, "file size value {value} exceeds allowed 32 bit width")
-            }
-            PduError::WrongDirectiveType { found, expected } => {
-                write!(f, "found directive type {found:?}, expected {expected:?}")
-            }
-            PduError::InvalidConditionCode(raw_code) => {
-                write!(f, "found invalid condition code with raw value {raw_code}")
-            }
-            PduError::InvalidDirectiveType { found, expected } => {
-                write!(
-                    f,
-                    "invalid directive type value {found}, expected {expected:?}"
-                )
-            }
-            PduError::InvalidChecksumType(checksum_type) => {
-                write!(f, "invalid checksum type {checksum_type}")
-            }
-            PduError::ChecksumError(checksum) => {
-                write!(f, "checksum error for CRC {checksum:#04x}")
-            }
-            PduError::TlvLvError(error) => {
-                write!(f, "pdu tlv error: {error}")
-            }
-            PduError::FormatError => {
-                write!(f, "generic PDU format error")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for PduError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        match self {
-            PduError::ByteConversion(e) => Some(e),
-            PduError::TlvLvError(e) => Some(e),
-            _ => None,
-        }
-    }
-}
-
-impl From<ByteConversionError> for PduError {
-    fn from(value: ByteConversionError) -> Self {
-        Self::ByteConversion(value)
-    }
-}
-
-impl From<TlvLvError> for PduError {
-    fn from(e: TlvLvError) -> Self {
-        Self::TlvLvError(e)
-    }
 }
 
 pub trait WritablePduPacket {
@@ -179,33 +101,42 @@ pub trait WritablePduPacket {
 pub trait CfdpPdu {
     fn pdu_header(&self) -> &PduHeader;
 
+    #[inline]
     fn source_id(&self) -> UnsignedByteField {
         self.pdu_header().common_pdu_conf().source_entity_id
     }
 
+    #[inline]
     fn dest_id(&self) -> UnsignedByteField {
         self.pdu_header().common_pdu_conf().dest_entity_id
     }
 
+    #[inline]
     fn transaction_seq_num(&self) -> UnsignedByteField {
         self.pdu_header().common_pdu_conf().transaction_seq_num
     }
 
+    #[inline]
     fn transmission_mode(&self) -> TransmissionMode {
         self.pdu_header().common_pdu_conf().trans_mode
     }
+
+    #[inline]
     fn direction(&self) -> Direction {
         self.pdu_header().common_pdu_conf().direction
     }
 
+    #[inline]
     fn crc_flag(&self) -> CrcFlag {
         self.pdu_header().common_pdu_conf().crc_flag
     }
 
+    #[inline]
     fn file_flag(&self) -> LargeFileFlag {
         self.pdu_header().common_pdu_conf().file_flag
     }
 
+    #[inline]
     fn pdu_type(&self) -> PduType {
         self.pdu_header().pdu_type()
     }
@@ -234,6 +165,7 @@ pub struct CommonPduConfig {
 
 // TODO: Builder pattern might be applicable here..
 impl CommonPduConfig {
+    #[inline]
     pub fn new(
         source_id: impl Into<UnsignedByteField>,
         dest_id: impl Into<UnsignedByteField>,
@@ -265,6 +197,7 @@ impl CommonPduConfig {
         })
     }
 
+    #[inline]
     pub fn new_with_byte_fields(
         source_id: impl Into<UnsignedByteField>,
         dest_id: impl Into<UnsignedByteField>,
@@ -281,10 +214,12 @@ impl CommonPduConfig {
         )
     }
 
+    #[inline]
     pub fn source_id(&self) -> UnsignedByteField {
         self.source_entity_id
     }
 
+    #[inline]
     fn source_dest_id_check(
         source_id: impl Into<UnsignedByteField>,
         dest_id: impl Into<UnsignedByteField>,
@@ -307,6 +242,7 @@ impl CommonPduConfig {
         Ok((source_id, dest_id))
     }
 
+    #[inline]
     pub fn set_source_and_dest_id(
         &mut self,
         source_id: impl Into<UnsignedByteField>,
@@ -318,6 +254,7 @@ impl CommonPduConfig {
         Ok(())
     }
 
+    #[inline]
     pub fn dest_id(&self) -> UnsignedByteField {
         self.dest_entity_id
     }
@@ -326,6 +263,7 @@ impl CommonPduConfig {
 impl Default for CommonPduConfig {
     /// The defaults for the source ID, destination ID and the transaction sequence number is the
     /// [UnsignedByteFieldU8] with an intitial value of 0
+    #[inline]
     fn default() -> Self {
         // The new function can not fail for these input parameters.
         Self::new(
@@ -342,6 +280,7 @@ impl Default for CommonPduConfig {
 }
 
 impl PartialEq for CommonPduConfig {
+    #[inline]
     fn eq(&self, other: &Self) -> bool {
         self.source_entity_id.value() == other.source_entity_id.value()
             && self.dest_entity_id.value() == other.dest_entity_id.value()
@@ -370,6 +309,7 @@ pub struct PduHeader {
 }
 
 impl PduHeader {
+    #[inline]
     pub fn new_for_file_data(
         pdu_conf: CommonPduConfig,
         pdu_datafield_len: u16,
@@ -385,6 +325,7 @@ impl PduHeader {
         )
     }
 
+    #[inline]
     pub fn new_for_file_data_default(pdu_conf: CommonPduConfig, pdu_datafield_len: u16) -> Self {
         Self::new_generic(
             PduType::FileData,
@@ -394,6 +335,7 @@ impl PduHeader {
             SegmentationControl::NoRecordBoundaryPreservation,
         )
     }
+    #[inline]
     pub fn new_no_file_data(pdu_conf: CommonPduConfig, pdu_datafield_len: u16) -> Self {
         Self::new_generic(
             PduType::FileDirective,
@@ -404,6 +346,7 @@ impl PduHeader {
         )
     }
 
+    #[inline]
     pub fn new_generic(
         pdu_type: PduType,
         pdu_conf: CommonPduConfig,
@@ -421,6 +364,7 @@ impl PduHeader {
     }
 
     /// Returns only the length of the PDU header when written to a raw buffer.
+    #[inline]
     pub fn header_len(&self) -> usize {
         FIXED_HEADER_LEN
             + self.pdu_conf.source_entity_id.size()
@@ -428,12 +372,14 @@ impl PduHeader {
             + self.pdu_conf.dest_entity_id.size()
     }
 
+    #[inline]
     pub fn pdu_datafield_len(&self) -> usize {
         self.pdu_datafield_len.into()
     }
 
     /// Returns the full length of the PDU when written to a raw buffer, which is the header length
     /// plus the PDU datafield length.
+    #[inline]
     pub fn pdu_len(&self) -> usize {
         self.header_len() + self.pdu_datafield_len as usize
     }
@@ -506,7 +452,7 @@ impl PduHeader {
             let mut digest = CRC_CCITT_FALSE.digest();
             digest.update(&buf[..self.pdu_len()]);
             if digest.finalize() != 0 {
-                return Err(PduError::ChecksumError(u16::from_be_bytes(
+                return Err(PduError::Checksum(u16::from_be_bytes(
                     buf[self.pdu_len() - 2..self.pdu_len()].try_into().unwrap(),
                 )));
             }
@@ -606,10 +552,13 @@ impl PduHeader {
             current_idx,
         ))
     }
+
+    #[inline]
     pub fn pdu_type(&self) -> PduType {
         self.pdu_type
     }
 
+    #[inline]
     pub fn common_pdu_conf(&self) -> &CommonPduConfig {
         &self.pdu_conf
     }
@@ -617,6 +566,8 @@ impl PduHeader {
     pub fn seg_metadata_flag(&self) -> SegmentMetadataFlag {
         self.seg_metadata_flag
     }
+
+    #[inline]
     pub fn seg_ctrl(&self) -> SegmentationControl {
         self.seg_ctrl
     }
@@ -950,7 +901,7 @@ mod tests {
             assert_eq!(raw_version, CFDP_VERSION_2 + 1);
             assert_eq!(
                 error.to_string(),
-                "cfdp version missmatch, found 2, expected 1"
+                "CFDP version missmatch, found 2, expected 1"
             );
         } else {
             panic!("invalid exception: {}", error);
@@ -998,7 +949,7 @@ mod tests {
             assert_eq!(expected, 7);
             assert_eq!(
                 error.to_string(),
-                "source slice with size 6 too small, expected at least 7 bytes"
+                "byte conversion error: source slice with size 6 too small, expected at least 7 bytes"
             );
         }
     }
@@ -1053,7 +1004,7 @@ mod tests {
             assert_eq!(dest_id_len, 2);
             assert_eq!(
                 error.to_string(),
-                "missmatch of PDU source length 1 and destination length 2"
+                "missmatch of PDU source ID length 1 and destination ID length 2"
             );
         }
     }

src/cfdp/pdu/nak.rs

@@ -751,7 +751,7 @@ mod tests {
         if let PduError::InvalidStartOrEndOfScopeValue = error {
             assert_eq!(
                 error.to_string(),
-                "invalid start or end of scope for NAK PDU"
+                "invalid start or end of scope value for NAK PDU"
             );
         } else {
             panic!("unexpected error {error}");
@@ -796,7 +796,7 @@ mod tests {
         nak_vec[nak_pdu.len_written() - 1] -= 1;
         let nak_pdu_deser = NakPduReader::new(&nak_vec);
         assert!(nak_pdu_deser.is_err());
-        if let Err(PduError::ChecksumError(raw)) = nak_pdu_deser {
+        if let Err(PduError::Checksum(raw)) = nak_pdu_deser {
             assert_eq!(
                 raw,
                 u16::from_be_bytes(nak_vec[nak_pdu.len_written() - 2..].try_into().unwrap())

src/cfdp/tlv/mod.rs

@@ -9,10 +9,14 @@ use crate::ByteConversionError;
 use alloc::vec;
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
+#[cfg(feature = "alloc")]
+pub use alloc_mod::*;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
+use super::{InvalidTlvTypeFieldError, TlvLvDataTooLargeError};
+
 pub mod msg_to_user;
 
 pub const MIN_TLV_LEN: usize = 2;
@@ -39,6 +43,26 @@ pub trait GenericTlv {
     }
 }
 
+pub trait ReadableTlv {
+    fn value(&self) -> &[u8];
+
+    /// Checks whether the value field is empty.
+    fn is_empty(&self) -> bool {
+        self.value().is_empty()
+    }
+
+    /// Helper method to retrieve the length of the value. Simply calls the [slice::len] method of
+    /// [Self::value]
+    fn len_value(&self) -> usize {
+        self.value().len()
+    }
+
+    /// Returns the full raw length, including the length byte.
+    fn len_full(&self) -> usize {
+        self.len_value() + 2
+    }
+}
+
 pub trait WritableTlv {
     fn write_to_bytes(&self, buf: &mut [u8]) -> Result<usize, ByteConversionError>;
     fn len_written(&self) -> usize;
@@ -129,14 +153,14 @@ pub struct Tlv<'data> {
 }
 
 impl<'data> Tlv<'data> {
-    pub fn new(tlv_type: TlvType, data: &[u8]) -> Result<Tlv, TlvLvError> {
+    pub fn new(tlv_type: TlvType, data: &[u8]) -> Result<Tlv, TlvLvDataTooLargeError> {
         Ok(Tlv {
             tlv_type_field: TlvTypeField::Standard(tlv_type),
             lv: Lv::new(data)?,
         })
     }
 
-    pub fn new_with_custom_type(tlv_type: u8, data: &[u8]) -> Result<Tlv, TlvLvError> {
+    pub fn new_with_custom_type(tlv_type: u8, data: &[u8]) -> Result<Tlv, TlvLvDataTooLargeError> {
         Ok(Tlv {
             tlv_type_field: TlvTypeField::Custom(tlv_type),
             lv: Lv::new(data)?,
@@ -151,31 +175,11 @@ impl<'data> Tlv<'data> {
         }
     }
 
-    pub fn value(&self) -> &[u8] {
-        self.lv.value()
-    }
-
-    /// Checks whether the value field is empty.
-    pub fn is_empty(&self) -> bool {
-        self.value().is_empty()
-    }
-
-    /// Helper method to retrieve the length of the value. Simply calls the [slice::len] method of
-    /// [Self::value]
-    pub fn len_value(&self) -> usize {
-        self.value().len()
-    }
-
-    /// Returns the full raw length, including the length byte.
-    pub fn len_full(&self) -> usize {
-        self.len_value() + 2
-    }
-
     /// Creates a TLV give a raw bytestream. Please note that is is not necessary to pass the
     /// bytestream with the exact size of the expected TLV. This function will take care
     /// of parsing the length byte, and the length of the parsed TLV can be retrieved using
     /// [Self::len_full].
-    pub fn from_bytes(buf: &'data [u8]) -> Result<Tlv<'data>, TlvLvError> {
+    pub fn from_bytes(buf: &'data [u8]) -> Result<Tlv<'data>, ByteConversionError> {
         generic_len_check_deserialization(buf, MIN_TLV_LEN)?;
         let mut tlv = Self {
             tlv_type_field: TlvTypeField::from(buf[0]),
@@ -192,6 +196,27 @@ impl<'data> Tlv<'data> {
     pub fn raw_data(&self) -> Option<&[u8]> {
         self.lv.raw_data()
     }
+
+    #[cfg(feature = "alloc")]
+    pub fn to_owned(&self) -> TlvOwned {
+        TlvOwned {
+            tlv_type_field: self.tlv_type_field,
+            data: self.value().to_vec(),
+        }
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl PartialEq<TlvOwned> for Tlv<'_> {
+    fn eq(&self, other: &TlvOwned) -> bool {
+        self.tlv_type_field == other.tlv_type_field && self.value() == other.value()
+    }
+}
+
+impl ReadableTlv for Tlv<'_> {
+    fn value(&self) -> &[u8] {
+        self.lv.value()
+    }
 }
 
 impl WritableTlv for Tlv<'_> {
@@ -212,18 +237,81 @@ impl GenericTlv for Tlv<'_> {
     }
 }
 
-pub(crate) fn verify_tlv_type(raw_type: u8, expected_tlv_type: TlvType) -> Result<(), TlvLvError> {
+#[cfg(feature = "alloc")]
-    let tlv_type = TlvType::try_from(raw_type).map_err(|_| TlvLvError::InvalidTlvTypeField {
+pub mod alloc_mod {
-        found: raw_type,
+    use super::*;
-        expected: Some(expected_tlv_type.into()),
+
-    })?;
+    /// Owned variant of [Tlv] which is consequently [Clone]able and does not have a lifetime
-    if tlv_type != expected_tlv_type {
+    /// associated to a data slice.
-        return Err(TlvLvError::InvalidTlvTypeField {
+    #[derive(Debug, Clone, PartialEq, Eq)]
-            found: tlv_type as u8,
+    #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
-            expected: Some(expected_tlv_type as u8),
+    #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-        });
+    pub struct TlvOwned {
+        pub(crate) tlv_type_field: TlvTypeField,
+        pub(crate) data: Vec<u8>,
+    }
+
+    impl TlvOwned {
+        pub fn new(tlv_type: TlvType, data: &[u8]) -> Self {
+            Self {
+                tlv_type_field: TlvTypeField::Standard(tlv_type),
+                data: data.to_vec(),
+            }
+        }
+
+        pub fn new_with_custom_type(tlv_type: u8, data: &[u8]) -> Self {
+            Self {
+                tlv_type_field: TlvTypeField::Custom(tlv_type),
+                data: data.to_vec(),
+            }
+        }
+
+        /// Creates a TLV with an empty value field.
+        pub fn new_empty(tlv_type: TlvType) -> Self {
+            Self {
+                tlv_type_field: TlvTypeField::Standard(tlv_type),
+                data: Vec::new(),
+            }
+        }
+    }
+
+    impl ReadableTlv for TlvOwned {
+        fn value(&self) -> &[u8] {
+            &self.data
+        }
+    }
+
+    impl WritableTlv for TlvOwned {
+        fn write_to_bytes(&self, buf: &mut [u8]) -> Result<usize, ByteConversionError> {
+            generic_len_check_data_serialization(buf, self.data.len(), MIN_TLV_LEN)?;
+            buf[0] = self.tlv_type_field.into();
+            buf[1] = self.data.len() as u8;
+            buf[2..2 + self.data.len()].copy_from_slice(&self.data);
+            Ok(self.len_written())
+        }
+
+        fn len_written(&self) -> usize {
+            self.data.len() + 2
+        }
+    }
+
+    impl GenericTlv for TlvOwned {
+        fn tlv_type_field(&self) -> TlvTypeField {
+            self.tlv_type_field
+        }
+    }
+
+    impl From<Tlv<'_>> for TlvOwned {
+        fn from(value: Tlv<'_>) -> Self {
+            value.to_owned()
+        }
+    }
+
+    impl PartialEq<Tlv<'_>> for TlvOwned {
+        fn eq(&self, other: &Tlv) -> bool {
+            self.tlv_type_field == other.tlv_type_field && self.data == other.value()
+        }
     }
-    Ok(())
 }
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
@@ -277,11 +365,8 @@ impl EntityIdTlv {
         Self::len_check(buf)?;
         self.entity_id
             .write_to_be_bytes(&mut buf[2..2 + self.entity_id.size()])?;
-        Tlv::new(TlvType::EntityId, &buf[2..2 + self.entity_id.size()]).map_err(|e| match e {
+        // Can't fail.
-            TlvLvError::ByteConversion(e) => e,
+        Ok(Tlv::new(TlvType::EntityId, &buf[2..2 + self.entity_id.size()]).unwrap())
-            // All other errors are impossible.
-            _ => panic!("unexpected TLV error"),
-        })
     }
 }
 
@@ -307,21 +392,23 @@ impl GenericTlv for EntityIdTlv {
 impl<'data> TryFrom<Tlv<'data>> for EntityIdTlv {
     type Error = TlvLvError;
 
-    fn try_from(value: Tlv) -> Result<Self, Self::Error> {
+    fn try_from(value: Tlv) -> Result<Self, TlvLvError> {
         match value.tlv_type_field {
             TlvTypeField::Standard(tlv_type) => {
                 if tlv_type != TlvType::EntityId {
-                    return Err(TlvLvError::InvalidTlvTypeField {
+                    return Err(InvalidTlvTypeFieldError {
                         found: tlv_type as u8,
                         expected: Some(TlvType::EntityId as u8),
-                    });
+                    }
+                    .into());
                 }
             }
             TlvTypeField::Custom(val) => {
-                return Err(TlvLvError::InvalidTlvTypeField {
+                return Err(InvalidTlvTypeFieldError {
                     found: val,
                     expected: Some(TlvType::EntityId as u8),
-                });
+                }
+                .into());
             }
         }
         let len_value = value.value().len();
@@ -752,6 +839,23 @@ impl GenericTlv for FilestoreResponseTlv<'_, '_, '_> {
     }
 }
 
+pub(crate) fn verify_tlv_type(
+    raw_type: u8,
+    expected_tlv_type: TlvType,
+) -> Result<(), InvalidTlvTypeFieldError> {
+    let tlv_type = TlvType::try_from(raw_type).map_err(|_| InvalidTlvTypeFieldError {
+        found: raw_type,
+        expected: Some(expected_tlv_type.into()),
+    })?;
+    if tlv_type != expected_tlv_type {
+        return Err(InvalidTlvTypeFieldError {
+            found: tlv_type as u8,
+            expected: Some(expected_tlv_type as u8),
+        });
+    }
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -939,14 +1043,14 @@ mod tests {
         let tlv_res = Tlv::new(TlvType::MsgToUser, &buf_too_large);
         assert!(tlv_res.is_err());
         let error = tlv_res.unwrap_err();
-        if let TlvLvError::DataTooLarge(size) = error {
+        match error {
-            assert_eq!(size, u8::MAX as usize + 1);
+            TlvLvDataTooLargeError(size) => {
-            assert_eq!(
+                assert_eq!(size, u8::MAX as usize + 1);
-                error.to_string(),
+                assert_eq!(
-                "data with size 256 larger than allowed 255 bytes"
+                    error.to_string(),
-            );
+                    "data with size 256 larger than allowed 255 bytes"
-        } else {
+                );
-            panic!("unexpected error {:?}", error);
+            }
         }
     }
 
@@ -1256,7 +1360,8 @@ mod tests {
         let error = EntityIdTlv::try_from(msg_to_user_tlv);
         assert!(error.is_err());
         let error = error.unwrap_err();
-        if let TlvLvError::InvalidTlvTypeField { found, expected } = error {
+        if let TlvLvError::InvalidTlvTypeField(InvalidTlvTypeFieldError { found, expected }) = error
+        {
             assert_eq!(found, TlvType::MsgToUser as u8);
             assert_eq!(expected, Some(TlvType::EntityId as u8));
             assert_eq!(
@@ -1300,4 +1405,71 @@ mod tests {
         assert_eq!(tlv_as_vec[0], 20);
         assert_eq!(tlv_as_vec[1], 0);
     }
+
+    #[test]
+    fn test_tlv_to_owned() {
+        let entity_id = UbfU8::new(5);
+        let mut buf: [u8; 4] = [0; 4];
+        assert!(entity_id.write_to_be_bytes(&mut buf).is_ok());
+        let tlv_res = Tlv::new(TlvType::EntityId, &buf[0..1]);
+        assert!(tlv_res.is_ok());
+        let tlv_res = tlv_res.unwrap();
+        let tlv_owned = tlv_res.to_owned();
+        assert_eq!(tlv_res, tlv_owned);
+        let tlv_owned_from_conversion: TlvOwned = tlv_res.into();
+        assert_eq!(tlv_owned_from_conversion, tlv_owned);
+        assert_eq!(tlv_owned_from_conversion, tlv_res);
+    }
+
+    #[test]
+    fn test_owned_tlv() {
+        let entity_id = UbfU8::new(5);
+        let mut buf: [u8; 4] = [0; 4];
+        assert!(entity_id.write_to_be_bytes(&mut buf).is_ok());
+        let tlv_res = TlvOwned::new(TlvType::EntityId, &buf[0..1]);
+        assert_eq!(
+            tlv_res.tlv_type_field(),
+            TlvTypeField::Standard(TlvType::EntityId)
+        );
+        assert_eq!(tlv_res.len_full(), 3);
+        assert_eq!(tlv_res.value().len(), 1);
+        assert_eq!(tlv_res.len_value(), 1);
+        assert!(!tlv_res.is_empty());
+        assert_eq!(tlv_res.value()[0], 5);
+    }
+
+    #[test]
+    fn test_owned_tlv_empty() {
+        let tlv_res = TlvOwned::new_empty(TlvType::FlowLabel);
+        assert_eq!(
+            tlv_res.tlv_type_field(),
+            TlvTypeField::Standard(TlvType::FlowLabel)
+        );
+        assert_eq!(tlv_res.len_full(), 2);
+        assert_eq!(tlv_res.value().len(), 0);
+        assert_eq!(tlv_res.len_value(), 0);
+        assert!(tlv_res.is_empty());
+    }
+
+    #[test]
+    fn test_owned_tlv_custom_type() {
+        let tlv_res = TlvOwned::new_with_custom_type(32, &[]);
+        assert_eq!(tlv_res.tlv_type_field(), TlvTypeField::Custom(32));
+        assert_eq!(tlv_res.len_full(), 2);
+        assert_eq!(tlv_res.value().len(), 0);
+        assert_eq!(tlv_res.len_value(), 0);
+        assert!(tlv_res.is_empty());
+    }
+
+    #[test]
+    fn test_owned_tlv_conversion_to_bytes() {
+        let entity_id = UbfU8::new(5);
+        let mut buf: [u8; 4] = [0; 4];
+        assert!(entity_id.write_to_be_bytes(&mut buf).is_ok());
+        let tlv_res = Tlv::new(TlvType::EntityId, &buf[0..1]);
+        assert!(tlv_res.is_ok());
+        let tlv_res = tlv_res.unwrap();
+        let tlv_owned_from_conversion: TlvOwned = tlv_res.into();
+        assert_eq!(tlv_res.to_vec(), tlv_owned_from_conversion.to_vec());
+    }
 }

src/cfdp/tlv/msg_to_user.rs

@@ -1,6 +1,8 @@
 //! Abstractions for the Message to User CFDP TLV subtype.
-use super::{GenericTlv, Tlv, TlvLvError, TlvType, TlvTypeField, WritableTlv};
+#[cfg(feature = "alloc")]
-use crate::ByteConversionError;
+use super::TlvOwned;
+use super::{GenericTlv, ReadableTlv, Tlv, TlvLvError, TlvType, TlvTypeField, WritableTlv};
+use crate::{cfdp::{InvalidTlvTypeFieldError, TlvLvDataTooLargeError}, ByteConversionError};
 use delegate::delegate;
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
@@ -10,7 +12,7 @@ pub struct MsgToUserTlv<'data> {
 
 impl<'data> MsgToUserTlv<'data> {
     /// Create a new message to user TLV where the type field is set correctly.
-    pub fn new(value: &'data [u8]) -> Result<MsgToUserTlv<'data>, TlvLvError> {
+    pub fn new(value: &'data [u8]) -> Result<MsgToUserTlv<'data>, TlvLvDataTooLargeError> {
         Ok(Self {
             tlv: Tlv::new(TlvType::MsgToUser, value)?,
         })
@@ -60,21 +62,36 @@ impl<'data> MsgToUserTlv<'data> {
         match msg_to_user.tlv.tlv_type_field() {
             TlvTypeField::Standard(tlv_type) => {
                 if tlv_type != TlvType::MsgToUser {
-                    return Err(TlvLvError::InvalidTlvTypeField {
+                    return Err(InvalidTlvTypeFieldError {
                         found: tlv_type as u8,
                         expected: Some(TlvType::MsgToUser as u8),
-                    });
+                    }.into());
                 }
             }
             TlvTypeField::Custom(raw) => {
-                return Err(TlvLvError::InvalidTlvTypeField {
+                return Err(InvalidTlvTypeFieldError {
                     found: raw,
                     expected: Some(TlvType::MsgToUser as u8),
-                });
+                }.into());
             }
         }
         Ok(msg_to_user)
     }
+
+    pub fn to_tlv(&self) -> Tlv<'data> {
+        self.tlv
+    }
+
+    #[cfg(feature = "alloc")]
+    pub fn to_owned(&self) -> TlvOwned {
+        self.tlv.to_owned()
+    }
+}
+
+impl<'a> From<MsgToUserTlv<'a>> for Tlv<'a> {
+    fn from(value: MsgToUserTlv<'a>) -> Tlv<'a> {
+        value.to_tlv()
+    }
 }
 
 impl WritableTlv for MsgToUserTlv<'_> {
@@ -139,6 +156,40 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_msg_to_user_type_reduction() {
+        let custom_value: [u8; 4] = [1, 2, 3, 4];
+        let msg_to_user = MsgToUserTlv::new(&custom_value).unwrap();
+        let tlv = msg_to_user.to_tlv();
+        assert_eq!(
+            tlv.tlv_type_field(),
+            TlvTypeField::Standard(TlvType::MsgToUser)
+        );
+
+        assert_eq!(tlv.value(), custom_value);
+    }
+
+    #[test]
+    fn test_msg_to_user_to_tlv() {
+        let custom_value: [u8; 4] = [1, 2, 3, 4];
+        let msg_to_user = MsgToUserTlv::new(&custom_value).unwrap();
+        let tlv: Tlv = msg_to_user.into();
+        assert_eq!(msg_to_user.to_tlv(), tlv);
+    }
+
+    #[test]
+    fn test_msg_to_user_owner_converter() {
+        let custom_value: [u8; 4] = [1, 2, 3, 4];
+        let msg_to_user = MsgToUserTlv::new(&custom_value).unwrap();
+        let tlv = msg_to_user.to_owned();
+        assert_eq!(
+            tlv.tlv_type_field(),
+            TlvTypeField::Standard(TlvType::MsgToUser)
+        );
+
+        assert_eq!(tlv.value(), custom_value);
+    }
+
     #[test]
     fn test_reserved_msg_deserialization() {
         let custom_value: [u8; 3] = [1, 2, 3];
@@ -154,9 +205,9 @@ mod tests {
     fn test_reserved_msg_deserialization_invalid_type() {
         let trash: [u8; 5] = [TlvType::FlowLabel as u8, 3, 1, 2, 3];
         let error = MsgToUserTlv::from_bytes(&trash).unwrap_err();
-        if let TlvLvError::InvalidTlvTypeField { found, expected } = error {
+        if let TlvLvError::InvalidTlvTypeField(inner) = error {
-            assert_eq!(found, TlvType::FlowLabel as u8);
+            assert_eq!(inner.found, TlvType::FlowLabel as u8);
-            assert_eq!(expected, Some(TlvType::MsgToUser as u8));
+            assert_eq!(inner.expected, Some(TlvType::MsgToUser as u8));
         } else {
             panic!("Wrong error type returned: {:?}", error);
         }

src/ecss/mod.rs

@@ -1,18 +1,16 @@
 //! Common definitions and helpers required to create PUS TMTC packets according to
 //! [ECSS-E-ST-70-41C](https://ecss.nl/standard/ecss-e-st-70-41c-space-engineering-telemetry-and-telecommand-packet-utilization-15-april-2016/)
 //!
-//! You can find the PUS telecommand definitions in the [tc] module and ithe PUS telemetry definitions
+//! You can find the PUS telecommand types in the [tc] module and the the PUS telemetry
-//! inside the [tm] module.
+//! types inside the [tm] module.
 use crate::{ByteConversionError, CcsdsPacket, CRC_CCITT_FALSE};
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
-use core::fmt::{Debug, Display, Formatter};
+use core::fmt::Debug;
 use core::mem::size_of;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-#[cfg(feature = "std")]
-use std::error::Error;
 
 pub mod event;
 pub mod hk;
@@ -22,7 +20,6 @@ pub mod tm;
 pub mod verification;
 
 pub type CrcType = u16;
-pub const CCSDS_HEADER_LEN: usize = size_of::<crate::zc::SpHeader>();
 
 #[derive(Debug, Copy, Clone, Eq, PartialEq, IntoPrimitive, TryFromPrimitive)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -149,50 +146,19 @@ pub enum PfcReal {
     DoubleMilStd = 4,
 }
 
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum PusError {
+    #[error("PUS version {0:?} not supported")]
     VersionNotSupported(PusVersion),
+    #[error("checksum verification for crc16 {0:#06x} failed")]
     ChecksumFailure(u16),
     /// CRC16 needs to be calculated first
-    CrcCalculationMissing,
+    //#[error("crc16 was not calculated")]
-    ByteConversion(ByteConversionError),
+    //CrcCalculationMissing,
-}
+    #[error("pus error: {0}")]
-
+    ByteConversion(#[from] ByteConversionError),
-impl Display for PusError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            PusError::VersionNotSupported(v) => {
-                write!(f, "PUS version {v:?} not supported")
-            }
-            PusError::ChecksumFailure(crc) => {
-                write!(f, "checksum verification for crc16 {crc:#06x} failed")
-            }
-            PusError::CrcCalculationMissing => {
-                write!(f, "crc16 was not calculated")
-            }
-            PusError::ByteConversion(e) => {
-                write!(f, "pus error: {e}")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for PusError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        if let PusError::ByteConversion(e) = self {
-            return Some(e);
-        }
-        None
-    }
-}
-
-impl From<ByteConversionError> for PusError {
-    fn from(e: ByteConversionError) -> Self {
-        PusError::ByteConversion(e)
-    }
 }
 
 /// Generic trait to describe common attributes for both PUS Telecommands (TC) and PUS Telemetry
@@ -246,7 +212,7 @@ pub(crate) fn verify_crc16_ccitt_false_from_raw_to_pus_error(
     crc16: u16,
 ) -> Result<(), PusError> {
     verify_crc16_ccitt_false_from_raw(raw_data)
-        .then(|| ())
+        .then_some(())
         .ok_or(PusError::ChecksumFailure(crc16))
 }
 
@@ -262,9 +228,13 @@ pub(crate) fn verify_crc16_ccitt_false_from_raw(raw_data: &[u8]) -> bool {
 macro_rules! ccsds_impl {
     () => {
         delegate!(to self.sp_header {
+            #[inline]
             fn ccsds_version(&self) -> u8;
+            #[inline]
             fn packet_id(&self) -> crate::PacketId;
+            #[inline]
             fn psc(&self) -> crate::PacketSequenceCtrl;
+            #[inline]
             fn data_len(&self) -> u16;
         });
     }
@@ -273,8 +243,11 @@ macro_rules! ccsds_impl {
 macro_rules! sp_header_impls {
     () => {
         delegate!(to self.sp_header {
+            #[inline]
             pub fn set_apid(&mut self, apid: u16) -> bool;
+            #[inline]
             pub fn set_seq_count(&mut self, seq_count: u16) -> bool;
+            #[inline]
             pub fn set_seq_flags(&mut self, seq_flag: SequenceFlags);
         });
     }

src/ecss/scheduling.rs

@@ -54,6 +54,7 @@ pub enum SchedStatus {
 }
 
 impl From<bool> for SchedStatus {
+    #[inline]
     fn from(value: bool) -> Self {
         if value {
             SchedStatus::Enabled

src/ecss/tc.rs

@@ -9,9 +9,11 @@
 //! use spacepackets::ecss::tc::{PusTcCreator, PusTcReader, PusTcSecondaryHeader};
 //!
 //! // Create a ping telecommand with no user application data
-//! let mut sph = SpHeader::tc_unseg(0x02, 0x34, 0).unwrap();
+//! let pus_tc = PusTcCreator::new_no_app_data(
-//! let tc_header = PusTcSecondaryHeader::new_simple(17, 1);
+//!     SpHeader::new_from_apid(0x02),
-//! let pus_tc = PusTcCreator::new_no_app_data(&mut sph, tc_header, true);
+//!     PusTcSecondaryHeader::new_simple(17, 1),
+//!     true
+//! );
 //! println!("{:?}", pus_tc);
 //! assert_eq!(pus_tc.service(), 17);
 //! assert_eq!(pus_tc.subservice(), 1);
@@ -43,7 +45,7 @@ use delegate::delegate;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-use zerocopy::AsBytes;
+use zerocopy::{FromBytes, IntoBytes};
 
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
@@ -84,9 +86,9 @@ pub trait GenericPusTcSecondaryHeader {
 pub mod zc {
     use crate::ecss::tc::GenericPusTcSecondaryHeader;
     use crate::ecss::{PusError, PusVersion};
-    use zerocopy::{AsBytes, FromBytes, FromZeroes, NetworkEndian, Unaligned, U16};
+    use zerocopy::{FromBytes, Immutable, IntoBytes, NetworkEndian, Unaligned, U16};
 
-    #[derive(FromZeroes, FromBytes, AsBytes, Unaligned)]
+    #[derive(FromBytes, IntoBytes, Immutable, Unaligned)]
     #[repr(C)]
     pub struct PusTcSecondaryHeader {
         version_ack: u8,
@@ -111,36 +113,31 @@ pub mod zc {
     }
 
     impl GenericPusTcSecondaryHeader for PusTcSecondaryHeader {
+        #[inline]
         fn pus_version(&self) -> PusVersion {
             PusVersion::try_from(self.version_ack >> 4 & 0b1111).unwrap_or(PusVersion::Invalid)
         }
 
+        #[inline]
         fn ack_flags(&self) -> u8 {
             self.version_ack & 0b1111
         }
 
+        #[inline]
         fn service(&self) -> u8 {
             self.service
         }
 
+        #[inline]
         fn subservice(&self) -> u8 {
             self.subservice
         }
 
+        #[inline]
         fn source_id(&self) -> u16 {
             self.source_id.get()
         }
     }
-
-    impl PusTcSecondaryHeader {
-        pub fn write_to_bytes(&self, slice: &mut [u8]) -> Option<()> {
-            self.write_to(slice)
-        }
-
-        pub fn from_bytes(slice: &[u8]) -> Option<Self> {
-            Self::read_from(slice)
-        }
-    }
 }
 
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]
@@ -155,22 +152,27 @@ pub struct PusTcSecondaryHeader {
 }
 
 impl GenericPusTcSecondaryHeader for PusTcSecondaryHeader {
+    #[inline]
     fn pus_version(&self) -> PusVersion {
         self.version
     }
 
+    #[inline]
     fn ack_flags(&self) -> u8 {
         self.ack
     }
 
+    #[inline]
     fn service(&self) -> u8 {
         self.service
     }
 
+    #[inline]
     fn subservice(&self) -> u8 {
         self.subservice
     }
 
+    #[inline]
     fn source_id(&self) -> u16 {
         self.source_id
     }
@@ -191,6 +193,7 @@ impl TryFrom<zc::PusTcSecondaryHeader> for PusTcSecondaryHeader {
 }
 
 impl PusTcSecondaryHeader {
+    #[inline]
     pub fn new_simple(service: u8, subservice: u8) -> Self {
         PusTcSecondaryHeader {
             service,
@@ -201,6 +204,7 @@ impl PusTcSecondaryHeader {
         }
     }
 
+    #[inline]
     pub fn new(service: u8, subservice: u8, ack: u8, source_id: u16) -> Self {
         PusTcSecondaryHeader {
             service,
@@ -223,35 +227,36 @@ impl PusTcSecondaryHeader {
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub struct PusTcCreator<'raw_data> {
+pub struct PusTcCreator<'app_data> {
     sp_header: SpHeader,
     pub sec_header: PusTcSecondaryHeader,
-    app_data: &'raw_data [u8],
+    app_data: &'app_data [u8],
 }
 
-impl<'raw_data> PusTcCreator<'raw_data> {
+impl<'app_data> PusTcCreator<'app_data> {
     /// Generates a new struct instance.
     ///
     /// # Arguments
     ///
-    /// * `sp_header` - Space packet header information. The correct packet type will be set
+    /// * `sp_header` - Space packet header information. The correct packet type and the secondary
-    ///     automatically
+    ///     header flag are set correctly by the constructor.
     /// * `sec_header` - Information contained in the data field header, including the service
     ///     and subservice type
     /// * `app_data` - Custom application data
     /// * `set_ccsds_len` - Can be used to automatically update the CCSDS space packet data length
     ///     field. If this is not set to true, [Self::update_ccsds_data_len] can be called to set
     ///     the correct value to this field manually
+    #[inline]
     pub fn new(
-        sp_header: &mut SpHeader,
+        mut sp_header: SpHeader,
         sec_header: PusTcSecondaryHeader,
-        app_data: &'raw_data [u8],
+        app_data: &'app_data [u8],
         set_ccsds_len: bool,
     ) -> Self {
         sp_header.set_packet_type(PacketType::Tc);
         sp_header.set_sec_header_flag();
         let mut pus_tc = Self {
-            sp_header: *sp_header,
+            sp_header,
             app_data,
             sec_header,
         };
@@ -263,11 +268,12 @@ impl<'raw_data> PusTcCreator<'raw_data> {
 
     /// Simplified version of the [Self::new] function which allows to only specify service
     /// and subservice instead of the full PUS TC secondary header.
+    #[inline]
     pub fn new_simple(
-        sph: &mut SpHeader,
+        sph: SpHeader,
         service: u8,
         subservice: u8,
-        app_data: &'raw_data [u8],
+        app_data: &'app_data [u8],
         set_ccsds_len: bool,
     ) -> Self {
         Self::new(
@@ -278,18 +284,26 @@ impl<'raw_data> PusTcCreator<'raw_data> {
         )
     }
 
+    #[inline]
     pub fn new_no_app_data(
-        sp_header: &mut SpHeader,
+        sp_header: SpHeader,
         sec_header: PusTcSecondaryHeader,
         set_ccsds_len: bool,
     ) -> Self {
         Self::new(sp_header, sec_header, &[], set_ccsds_len)
     }
 
+    #[inline]
     pub fn sp_header(&self) -> &SpHeader {
         &self.sp_header
     }
 
+    #[inline]
+    pub fn sp_header_mut(&mut self) -> &mut SpHeader {
+        &mut self.sp_header
+    }
+
+    #[inline]
     pub fn set_ack_field(&mut self, ack: u8) -> bool {
         if ack > 0b1111 {
             return false;
@@ -298,6 +312,7 @@ impl<'raw_data> PusTcCreator<'raw_data> {
         true
     }
 
+    #[inline]
     pub fn set_source_id(&mut self, source_id: u16) {
         self.sec_header.source_id = source_id;
     }
@@ -310,6 +325,7 @@ impl<'raw_data> PusTcCreator<'raw_data> {
     /// If this was not done or the application data is set or changed after construction,
     /// this function needs to be called to ensure that the data length field of the CCSDS header
     /// is set correctly.
+    #[inline]
     pub fn update_ccsds_data_len(&mut self) {
         self.sp_header.data_len =
             self.len_written() as u16 - size_of::<crate::zc::SpHeader>() as u16 - 1;
@@ -345,6 +361,7 @@ impl<'raw_data> PusTcCreator<'raw_data> {
 }
 
 impl WritablePusPacket for PusTcCreator<'_> {
+    #[inline]
     fn len_written(&self) -> usize {
         PUS_TC_MIN_LEN_WITHOUT_APP_DATA + self.app_data.len()
     }
@@ -365,8 +382,8 @@ impl WritablePusPacket for PusTcCreator<'_> {
         curr_idx += CCSDS_HEADER_LEN;
         let sec_header = zc::PusTcSecondaryHeader::try_from(self.sec_header).unwrap();
         sec_header
-            .write_to_bytes(&mut slice[curr_idx..curr_idx + tc_header_len])
+            .write_to(&mut slice[curr_idx..curr_idx + tc_header_len])
-            .ok_or(ByteConversionError::ZeroCopyToError)?;
+            .map_err(|_| ByteConversionError::ZeroCopyToError)?;
 
         curr_idx += tc_header_len;
         slice[curr_idx..curr_idx + self.app_data.len()].copy_from_slice(self.app_data);
@@ -385,15 +402,20 @@ impl CcsdsPacket for PusTcCreator<'_> {
 
 impl PusPacket for PusTcCreator<'_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
     });
 
+    #[inline]
     fn user_data(&self) -> &[u8] {
         self.app_data
     }
 
+    #[inline]
     fn crc16(&self) -> Option<u16> {
         Some(self.calc_own_crc16())
     }
@@ -401,10 +423,15 @@ impl PusPacket for PusTcCreator<'_> {
 
 impl GenericPusTcSecondaryHeader for PusTcCreator<'_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
+        #[inline]
         fn source_id(&self) -> u16;
+        #[inline]
         fn ack_flags(&self) -> u8;
     });
 }
@@ -465,10 +492,10 @@ impl<'raw_data> PusTcReader<'raw_data> {
             }
             .into());
         }
-        let sec_header = zc::PusTcSecondaryHeader::from_bytes(
+        let sec_header = zc::PusTcSecondaryHeader::read_from_bytes(
             &slice[current_idx..current_idx + PUC_TC_SECONDARY_HEADER_LEN],
         )
-        .ok_or(ByteConversionError::ZeroCopyFromError)?;
+        .map_err(|_| ByteConversionError::ZeroCopyFromError)?;
         current_idx += PUC_TC_SECONDARY_HEADER_LEN;
         let raw_data = &slice[0..total_len];
         let pus_tc = Self {
@@ -482,24 +509,29 @@ impl<'raw_data> PusTcReader<'raw_data> {
         Ok((pus_tc, total_len))
     }
 
+    #[inline]
     pub fn app_data(&self) -> &[u8] {
         self.user_data()
     }
 
+    #[inline]
     pub fn raw_data(&self) -> &[u8] {
         self.raw_data
     }
 
+    #[inline]
     pub fn len_packed(&self) -> usize {
         self.sp_header.total_len()
     }
 
+    #[inline]
     pub fn sp_header(&self) -> &SpHeader {
         &self.sp_header
     }
 }
 
 impl PartialEq for PusTcReader<'_> {
+    #[inline]
     fn eq(&self, other: &Self) -> bool {
         self.raw_data == other.raw_data
     }
@@ -511,15 +543,20 @@ impl CcsdsPacket for PusTcReader<'_> {
 
 impl PusPacket for PusTcReader<'_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
     });
 
+    #[inline]
     fn user_data(&self) -> &[u8] {
         self.app_data
     }
 
+    #[inline]
     fn crc16(&self) -> Option<u16> {
         Some(self.crc16)
     }
@@ -527,10 +564,15 @@ impl PusPacket for PusTcReader<'_> {
 
 impl GenericPusTcSecondaryHeader for PusTcReader<'_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
+        #[inline]
         fn source_id(&self) -> u16;
+        #[inline]
         fn ack_flags(&self) -> u8;
     });
 }
@@ -568,19 +610,19 @@ mod tests {
     use postcard::{from_bytes, to_allocvec};
 
     fn base_ping_tc_full_ctor() -> PusTcCreator<'static> {
-        let mut sph = SpHeader::tc_unseg(0x02, 0x34, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tc_checked(0x02, 0x34, 0).unwrap();
         let tc_header = PusTcSecondaryHeader::new_simple(17, 1);
-        PusTcCreator::new_no_app_data(&mut sph, tc_header, true)
+        PusTcCreator::new_no_app_data(sph, tc_header, true)
     }
 
     fn base_ping_tc_simple_ctor() -> PusTcCreator<'static> {
-        let mut sph = SpHeader::tc_unseg(0x02, 0x34, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tc_checked(0x02, 0x34, 0).unwrap();
-        PusTcCreator::new_simple(&mut sph, 17, 1, &[], true)
+        PusTcCreator::new_simple(sph, 17, 1, &[], true)
     }
 
     fn base_ping_tc_simple_ctor_with_app_data(app_data: &'static [u8]) -> PusTcCreator<'static> {
-        let mut sph = SpHeader::tc_unseg(0x02, 0x34, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tc_checked(0x02, 0x34, 0).unwrap();
-        PusTcCreator::new_simple(&mut sph, 17, 1, app_data, true)
+        PusTcCreator::new_simple(sph, 17, 1, app_data, true)
     }
 
     #[test]
@@ -636,8 +678,8 @@ mod tests {
 
     #[test]
     fn test_update_func() {
-        let mut sph = SpHeader::tc_unseg(0x02, 0x34, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tc_checked(0x02, 0x34, 0).unwrap();
-        let mut tc = PusTcCreator::new_simple(&mut sph, 17, 1, &[], false);
+        let mut tc = PusTcCreator::new_simple(sph, 17, 1, &[], false);
         assert_eq!(tc.data_len(), 0);
         tc.update_ccsds_data_len();
         assert_eq!(tc.data_len(), 6);
@@ -809,7 +851,8 @@ mod tests {
         if !has_user_data {
             assert!(tc.user_data().is_empty());
         }
-        let mut comp_header = SpHeader::tc_unseg(0x02, 0x34, exp_full_len as u16 - 7).unwrap();
+        let mut comp_header =
+            SpHeader::new_for_unseg_tc_checked(0x02, 0x34, exp_full_len as u16 - 7).unwrap();
         comp_header.set_sec_header_flag();
         assert_eq!(*tc.sp_header(), comp_header);
     }
@@ -820,7 +863,8 @@ mod tests {
             assert!(tc.user_data().is_empty());
         }
         assert_eq!(tc.len_packed(), exp_full_len);
-        let mut comp_header = SpHeader::tc_unseg(0x02, 0x34, exp_full_len as u16 - 7).unwrap();
+        let mut comp_header =
+            SpHeader::new_for_unseg_tc_checked(0x02, 0x34, exp_full_len as u16 - 7).unwrap();
         comp_header.set_sec_header_flag();
         assert_eq!(*tc.sp_header(), comp_header);
     }

src/ecss/tm.rs

@@ -1,5 +1,47 @@
 //! This module contains all components required to create a ECSS PUS C telemetry packets according
 //! to [ECSS-E-ST-70-41C](https://ecss.nl/standard/ecss-e-st-70-41c-space-engineering-telemetry-and-telecommand-packet-utilization-15-april-2016/).
+//!
+//! # Examples
+//!
+//! ```rust
+//! use spacepackets::time::TimeWriter;
+//! use spacepackets::time::cds::CdsTime;
+//! use spacepackets::{CcsdsPacket, SpHeader};
+//! use spacepackets::ecss::{PusPacket, WritablePusPacket};
+//! use spacepackets::ecss::tm::{PusTmCreator, PusTmReader, PusTmSecondaryHeader};
+//!
+//! let mut time_buf: [u8; 7] = [0; 7];
+//! let time_now = CdsTime::now_with_u16_days().expect("creating CDS timestamp failed");
+//! // This can definitely hold the timestamp, so it is okay to unwrap.
+//! time_now.write_to_bytes(&mut time_buf).unwrap();
+//!
+//! // Create a ping telemetry with no user source data
+//! let ping_tm = PusTmCreator::new_no_source_data(
+//!     SpHeader::new_from_apid(0x02),
+//!     PusTmSecondaryHeader::new_simple(17, 2, &time_buf),
+//!     true
+//! );
+//! println!("{:?}", ping_tm);
+//! assert_eq!(ping_tm.service(), 17);
+//! assert_eq!(ping_tm.subservice(), 2);
+//! assert_eq!(ping_tm.apid(), 0x02);
+//!
+//! // Serialize TM into a raw buffer
+//! let mut test_buf: [u8; 32] = [0; 32];
+//! let written_size = ping_tm
+//!     .write_to_bytes(test_buf.as_mut_slice())
+//!     .expect("Error writing TC to buffer");
+//! assert_eq!(written_size, 22);
+//! println!("{:?}", &test_buf[0..written_size]);
+//!
+//! // Deserialize from the raw byte representation
+//! let (ping_tm_reader, read_size) = PusTmReader::new(&test_buf, 7).expect("Deserialization failed");
+//! assert_eq!(written_size, read_size);
+//! assert_eq!(ping_tm_reader.service(), 17);
+//! assert_eq!(ping_tm_reader.subservice(), 2);
+//! assert_eq!(ping_tm_reader.apid(), 0x02);
+//! assert_eq!(ping_tm_reader.timestamp(), &time_buf);
+//! ```
 use crate::ecss::{
     calc_pus_crc16, ccsds_impl, crc_from_raw_data, sp_header_impls, user_data_from_raw,
     verify_crc16_ccitt_false_from_raw_to_pus_error, CrcType, PusError, PusPacket, PusVersion,
@@ -12,7 +54,7 @@ use crate::{
 use core::mem::size_of;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
-use zerocopy::AsBytes;
+use zerocopy::{FromBytes, IntoBytes};
 
 #[cfg(feature = "alloc")]
 use alloc::vec::Vec;
@@ -41,9 +83,9 @@ pub trait GenericPusTmSecondaryHeader {
 pub mod zc {
     use super::GenericPusTmSecondaryHeader;
     use crate::ecss::{PusError, PusVersion};
-    use zerocopy::{AsBytes, FromBytes, FromZeroes, NetworkEndian, Unaligned, U16};
+    use zerocopy::{FromBytes, Immutable, IntoBytes, NetworkEndian, Unaligned, U16};
 
-    #[derive(FromBytes, FromZeroes, AsBytes, Unaligned)]
+    #[derive(FromBytes, IntoBytes, Immutable, Unaligned)]
     #[repr(C)]
     pub struct PusTmSecHeaderWithoutTimestamp {
         pus_version_and_sc_time_ref_status: u8,
@@ -75,38 +117,34 @@ pub mod zc {
         }
     }
 
-    impl PusTmSecHeaderWithoutTimestamp {
-        pub fn write_to_bytes(&self, slice: &mut [u8]) -> Option<()> {
-            self.write_to(slice)
-        }
-
-        pub fn from_bytes(slice: &[u8]) -> Option<Self> {
-            Self::read_from(slice)
-        }
-    }
-
     impl GenericPusTmSecondaryHeader for PusTmSecHeaderWithoutTimestamp {
+        #[inline]
         fn pus_version(&self) -> PusVersion {
             PusVersion::try_from(self.pus_version_and_sc_time_ref_status >> 4 & 0b1111)
                 .unwrap_or(PusVersion::Invalid)
         }
 
+        #[inline]
         fn sc_time_ref_status(&self) -> u8 {
             self.pus_version_and_sc_time_ref_status & 0b1111
         }
 
+        #[inline]
         fn service(&self) -> u8 {
             self.service
         }
 
+        #[inline]
         fn subservice(&self) -> u8 {
             self.subservice
         }
 
+        #[inline]
         fn msg_counter(&self) -> u16 {
             self.msg_counter.get()
         }
 
+        #[inline]
         fn dest_id(&self) -> u16 {
             self.dest_id.get()
         }
@@ -123,25 +161,28 @@ pub struct PusTmSecondaryHeader<'stamp> {
     pub subservice: u8,
     pub msg_counter: u16,
     pub dest_id: u16,
-    pub time_stamp: &'stamp [u8],
+    pub timestamp: &'stamp [u8],
 }
 
 impl<'stamp> PusTmSecondaryHeader<'stamp> {
-    pub fn new_simple(service: u8, subservice: u8, time_stamp: &'stamp [u8]) -> Self {
+    #[inline]
-        Self::new(service, subservice, 0, 0, time_stamp)
+    pub fn new_simple(service: u8, subservice: u8, timestamp: &'stamp [u8]) -> Self {
+        Self::new(service, subservice, 0, 0, timestamp)
     }
 
     /// Like [Self::new_simple] but without a timestamp.
+    #[inline]
     pub fn new_simple_no_timestamp(service: u8, subservice: u8) -> Self {
         Self::new(service, subservice, 0, 0, &[])
     }
 
+    #[inline]
     pub fn new(
         service: u8,
         subservice: u8,
         msg_counter: u16,
         dest_id: u16,
-        time_stamp: &'stamp [u8],
+        timestamp: &'stamp [u8],
     ) -> Self {
         PusTmSecondaryHeader {
             pus_version: PusVersion::PusC,
@@ -150,32 +191,38 @@ impl<'stamp> PusTmSecondaryHeader<'stamp> {
             subservice,
             msg_counter,
             dest_id,
-            time_stamp,
+            timestamp,
         }
     }
 }
 
 impl GenericPusTmSecondaryHeader for PusTmSecondaryHeader<'_> {
+    #[inline]
     fn pus_version(&self) -> PusVersion {
         self.pus_version
     }
 
+    #[inline]
     fn sc_time_ref_status(&self) -> u8 {
         self.sc_time_ref_status
     }
 
+    #[inline]
     fn service(&self) -> u8 {
         self.service
     }
 
+    #[inline]
     fn subservice(&self) -> u8 {
         self.subservice
     }
 
+    #[inline]
     fn msg_counter(&self) -> u16 {
         self.msg_counter
     }
 
+    #[inline]
     fn dest_id(&self) -> u16 {
         self.dest_id
     }
@@ -184,6 +231,7 @@ impl GenericPusTmSecondaryHeader for PusTmSecondaryHeader<'_> {
 impl<'slice> TryFrom<zc::PusTmSecHeader<'slice>> for PusTmSecondaryHeader<'slice> {
     type Error = ();
 
+    #[inline]
     fn try_from(sec_header: zc::PusTmSecHeader<'slice>) -> Result<Self, Self::Error> {
         Ok(PusTmSecondaryHeader {
             pus_version: sec_header.zc_header.pus_version(),
@@ -192,7 +240,7 @@ impl<'slice> TryFrom<zc::PusTmSecHeader<'slice>> for PusTmSecondaryHeader<'slice
             subservice: sec_header.zc_header.subservice(),
             msg_counter: sec_header.zc_header.msg_counter(),
             dest_id: sec_header.zc_header.dest_id(),
-            time_stamp: sec_header.timestamp,
+            timestamp: sec_header.timestamp,
         })
     }
 }
@@ -208,43 +256,45 @@ impl<'slice> TryFrom<zc::PusTmSecHeader<'slice>> for PusTmSecondaryHeader<'slice
 ///
 /// # Lifetimes
 ///
-/// * `'raw_data` - This is the lifetime of the user provided time stamp and source data.
+/// * `'time` - This is the lifetime of the user provided timestamp.
+/// * `'src_data` - This is the lifetime of the user provided source data.
 #[derive(Eq, Debug, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
-pub struct PusTmCreator<'time, 'raw_data> {
+pub struct PusTmCreator<'time, 'src_data> {
     pub sp_header: SpHeader,
     #[cfg_attr(feature = "serde", serde(borrow))]
     pub sec_header: PusTmSecondaryHeader<'time>,
-    source_data: &'raw_data [u8],
+    source_data: &'src_data [u8],
     /// If this is set to false, a manual call to [Self::calc_own_crc16] or
     /// [Self::update_packet_fields] is necessary for the serialized or cached CRC16 to be valid.
     pub calc_crc_on_serialization: bool,
 }
 
-impl<'time, 'raw_data> PusTmCreator<'time, 'raw_data> {
+impl<'time, 'src_data> PusTmCreator<'time, 'src_data> {
     /// Generates a new struct instance.
     ///
     /// # Arguments
     ///
-    /// * `sp_header` - Space packet header information. The correct packet type will be set
+    /// * `sp_header` - Space packet header information. The correct packet type and the secondary
-    ///     automatically
+    ///     header flag are set correctly by the constructor.
     /// * `sec_header` - Information contained in the secondary header, including the service
     ///     and subservice type
     /// * `source_data` - Custom application data
     /// * `set_ccsds_len` - Can be used to automatically update the CCSDS space packet data length
     ///     field. If this is not set to true, [Self::update_ccsds_data_len] can be called to set
     ///     the correct value to this field manually
+    #[inline]
     pub fn new(
-        sp_header: &mut SpHeader,
+        mut sp_header: SpHeader,
         sec_header: PusTmSecondaryHeader<'time>,
-        source_data: &'raw_data [u8],
+        source_data: &'src_data [u8],
         set_ccsds_len: bool,
     ) -> Self {
         sp_header.set_packet_type(PacketType::Tm);
         sp_header.set_sec_header_flag();
         let mut pus_tm = Self {
-            sp_header: *sp_header,
+            sp_header,
             source_data,
             sec_header,
             calc_crc_on_serialization: true,
@@ -255,50 +305,52 @@ impl<'time, 'raw_data> PusTmCreator<'time, 'raw_data> {
         pus_tm
     }
 
+    #[inline]
     pub fn new_simple(
-        sp_header: &mut SpHeader,
+        sp_header: SpHeader,
         service: u8,
         subservice: u8,
         time_provider: &impl TimeWriter,
         stamp_buf: &'time mut [u8],
-        source_data: Option<&'raw_data [u8]>,
+        source_data: &'src_data [u8],
         set_ccsds_len: bool,
     ) -> Result<Self, TimestampError> {
         let stamp_size = time_provider.write_to_bytes(stamp_buf)?;
         let sec_header =
             PusTmSecondaryHeader::new_simple(service, subservice, &stamp_buf[0..stamp_size]);
-        Ok(Self::new(
+        Ok(Self::new(sp_header, sec_header, source_data, set_ccsds_len))
-            sp_header,
-            sec_header,
-            source_data.unwrap_or(&[]),
-            set_ccsds_len,
-        ))
     }
 
+    #[inline]
     pub fn new_no_source_data(
-        sp_header: &mut SpHeader,
+        sp_header: SpHeader,
         sec_header: PusTmSecondaryHeader<'time>,
         set_ccsds_len: bool,
     ) -> Self {
         Self::new(sp_header, sec_header, &[], set_ccsds_len)
     }
 
+    #[inline]
     pub fn timestamp(&self) -> &[u8] {
-        self.sec_header.time_stamp
+        self.sec_header.timestamp
     }
 
+    #[inline]
     pub fn source_data(&self) -> &[u8] {
         self.source_data
     }
 
+    #[inline]
     pub fn set_dest_id(&mut self, dest_id: u16) {
         self.sec_header.dest_id = dest_id;
     }
 
+    #[inline]
     pub fn set_msg_counter(&mut self, msg_counter: u16) {
         self.sec_header.msg_counter = msg_counter
     }
 
+    #[inline]
     pub fn set_sc_time_ref_status(&mut self, sc_time_ref_status: u8) {
         self.sec_header.sc_time_ref_status = sc_time_ref_status & 0b1111;
     }
@@ -310,6 +362,7 @@ impl<'time, 'raw_data> PusTmCreator<'time, 'raw_data> {
     /// If this was not done or the time stamp or source data is set or changed after construction,
     /// this function needs to be called to ensure that the data length field of the CCSDS header
     /// is set correctly
+    #[inline]
     pub fn update_ccsds_data_len(&mut self) {
         self.sp_header.data_len =
             self.len_written() as u16 - size_of::<crate::zc::SpHeader>() as u16 - 1;
@@ -323,12 +376,13 @@ impl<'time, 'raw_data> PusTmCreator<'time, 'raw_data> {
         digest.update(sph_zc.as_bytes());
         let pus_tc_header = zc::PusTmSecHeaderWithoutTimestamp::try_from(self.sec_header).unwrap();
         digest.update(pus_tc_header.as_bytes());
-        digest.update(self.sec_header.time_stamp);
+        digest.update(self.sec_header.timestamp);
         digest.update(self.source_data);
         digest.finalize()
     }
 
     /// This helper function calls both [Self::update_ccsds_data_len] and [Self::calc_own_crc16]
+    #[inline]
     pub fn update_packet_fields(&mut self) {
         self.update_ccsds_data_len();
     }
@@ -349,12 +403,12 @@ impl<'time, 'raw_data> PusTmCreator<'time, 'raw_data> {
         let sec_header_len = size_of::<zc::PusTmSecHeaderWithoutTimestamp>();
         let sec_header = zc::PusTmSecHeaderWithoutTimestamp::try_from(self.sec_header).unwrap();
         sec_header
-            .write_to_bytes(&mut slice[curr_idx..curr_idx + sec_header_len])
+            .write_to(&mut slice[curr_idx..curr_idx + sec_header_len])
-            .ok_or(ByteConversionError::ZeroCopyToError)?;
+            .map_err(|_| ByteConversionError::ZeroCopyToError)?;
         curr_idx += sec_header_len;
-        slice[curr_idx..curr_idx + self.sec_header.time_stamp.len()]
+        slice[curr_idx..curr_idx + self.sec_header.timestamp.len()]
-            .copy_from_slice(self.sec_header.time_stamp);
+            .copy_from_slice(self.sec_header.timestamp);
-        curr_idx += self.sec_header.time_stamp.len();
+        curr_idx += self.sec_header.timestamp.len();
         slice[curr_idx..curr_idx + self.source_data.len()].copy_from_slice(self.source_data);
         curr_idx += self.source_data.len();
         let mut digest = CRC_CCITT_FALSE.digest();
@@ -368,15 +422,14 @@ impl<'time, 'raw_data> PusTmCreator<'time, 'raw_data> {
     #[cfg(feature = "alloc")]
     pub fn append_to_vec(&self, vec: &mut Vec<u8>) -> Result<usize, PusError> {
         let sph_zc = crate::zc::SpHeader::from(self.sp_header);
-        let mut appended_len =
+        let mut appended_len = PUS_TM_MIN_LEN_WITHOUT_SOURCE_DATA + self.sec_header.timestamp.len();
-            PUS_TM_MIN_LEN_WITHOUT_SOURCE_DATA + self.sec_header.time_stamp.len();
         appended_len += self.source_data.len();
         let start_idx = vec.len();
         vec.extend_from_slice(sph_zc.as_bytes());
         // The PUS version is hardcoded to PUS C
         let sec_header = zc::PusTmSecHeaderWithoutTimestamp::try_from(self.sec_header).unwrap();
         vec.extend_from_slice(sec_header.as_bytes());
-        vec.extend_from_slice(self.sec_header.time_stamp);
+        vec.extend_from_slice(self.sec_header.timestamp);
         vec.extend_from_slice(self.source_data);
         let mut digest = CRC_CCITT_FALSE.digest();
         digest.update(&vec[start_idx..start_idx + appended_len - 2]);
@@ -386,9 +439,10 @@ impl<'time, 'raw_data> PusTmCreator<'time, 'raw_data> {
 }
 
 impl WritablePusPacket for PusTmCreator<'_, '_> {
+    #[inline]
     fn len_written(&self) -> usize {
         PUS_TM_MIN_LEN_WITHOUT_SOURCE_DATA
-            + self.sec_header.time_stamp.len()
+            + self.sec_header.timestamp.len()
             + self.source_data.len()
     }
     /// Write the raw PUS byte representation to a provided buffer.
@@ -411,15 +465,20 @@ impl CcsdsPacket for PusTmCreator<'_, '_> {
 
 impl PusPacket for PusTmCreator<'_, '_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
     });
 
+    #[inline]
     fn user_data(&self) -> &[u8] {
         self.source_data
     }
 
+    #[inline]
     fn crc16(&self) -> Option<u16> {
         Some(self.calc_own_crc16())
     }
@@ -427,11 +486,17 @@ impl PusPacket for PusTmCreator<'_, '_> {
 
 impl GenericPusTmSecondaryHeader for PusTmCreator<'_, '_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
+        #[inline]
         fn dest_id(&self) -> u16;
+        #[inline]
         fn msg_counter(&self) -> u16;
+        #[inline]
         fn sc_time_ref_status(&self) -> u8;
     });
 }
@@ -496,10 +561,10 @@ impl<'raw_data> PusTmReader<'raw_data> {
             }
             .into());
         }
-        let sec_header_zc = zc::PusTmSecHeaderWithoutTimestamp::from_bytes(
+        let sec_header_zc = zc::PusTmSecHeaderWithoutTimestamp::read_from_bytes(
             &slice[current_idx..current_idx + PUS_TM_MIN_SEC_HEADER_LEN],
         )
-        .ok_or(ByteConversionError::ZeroCopyFromError)?;
+        .map_err(|_| ByteConversionError::ZeroCopyFromError)?;
         current_idx += PUS_TM_MIN_SEC_HEADER_LEN;
         let zc_sec_header_wrapper = zc::PusTmSecHeader {
             zc_header: sec_header_zc,
@@ -518,19 +583,23 @@ impl<'raw_data> PusTmReader<'raw_data> {
         Ok((pus_tm, total_len))
     }
 
+    #[inline]
     pub fn len_packed(&self) -> usize {
         self.sp_header.total_len()
     }
 
+    #[inline]
     pub fn source_data(&self) -> &[u8] {
         self.user_data()
     }
 
+    #[inline]
     pub fn timestamp(&self) -> &[u8] {
-        self.sec_header.time_stamp
+        self.sec_header.timestamp
     }
 
     /// This function will return the slice [Self] was constructed from.
+    #[inline]
     pub fn raw_data(&self) -> &[u8] {
         self.raw_data
     }
@@ -551,15 +620,20 @@ impl CcsdsPacket for PusTmReader<'_> {
 
 impl PusPacket for PusTmReader<'_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
     });
 
+    #[inline]
     fn user_data(&self) -> &[u8] {
         self.source_data
     }
 
+    #[inline]
     fn crc16(&self) -> Option<u16> {
         Some(self.crc16)
     }
@@ -567,11 +641,17 @@ impl PusPacket for PusTmReader<'_> {
 
 impl GenericPusTmSecondaryHeader for PusTmReader<'_> {
     delegate!(to self.sec_header {
+        #[inline]
         fn pus_version(&self) -> PusVersion;
+        #[inline]
         fn service(&self) -> u8;
+        #[inline]
         fn subservice(&self) -> u8;
+        #[inline]
         fn dest_id(&self) -> u16;
+        #[inline]
         fn msg_counter(&self) -> u16;
+        #[inline]
         fn sc_time_ref_status(&self) -> u8;
     });
 }
@@ -620,7 +700,7 @@ impl<'raw> PusTmZeroCopyWriter<'raw> {
         if raw_tm_len < CCSDS_HEADER_LEN + PUS_TM_MIN_SEC_HEADER_LEN + timestamp_len {
             return None;
         }
-        let sp_header = crate::zc::SpHeader::from_bytes(&raw_tm[0..CCSDS_HEADER_LEN]).unwrap();
+        let sp_header = crate::zc::SpHeader::read_from_bytes(&raw_tm[0..CCSDS_HEADER_LEN]).unwrap();
         if raw_tm_len < sp_header.total_len() {
             return None;
         }
@@ -633,6 +713,7 @@ impl<'raw> PusTmZeroCopyWriter<'raw> {
 
     /// Set the sequence count. Returns false and does not update the value if the passed value
     /// exceeds [MAX_APID].
+    #[inline]
     pub fn set_apid(&mut self, apid: u16) -> bool {
         if apid > MAX_APID {
             return false;
@@ -645,11 +726,13 @@ impl<'raw> PusTmZeroCopyWriter<'raw> {
     }
 
     /// This function sets the message counter in the PUS TM secondary header.
+    #[inline]
     pub fn set_msg_count(&mut self, msg_count: u16) {
         self.raw_tm[9..11].copy_from_slice(&msg_count.to_be_bytes());
     }
 
     /// This function sets the destination ID in the PUS TM secondary header.
+    #[inline]
     pub fn set_destination_id(&mut self, dest_id: u16) {
         self.raw_tm[11..13].copy_from_slice(&dest_id.to_be_bytes())
     }
@@ -658,7 +741,7 @@ impl<'raw> PusTmZeroCopyWriter<'raw> {
     #[inline]
     pub fn sp_header(&self) -> crate::zc::SpHeader {
         // Valid minimum length of packet was checked before.
-        crate::zc::SpHeader::from_bytes(&self.raw_tm[0..CCSDS_HEADER_LEN]).unwrap()
+        crate::zc::SpHeader::read_from_bytes(&self.raw_tm[0..CCSDS_HEADER_LEN]).unwrap()
     }
 
     /// Helper API to generate the portion of the secondary header without a timestamp from the
@@ -666,7 +749,7 @@ impl<'raw> PusTmZeroCopyWriter<'raw> {
     #[inline]
     pub fn sec_header_without_timestamp(&self) -> PusTmSecHeaderWithoutTimestamp {
         // Valid minimum length of packet was checked before.
-        PusTmSecHeaderWithoutTimestamp::from_bytes(
+        PusTmSecHeaderWithoutTimestamp::read_from_bytes(
             &self.raw_tm[CCSDS_HEADER_LEN..CCSDS_HEADER_LEN + PUS_TM_MIN_SEC_HEADER_LEN],
         )
         .unwrap()
@@ -674,6 +757,7 @@ impl<'raw> PusTmZeroCopyWriter<'raw> {
 
     /// Set the sequence count. Returns false and does not update the value if the passed value
     /// exceeds [MAX_SEQ_COUNT].
+    #[inline]
     pub fn set_seq_count(&mut self, seq_count: u16) -> bool {
         if seq_count > MAX_SEQ_COUNT {
             return false;
@@ -788,20 +872,20 @@ mod tests {
     const DUMMY_DATA: &[u8] = &[0, 1, 2];
 
     fn base_ping_reply_full_ctor(timestamp: &[u8]) -> PusTmCreator {
-        let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tm_checked(0x123, 0x234, 0).unwrap();
         let tm_header = PusTmSecondaryHeader::new_simple(17, 2, timestamp);
-        PusTmCreator::new_no_source_data(&mut sph, tm_header, true)
+        PusTmCreator::new_no_source_data(sph, tm_header, true)
     }
     fn ping_reply_with_data(timestamp: &[u8]) -> PusTmCreator {
-        let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tm_checked(0x123, 0x234, 0).unwrap();
         let tm_header = PusTmSecondaryHeader::new_simple(17, 2, timestamp);
-        PusTmCreator::new(&mut sph, tm_header, DUMMY_DATA, true)
+        PusTmCreator::new(sph, tm_header, DUMMY_DATA, true)
     }
 
     fn base_hk_reply<'a, 'b>(timestamp: &'a [u8], src_data: &'b [u8]) -> PusTmCreator<'a, 'b> {
-        let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tm_checked(0x123, 0x234, 0).unwrap();
         let tc_header = PusTmSecondaryHeader::new_simple(3, 5, timestamp);
-        PusTmCreator::new(&mut sph, tc_header, src_data, true)
+        PusTmCreator::new(sph, tc_header, src_data, true)
     }
 
     fn dummy_timestamp() -> &'static [u8] {
@@ -816,11 +900,11 @@ mod tests {
     }
     #[test]
     fn test_basic_simple_api() {
-        let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tm_checked(0x123, 0x234, 0).unwrap();
         let time_provider = CdsTime::new_with_u16_days(0, 0);
         let mut stamp_buf: [u8; 8] = [0; 8];
         let pus_tm =
-            PusTmCreator::new_simple(&mut sph, 17, 2, &time_provider, &mut stamp_buf, None, true)
+            PusTmCreator::new_simple(sph, 17, 2, &time_provider, &mut stamp_buf, &[], true)
                 .unwrap();
         verify_ping_reply(&pus_tm, false, 22, &[64, 0, 0, 0, 0, 0, 0]);
     }
@@ -917,9 +1001,9 @@ mod tests {
 
     #[test]
     fn test_manual_field_update() {
-        let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tm_checked(0x123, 0x234, 0).unwrap();
         let tc_header = PusTmSecondaryHeader::new_simple(17, 2, dummy_timestamp());
-        let mut tm = PusTmCreator::new_no_source_data(&mut sph, tc_header, false);
+        let mut tm = PusTmCreator::new_no_source_data(sph, tc_header, false);
         tm.calc_crc_on_serialization = false;
         assert_eq!(tm.data_len(), 0x00);
         let mut buf: [u8; 32] = [0; 32];
@@ -1147,7 +1231,7 @@ mod tests {
     #[test]
     fn test_sec_header_without_stamp() {
         let sec_header = PusTmSecondaryHeader::new_simple_no_timestamp(17, 1);
-        assert_eq!(sec_header.time_stamp, &[]);
+        assert_eq!(sec_header.timestamp, &[]);
     }
 
     #[test]
@@ -1207,11 +1291,11 @@ mod tests {
     #[test]
     #[cfg(feature = "serde")]
     fn test_serialization_creator_serde() {
-        let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tm_checked(0x123, 0x234, 0).unwrap();
         let time_provider = CdsTime::new_with_u16_days(0, 0);
         let mut stamp_buf: [u8; 8] = [0; 8];
         let pus_tm =
-            PusTmCreator::new_simple(&mut sph, 17, 2, &time_provider, &mut stamp_buf, None, true)
+            PusTmCreator::new_simple(sph, 17, 2, &time_provider, &mut stamp_buf, &[], true)
                 .unwrap();
 
         let output = to_allocvec(&pus_tm).unwrap();
@@ -1222,11 +1306,11 @@ mod tests {
     #[test]
     #[cfg(feature = "serde")]
     fn test_serialization_reader_serde() {
-        let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
+        let sph = SpHeader::new_for_unseg_tm_checked(0x123, 0x234, 0).unwrap();
         let time_provider = CdsTime::new_with_u16_days(0, 0);
         let mut stamp_buf: [u8; 8] = [0; 8];
         let pus_tm =
-            PusTmCreator::new_simple(&mut sph, 17, 2, &time_provider, &mut stamp_buf, None, true)
+            PusTmCreator::new_simple(sph, 17, 2, &time_provider, &mut stamp_buf, &[], true)
                 .unwrap();
         let pus_tm_vec = pus_tm.to_vec().unwrap();
         let (tm_reader, _) = PusTmReader::new(&pus_tm_vec, time_provider.len_as_bytes()).unwrap();

src/lib.rs

@@ -22,10 +22,6 @@
 //!
 //! `spacepackets` supports various runtime environments and is also suitable for `no_std` environments.
 //!
-//! It also offers optional support for [`serde`](https://serde.rs/). This allows serializing and
-//! deserializing them with an appropriate `serde` provider like
-//! [`postcard`](https://github.com/jamesmunns/postcard).
-//!
 //! ### Default features
 //!
 //!  - [`std`](https://doc.rust-lang.org/std/): Enables functionality relying on the standard library.
@@ -52,35 +48,30 @@
 //!
 //! ```rust
 //! use spacepackets::SpHeader;
-//! let sp_header = SpHeader::tc_unseg(0x42, 12, 1).expect("Error creating CCSDS TC header");
+//! let sp_header = SpHeader::new_for_unseg_tc_checked(0x42, 12, 1).expect("error creating CCSDS TC header");
 //! println!("{:?}", sp_header);
 //! let mut ccsds_buf: [u8; 32] = [0; 32];
 //! sp_header.write_to_be_bytes(&mut ccsds_buf).expect("Writing CCSDS TC header failed");
 //! println!("{:x?}", &ccsds_buf[0..6]);
 //! ```
 #![no_std]
-#![cfg_attr(docs_rs, feature(doc_auto_cfg))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 #[cfg(feature = "alloc")]
 extern crate alloc;
 #[cfg(any(feature = "std", test))]
 extern crate std;
 
-use crate::ecss::CCSDS_HEADER_LEN;
+use core::{fmt::Debug, hash::Hash};
-use core::{
-    fmt::{Debug, Display, Formatter},
-    hash::Hash,
-};
 use crc::{Crc, CRC_16_IBM_3740};
 use delegate::delegate;
-
+use zerocopy::{FromBytes, IntoBytes};
-#[cfg(feature = "std")]
-use std::error::Error;
 
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
 pub mod cfdp;
 pub mod ecss;
+pub mod seq_count;
 pub mod time;
 pub mod util;
 
@@ -88,6 +79,8 @@ mod private {
     pub trait Sealed {}
 }
 
+pub const CCSDS_HEADER_LEN: usize = core::mem::size_of::<crate::zc::SpHeader>();
+
 /// CRC algorithm used by the PUS standard, the CCSDS TC standard and the CFDP standard.
 pub const CRC_CCITT_FALSE: Crc<u16> = Crc::<u16>::new(&CRC_16_IBM_3740);
 
@@ -95,55 +88,24 @@ pub const MAX_APID: u16 = 2u16.pow(11) - 1;
 pub const MAX_SEQ_COUNT: u16 = 2u16.pow(14) - 1;
 
 /// Generic error type when converting to and from raw byte slices.
-#[derive(Debug, Copy, Clone, PartialEq, Eq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum ByteConversionError {
     /// The passed slice is too small. Returns the passed slice length and expected minimum size
-    ToSliceTooSmall {
+    #[error("target slice with size {found} is too small, expected size of at least {expected}")]
-        found: usize,
+    ToSliceTooSmall { found: usize, expected: usize },
-        expected: usize,
-    },
     /// The provider buffer is too small. Returns the passed slice length and expected minimum size
-    FromSliceTooSmall {
+    #[error("source slice with size {found} too small, expected at least {expected} bytes")]
-        found: usize,
+    FromSliceTooSmall { found: usize, expected: usize },
-        expected: usize,
-    },
     /// The [zerocopy] library failed to write to bytes
+    #[error("zerocopy serialization error")]
     ZeroCopyToError,
+    /// The [zerocopy] library failed to read from bytes
+    #[error("zerocopy deserialization error")]
     ZeroCopyFromError,
 }
 
-impl Display for ByteConversionError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            ByteConversionError::ToSliceTooSmall { found, expected } => {
-                write!(
-                    f,
-                    "target slice with size {} is too small, expected size of at least {}",
-                    found, expected
-                )
-            }
-            ByteConversionError::FromSliceTooSmall { found, expected } => {
-                write!(
-                    f,
-                    "source slice with size {} too small, expected at least {} bytes",
-                    found, expected
-                )
-            }
-            ByteConversionError::ZeroCopyToError => {
-                write!(f, "zerocopy serialization error")
-            }
-            ByteConversionError::ZeroCopyFromError => {
-                write!(f, "zerocopy deserialization error")
-            }
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for ByteConversionError {}
-
 /// CCSDS packet type enumeration.
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -207,18 +169,21 @@ pub struct PacketId {
 }
 
 impl PartialEq for PacketId {
+    #[inline]
     fn eq(&self, other: &Self) -> bool {
         self.raw().eq(&other.raw())
     }
 }
 
 impl PartialOrd for PacketId {
+    #[inline]
     fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
         Some(self.cmp(other))
     }
 }
 
 impl Ord for PacketId {
+    #[inline]
     fn cmp(&self, other: &Self) -> core::cmp::Ordering {
         self.raw().cmp(&other.raw())
     }
@@ -232,6 +197,7 @@ impl Hash for PacketId {
 }
 
 impl Default for PacketId {
+    #[inline]
     fn default() -> Self {
         PacketId {
             ptype: PacketType::Tm,
@@ -242,23 +208,34 @@ impl Default for PacketId {
 }
 
 impl PacketId {
-    pub const fn const_tc(sec_header: bool, apid: u16) -> Self {
+    /// This constructor will panic if the passed APID exceeds [MAX_APID].
-        Self::const_new(PacketType::Tc, sec_header, apid)
+    /// Use the checked constructor variants to avoid panics.
-    }
+    #[inline]
-
+    pub const fn new_for_tc(sec_header: bool, apid: u16) -> Self {
-    pub const fn const_tm(sec_header: bool, apid: u16) -> Self {
-        Self::const_new(PacketType::Tm, sec_header, apid)
-    }
-
-    pub fn tc(sec_header: bool, apid: u16) -> Option<Self> {
         Self::new(PacketType::Tc, sec_header, apid)
     }
 
-    pub fn tm(sec_header: bool, apid: u16) -> Option<Self> {
+    /// This constructor will panic if the passed APID exceeds [MAX_APID].
+    /// Use the checked constructor variants to avoid panics.
+    #[inline]
+    pub const fn new_for_tm(sec_header: bool, apid: u16) -> Self {
         Self::new(PacketType::Tm, sec_header, apid)
     }
 
-    pub const fn const_new(ptype: PacketType, sec_header: bool, apid: u16) -> Self {
+    #[inline]
+    pub fn new_for_tc_checked(sec_header: bool, apid: u16) -> Option<Self> {
+        Self::new_checked(PacketType::Tc, sec_header, apid)
+    }
+
+    #[inline]
+    pub fn new_for_tm_checked(sec_header: bool, apid: u16) -> Option<Self> {
+        Self::new_checked(PacketType::Tm, sec_header, apid)
+    }
+
+    /// This constructor will panic if the passed APID exceeds [MAX_APID].
+    /// Use the checked variants to avoid panics.
+    #[inline]
+    pub const fn new(ptype: PacketType, sec_header: bool, apid: u16) -> Self {
         if apid > MAX_APID {
             panic!("APID too large");
         }
@@ -269,16 +246,18 @@ impl PacketId {
         }
     }
 
-    pub fn new(ptype: PacketType, sec_header_flag: bool, apid: u16) -> Option<PacketId> {
+    #[inline]
+    pub fn new_checked(ptype: PacketType, sec_header_flag: bool, apid: u16) -> Option<PacketId> {
         if apid > MAX_APID {
             return None;
         }
-        Some(PacketId::const_new(ptype, sec_header_flag, apid))
+        Some(PacketId::new(ptype, sec_header_flag, apid))
     }
 
     /// Set a new Application Process ID (APID). If the passed number is invalid, the APID will
     /// not be set and false will be returned. The maximum allowed value for the 11-bit field is
     /// 2047
+    #[inline]
     pub fn set_apid(&mut self, apid: u16) -> bool {
         if apid > MAX_APID {
             return false;
@@ -287,6 +266,7 @@ impl PacketId {
         true
     }
 
+    #[inline]
     pub fn apid(&self) -> u16 {
         self.apid
     }
@@ -318,9 +298,10 @@ pub struct PacketSequenceCtrl {
 }
 
 impl PacketSequenceCtrl {
-    /// const variant of [PacketSequenceCtrl::new], but panics if the sequence count exceeds
+    /// This constructor panics if the sequence count exceeds [MAX_SEQ_COUNT].
-    /// [MAX_SEQ_COUNT].
+    /// Use [Self::new_checked] to avoid panics.
-    pub const fn const_new(seq_flags: SequenceFlags, seq_count: u16) -> PacketSequenceCtrl {
+    #[inline]
+    pub const fn new(seq_flags: SequenceFlags, seq_count: u16) -> PacketSequenceCtrl {
         if seq_count > MAX_SEQ_COUNT {
             panic!("Sequence count too large");
         }
@@ -331,18 +312,22 @@ impl PacketSequenceCtrl {
     }
 
     /// Returns [None] if the passed sequence count exceeds [MAX_SEQ_COUNT].
-    pub fn new(seq_flags: SequenceFlags, seq_count: u16) -> Option<PacketSequenceCtrl> {
+    #[inline]
+    pub fn new_checked(seq_flags: SequenceFlags, seq_count: u16) -> Option<PacketSequenceCtrl> {
         if seq_count > MAX_SEQ_COUNT {
             return None;
         }
-        Some(PacketSequenceCtrl::const_new(seq_flags, seq_count))
+        Some(PacketSequenceCtrl::new(seq_flags, seq_count))
     }
+
+    #[inline]
     pub fn raw(&self) -> u16 {
         ((self.seq_flags as u16) << 14) | self.seq_count
     }
 
     /// Set a new sequence count. If the passed number is invalid, the sequence count will not be
     /// set and false will be returned. The maximum allowed value for the 14-bit field is 16383.
+    #[inline]
     pub fn set_seq_count(&mut self, ssc: u16) -> bool {
         if ssc > MAX_SEQ_COUNT {
             return false;
@@ -351,6 +336,7 @@ impl PacketSequenceCtrl {
         true
     }
 
+    #[inline]
     pub fn seq_count(&self) -> u16 {
         self.seq_count
     }
@@ -392,6 +378,7 @@ pub trait CcsdsPacket {
     /// Retrieve data length field
     fn data_len(&self) -> u16;
     /// Retrieve the total packet size based on the data length field
+    #[inline]
     fn total_len(&self) -> usize {
         usize::from(self.data_len()) + CCSDS_HEADER_LEN + 1
     }
@@ -480,9 +467,12 @@ pub struct SpHeader {
     pub data_len: u16,
 }
 
+pub type SpacePacketHeader = SpHeader;
+
 impl Default for SpHeader {
-    /// The default function sets the sequence flag field to [SequenceFlags::Unsegmented]. The data
+    /// The default function sets the sequence flag field to [SequenceFlags::Unsegmented] and the
-    /// length field is set to 1, which denotes an empty space packets.
+    /// data length to 0.
+    #[inline]
     fn default() -> Self {
         SpHeader {
             version: 0,
@@ -491,12 +481,13 @@ impl Default for SpHeader {
                 seq_flags: SequenceFlags::Unsegmented,
                 seq_count: 0,
             },
-            data_len: 1,
+            data_len: 0,
         }
     }
 }
 
 impl SpHeader {
+    #[inline]
     pub const fn new(packet_id: PacketId, psc: PacketSequenceCtrl, data_len: u16) -> Self {
         Self {
             version: 0,
@@ -506,9 +497,43 @@ impl SpHeader {
         }
     }
 
-    /// const variant of the [SpHeader::new_fron_single_fields] function. Panics if the passed
+    /// This constructor sets the sequence flag field to [SequenceFlags::Unsegmented] and the data
-    /// APID exceeds [MAX_APID] or the passed packet sequence count exceeds [MAX_SEQ_COUNT].
+    /// length to 0.
-    const fn const_new_from_single_fields(
+    ///
+    /// This constructor will panic if the APID exceeds [MAX_APID].
+    #[inline]
+    pub const fn new_from_apid(apid: u16) -> Self {
+        SpHeader {
+            version: 0,
+            packet_id: PacketId::new(PacketType::Tm, false, apid),
+            psc: PacketSequenceCtrl {
+                seq_flags: SequenceFlags::Unsegmented,
+                seq_count: 0,
+            },
+            data_len: 0,
+        }
+    }
+
+    /// Checked variant of [Self::new_from_apid].
+    #[inline]
+    pub fn new_from_apid_checked(apid: u16) -> Option<Self> {
+        Some(SpHeader {
+            version: 0,
+            packet_id: PacketId::new_checked(PacketType::Tm, false, apid)?,
+            psc: PacketSequenceCtrl {
+                seq_flags: SequenceFlags::Unsegmented,
+                seq_count: 0,
+            },
+            data_len: 0,
+        })
+    }
+
+    /// This constructor panics if the passed APID exceeds [MAX_APID] or the passed packet sequence
+    /// count exceeds [MAX_SEQ_COUNT].
+    ///
+    /// The checked constructor variants can be used to avoid panics.
+    #[inline]
+    pub const fn new_from_fields(
         ptype: PacketType,
         sec_header: bool,
         apid: u16,
@@ -523,17 +548,20 @@ impl SpHeader {
             panic!("APID is too large");
         }
         Self {
-            psc: PacketSequenceCtrl::const_new(seq_flags, seq_count),
+            psc: PacketSequenceCtrl::new(seq_flags, seq_count),
-            packet_id: PacketId::const_new(ptype, sec_header, apid),
+            packet_id: PacketId::new(ptype, sec_header, apid),
             data_len,
             version: 0,
         }
     }
 
     /// Create a new Space Packet Header instance which can be used to create generic
-    /// Space Packets. This will return [None] if the APID or sequence count argument
+    /// Space Packets.
+    ///
+    /// This will return [None] if the APID or sequence count argument
     /// exceed [MAX_APID] or [MAX_SEQ_COUNT] respectively. The version field is set to 0b000.
-    pub fn new_from_single_fields(
+    #[inline]
+    pub fn new_from_fields_checked(
         ptype: PacketType,
         sec_header: bool,
         apid: u16,
@@ -544,56 +572,117 @@ impl SpHeader {
         if seq_count > MAX_SEQ_COUNT || apid > MAX_APID {
             return None;
         }
-        Some(SpHeader::const_new_from_single_fields(
+        Some(SpHeader::new_from_fields(
             ptype, sec_header, apid, seq_flags, seq_count, data_len,
         ))
     }
 
     /// Helper function for telemetry space packet headers. The packet type field will be
     /// set accordingly. The secondary header flag field is set to false.
-    pub fn tm(apid: u16, seq_flags: SequenceFlags, seq_count: u16, data_len: u16) -> Option<Self> {
+    #[inline]
-        Self::new_from_single_fields(PacketType::Tm, false, apid, seq_flags, seq_count, data_len)
+    pub fn new_for_tm_checked(
+        apid: u16,
+        seq_flags: SequenceFlags,
+        seq_count: u16,
+        data_len: u16,
+    ) -> Option<Self> {
+        Self::new_from_fields_checked(PacketType::Tm, false, apid, seq_flags, seq_count, data_len)
     }
 
     /// Helper function for telemetry space packet headers. The packet type field will be
     /// set accordingly. The secondary header flag field is set to false.
-    pub fn tc(apid: u16, seq_flags: SequenceFlags, seq_count: u16, data_len: u16) -> Option<Self> {
+    #[inline]
-        Self::new_from_single_fields(PacketType::Tc, false, apid, seq_flags, seq_count, data_len)
+    pub fn new_for_tc_checked(
+        apid: u16,
+        seq_flags: SequenceFlags,
+        seq_count: u16,
+        data_len: u16,
+    ) -> Option<Self> {
+        Self::new_from_fields_checked(PacketType::Tc, false, apid, seq_flags, seq_count, data_len)
     }
 
-    /// Variant of [SpHeader::tm] which sets the sequence flag field to [SequenceFlags::Unsegmented]
+    /// This is an unchecked constructor which can panic on invalid input.
-    pub fn tm_unseg(apid: u16, seq_count: u16, data_len: u16) -> Option<Self> {
+    #[inline]
-        Self::tm(apid, SequenceFlags::Unsegmented, seq_count, data_len)
+    pub const fn new_for_tm(
+        apid: u16,
+        seq_flags: SequenceFlags,
+        seq_count: u16,
+        data_len: u16,
+    ) -> Self {
+        Self::new_from_fields(PacketType::Tm, false, apid, seq_flags, seq_count, data_len)
     }
 
-    /// Variant of [SpHeader::tc] which sets the sequence flag field to [SequenceFlags::Unsegmented]
+    /// This is an unchecked constructor which can panic on invalid input.
-    pub fn tc_unseg(apid: u16, seq_count: u16, data_len: u16) -> Option<Self> {
+    #[inline]
-        Self::tc(apid, SequenceFlags::Unsegmented, seq_count, data_len)
+    pub const fn new_for_tc(
+        apid: u16,
+        seq_flags: SequenceFlags,
+        seq_count: u16,
+        data_len: u16,
+    ) -> Self {
+        Self::new_from_fields(PacketType::Tc, false, apid, seq_flags, seq_count, data_len)
     }
 
-    //noinspection RsTraitImplementation
+    /// Variant of [SpHeader::new_for_tm_checked] which sets the sequence flag field to [SequenceFlags::Unsegmented]
-    delegate!(to self.packet_id {
+    #[inline]
-        /// Returns [false] and fails if the APID exceeds [MAX_APID]
+    pub fn new_for_unseg_tm_checked(apid: u16, seq_count: u16, data_len: u16) -> Option<Self> {
-        pub fn set_apid(&mut self, apid: u16) -> bool;
+        Self::new_for_tm_checked(apid, SequenceFlags::Unsegmented, seq_count, data_len)
-    });
+    }
 
-    delegate!(to self.psc {
+    /// Variant of [SpHeader::new_for_tc_checked] which sets the sequence flag field to [SequenceFlags::Unsegmented]
-        /// Returns [false] and fails if the sequence count exceeds [MAX_SEQ_COUNT]
+    #[inline]
-        pub fn set_seq_count(&mut self, seq_count: u16) -> bool;
+    pub fn new_for_unseg_tc_checked(apid: u16, seq_count: u16, data_len: u16) -> Option<Self> {
-    });
+        Self::new_for_tc_checked(apid, SequenceFlags::Unsegmented, seq_count, data_len)
+    }
 
+    /// Variant of [SpHeader::new_for_tc] which sets the sequence flag field to [SequenceFlags::Unsegmented].
+    ///
+    /// This is an unchecked constructor which can panic on invalid input.
+    #[inline]
+    pub const fn new_for_unseg_tc(apid: u16, seq_count: u16, data_len: u16) -> Self {
+        Self::new_for_tc(apid, SequenceFlags::Unsegmented, seq_count, data_len)
+    }
+
+    /// Variant of [SpHeader::new_for_tm] which sets the sequence flag field to [SequenceFlags::Unsegmented].
+    ///
+    /// This is an unchecked constructor which can panic on invalid input.
+    #[inline]
+    pub const fn new_for_unseg_tm(apid: u16, seq_count: u16, data_len: u16) -> Self {
+        Self::new_for_tm(apid, SequenceFlags::Unsegmented, seq_count, data_len)
+    }
+
+    delegate! {
+        to self.packet_id {
+            /// Returns [false] and fails if the APID exceeds [MAX_APID]
+            #[inline]
+            pub fn set_apid(&mut self, apid: u16) -> bool;
+        }
+    }
+
+    delegate! {
+        to self.psc {
+            /// Returns [false] and fails if the sequence count exceeds [MAX_SEQ_COUNT]
+            #[inline]
+            pub fn set_seq_count(&mut self, seq_count: u16) -> bool;
+        }
+    }
+
+    #[inline]
     pub fn set_seq_flags(&mut self, seq_flags: SequenceFlags) {
         self.psc.seq_flags = seq_flags;
     }
 
+    #[inline]
     pub fn set_sec_header_flag(&mut self) {
         self.packet_id.sec_header_flag = true;
     }
 
+    #[inline]
     pub fn clear_sec_header_flag(&mut self) {
         self.packet_id.sec_header_flag = false;
     }
 
+    #[inline]
     pub fn set_packet_type(&mut self, packet_type: PacketType) {
         self.packet_id.ptype = packet_type;
     }
@@ -608,8 +697,8 @@ impl SpHeader {
                 expected: CCSDS_HEADER_LEN,
             });
         }
-        let zc_header = zc::SpHeader::from_bytes(&buf[0..CCSDS_HEADER_LEN])
+        let zc_header = zc::SpHeader::read_from_bytes(&buf[0..CCSDS_HEADER_LEN])
-            .ok_or(ByteConversionError::ZeroCopyFromError)?;
+            .map_err(|_| ByteConversionError::ZeroCopyFromError)?;
         Ok((Self::from(zc_header), &buf[CCSDS_HEADER_LEN..]))
     }
 
@@ -627,10 +716,19 @@ impl SpHeader {
         }
         let zc_header: zc::SpHeader = zc::SpHeader::from(*self);
         zc_header
-            .to_bytes(&mut buf[0..CCSDS_HEADER_LEN])
+            .write_to(&mut buf[0..CCSDS_HEADER_LEN])
-            .ok_or(ByteConversionError::ZeroCopyToError)?;
+            .map_err(|_| ByteConversionError::ZeroCopyToError)?;
         Ok(&mut buf[CCSDS_HEADER_LEN..])
     }
+
+    /// Create a vector containing the CCSDS header.
+    #[cfg(feature = "alloc")]
+    pub fn to_vec(&self) -> alloc::vec::Vec<u8> {
+        let mut vec = alloc::vec![0; CCSDS_HEADER_LEN];
+        // This can not fail.
+        self.write_to_be_bytes(&mut vec[..]).unwrap();
+        vec
+    }
 }
 
 impl CcsdsPacket for SpHeader {
@@ -656,6 +754,7 @@ impl CcsdsPacket for SpHeader {
 }
 
 impl CcsdsPrimaryHeader for SpHeader {
+    #[inline]
     fn from_composite_fields(
         packet_id: PacketId,
         psc: PacketSequenceCtrl,
@@ -680,9 +779,9 @@ sph_from_other!(SpHeader, crate::zc::SpHeader);
 pub mod zc {
     use crate::{CcsdsPacket, CcsdsPrimaryHeader, PacketId, PacketSequenceCtrl, VERSION_MASK};
     use zerocopy::byteorder::NetworkEndian;
-    use zerocopy::{AsBytes, FromBytes, FromZeroes, Unaligned, U16};
+    use zerocopy::{FromBytes, Immutable, IntoBytes, Unaligned, U16};
 
-    #[derive(FromBytes, FromZeroes, AsBytes, Unaligned, Debug)]
+    #[derive(FromBytes, IntoBytes, Immutable, Unaligned, Debug)]
     #[repr(C)]
     pub struct SpHeader {
         version_packet_id: U16<NetworkEndian>,
@@ -707,14 +806,6 @@ pub mod zc {
                 data_len: U16::from(data_len),
             }
         }
-
-        pub fn from_bytes(slice: &[u8]) -> Option<Self> {
-            SpHeader::read_from(slice)
-        }
-
-        pub fn to_bytes(&self, slice: &mut [u8]) -> Option<()> {
-            self.write_to(slice)
-        }
     }
 
     impl CcsdsPacket for SpHeader {
@@ -723,9 +814,12 @@ pub mod zc {
             ((self.version_packet_id.get() >> 13) as u8) & 0b111
         }
 
+        #[inline]
         fn packet_id(&self) -> PacketId {
             PacketId::from(self.packet_id_raw())
         }
+
+        #[inline]
         fn psc(&self) -> PacketSequenceCtrl {
             PacketSequenceCtrl::from(self.psc_raw())
         }
@@ -735,10 +829,12 @@ pub mod zc {
             self.data_len.get()
         }
 
+        #[inline]
         fn packet_id_raw(&self) -> u16 {
             self.version_packet_id.get() & (!VERSION_MASK)
         }
 
+        #[inline]
         fn psc_raw(&self) -> u16 {
             self.psc.get()
         }
@@ -762,6 +858,8 @@ pub mod zc {
 pub(crate) mod tests {
     use std::collections::HashSet;
 
+    #[allow(unused_imports)]
+    use crate::ByteConversionError;
     #[cfg(feature = "serde")]
     use crate::CcsdsPrimaryHeader;
     use crate::{
@@ -776,14 +874,15 @@ pub(crate) mod tests {
     use postcard::{from_bytes, to_allocvec};
     #[cfg(feature = "serde")]
     use serde::{de::DeserializeOwned, Serialize};
+    use zerocopy::FromBytes;
 
     const CONST_SP: SpHeader = SpHeader::new(
-        PacketId::const_tc(true, 0x36),
+        PacketId::new_for_tc(true, 0x36),
-        PacketSequenceCtrl::const_new(SequenceFlags::ContinuationSegment, 0x88),
+        PacketSequenceCtrl::new(SequenceFlags::ContinuationSegment, 0x88),
         0x90,
     );
 
-    const PACKET_ID_TM: PacketId = PacketId::const_tm(true, 0x22);
+    const PACKET_ID_TM: PacketId = PacketId::new_for_tm(true, 0x22);
 
     #[cfg(feature = "serde")]
     pub(crate) fn generic_serde_test<T: Serialize + DeserializeOwned + PartialEq + Debug>(
@@ -795,11 +894,12 @@ pub(crate) mod tests {
     }
 
     #[test]
+    #[allow(clippy::assertions_on_constants)]
     fn verify_const_packet_id() {
         assert_eq!(PACKET_ID_TM.apid(), 0x22);
         assert!(PACKET_ID_TM.sec_header_flag);
         assert_eq!(PACKET_ID_TM.ptype, PacketType::Tm);
-        let const_tc_id = PacketId::const_tc(true, 0x23);
+        let const_tc_id = PacketId::new_for_tc(true, 0x23);
         assert_eq!(const_tc_id.ptype, PacketType::Tc);
     }
 
@@ -813,27 +913,27 @@ pub(crate) mod tests {
 
     #[test]
     fn test_packet_id_ctors() {
-        let packet_id = PacketId::new(PacketType::Tc, true, 0x1ff);
+        let packet_id = PacketId::new_checked(PacketType::Tc, true, 0x1ff);
         assert!(packet_id.is_some());
         let packet_id = packet_id.unwrap();
         assert_eq!(packet_id.apid(), 0x1ff);
         assert_eq!(packet_id.ptype, PacketType::Tc);
         assert!(packet_id.sec_header_flag);
-        let packet_id_tc = PacketId::tc(true, 0x1ff);
+        let packet_id_tc = PacketId::new_for_tc_checked(true, 0x1ff);
         assert!(packet_id_tc.is_some());
         let packet_id_tc = packet_id_tc.unwrap();
         assert_eq!(packet_id_tc, packet_id);
-        let packet_id_tm = PacketId::tm(true, 0x2ff);
+        let packet_id_tm = PacketId::new_for_tm_checked(true, 0x2ff);
         assert!(packet_id_tm.is_some());
         let packet_id_tm = packet_id_tm.unwrap();
-        assert_eq!(packet_id_tm.sec_header_flag, true);
+        assert!(packet_id_tm.sec_header_flag);
         assert_eq!(packet_id_tm.ptype, PacketType::Tm);
         assert_eq!(packet_id_tm.apid, 0x2ff);
     }
 
     #[test]
     fn verify_const_sp_header() {
-        assert_eq!(CONST_SP.sec_header_flag(), true);
+        assert!(CONST_SP.sec_header_flag());
         assert_eq!(CONST_SP.apid(), 0x36);
         assert_eq!(
             CONST_SP.sequence_flags(),
@@ -874,7 +974,7 @@ pub(crate) mod tests {
     #[test]
     fn test_packet_id() {
         let packet_id =
-            PacketId::new(PacketType::Tm, false, 0x42).expect("Packet ID creation failed");
+            PacketId::new_checked(PacketType::Tm, false, 0x42).expect("Packet ID creation failed");
         assert_eq!(packet_id.raw(), 0x0042);
         let packet_id_from_raw = PacketId::from(packet_id.raw());
         assert_eq!(
@@ -882,26 +982,26 @@ pub(crate) mod tests {
             PacketType::Tm
         );
         assert_eq!(packet_id_from_raw, packet_id);
-        let packet_id_from_new = PacketId::new(PacketType::Tm, false, 0x42).unwrap();
+        let packet_id_from_new = PacketId::new_checked(PacketType::Tm, false, 0x42).unwrap();
         assert_eq!(packet_id_from_new, packet_id);
     }
 
     #[test]
     fn test_invalid_packet_id() {
-        let packet_id_invalid = PacketId::new(PacketType::Tc, true, 0xFFFF);
+        let packet_id_invalid = PacketId::new_checked(PacketType::Tc, true, 0xFFFF);
         assert!(packet_id_invalid.is_none());
     }
 
     #[test]
     fn test_invalid_apid_setter() {
         let mut packet_id =
-            PacketId::new(PacketType::Tm, false, 0x42).expect("Packet ID creation failed");
+            PacketId::new_checked(PacketType::Tm, false, 0x42).expect("Packet ID creation failed");
         assert!(!packet_id.set_apid(0xffff));
     }
 
     #[test]
     fn test_invalid_seq_count() {
-        let mut psc = PacketSequenceCtrl::new(SequenceFlags::ContinuationSegment, 77)
+        let mut psc = PacketSequenceCtrl::new_checked(SequenceFlags::ContinuationSegment, 77)
             .expect("PSC creation failed");
         assert_eq!(psc.seq_count(), 77);
         assert!(!psc.set_seq_count(0xffff));
@@ -909,7 +1009,7 @@ pub(crate) mod tests {
 
     #[test]
     fn test_packet_seq_ctrl() {
-        let mut psc = PacketSequenceCtrl::new(SequenceFlags::ContinuationSegment, 77)
+        let mut psc = PacketSequenceCtrl::new_checked(SequenceFlags::ContinuationSegment, 77)
             .expect("PSC creation failed");
         assert_eq!(psc.raw(), 77);
         let psc_from_raw = PacketSequenceCtrl::from(psc.raw());
@@ -918,16 +1018,18 @@ pub(crate) mod tests {
         assert!(!psc.set_seq_count(2u16.pow(15)));
         assert_eq!(psc.raw(), 77);
 
-        let psc_invalid = PacketSequenceCtrl::new(SequenceFlags::FirstSegment, 0xFFFF);
+        let psc_invalid = PacketSequenceCtrl::new_checked(SequenceFlags::FirstSegment, 0xFFFF);
         assert!(psc_invalid.is_none());
-        let psc_from_new = PacketSequenceCtrl::new(SequenceFlags::ContinuationSegment, 77).unwrap();
+        let psc_from_new =
+            PacketSequenceCtrl::new_checked(SequenceFlags::ContinuationSegment, 77).unwrap();
         assert_eq!(psc_from_new, psc);
     }
 
     #[test]
     #[cfg(feature = "serde")]
     fn test_serde_sph() {
-        let sp_header = SpHeader::tc_unseg(0x42, 12, 0).expect("Error creating SP header");
+        let sp_header =
+            SpHeader::new_for_unseg_tc_checked(0x42, 12, 0).expect("Error creating SP header");
         assert_eq!(sp_header.ccsds_version(), 0b000);
         assert!(sp_header.is_tc());
         assert!(!sp_header.sec_header_flag());
@@ -949,7 +1051,8 @@ pub(crate) mod tests {
         assert_eq!(sp_header.ccsds_version(), 0b000);
         assert_eq!(sp_header.data_len, 0);
 
-        let sp_header = SpHeader::tm_unseg(0x7, 22, 36).expect("Error creating SP header");
+        let sp_header =
+            SpHeader::new_for_unseg_tm_checked(0x7, 22, 36).expect("Error creating SP header");
         assert_eq!(sp_header.ccsds_version(), 0b000);
         assert!(sp_header.is_tm());
         assert!(!sp_header.sec_header_flag());
@@ -963,8 +1066,8 @@ pub(crate) mod tests {
         assert_eq!(sp_header.ccsds_version(), 0b000);
 
         let from_comp_fields = SpHeader::from_composite_fields(
-            PacketId::new(PacketType::Tc, true, 0x42).unwrap(),
+            PacketId::new(PacketType::Tc, true, 0x42),
-            PacketSequenceCtrl::new(SequenceFlags::Unsegmented, 0x7).unwrap(),
+            PacketSequenceCtrl::new(SequenceFlags::Unsegmented, 0x7),
             0,
             None,
         );
@@ -981,7 +1084,7 @@ pub(crate) mod tests {
 
     #[test]
     fn test_setters() {
-        let sp_header = SpHeader::tc(0x42, SequenceFlags::Unsegmented, 25, 0);
+        let sp_header = SpHeader::new_for_tc_checked(0x42, SequenceFlags::Unsegmented, 25, 0);
         assert!(sp_header.is_some());
         let mut sp_header = sp_header.unwrap();
         sp_header.set_apid(0x12);
@@ -999,7 +1102,7 @@ pub(crate) mod tests {
 
     #[test]
     fn test_tc_ctor() {
-        let sp_header = SpHeader::tc(0x42, SequenceFlags::Unsegmented, 25, 0);
+        let sp_header = SpHeader::new_for_tc_checked(0x42, SequenceFlags::Unsegmented, 25, 0);
         assert!(sp_header.is_some());
         let sp_header = sp_header.unwrap();
         verify_sp_fields(PacketType::Tc, &sp_header);
@@ -1007,23 +1110,35 @@ pub(crate) mod tests {
 
     #[test]
     fn test_tc_ctor_unseg() {
-        let sp_header = SpHeader::tc_unseg(0x42, 25, 0);
+        let sp_header = SpHeader::new_for_unseg_tc_checked(0x42, 25, 0);
         assert!(sp_header.is_some());
         let sp_header = sp_header.unwrap();
         verify_sp_fields(PacketType::Tc, &sp_header);
     }
 
+    #[test]
+    fn test_tc_ctor_unseg_const() {
+        let sp_header = SpHeader::new_for_unseg_tc(0x42, 25, 0);
+        verify_sp_fields(PacketType::Tc, &sp_header);
+    }
+
     #[test]
     fn test_tm_ctor() {
-        let sp_header = SpHeader::tm(0x42, SequenceFlags::Unsegmented, 25, 0);
+        let sp_header = SpHeader::new_for_tm_checked(0x42, SequenceFlags::Unsegmented, 25, 0);
         assert!(sp_header.is_some());
         let sp_header = sp_header.unwrap();
         verify_sp_fields(PacketType::Tm, &sp_header);
     }
 
+    #[test]
+    fn test_tm_ctor_const() {
+        let sp_header = SpHeader::new_for_tm(0x42, SequenceFlags::Unsegmented, 25, 0);
+        verify_sp_fields(PacketType::Tm, &sp_header);
+    }
+
     #[test]
     fn test_tm_ctor_unseg() {
-        let sp_header = SpHeader::tm_unseg(0x42, 25, 0);
+        let sp_header = SpHeader::new_for_unseg_tm_checked(0x42, 25, 0);
         assert!(sp_header.is_some());
         let sp_header = sp_header.unwrap();
         verify_sp_fields(PacketType::Tm, &sp_header);
@@ -1039,10 +1154,10 @@ pub(crate) mod tests {
 
     #[test]
     fn test_zc_sph() {
-        use zerocopy::AsBytes;
+        use zerocopy::IntoBytes;
 
-        let sp_header =
+        let sp_header = SpHeader::new_for_unseg_tc_checked(0x7FF, pow(2, 14) - 1, 0)
-            SpHeader::tc_unseg(0x7FF, pow(2, 14) - 1, 0).expect("Error creating SP header");
+            .expect("Error creating SP header");
         assert_eq!(sp_header.ptype(), PacketType::Tc);
         assert_eq!(sp_header.apid(), 0x7FF);
         assert_eq!(sp_header.data_len(), 0);
@@ -1059,7 +1174,7 @@ pub(crate) mod tests {
         assert_eq!(slice[5], 0x00);
 
         let mut slice = [0; 6];
-        sp_header_zc.write_to(slice.as_mut_slice());
+        sp_header_zc.write_to(slice.as_mut_slice()).unwrap();
         assert_eq!(slice.len(), 6);
         assert_eq!(slice[0], 0x17);
         assert_eq!(slice[1], 0xFF);
@@ -1070,7 +1185,7 @@ pub(crate) mod tests {
 
         let mut test_vec = vec![0_u8; 6];
         let slice = test_vec.as_mut_slice();
-        sp_header_zc.write_to(slice);
+        sp_header_zc.write_to(slice).unwrap();
         let slice = test_vec.as_slice();
         assert_eq!(slice.len(), 6);
         assert_eq!(slice[0], 0x17);
@@ -1080,8 +1195,8 @@ pub(crate) mod tests {
         assert_eq!(slice[4], 0x00);
         assert_eq!(slice[5], 0x00);
 
-        let sp_header = zc::SpHeader::from_bytes(slice);
+        let sp_header = zc::SpHeader::read_from_bytes(slice);
-        assert!(sp_header.is_some());
+        assert!(sp_header.is_ok());
         let sp_header = sp_header.unwrap();
         assert_eq!(sp_header.ccsds_version(), 0b000);
         assert_eq!(sp_header.packet_id_raw(), 0x17FF);
@@ -1107,4 +1222,40 @@ pub(crate) mod tests {
         let mut id_set = HashSet::new();
         id_set.insert(PacketId::from(1_u16));
     }
+
+    #[test]
+    fn sp_header_from_apid() {
+        let sp_header = SpHeader::new_from_apid(0x03);
+        assert_eq!(sp_header.apid(), 0x03);
+        assert_eq!(sp_header.data_len(), 0);
+    }
+
+    #[test]
+    fn sp_header_from_apid_checked() {
+        let sp_header = SpHeader::new_from_apid_checked(0x03).unwrap();
+        assert_eq!(sp_header.apid(), 0x03);
+        assert_eq!(sp_header.data_len(), 0);
+    }
+
+    #[cfg(feature = "defmt")]
+    fn is_defmt_format<T: defmt::Format>(_t: T) {}
+
+    #[test]
+    #[cfg(feature = "defmt")]
+    fn test_defmt_format() {
+        is_defmt_format(ByteConversionError::ToSliceTooSmall {
+            found: 1,
+            expected: 2,
+        });
+    }
+
+    #[test]
+    fn test_sp_header_as_vec() {
+        let sp_header = SpHeader::new_for_unseg_tc(0x42, 25, 1);
+        let sp_header_as_vec = sp_header.to_vec();
+        let sp_header_read_back = SpHeader::from_be_bytes(&sp_header_as_vec)
+            .expect("Error reading back SP header")
+            .0;
+        assert_eq!(sp_header, sp_header_read_back);
+    }
 }

src/seq_count.rs

@@ -0,0 +1,250 @@
+use crate::MAX_SEQ_COUNT;
+use core::cell::Cell;
+use paste::paste;
+#[cfg(feature = "std")]
+pub use stdmod::*;
+
+/// Core trait for objects which can provide a sequence count.
+///
+/// The core functions are not mutable on purpose to allow easier usage with
+/// static structs when using the interior mutability pattern. This can be achieved by using
+/// [Cell], [core::cell::RefCell] or atomic types.
+pub trait SequenceCountProvider {
+    type Raw: Into<u64>;
+    const MAX_BIT_WIDTH: usize;
+
+    fn get(&self) -> Self::Raw;
+
+    fn increment(&self);
+
+    fn get_and_increment(&self) -> Self::Raw {
+        let val = self.get();
+        self.increment();
+        val
+    }
+}
+
+#[derive(Clone)]
+pub struct SeqCountProviderSimple<T: Copy> {
+    seq_count: Cell<T>,
+    max_val: T,
+}
+
+macro_rules! impl_for_primitives {
+    ($($ty: ident,)+) => {
+        $(
+            paste! {
+                impl SeqCountProviderSimple<$ty> {
+                    pub fn [<new_custom_max_val_ $ty>](max_val: $ty) -> Self {
+                        Self {
+                            seq_count: Cell::new(0),
+                            max_val,
+                        }
+                    }
+                    pub fn [<new_ $ty>]() -> Self {
+                        Self {
+                            seq_count: Cell::new(0),
+                            max_val: $ty::MAX
+                        }
+                    }
+                }
+
+                impl Default for SeqCountProviderSimple<$ty> {
+                    fn default() -> Self {
+                        Self::[<new_ $ty>]()
+                    }
+                }
+
+                impl SequenceCountProvider for SeqCountProviderSimple<$ty> {
+                    type Raw = $ty;
+                    const MAX_BIT_WIDTH: usize = core::mem::size_of::<Self::Raw>() * 8;
+
+                    fn get(&self) -> Self::Raw {
+                        self.seq_count.get()
+                    }
+
+                    fn increment(&self) {
+                        self.get_and_increment();
+                    }
+
+                    fn get_and_increment(&self) -> Self::Raw {
+                        let curr_count = self.seq_count.get();
+
+                        if curr_count == self.max_val {
+                            self.seq_count.set(0);
+                        } else {
+                            self.seq_count.set(curr_count + 1);
+                        }
+                        curr_count
+                    }
+                }
+            }
+        )+
+    }
+}
+
+impl_for_primitives!(u8, u16, u32, u64,);
+
+/// This is a sequence count provider which wraps around at [MAX_SEQ_COUNT].
+#[derive(Clone)]
+pub struct CcsdsSimpleSeqCountProvider {
+    provider: SeqCountProviderSimple<u16>,
+}
+
+impl Default for CcsdsSimpleSeqCountProvider {
+    fn default() -> Self {
+        Self {
+            provider: SeqCountProviderSimple::new_custom_max_val_u16(MAX_SEQ_COUNT),
+        }
+    }
+}
+
+impl SequenceCountProvider for CcsdsSimpleSeqCountProvider {
+    type Raw = u16;
+    const MAX_BIT_WIDTH: usize = core::mem::size_of::<Self::Raw>() * 8;
+    delegate::delegate! {
+        to self.provider {
+            fn get(&self) -> u16;
+            fn increment(&self);
+            fn get_and_increment(&self) -> u16;
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+pub mod stdmod {
+    use super::*;
+    use std::sync::{Arc, Mutex};
+
+    macro_rules! sync_clonable_seq_counter_impl {
+         ($($ty: ident,)+) => {
+             $(paste! {
+                 /// These sequence counters can be shared between threads and can also be
+                 /// configured to wrap around at specified maximum values. Please note that
+                 /// that the API provided by this class will not panic und [Mutex] lock errors,
+                 /// but it will yield 0 for the getter functions.
+                 #[derive(Clone, Default)]
+                 pub struct [<SeqCountProviderSync $ty:upper>] {
+                     seq_count: Arc<Mutex<$ty>>,
+                     max_val: $ty
+                 }
+
+                 impl [<SeqCountProviderSync $ty:upper>] {
+                     pub fn new() -> Self {
+                        Self::new_with_max_val($ty::MAX)
+                     }
+
+                     pub fn new_with_max_val(max_val: $ty) -> Self {
+                         Self {
+                             seq_count: Arc::default(),
+                             max_val
+                         }
+                     }
+                 }
+                 impl SequenceCountProvider for [<SeqCountProviderSync $ty:upper>] {
+                    type Raw = $ty;
+                    const MAX_BIT_WIDTH: usize = core::mem::size_of::<Self::Raw>() * 8;
+
+                    fn get(&self) -> $ty {
+                        match self.seq_count.lock() {
+                            Ok(counter) => *counter,
+                            Err(_) => 0
+                        }
+                    }
+
+                    fn increment(&self) {
+                        self.get_and_increment();
+                    }
+
+                    fn get_and_increment(&self) -> $ty {
+                        match self.seq_count.lock() {
+                            Ok(mut counter) => {
+                                let val = *counter;
+                                if val == self.max_val {
+                                    *counter = 0;
+                                } else {
+                                    *counter += 1;
+                                }
+                                val
+                            }
+                            Err(_) => 0,
+                        }
+                    }
+                 }
+             })+
+         }
+    }
+    sync_clonable_seq_counter_impl!(u8, u16, u32, u64,);
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::seq_count::{
+        CcsdsSimpleSeqCountProvider, SeqCountProviderSimple, SeqCountProviderSyncU8,
+        SequenceCountProvider,
+    };
+    use crate::MAX_SEQ_COUNT;
+
+    #[test]
+    fn test_u8_counter() {
+        let u8_counter = SeqCountProviderSimple::<u8>::default();
+        assert_eq!(u8_counter.get(), 0);
+        assert_eq!(u8_counter.get_and_increment(), 0);
+        assert_eq!(u8_counter.get_and_increment(), 1);
+        assert_eq!(u8_counter.get(), 2);
+    }
+
+    #[test]
+    fn test_u8_counter_overflow() {
+        let u8_counter = SeqCountProviderSimple::new_u8();
+        for _ in 0..256 {
+            u8_counter.increment();
+        }
+        assert_eq!(u8_counter.get(), 0);
+    }
+
+    #[test]
+    fn test_ccsds_counter() {
+        let ccsds_counter = CcsdsSimpleSeqCountProvider::default();
+        assert_eq!(ccsds_counter.get(), 0);
+        assert_eq!(ccsds_counter.get_and_increment(), 0);
+        assert_eq!(ccsds_counter.get_and_increment(), 1);
+        assert_eq!(ccsds_counter.get(), 2);
+    }
+
+    #[test]
+    fn test_ccsds_counter_overflow() {
+        let ccsds_counter = CcsdsSimpleSeqCountProvider::default();
+        for _ in 0..MAX_SEQ_COUNT + 1 {
+            ccsds_counter.increment();
+        }
+        assert_eq!(ccsds_counter.get(), 0);
+    }
+
+    #[test]
+    fn test_atomic_ref_counters() {
+        let sync_u8_counter = SeqCountProviderSyncU8::new();
+        assert_eq!(sync_u8_counter.get(), 0);
+        assert_eq!(sync_u8_counter.get_and_increment(), 0);
+        assert_eq!(sync_u8_counter.get_and_increment(), 1);
+        assert_eq!(sync_u8_counter.get(), 2);
+    }
+
+    #[test]
+    fn test_atomic_ref_counters_overflow() {
+        let sync_u8_counter = SeqCountProviderSyncU8::new();
+        for _ in 0..u8::MAX as u16 + 1 {
+            sync_u8_counter.increment();
+        }
+        assert_eq!(sync_u8_counter.get(), 0);
+    }
+
+    #[test]
+    fn test_atomic_ref_counters_overflow_custom_max_val() {
+        let sync_u8_counter = SeqCountProviderSyncU8::new_with_max_val(128);
+        for _ in 0..129 {
+            sync_u8_counter.increment();
+        }
+        assert_eq!(sync_u8_counter.get(), 0);
+    }
+}

src/time/ascii.rs

@@ -71,7 +71,19 @@ mod tests {
     use std::format;
 
     #[test]
-    fn test_ascii_timestamp_a_unterminated() {
+    fn test_ascii_timestamp_a_unterminated_epoch() {
+        let date = chrono::DateTime::UNIX_EPOCH;
+        let stamp_formatter = generate_time_code_a(&date);
+        let stamp = format!("{}", stamp_formatter);
+        let t_sep = stamp.find('T');
+        assert!(t_sep.is_some());
+        assert_eq!(t_sep.unwrap(), 10);
+        assert_eq!(stamp.len(), FMT_STR_CODE_A_WITH_SIZE.1);
+    }
+
+    #[test]
+    #[cfg_attr(miri, ignore)]
+    fn test_ascii_timestamp_a_unterminated_now() {
         let date = Utc::now();
         let stamp_formatter = generate_time_code_a(&date);
         let stamp = format!("{}", stamp_formatter);
@@ -82,7 +94,24 @@ mod tests {
     }
 
     #[test]
-    fn test_ascii_timestamp_a_terminated() {
+    fn test_ascii_timestamp_a_terminated_epoch() {
+        let date = chrono::DateTime::UNIX_EPOCH;
+        let stamp_formatter = generate_time_code_a_terminated(&date);
+        let stamp = format!("{}", stamp_formatter);
+        let t_sep = stamp.find('T');
+        assert!(t_sep.is_some());
+        assert_eq!(t_sep.unwrap(), 10);
+        let z_terminator = stamp.find('Z');
+        assert!(z_terminator.is_some());
+        assert_eq!(
+            z_terminator.unwrap(),
+            FMT_STR_CODE_A_TERMINATED_WITH_SIZE.1 - 1
+        );
+        assert_eq!(stamp.len(), FMT_STR_CODE_A_TERMINATED_WITH_SIZE.1);
+    }
+    #[test]
+    #[cfg_attr(miri, ignore)]
+    fn test_ascii_timestamp_a_terminated_now() {
         let date = Utc::now();
         let stamp_formatter = generate_time_code_a_terminated(&date);
         let stamp = format!("{}", stamp_formatter);
@@ -99,7 +128,19 @@ mod tests {
     }
 
     #[test]
-    fn test_ascii_timestamp_b_unterminated() {
+    fn test_ascii_timestamp_b_unterminated_epoch() {
+        let date = chrono::DateTime::UNIX_EPOCH;
+        let stamp_formatter = generate_time_code_b(&date);
+        let stamp = format!("{}", stamp_formatter);
+        let t_sep = stamp.find('T');
+        assert!(t_sep.is_some());
+        assert_eq!(t_sep.unwrap(), 8);
+        assert_eq!(stamp.len(), FMT_STR_CODE_B_WITH_SIZE.1);
+    }
+
+    #[test]
+    #[cfg_attr(miri, ignore)]
+    fn test_ascii_timestamp_b_unterminated_now() {
         let date = Utc::now();
         let stamp_formatter = generate_time_code_b(&date);
         let stamp = format!("{}", stamp_formatter);
@@ -110,7 +151,25 @@ mod tests {
     }
 
     #[test]
-    fn test_ascii_timestamp_b_terminated() {
+    fn test_ascii_timestamp_b_terminated_epoch() {
+        let date = chrono::DateTime::UNIX_EPOCH;
+        let stamp_formatter = generate_time_code_b_terminated(&date);
+        let stamp = format!("{}", stamp_formatter);
+        let t_sep = stamp.find('T');
+        assert!(t_sep.is_some());
+        assert_eq!(t_sep.unwrap(), 8);
+        let z_terminator = stamp.find('Z');
+        assert!(z_terminator.is_some());
+        assert_eq!(
+            z_terminator.unwrap(),
+            FMT_STR_CODE_B_TERMINATED_WITH_SIZE.1 - 1
+        );
+        assert_eq!(stamp.len(), FMT_STR_CODE_B_TERMINATED_WITH_SIZE.1);
+    }
+
+    #[test]
+    #[cfg_attr(miri, ignore)]
+    fn test_ascii_timestamp_b_terminated_now() {
         let date = Utc::now();
         let stamp_formatter = generate_time_code_b_terminated(&date);
         let stamp = format!("{}", stamp_formatter);

src/time/cds.rs

@@ -7,17 +7,13 @@
 use crate::private::Sealed;
 use crate::ByteConversionError;
 use core::cmp::Ordering;
-use core::fmt::{Debug, Display, Formatter};
+use core::fmt::Debug;
 use core::ops::{Add, AddAssign};
 use core::time::Duration;
 
-use delegate::delegate;
-
 #[cfg(feature = "std")]
 use super::StdTimestampError;
 #[cfg(feature = "std")]
-use std::error::Error;
-#[cfg(feature = "std")]
 use std::time::{SystemTime, SystemTimeError};
 
 #[cfg(feature = "chrono")]
@@ -93,49 +89,19 @@ pub enum SubmillisPrecision {
     Reserved = 0b11,
 }
 
-#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum CdsError {
     /// CCSDS days value exceeds maximum allowed size or is negative
+    #[error("invalid ccsds days {0}")]
     InvalidCcsdsDays(i64),
     /// There are distinct constructors depending on the days field width detected in the preamble
     /// field. This error will be returned if there is a missmatch.
+    #[error("wrong constructor for length of day {0:?} detected in preamble")]
     InvalidCtorForDaysOfLenInPreamble(LengthOfDaySegment),
-    DateBeforeCcsdsEpoch(DateBeforeCcsdsEpochError),
+    #[error("date before CCSDS epoch: {0}")]
-}
+    DateBeforeCcsdsEpoch(#[from] DateBeforeCcsdsEpochError),
-
-impl Display for CdsError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        match self {
-            CdsError::InvalidCcsdsDays(days) => {
-                write!(f, "invalid ccsds days {days}")
-            }
-            CdsError::InvalidCtorForDaysOfLenInPreamble(length_of_day) => {
-                write!(
-                    f,
-                    "wrong constructor for length of day {length_of_day:?} detected in preamble",
-                )
-            }
-            CdsError::DateBeforeCcsdsEpoch(e) => write!(f, "date before CCSDS epoch: {e}"),
-        }
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for CdsError {
-    fn source(&self) -> Option<&(dyn Error + 'static)> {
-        match self {
-            CdsError::DateBeforeCcsdsEpoch(e) => Some(e),
-            _ => None,
-        }
-    }
-}
-
-impl From<DateBeforeCcsdsEpochError> for CdsError {
-    fn from(value: DateBeforeCcsdsEpochError) -> Self {
-        Self::DateBeforeCcsdsEpoch(value)
-    }
 }
 
 pub fn length_of_day_segment_from_pfield(pfield: u8) -> LengthOfDaySegment {
@@ -145,6 +111,7 @@ pub fn length_of_day_segment_from_pfield(pfield: u8) -> LengthOfDaySegment {
     LengthOfDaySegment::Short16Bits
 }
 
+#[inline]
 pub fn precision_from_pfield(pfield: u8) -> SubmillisPrecision {
     match pfield & 0b11 {
         0b01 => SubmillisPrecision::Microseconds,
@@ -272,54 +239,70 @@ impl ConversionFromUnix {
 }
 
 impl CdsCommon for ConversionFromUnix {
+    #[inline]
     fn submillis_precision(&self) -> SubmillisPrecision {
         self.submilis_prec
     }
 
+    #[inline]
     fn ms_of_day(&self) -> u32 {
         self.ms_of_day
     }
 
+    #[inline]
     fn ccsds_days_as_u32(&self) -> u32 {
         self.ccsds_days
     }
 
+    #[inline]
     fn submillis(&self) -> u32 {
         self.submillis
     }
 }
 
 impl CdsConverter for ConversionFromUnix {
+    #[inline]
     fn unix_days_seconds(&self) -> i64 {
         self.unix_days_seconds
     }
 }
+
 /// Helper struct which generates fields for the CDS time provider from a datetime.
+#[cfg(feature = "chrono")]
 struct ConversionFromChronoDatetime {
     unix_conversion: ConversionFromUnix,
     submillis_prec: SubmillisPrecision,
     submillis: u32,
 }
 
+#[cfg(feature = "chrono")]
 impl CdsCommon for ConversionFromChronoDatetime {
+    #[inline]
     fn submillis_precision(&self) -> SubmillisPrecision {
         self.submillis_prec
     }
 
-    delegate! {
+    delegate::delegate! {
         to self.unix_conversion {
+            #[inline]
             fn ms_of_day(&self) -> u32;
+            #[inline]
             fn ccsds_days_as_u32(&self) -> u32;
         }
     }
 
+    #[inline]
     fn submillis(&self) -> u32 {
         self.submillis
     }
 }
 
+#[cfg(feature = "chrono")]
 impl CdsConverter for ConversionFromChronoDatetime {
-    delegate! {to self.unix_conversion { fn unix_days_seconds(&self) -> i64; }}
+    delegate::delegate! {to self.unix_conversion {
+        #[inline]
+        fn unix_days_seconds(&self) -> i64;
+    }}
 }
 
 #[inline]
@@ -353,7 +336,6 @@ impl ConversionFromChronoDatetime {
         Self::new_generic(dt, SubmillisPrecision::Picoseconds)
     }
 
-    #[cfg(feature = "chrono")]
     fn new_generic(
         dt: &chrono::DateTime<chrono::Utc>,
         prec: SubmillisPrecision,
@@ -435,7 +417,7 @@ impl CdsCommon for ConversionFromNow {
     fn submillis_precision(&self) -> SubmillisPrecision {
         self.submillis_prec
     }
-    delegate! {
+    delegate::delegate! {
         to self.unix_conversion {
             fn ms_of_day(&self) -> u32;
             fn ccsds_days_as_u32(&self) -> u32;
@@ -449,7 +431,7 @@ impl CdsCommon for ConversionFromNow {
 
 #[cfg(feature = "std")]
 impl CdsConverter for ConversionFromNow {
-    delegate! {to self.unix_conversion { fn unix_days_seconds(&self) -> i64; }}
+    delegate::delegate! {to self.unix_conversion { fn unix_days_seconds(&self) -> i64; }}
 }
 
 #[cfg(feature = "alloc")]
@@ -1609,6 +1591,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_time_now() {
         let timestamp_now = CdsTime::now_with_u16_days().unwrap();
         let compare_stamp = chrono::Utc::now();
@@ -1616,6 +1599,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_time_now_us_prec() {
         let timestamp_now = CdsTime::now_with_u16_days_us_precision().unwrap();
         let compare_stamp = chrono::Utc::now();
@@ -1623,6 +1607,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_time_now_ps_prec() {
         let timestamp_now = CdsTime::from_now_with_u16_days_ps_precision().unwrap();
         let compare_stamp = chrono::Utc::now();
@@ -1630,6 +1615,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_time_now_ps_prec_u16_days() {
         let timestamp_now = CdsTime::from_now_with_u16_days_ps_precision().unwrap();
         let compare_stamp = chrono::Utc::now();
@@ -1637,6 +1623,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_time_now_ps_prec_u24_days() {
         let timestamp_now = CdsTime::now_with_u24_days_ps_precision().unwrap();
         let compare_stamp = chrono::Utc::now();
@@ -2293,6 +2280,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_update_from_now() {
         let mut stamp = CdsTime::new_with_u16_days(0, 0);
         let _ = stamp.update_from_now();
@@ -2308,6 +2296,7 @@ mod tests {
 
     #[test]
     #[cfg(feature = "serde")]
+    #[cfg_attr(miri, ignore)]
     fn test_serialization() {
         let stamp_now = CdsTime::now_with_u16_days().expect("Error retrieving time");
         let val = to_allocvec(&stamp_now).expect("Serializing timestamp failed");

src/time/cuc.rs

@@ -9,7 +9,6 @@ use serde::{Deserialize, Serialize};
 use core::fmt::{Debug, Display, Formatter};
 use core::ops::{Add, AddAssign};
 use core::time::Duration;
-use core::u64;
 
 use crate::ByteConversionError;
 
@@ -177,6 +176,7 @@ pub struct FractionalPart {
 }
 
 impl FractionalPart {
+    #[inline]
     pub const fn new(resolution: FractionalResolution, counter: u32) -> Self {
         let div = fractional_res_to_div(resolution);
         assert!(counter <= div, "invalid counter for resolution");
@@ -187,15 +187,18 @@ impl FractionalPart {
     }
 
     /// An empty fractional part for second resolution only.
+    #[inline]
     pub const fn new_with_seconds_resolution() -> Self {
         Self::new(FractionalResolution::Seconds, 0)
     }
 
     /// Helper method which simply calls [Self::new_with_seconds_resolution].
+    #[inline]
     pub const fn new_empty() -> Self {
         Self::new_with_seconds_resolution()
     }
 
+    #[inline]
     pub fn new_checked(resolution: FractionalResolution, counter: u32) -> Option<Self> {
         let div = fractional_res_to_div(resolution);
         if counter > div {
@@ -207,14 +210,17 @@ impl FractionalPart {
         })
     }
 
+    #[inline]
     pub fn resolution(&self) -> FractionalResolution {
         self.resolution
     }
 
+    #[inline]
     pub fn counter(&self) -> u32 {
         self.counter
     }
 
+    #[inline]
     pub fn no_fractional_part(&self) -> bool {
         self.resolution == FractionalResolution::Seconds
     }
@@ -285,6 +291,7 @@ pub struct CucTimeWithLeapSecs {
 }
 
 impl CucTimeWithLeapSecs {
+    #[inline]
     pub fn new(time: CucTime, leap_seconds: u32) -> Self {
         Self { time, leap_seconds }
     }
@@ -300,6 +307,7 @@ pub fn pfield_len(pfield: u8) -> usize {
 
 impl CucTime {
     /// Create a time provider with a four byte counter and no fractional part.
+    #[inline]
     pub fn new(counter: u32) -> Self {
         // These values are definitely valid, so it is okay to unwrap here.
         Self::new_generic(
@@ -310,11 +318,13 @@ impl CucTime {
     }
 
     /// Like [CucTime::new] but allow to supply a fractional part as well.
+    #[inline]
     pub fn new_with_fractions(counter: u32, fractions: FractionalPart) -> Result<Self, CucError> {
         Self::new_generic(WidthCounterPair(4, counter), fractions)
     }
 
     /// Fractions with a resolution of ~ 4 ms
+    #[inline]
     pub fn new_with_coarse_fractions(counter: u32, subsec_fractions: u8) -> Self {
         // These values are definitely valid, so it is okay to unwrap here.
         Self::new_generic(
@@ -328,6 +338,7 @@ impl CucTime {
     }
 
     /// Fractions with a resolution of ~ 16 us
+    #[inline]
     pub fn new_with_medium_fractions(counter: u32, subsec_fractions: u16) -> Self {
         // These values are definitely valid, so it is okay to unwrap here.
         Self::new_generic(
@@ -343,6 +354,7 @@ impl CucTime {
     /// Fractions with a resolution of ~ 60 ns. The fractional part value is limited by the
     /// 24 bits of the fractional field, so this function will fail with
     /// [CucError::InvalidFractions] if the fractional value exceeds the value.
+    #[inline]
     pub fn new_with_fine_fractions(counter: u32, subsec_fractions: u32) -> Result<Self, CucError> {
         Self::new_generic(
             WidthCounterPair(4, counter),
@@ -457,6 +469,7 @@ impl CucTime {
 
     /// Most generic constructor which allows full configurability for the counter and for the
     /// fractions.
+    #[inline]
     pub fn new_generic(
         width_and_counter: WidthCounterPair,
         fractions: FractionalPart,
@@ -476,31 +489,38 @@ impl CucTime {
         })
     }
 
+    #[inline]
     pub fn ccsds_time_code(&self) -> CcsdsTimeCode {
         CcsdsTimeCode::CucCcsdsEpoch
     }
 
+    #[inline]
     pub fn width_counter_pair(&self) -> WidthCounterPair {
         self.counter
     }
 
+    #[inline]
     pub fn counter_width(&self) -> u8 {
         self.counter.0
     }
 
+    #[inline]
     pub fn counter(&self) -> u32 {
         self.counter.1
     }
 
     /// Subsecond fractional part of the CUC time.
+    #[inline]
     pub fn fractions(&self) -> FractionalPart {
         self.fractions
     }
 
+    #[inline]
     pub fn to_leap_sec_helper(&self, leap_seconds: u32) -> CucTimeWithLeapSecs {
         CucTimeWithLeapSecs::new(*self, leap_seconds)
     }
 
+    #[inline]
     pub fn set_fractions(&mut self, fractions: FractionalPart) -> Result<(), CucError> {
         Self::verify_fractions_value(fractions)?;
         self.fractions = fractions;
@@ -510,6 +530,7 @@ impl CucTime {
 
     /// Set a fractional resolution. Please note that this function will reset the fractional value
     /// to 0 if the resolution changes.
+    #[inline]
     pub fn set_fractional_resolution(&mut self, res: FractionalResolution) {
         if res == FractionalResolution::Seconds {
             self.fractions = FractionalPart::new_with_seconds_resolution();
@@ -519,6 +540,7 @@ impl CucTime {
         }
     }
 
+    #[inline]
     fn build_p_field(counter_width: u8, resolution: FractionalResolution) -> u8 {
         let mut pfield = P_FIELD_BASE;
         if !(1..=4).contains(&counter_width) {
@@ -538,6 +560,7 @@ impl CucTime {
         pfield
     }
 
+    #[inline]
     fn update_p_field_fractions(&mut self) {
         self.pfield &= !(0b11);
         self.pfield |= self.fractions.resolution() as u8;
@@ -582,6 +605,7 @@ impl CucTime {
         )
     }
 
+    #[inline]
     pub fn len_packed_from_pfield(pfield: u8) -> usize {
         let mut base_len: usize = 1;
         base_len += Self::len_cntr_from_pfield(pfield) as usize;
@@ -590,6 +614,7 @@ impl CucTime {
     }
 
     /// Verifies the raw width parameter.
+    #[inline]
     fn verify_counter_width(width: u8) -> Result<(), CucError> {
         if width == 0 || width > 4 {
             return Err(CucError::InvalidCounterWidth(width));
@@ -597,6 +622,7 @@ impl CucTime {
         Ok(())
     }
 
+    #[inline]
     fn verify_fractions_value(val: FractionalPart) -> Result<(), CucError> {
         if val.counter > 2u32.pow((val.resolution as u32) * 8) - 1 {
             return Err(CucError::InvalidFractions {
@@ -607,10 +633,12 @@ impl CucTime {
         Ok(())
     }
 
+    #[inline]
     fn len_as_bytes(&self) -> usize {
         Self::len_packed_from_pfield(self.pfield)
     }
 
+    #[inline]
     fn subsec_nanos(&self) -> u32 {
         if self.fractions.resolution() == FractionalResolution::Seconds {
             return 0;
@@ -751,22 +779,27 @@ impl TimeWriter for CucTime {
 }
 
 impl CcsdsTimeProvider for CucTimeWithLeapSecs {
+    #[inline]
     fn len_as_bytes(&self) -> usize {
         self.time.len_as_bytes()
     }
 
+    #[inline]
     fn p_field(&self) -> (usize, [u8; 2]) {
         (1, [self.time.pfield, 0])
     }
 
+    #[inline]
     fn ccdsd_time_code(&self) -> CcsdsTimeCode {
         self.time.ccsds_time_code()
     }
 
+    #[inline]
     fn unix_secs(&self) -> i64 {
         self.time.unix_secs(self.leap_seconds)
     }
 
+    #[inline]
     fn subsec_nanos(&self) -> u32 {
         self.time.subsec_nanos()
     }
@@ -913,6 +946,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_datetime_now() {
         let now = chrono::Utc::now();
         let cuc_now = CucTime::now(FractionalResolution::SixtyNs, LEAP_SECONDS);
@@ -1244,6 +1278,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn set_fract_resolution() {
         let mut stamp = CucTime::new(2000);
         stamp.set_fractional_resolution(FractionalResolution::SixtyNs);

src/time/mod.rs

@@ -6,7 +6,6 @@ use core::cmp::Ordering;
 use core::fmt::{Display, Formatter};
 use core::ops::{Add, AddAssign, Sub};
 use core::time::Duration;
-use core::u8;
 
 #[allow(unused_imports)]
 #[cfg(not(feature = "std"))]
@@ -64,20 +63,12 @@ pub fn ccsds_time_code_from_p_field(pfield: u8) -> Result<CcsdsTimeCode, u8> {
     CcsdsTimeCode::try_from(raw_bits).map_err(|_| raw_bits)
 }
 
-#[derive(Debug, PartialEq, Eq, Copy, Clone)]
+#[derive(Debug, PartialEq, Eq, Copy, Clone, thiserror::Error)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
+#[error("date before ccsds epoch: {0:?}")]
 pub struct DateBeforeCcsdsEpochError(UnixTime);
 
-impl Display for DateBeforeCcsdsEpochError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
-        write!(f, "date before ccsds epoch: {:?}", self.0)
-    }
-}
-
-#[cfg(feature = "std")]
-impl Error for DateBeforeCcsdsEpochError {}
-
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
@@ -166,6 +157,7 @@ pub fn seconds_since_epoch() -> f64 {
 ///
 ///  - CCSDS epoch: 1958-01-01T00:00:00+00:00
 ///  - UNIX Epoch: 1970-01-01T00:00:00+00:00
+#[inline]
 pub const fn unix_to_ccsds_days(unix_days: i64) -> i64 {
     unix_days - DAYS_CCSDS_TO_UNIX as i64
 }
@@ -174,16 +166,19 @@ pub const fn unix_to_ccsds_days(unix_days: i64) -> i64 {
 ///
 ///  - CCSDS epoch: 1958-01-01T00:00:00+00:00
 ///  - UNIX Epoch: 1970-01-01T00:00:00+00:00
+#[inline]
 pub const fn ccsds_to_unix_days(ccsds_days: i64) -> i64 {
     ccsds_days + DAYS_CCSDS_TO_UNIX as i64
 }
 
 /// Similar to [unix_to_ccsds_days] but converts the epoch instead, which is the number of elpased
 /// seconds since the CCSDS and UNIX epoch times.
+#[inline]
 pub const fn unix_epoch_to_ccsds_epoch(unix_epoch: i64) -> i64 {
     unix_epoch - (DAYS_CCSDS_TO_UNIX as i64 * SECONDS_PER_DAY as i64)
 }
 
+#[inline]
 pub const fn ccsds_epoch_to_unix_epoch(ccsds_epoch: i64) -> i64 {
     ccsds_epoch + (DAYS_CCSDS_TO_UNIX as i64 * SECONDS_PER_DAY as i64)
 }
@@ -547,6 +542,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_get_current_time() {
         let sec_floats = seconds_since_epoch();
         assert!(sec_floats > 0.0);
@@ -561,6 +557,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_ccsds_epoch() {
         let now = SystemTime::now()
             .duration_since(SystemTime::UNIX_EPOCH)
@@ -681,6 +678,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg_attr(miri, ignore)]
     fn test_from_now() {
         let stamp_now = UnixTime::now().unwrap();
         let dt_now = stamp_now.chrono_date_time().unwrap();

src/util.rs

@@ -15,10 +15,12 @@ pub trait ToBeBytes {
 impl ToBeBytes for () {
     type ByteArray = [u8; 0];
 
+    #[inline]
     fn written_len(&self) -> usize {
         0
     }
 
+    #[inline]
     fn to_be_bytes(&self) -> Self::ByteArray {
         []
     }
@@ -27,9 +29,12 @@ impl ToBeBytes for () {
 impl ToBeBytes for u8 {
     type ByteArray = [u8; 1];
 
+    #[inline]
     fn written_len(&self) -> usize {
         1
     }
+
+    #[inline]
     fn to_be_bytes(&self) -> Self::ByteArray {
         u8::to_be_bytes(*self)
     }
@@ -38,9 +43,12 @@ impl ToBeBytes for u8 {
 impl ToBeBytes for u16 {
     type ByteArray = [u8; 2];
 
+    #[inline]
     fn written_len(&self) -> usize {
         2
     }
+
+    #[inline]
     fn to_be_bytes(&self) -> Self::ByteArray {
         u16::to_be_bytes(*self)
     }
@@ -49,9 +57,12 @@ impl ToBeBytes for u16 {
 impl ToBeBytes for u32 {
     type ByteArray = [u8; 4];
 
+    #[inline]
     fn written_len(&self) -> usize {
         4
     }
+
+    #[inline]
     fn to_be_bytes(&self) -> Self::ByteArray {
         u32::to_be_bytes(*self)
     }
@@ -60,9 +71,12 @@ impl ToBeBytes for u32 {
 impl ToBeBytes for u64 {
     type ByteArray = [u8; 8];
 
+    #[inline]
     fn written_len(&self) -> usize {
         8
     }
+
+    #[inline]
     fn to_be_bytes(&self) -> Self::ByteArray {
         u64::to_be_bytes(*self)
     }
@@ -104,6 +118,7 @@ pub enum UnsignedByteFieldError {
 }
 
 impl From<ByteConversionError> for UnsignedByteFieldError {
+    #[inline]
     fn from(value: ByteConversionError) -> Self {
         Self::ByteConversionError(value)
     }
@@ -138,14 +153,17 @@ pub struct UnsignedByteField {
 }
 
 impl UnsignedByteField {
+    #[inline]
     pub const fn new(width: usize, value: u64) -> Self {
         Self { width, value }
     }
 
+    #[inline]
     pub const fn value_const(&self) -> u64 {
         self.value
     }
 
+    #[inline]
     pub fn new_from_be_bytes(width: usize, buf: &[u8]) -> Result<Self, UnsignedByteFieldError> {
         if width > buf.len() {
             return Err(ByteConversionError::FromSliceTooSmall {
@@ -178,10 +196,12 @@ impl UnsignedByteField {
 }
 
 impl UnsignedEnum for UnsignedByteField {
+    #[inline]
     fn size(&self) -> usize {
         self.width
     }
 
+    #[inline]
     fn value(&self) -> u64 {
         self.value_const()
     }
@@ -237,6 +257,7 @@ impl<TYPE: Copy + Into<u64>> GenericUnsignedByteField<TYPE> {
 }
 
 impl<TYPE: Copy + ToBeBytes + Into<u64>> UnsignedEnum for GenericUnsignedByteField<TYPE> {
+    #[inline]
     fn size(&self) -> usize {
         self.value.written_len()
     }
@@ -252,6 +273,7 @@ impl<TYPE: Copy + ToBeBytes + Into<u64>> UnsignedEnum for GenericUnsignedByteFie
         Ok(self.value.written_len())
     }
 
+    #[inline]
     fn value(&self) -> u64 {
         self.value_typed().into()
     }
@@ -277,6 +299,7 @@ impl From<UnsignedByteFieldU8> for UnsignedByteField {
 impl TryFrom<UnsignedByteField> for UnsignedByteFieldU8 {
     type Error = UnsignedByteFieldError;
 
+    #[inline]
     fn try_from(value: UnsignedByteField) -> Result<Self, Self::Error> {
         if value.width != 1 {
             return Err(UnsignedByteFieldError::InvalidWidth {
@@ -289,6 +312,7 @@ impl TryFrom<UnsignedByteField> for UnsignedByteFieldU8 {
 }
 
 impl From<UnsignedByteFieldU16> for UnsignedByteField {
+    #[inline]
     fn from(value: UnsignedByteFieldU16) -> Self {
         Self::new(2, value.value as u64)
     }
@@ -297,6 +321,7 @@ impl From<UnsignedByteFieldU16> for UnsignedByteField {
 impl TryFrom<UnsignedByteField> for UnsignedByteFieldU16 {
     type Error = UnsignedByteFieldError;
 
+    #[inline]
     fn try_from(value: UnsignedByteField) -> Result<Self, Self::Error> {
         if value.width != 2 {
             return Err(UnsignedByteFieldError::InvalidWidth {
@@ -309,6 +334,7 @@ impl TryFrom<UnsignedByteField> for UnsignedByteFieldU16 {
 }
 
 impl From<UnsignedByteFieldU32> for UnsignedByteField {
+    #[inline]
     fn from(value: UnsignedByteFieldU32) -> Self {
         Self::new(4, value.value as u64)
     }
@@ -317,6 +343,7 @@ impl From<UnsignedByteFieldU32> for UnsignedByteField {
 impl TryFrom<UnsignedByteField> for UnsignedByteFieldU32 {
     type Error = UnsignedByteFieldError;
 
+    #[inline]
     fn try_from(value: UnsignedByteField) -> Result<Self, Self::Error> {
         if value.width != 4 {
             return Err(UnsignedByteFieldError::InvalidWidth {
@@ -329,6 +356,7 @@ impl TryFrom<UnsignedByteField> for UnsignedByteFieldU32 {
 }
 
 impl From<UnsignedByteFieldU64> for UnsignedByteField {
+    #[inline]
     fn from(value: UnsignedByteFieldU64) -> Self {
         Self::new(8, value.value)
     }
@@ -337,6 +365,7 @@ impl From<UnsignedByteFieldU64> for UnsignedByteField {
 impl TryFrom<UnsignedByteField> for UnsignedByteFieldU64 {
     type Error = UnsignedByteFieldError;
 
+    #[inline]
     fn try_from(value: UnsignedByteField) -> Result<Self, Self::Error> {
         if value.width != 8 {
             return Err(UnsignedByteFieldError::InvalidWidth {