Merge branch 'main' into all_features

.github/workflows/ci.yml

@@ -20,21 +20,6 @@ jobs:
           command: check
           args: --release
 
-  msrv:
-    name: Check with MSRV
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.60.0
-          override: true
-          profile: minimal
-      - uses: actions-rs/cargo@v1
-        with:
-          command: check
-          args: --release
-
   cross-check:
     name: Check Cross
     runs-on: ubuntu-latest
@@ -73,21 +58,6 @@ jobs:
           command: fmt
           args: --all -- --check
 
-  check-doc:
-    name: Check Documentation Build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: nightly
-          override: true
-          profile: minimal
-      - uses: actions-rs/cargo@v1
-        with:
-          command: doc
-          args: --all-features
-
   clippy:
     name: Clippy
     runs-on: ubuntu-latest

CHANGELOG.md

@@ -8,87 +8,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 # [unreleased]
 
-The timestamp of `PusTm` is now optional. See Added and Changed section for details.
-
-## Added
-
-- `PusTmSecondaryHeader`: New `new_simple_no_timestamp` API to create secondary header without
-  timestamp.
-- `PusTm`: Add `new_simple_no_timestamp` method to create TM without timestamp
-- New `UnixTimestamp` abstraction which contains the unix seconds as an `i64`
-  and an optional subsecond millisecond counter (`u16`)
-- `MS_PER_DAY` constant.
-- CUC: Added `from_date_time` and `from_unix_stamp` constructors for time provider.
-- CUC: Add `Add<Duration>` and `AddAssign<Duration>` impl for time provider.
-
-### CDS time module
-
-- Implement `Add<Duration>` and `AddAssign<Duration>` for time providers, which allows
-  easily adding offsets to the providers.
-- Implement `TryFrom<DateTime<Utc>>` for time providers.
-- `get_dyn_time_provider_from_bytes`: Requires `alloc` support and returns
-  the correct `TimeProvider` instance wrapped as a boxed trait object
-  `Box<DynCdsTimeProvider>` by checking the length of days field.
-- Added constructor function to create the time provider
-  from `chrono::DateTime<Utc>` and a generic UNIX timestamp (`i64` seconds
-  and subsecond milliseconds).
-- `MAX_DAYS_24_BITS` which contains maximum value which can be supplied
-  to the days field of a CDS time provider with 24 bits days field width.
-- New `CdsTimestamp` trait which encapsulates common fields for all CDS time providers.
-- `from_unix_secs_with_u24_days` and `from_unix_secs_with_u16_days` which create
-   the time provider from a `UnixTimestamp` reference.
-- `from_dt_with_u16_days`, `from_dt_with_u24_days` and their `..._us_precision` and
-   `..._ps_precision` variants which allow to create time providers from
-   a `chrono::DateTime<Utc>`.
-- Add `from_bytes_with_u24_days` and `from_bytes_with_u16_days` associated methods
-
-## Changed
-
-
-- (breaking) `unix_epoch_to_ccsds_epoch`: Expect and return `i64` instead of `u64` now.
-- (breaking) `ccsds_epoch_to_unix_epoch`: Expect and return `i64` instead of `u64` now.
-- (breaking) `PusTmSecondaryHeader`: Timestamp is optional now, which translates to a
-  timestamp of size 0.
-- (breaking): `PusTm`: Renamed `time_stamp` method to `timestamp`, also returns
-  `Optional<&'src_data [u8]>` now.
-- (breaking): `PusTmSecondaryHeader`: Renamed `time_stamp` field to `timestamp` for consistency.
-- (breaking): Renamed `from_now_with_u24_days_and_us_prec` to `from_now_with_u24_days_us_precision`.
-  Also did the same for the `u16` variant.
-- (breaking): Renamed `from_now_with_u24_days_and_ps_prec` to `from_now_with_u24_days_ps_precision`.
-  Also did the same for the `u16` variant.
-- `CcsdsTimeProvider` trait (breaking):
-  - Add new `unix_stamp` method returning the new `UnixTimeStamp` struct.
-  - Add new  `subsecond_millis` method returning counter `Option<u16>`.
-  - Default impl for `unix_stamp` which re-uses `subsecond_millis` and
-    existing `unix_seconds` method.
-- `TimestampError` (breaking): Add `DateBeforeCcsdsEpoch` error type
-  because new CDS API allow supplying invalid date times before CCSDS epoch.
-  Make `TimestampError` with `#[non_exhaustive]` attribute to prevent
-  future breakages if new error variants are added.
-
-# [v0.4.2] 14.01.2023
-
-## Fixed
-
-- CDS timestamp: Fixed another small logic error for stamp creation from the current
-  time with picosecond precision.
-  PR: https://egit.irs.uni-stuttgart.de/rust/spacepackets/pulls/8
-
-# [v0.4.1] 14.01.2023
-
-## Fixed
-
-- CDS timestamp: The conversion function from the current time were buggy
-  when specifying picoseconds precision, which could lead to overflow
-  multiplications and/or incorrect precision fields.
-  PR: https://egit.irs.uni-stuttgart.de/rust/spacepackets/pulls/7
-
-# [v0.4.0] 10.01.2023
-
-## Fixed
-
-- Remove `Default` derive on CDS time provider. This can lead to uninitialized preamble fields.
-
 ## Changed
 
 - `serde` support is now optional and behind the `serde` feature.
@@ -100,18 +19,12 @@ The timestamp of `PusTm` is now optional. See Added and Changed section for deta
   The function now returns the remaining slice as well.
 - All CDS specific functionality was moved into the `cds` submodule of the `time`
   module. `CdsShortTimeProvider` was renamed to `TimeProvider`.
-  PR: https://egit.irs.uni-stuttgart.de/rust/spacepackets/pulls/3
 
 ## Added
 
-- `SpHeader` getter function `sp_header` added for `PusTc`
-  PR: https://egit.irs.uni-stuttgart.de/rust/spacepackets/pulls/6
-- Added PFC enumerations: `ecss::UnsignedPfc` and `ecss::RealPfc`.
-  PR: https://egit.irs.uni-stuttgart.de/rust/spacepackets/pulls/5
 - Added `std::error::Error` implementation for all error enumerations if the `std` feature
   is enabled.
 - CUC timestamp implementation as specified in CCSDS 301.0-B-4 section 3.2.
-  PR: https://egit.irs.uni-stuttgart.de/rust/spacepackets/pulls/4/files
 - ACII timestamps as specified in CCSDS 301.0-B-4 section 3.5.
 - Added MSRV in `Cargo.toml` with the `rust-version` field set to Rust 1.60.
 - `serde` `Serialize` and `Deserialize` added to all types.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "spacepackets"
-version = "0.5.0"
+version = "0.3.1"
 edition = "2021"
 rust-version = "1.60"
 authors = ["Robin Mueller <muellerr@irs.uni-stuttgart.de>"]
@@ -14,11 +14,11 @@ categories = ["aerospace", "aerospace::space-protocols", "no-std", "hardware-sup
 
 [dependencies]
 zerocopy = "0.6"
-crc = "3"
+crc = "3.0"
 delegate = "0.8"
 
 [dependencies.serde]
-version = "1"
+version = "1.0"
 optional = true
 default-features = false
 features = ["derive"]

README.md

@@ -15,9 +15,7 @@ Currently, this includes the following components:
   [CCSDS Blue Book 133.0-B-2](https://public.ccsds.org/Pubs/133x0b2e1.pdf)
 - PUS Telecommand and PUS Telemetry implementation according to the
   [ECSS-E-ST-70-41C standard](https://ecss.nl/standard/ecss-e-st-70-41c-space-engineering-telemetry-and-telecommand-packet-utilization-15-april-2016/).
-- CUC (CCSDS Unsegmented Time Code) implementation according to
-  [CCSDS 301.0-B-4 3.2](https://public.ccsds.org/Pubs/301x0b4e1.pdf)
-- CDS (CCSDS Day Segmented Time Code) implementation according to
+- CDS Short Time Code implementation according to
   [CCSDS 301.0-B-4 3.3](https://public.ccsds.org/Pubs/301x0b4e1.pdf)
 - Some helper types to support ASCII timecodes ad specified in
   [CCSDS 301.0-B-4 3.5](https://public.ccsds.org/Pubs/301x0b4e1.pdf)

automation/Dockerfile

@@ -10,6 +10,6 @@ ARG DEBIAN_FRONTEND=noninteractive
 # set CROSS_CONTAINER_IN_CONTAINER to inform `cross` that it is executed from within a container
 ENV CROSS_CONTAINER_IN_CONTAINER=true
 
-RUN rustup install nightly && \
-    rustup target add thumbv7em-none-eabihf armv7-unknown-linux-gnueabihf && \
+# TODO: installing cross is problematic, permission issues
+RUN rustup target add thumbv7em-none-eabihf armv7-unknown-linux-gnueabihf && \
     rustup component add rustfmt clippy

automation/Jenkinsfile

@@ -13,29 +13,19 @@ pipeline {
                 sh 'cargo clippy'
             }
         }
-        stage('Docs') {
-            steps {
-                sh 'cargo +nightly doc --all-features'
-            }
-        }
         stage('Rustfmt') {
             steps {
-                sh 'cargo fmt --all --check'
+                sh 'cargo fmt'
             }
         }
         stage('Test') {
             steps {
-                sh 'cargo test --all-features'
+                sh 'cargo test'
             }
         }
-        stage('Check with all features') {
+        stage('Check') {
             steps {
-                sh 'cargo check --all-features'
-            }
-        }
-        stage('Check with no features') {
-            steps {
-                sh 'cargo check --no-default-features'
+                sh 'cargo check'
             }
         }
         stage('Check Cross Embedded Bare Metal') {

src/ecss.rs

@@ -15,21 +15,6 @@ pub type CrcType = u16;
 pub const CRC_CCITT_FALSE: Crc<u16> = Crc::<u16>::new(&CRC_16_IBM_3740);
 pub const CCSDS_HEADER_LEN: usize = size_of::<crate::zc::SpHeader>();
 
-#[derive(Debug, Copy, Clone, Eq, PartialEq)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub enum PusServiceId {
-    /// Service 1
-    Verification = 1,
-    /// Service 3
-    Housekeeping = 3,
-    /// Service 5
-    Event = 5,
-    /// Service 8
-    Action = 8,
-    /// Service 17
-    Test = 17,
-}
-
 /// All PUS versions. Only PUS C is supported by this library.
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -53,7 +38,6 @@ impl TryFrom<u8> for PusVersion {
     }
 }
 
-/// ECSS Packet Type Codes (PTC)s.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum PacketTypeCodes {
@@ -73,7 +57,6 @@ pub enum PacketTypeCodes {
 
 pub type Ptc = PacketTypeCodes;
 
-/// ECSS Packet Field Codes (PFC)s for the unsigned [Ptc].
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum UnsignedPfc {
@@ -89,7 +72,6 @@ pub enum UnsignedPfc {
     ThreeBits = 19,
 }
 
-/// ECSS Packet Field Codes (PFC)s for the real (floating point) [Ptc].
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum RealPfc {
@@ -160,8 +142,6 @@ impl From<ByteConversionError> for PusError {
     }
 }
 
-/// Generic trait to describe common attributes for both PUS Telecommands (TC) and PUS Telemetry
-/// (TM) packets. All PUS packets are also a special type of [CcsdsPacket]s.
 pub trait PusPacket: CcsdsPacket {
     const PUS_VERSION: PusVersion = PusVersion::PusC;
 

src/lib.rs

@@ -9,11 +9,9 @@
 //!    [CCSDS Blue Book 133.0-B-2](https://public.ccsds.org/Pubs/133x0b2e1.pdf)
 //!  - PUS Telecommand and PUS Telemetry implementation according to the
 //!    [ECSS-E-ST-70-41C standard](https://ecss.nl/standard/ecss-e-st-70-41c-space-engineering-telemetry-and-telecommand-packet-utilization-15-april-2016/).
-//!  - CUC (CCSDS Unsegmented Time Code) implementation according to
-//!    [CCSDS 301.0-B-4 3.2](https://public.ccsds.org/Pubs/301x0b4e1.pdf)
-//!  - CDS (CCSDS Day Segmented Time Code) implementation according to
-//!    [CCSDS 301.0-B-4 3.3](https://public.ccsds.org/Pubs/301x0b4e1.pdf)
-//!  - Some helper types to support ASCII timecodes ad specified in
+//!  - CDS Short Time Code implementation according to
+//!    [CCSDS CCSDS 301.0-B-4](https://public.ccsds.org/Pubs/301x0b4e1.pdf)
+//!  - Some helper types and functions to support ASCII timecodes ad specified in
 //!    [CCSDS 301.0-B-4 3.5](https://public.ccsds.org/Pubs/301x0b4e1.pdf)
 //!
 //! ## Features
@@ -129,7 +127,6 @@ impl Display for ByteConversionError {
 #[cfg(feature = "std")]
 impl Error for ByteConversionError {}
 
-/// CCSDS packet type enumeration.
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum PacketType {
@@ -178,8 +175,6 @@ impl TryFrom<u8> for SequenceFlags {
     }
 }
 
-/// Abstraction for the CCSDS Packet ID, which forms the last thirteen bits
-/// of the first two bytes in the CCSDS primary header.
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct PacketId {
@@ -263,8 +258,6 @@ impl From<u16> for PacketId {
     }
 }
 
-/// Abstraction for the CCSDS Packet Sequence Control (PSC) field which is the
-/// third and the fourth byte in the CCSDS primary header.
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct PacketSequenceCtrl {

src/tc.rs

@@ -215,19 +215,19 @@ impl PusTcSecondaryHeader {
 /// There is no spare bytes support yet.
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub struct PusTc<'app_data> {
+pub struct PusTc<'slice> {
     sp_header: SpHeader,
     pub sec_header: PusTcSecondaryHeader,
     /// If this is set to false, a manual call to [PusTc::calc_own_crc16] or
     /// [PusTc::update_packet_fields] is necessary for the serialized or cached CRC16 to be valid.
     pub calc_crc_on_serialization: bool,
     #[cfg_attr(feature = "serde", serde(skip))]
-    raw_data: Option<&'app_data [u8]>,
-    app_data: Option<&'app_data [u8]>,
+    raw_data: Option<&'slice [u8]>,
+    app_data: Option<&'slice [u8]>,
     crc16: Option<u16>,
 }
 
-impl<'app_data> PusTc<'app_data> {
+impl<'slice> PusTc<'slice> {
     /// Generates a new struct instance.
     ///
     /// # Arguments
@@ -243,7 +243,7 @@ impl<'app_data> PusTc<'app_data> {
     pub fn new(
         sp_header: &mut SpHeader,
         sec_header: PusTcSecondaryHeader,
-        app_data: Option<&'app_data [u8]>,
+        app_data: Option<&'slice [u8]>,
         set_ccsds_len: bool,
     ) -> Self {
         sp_header.set_packet_type(PacketType::Tc);
@@ -268,7 +268,7 @@ impl<'app_data> PusTc<'app_data> {
         sph: &mut SpHeader,
         service: u8,
         subservice: u8,
-        app_data: Option<&'app_data [u8]>,
+        app_data: Option<&'slice [u8]>,
         set_ccsds_len: bool,
     ) -> Self {
         Self::new(
@@ -279,10 +279,6 @@ impl<'app_data> PusTc<'app_data> {
         )
     }
 
-    pub fn sp_header(&self) -> &SpHeader {
-        &self.sp_header
-    }
-
     pub fn len_packed(&self) -> usize {
         let mut length = PUS_TC_MIN_LEN_WITHOUT_APP_DATA;
         if let Some(app_data) = self.app_data {
@@ -405,7 +401,7 @@ impl<'app_data> PusTc<'app_data> {
 
     /// Create a [PusTc] instance from a raw slice. On success, it returns a tuple containing
     /// the instance and the found byte length of the packet.
-    pub fn from_bytes(slice: &'app_data [u8]) -> Result<(Self, usize), PusError> {
+    pub fn from_bytes(slice: &'slice [u8]) -> Result<(Self, usize), PusError> {
         let raw_data_len = slice.len();
         if raw_data_len < PUS_TC_MIN_LEN_WITHOUT_APP_DATA {
             return Err(PusError::RawDataTooShort(raw_data_len));
@@ -435,7 +431,7 @@ impl<'app_data> PusTc<'app_data> {
         Ok((pus_tc, total_len))
     }
 
-    pub fn raw(&self) -> Option<&'app_data [u8]> {
+    pub fn raw(&self) -> Option<&'slice [u8]> {
         self.raw_data
     }
 }

src/time/ascii.rs

@@ -3,10 +3,8 @@
 //! See [chrono::DateTime::format] for a usage example of the generated
 //! [chrono::format::DelayedFormat] structs.
 #[cfg(feature = "alloc")]
-use chrono::{
-    format::{DelayedFormat, StrftimeItems},
-    DateTime, Utc,
-};
+use chrono::format::{DelayedFormat, StrftimeItems};
+use chrono::{DateTime, Utc};
 
 /// Tuple of format string and formatted size for time code A.
 ///

src/time/cuc.rs

@@ -3,15 +3,9 @@
 //!
 //! The core data structure to do this is the [TimeProviderCcsdsEpoch] struct.
 use super::*;
-use chrono::Datelike;
 use core::fmt::Debug;
-use core::ops::{Add, AddAssign};
-use core::time::Duration;
 
 const MIN_CUC_LEN: usize = 2;
-
-/// Base value for the preamble field for a time field parser to determine the time field type.
-pub const P_FIELD_BASE: u8 = (CcsdsTimeCodes::CucCcsdsEpoch as u8) << 4;
 /// Maximum length if the preamble field is not extended.
 pub const MAX_CUC_LEN_SMALL_PREAMBLE: usize = 8;
 
@@ -45,14 +39,12 @@ impl TryFrom<u8> for FractionalResolution {
 /// Please note that this function will panic if the fractional value is not smaller than
 /// the maximum number of fractions allowed for the particular resolution.
 /// (e.g. passing 270 when the resolution only allows 255 values).
-#[inline]
 pub fn convert_fractional_part_to_ns(fractional_part: FractionalPart) -> u64 {
     let div = fractional_res_to_div(fractional_part.0);
     assert!(fractional_part.1 < div);
     10_u64.pow(9) * fractional_part.1 as u64 / div as u64
 }
 
-#[inline(always)]
 pub const fn fractional_res_to_div(res: FractionalResolution) -> u32 {
     2_u32.pow(8 * res as u32) - 1
 }
@@ -72,20 +64,10 @@ pub fn fractional_part_from_subsec_ns(
     if ns > sec_as_ns {
         panic!("passed nanosecond value larger than 1 second");
     }
-    let resolution = fractional_res_to_div(res) as u64;
-    // Use integer division because this can reduce code size of really small systems.
     // First determine the nanoseconds for the smallest segment given the resolution.
-    // Then divide by that to find out the fractional part. For the calculation of the smallest
-    // fraction, we perform a ceiling division. This is because if we would use the default
-    // flooring division, we would divide by a smaller value, thereby allowing the calculation to
-    // invalid fractional parts which are too large. For the division of the nanoseconds by the
-    // smallest fraction, a flooring division is correct.
-    // The multiplication with 100000 is necessary to avoid precision loss during integer division.
-    // TODO: Floating point division might actually be faster option, but requires additional
-    //       code on small embedded systems..
-    let fractional_part = ns * 100000 / ((sec_as_ns * 100000 + resolution) / resolution);
-    // Floating point division.
-    //let fractional_part = (ns as f64 / ((sec_as_ns as f64) / resolution as f64)).floor() as u32;
+    // Then divide by that to find out the fractional part. An integer division floors
+    // which is what we want here.
+    let fractional_part = ns / (sec_as_ns / fractional_res_to_div(res) as u64);
     Some(FractionalPart(res, fractional_part as u32))
 }
 
@@ -94,7 +76,6 @@ pub fn fractional_part_from_subsec_ns(
 pub enum CucError {
     InvalidCounterWidth(u8),
     InvalidFractionResolution(FractionalResolution),
-    /// Invalid counter supplied.
     InvalidCounter(u8, u64),
     InvalidFractions(FractionalResolution, u64),
 }
@@ -234,10 +215,9 @@ impl TimeProviderCcsdsEpoch {
     /// The counter width will always be set to 4 bytes because the normal CCSDS epoch will overflow
     /// when using less than that.
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
     pub fn from_now(fraction_resolution: FractionalResolution) -> Result<Self, StdTimestampError> {
         let now = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)?;
-        let ccsds_epoch = unix_epoch_to_ccsds_epoch(now.as_secs() as i64);
+        let ccsds_epoch = unix_epoch_to_ccsds_epoch(now.as_secs());
         if fraction_resolution == FractionalResolution::Seconds {
             return Ok(Self::new(ccsds_epoch as u32));
         }
@@ -250,10 +230,9 @@ impl TimeProviderCcsdsEpoch {
     /// Updates the current time stamp from the current time. The fractional field width remains
     /// the same and will be updated accordingly.
     #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
     pub fn update_from_now(&mut self) -> Result<(), StdTimestampError> {
         let now = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)?;
-        self.counter.1 = unix_epoch_to_ccsds_epoch(now.as_secs() as i64) as u32;
+        self.counter.1 = unix_epoch_to_ccsds_epoch(now.as_secs()) as u32;
         if self.fractions.is_some() {
             self.fractions = fractional_part_from_subsec_ns(
                 self.fractions.unwrap().0,
@@ -263,42 +242,6 @@ impl TimeProviderCcsdsEpoch {
         Ok(())
     }
 
-    pub fn from_date_time(
-        dt: &DateTime<Utc>,
-        res: FractionalResolution,
-    ) -> Result<Self, TimestampError> {
-        // Year before CCSDS epoch is invalid.
-        if dt.year() < 1958 {
-            return Err(TimestampError::DateBeforeCcsdsEpoch(*dt));
-        }
-        Self::new_generic(
-            WidthCounterPair(4, dt.timestamp() as u32),
-            fractional_part_from_subsec_ns(res, dt.timestamp_subsec_nanos() as u64),
-        )
-        .map_err(|e| e.into())
-    }
-
-    pub fn from_unix_stamp(
-        unix_stamp: &UnixTimestamp,
-        res: FractionalResolution,
-    ) -> Result<Self, TimestampError> {
-        let ccsds_epoch = unix_epoch_to_ccsds_epoch(unix_stamp.unix_seconds);
-        // Negative CCSDS epoch is invalid.
-        if ccsds_epoch < 0 {
-            return Err(TimestampError::DateBeforeCcsdsEpoch(
-                unix_stamp.as_date_time().unwrap(),
-            ));
-        }
-        if ccsds_epoch > u32::MAX as i64 {
-            return Err(CucError::InvalidCounter(4, ccsds_epoch as u64).into());
-        }
-        let mut fractions = None;
-        if let Some(subsec_millis) = unix_stamp.subsecond_millis {
-            fractions = fractional_part_from_subsec_ns(res, subsec_millis as u64 * 10_u64.pow(6));
-        }
-        Self::new_generic(WidthCounterPair(4, ccsds_epoch as u32), fractions).map_err(|e| e.into())
-    }
-
     pub fn new_u16_counter(counter: u16) -> Self {
         // These values are definitely valid, so it is okay to unwrap here.
         Self::new_generic(WidthCounterPair(2, counter as u32), None).unwrap()
@@ -357,7 +300,7 @@ impl TimeProviderCcsdsEpoch {
     }
 
     fn build_p_field(counter_width: u8, fractions_width: Option<FractionalResolution>) -> u8 {
-        let mut pfield = P_FIELD_BASE;
+        let mut pfield = (CcsdsTimeCodes::CucCcsdsEpoch as u8) << 4;
         if !(1..=4).contains(&counter_width) {
             // Okay to panic here, this function is private and all input values should
             // have been sanitized
@@ -395,11 +338,6 @@ impl TimeProviderCcsdsEpoch {
         pfield & 0b11
     }
 
-    #[inline]
-    fn unix_seconds(&self) -> i64 {
-        ccsds_epoch_to_unix_epoch(self.counter.1 as i64)
-    }
-
     /// This returns the length of the individual components of the CUC timestamp in addition
     /// to the total size.
     ///
@@ -592,19 +530,10 @@ impl CcsdsTimeProvider for TimeProviderCcsdsEpoch {
         CcsdsTimeCodes::CucCcsdsEpoch
     }
 
+    /// Please note that this function only works as intended if the time counter resolution
+    /// is one second.
     fn unix_seconds(&self) -> i64 {
-        self.unix_seconds()
-    }
-
-    fn subsecond_millis(&self) -> Option<u16> {
-        if let Some(fractions) = self.fractions {
-            if fractions.0 == FractionalResolution::Seconds {
-                return None;
-            }
-            // Rounding down here is the correct approach.
-            return Some((convert_fractional_part_to_ns(fractions) / 10_u32.pow(6) as u64) as u16);
-        }
-        None
+        ccsds_epoch_to_unix_epoch(self.counter.1 as u64) as i64
     }
 
     fn date_time(&self) -> Option<DateTime<Utc>> {
@@ -621,81 +550,6 @@ impl CcsdsTimeProvider for TimeProviderCcsdsEpoch {
     }
 }
 
-fn get_provider_values_after_duration_addition(
-    provider: &TimeProviderCcsdsEpoch,
-    duration: Duration,
-) -> (u32, Option<FractionalPart>) {
-    let mut new_counter = provider.counter.1;
-    let subsec_nanos = duration.subsec_nanos();
-    let mut increment_counter = |amount: u32| {
-        let mut sum: u64 = 0;
-        let mut counter_inc_handler = |max_val: u64| {
-            sum = new_counter as u64 + amount as u64;
-            if sum >= max_val {
-                new_counter = (sum % max_val) as u32;
-                return;
-            }
-            new_counter = sum as u32;
-        };
-        match provider.counter.0 {
-            1 => counter_inc_handler(u8::MAX as u64),
-            2 => counter_inc_handler(u16::MAX as u64),
-            3 => counter_inc_handler((2_u32.pow(24) - 1) as u64),
-            4 => counter_inc_handler(u32::MAX as u64),
-            _ => {
-                // Should never happen
-                panic!("invalid counter width")
-            }
-        }
-    };
-    let fractional_part = if let Some(fractional_part) = &provider.fractions {
-        let fractional_increment =
-            fractional_part_from_subsec_ns(fractional_part.0, subsec_nanos as u64).unwrap();
-        let mut increment_fractions = |resolution| {
-            let mut new_fractions = fractional_part.1 + fractional_increment.1;
-            let max_fractions = fractional_res_to_div(resolution);
-            if new_fractions > max_fractions {
-                increment_counter(1);
-                new_fractions -= max_fractions;
-            }
-            Some(FractionalPart(resolution, new_fractions))
-        };
-        match fractional_increment.0 {
-            FractionalResolution::Seconds => None,
-            _ => increment_fractions(fractional_increment.0),
-        }
-    } else {
-        None
-    };
-    increment_counter(duration.as_secs() as u32);
-    (new_counter, fractional_part)
-}
-
-impl AddAssign<Duration> for TimeProviderCcsdsEpoch {
-    fn add_assign(&mut self, duration: Duration) {
-        let (new_counter, new_fractional_part) =
-            get_provider_values_after_duration_addition(self, duration);
-        self.counter.1 = new_counter;
-        if self.fractions.is_some() {
-            self.fractions = new_fractional_part;
-        }
-    }
-}
-
-impl Add<Duration> for TimeProviderCcsdsEpoch {
-    type Output = Self;
-
-    fn add(self, duration: Duration) -> Self::Output {
-        let (new_counter, new_fractional_part) =
-            get_provider_values_after_duration_addition(&self, duration);
-        if let Some(fractional_part) = new_fractional_part {
-            // The generated fractional part should always be valid, so its okay to unwrap here.
-            return Self::new_with_fractions(new_counter, fractional_part).unwrap();
-        }
-        Self::new(new_counter)
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -732,7 +586,6 @@ mod tests {
         let zero_cuc = zero_cuc.unwrap();
         let res = zero_cuc.write_to_bytes(&mut buf);
         assert!(res.is_ok());
-        assert!(zero_cuc.subsecond_millis().is_none());
         assert_eq!(zero_cuc.len_as_bytes(), 5);
         assert_eq!(pfield_len(buf[0]), 1);
         let written = res.unwrap();
@@ -1014,39 +867,29 @@ mod tests {
     #[test]
     fn fractional_part_formula() {
         let fractional_part =
-            fractional_part_from_subsec_ns(FractionalResolution::FourMs, 7843138).unwrap();
-        assert_eq!(fractional_part.1, 2);
+            7843137 / (10_u64.pow(9) / fractional_res_to_div(FractionalResolution::FourMs) as u64);
+        assert_eq!(fractional_part, 2);
     }
 
     #[test]
     fn fractional_part_formula_2() {
         let fractional_part =
-            fractional_part_from_subsec_ns(FractionalResolution::FourMs, 12000000).unwrap();
-        assert_eq!(fractional_part.1, 3);
+            12000000 / (10_u64.pow(9) / fractional_res_to_div(FractionalResolution::FourMs) as u64);
+        assert_eq!(fractional_part, 3);
     }
 
     #[test]
     fn fractional_part_formula_3() {
-        let one_fraction_with_width_two_in_ns =
-            10_u64.pow(9) as f64 / (2_u32.pow(8 * 2) - 1) as f64;
-        assert_eq!(one_fraction_with_width_two_in_ns.ceil(), 15260.0);
-        let hundred_fractions_and_some =
-            (100.0 * one_fraction_with_width_two_in_ns).floor() as u64 + 7000;
-        let fractional_part = fractional_part_from_subsec_ns(
-            FractionalResolution::FifteenUs,
-            hundred_fractions_and_some,
-        )
-        .unwrap();
-        assert_eq!(fractional_part.1, 100);
-        // Using exactly 101.0 can yield values which will later be rounded down to 100
-        let hundred_and_one_fractions =
-            (101.001 * one_fraction_with_width_two_in_ns).floor() as u64;
-        let fractional_part = fractional_part_from_subsec_ns(
-            FractionalResolution::FifteenUs,
-            hundred_and_one_fractions,
-        )
-        .unwrap();
-        assert_eq!(fractional_part.1, 101);
+        let one_fraction_with_width_two_in_ns = 10_u64.pow(9) / (2_u32.pow(8 * 2) - 1) as u64;
+        assert_eq!(one_fraction_with_width_two_in_ns, 15259);
+        let hundred_fractions_and_some = 100 * one_fraction_with_width_two_in_ns + 7000;
+        let fractional_part = hundred_fractions_and_some
+            / (10_u64.pow(9) / fractional_res_to_div(FractionalResolution::FifteenUs) as u64);
+        assert_eq!(fractional_part, 100);
+        let hundred_and_one_fractions = 101 * one_fraction_with_width_two_in_ns;
+        let fractional_part = hundred_and_one_fractions
+            / (10_u64.pow(9) / fractional_res_to_div(FractionalResolution::FifteenUs) as u64);
+        assert_eq!(fractional_part, 101);
     }
 
     #[test]
@@ -1071,41 +914,4 @@ mod tests {
         let res = stamp.update_from_now();
         assert!(res.is_ok());
     }
-
-    #[test]
-    fn assert_largest_fractions() {
-        let fractions =
-            fractional_part_from_subsec_ns(FractionalResolution::SixtyNs, 10u64.pow(9) - 1)
-                .unwrap();
-        // The value can not be larger than representable by 3 bytes
-        // Assert that the maximum resolution can be reached
-        assert_eq!(fractions.1, 2_u32.pow(3 * 8) - 2);
-    }
-
-    #[test]
-    fn add_duration_basic() {
-        let mut cuc_stamp = TimeProviderCcsdsEpoch::new(200);
-        cuc_stamp.set_fractional_resolution(FractionalResolution::FifteenUs);
-        let duration = Duration::from_millis(2500);
-        cuc_stamp += duration;
-        assert_eq!(cuc_stamp.width_counter_pair().1, 202);
-        let fractions = cuc_stamp.width_fractions_pair().unwrap().1;
-        let expected_val =
-            (0.5 * fractional_res_to_div(FractionalResolution::FifteenUs) as f64).floor() as u32;
-        assert_eq!(fractions, expected_val);
-        let cuc_stamp2 = cuc_stamp + Duration::from_millis(501);
-        // What I would roughly expect
-        assert_eq!(cuc_stamp2.counter.1, 203);
-        assert!(cuc_stamp2.fractions.unwrap().1 < 100);
-        assert!(cuc_stamp2.subsecond_millis().unwrap() <= 1);
-    }
-
-    #[test]
-    fn add_duration_overflow() {
-        let mut cuc_stamp =
-            TimeProviderCcsdsEpoch::new_generic(WidthCounterPair(1, 255), None).unwrap();
-        let duration = Duration::from_secs(10);
-        cuc_stamp += duration;
-        assert_eq!(cuc_stamp.counter.1, 10);
-    }
 }

src/time/mod.rs

@@ -20,7 +20,6 @@ pub mod cuc;
 
 pub const DAYS_CCSDS_TO_UNIX: i32 = -4383;
 pub const SECONDS_PER_DAY: u32 = 86400;
-pub const MS_PER_DAY: u32 = SECONDS_PER_DAY * 1000;
 
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
@@ -56,7 +55,6 @@ pub fn ccsds_time_code_from_p_field(pfield: u8) -> Result<CcsdsTimeCodes, u8> {
 
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[non_exhaustive]
 pub enum TimestampError {
     /// Contains tuple where first value is the expected time code and the second
     /// value is the found raw value
@@ -64,7 +62,6 @@ pub enum TimestampError {
     ByteConversionError(ByteConversionError),
     CdsError(cds::CdsError),
     CucError(cuc::CucError),
-    DateBeforeCcsdsEpoch(DateTime<Utc>),
     CustomEpochNotSupported,
 }
 
@@ -121,9 +118,6 @@ impl Display for TimestampError {
             TimestampError::ByteConversionError(e) => {
                 write!(f, "byte conversion error {}", e)
             }
-            TimestampError::DateBeforeCcsdsEpoch(e) => {
-                write!(f, "datetime with date before ccsds epoch: {}", e)
-            }
             TimestampError::CustomEpochNotSupported => {
                 write!(f, "custom epochs are not supported")
             }
@@ -170,12 +164,12 @@ pub const fn ccsds_to_unix_days(ccsds_days: i64) -> 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.
-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)
+pub const fn unix_epoch_to_ccsds_epoch(unix_epoch: u64) -> u64 {
+    (unix_epoch as i64 - (DAYS_CCSDS_TO_UNIX as i64 * SECONDS_PER_DAY as i64)) as u64
 }
 
-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)
+pub const fn ccsds_epoch_to_unix_epoch(ccsds_epoch: u64) -> u64 {
+    (ccsds_epoch as i64 + (DAYS_CCSDS_TO_UNIX as i64 * SECONDS_PER_DAY as i64)) as u64
 }
 
 #[cfg(feature = "std")]
@@ -205,9 +199,6 @@ pub trait TimeReader {
 }
 
 /// Trait for generic CCSDS time providers.
-///
-/// The UNIX helper methods and the [Self::date_time] method are not strictly necessary but extremely
-/// practical because they are a very common and simple exchange format for time information.
 pub trait CcsdsTimeProvider {
     fn len_as_bytes(&self) -> usize;
 
@@ -217,99 +208,10 @@ pub trait CcsdsTimeProvider {
     /// in big endian format.
     fn p_field(&self) -> (usize, [u8; 2]);
     fn ccdsd_time_code(&self) -> CcsdsTimeCodes;
-
     fn unix_seconds(&self) -> i64;
-    fn subsecond_millis(&self) -> Option<u16>;
-    fn unix_stamp(&self) -> UnixTimestamp {
-        UnixTimestamp {
-            unix_seconds: self.unix_seconds(),
-            subsecond_millis: self.subsecond_millis(),
-        }
-    }
-
     fn date_time(&self) -> Option<DateTime<Utc>>;
 }
 
-/// UNIX timestamp: Elapsed seconds since 01-01-1970 00:00:00.
-///
-/// Also can optionally include subsecond millisecond for greater accuracy.
-#[derive(Default, Debug, Copy, Clone, PartialEq, Eq)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub struct UnixTimestamp {
-    pub unix_seconds: i64,
-    subsecond_millis: Option<u16>,
-}
-
-impl UnixTimestamp {
-    /// Returns none if the subsecond millisecond value is larger than 999.
-    pub fn new(unix_seconds: i64, subsec_millis: u16) -> Option<Self> {
-        if subsec_millis > 999 {
-            return None;
-        }
-        Some(Self {
-            unix_seconds,
-            subsecond_millis: Some(subsec_millis),
-        })
-    }
-
-    pub const fn const_new(unix_seconds: i64, subsec_millis: u16) -> Self {
-        if subsec_millis > 999 {
-            panic!("subsec milliseconds exceeds 999");
-        }
-        Self {
-            unix_seconds,
-            subsecond_millis: Some(subsec_millis),
-        }
-    }
-
-    pub fn new_only_seconds(unix_seconds: i64) -> Self {
-        Self {
-            unix_seconds,
-            subsecond_millis: None,
-        }
-    }
-
-    pub fn subsecond_millis(&self) -> Option<u16> {
-        self.subsecond_millis
-    }
-
-    #[cfg(feature = "std")]
-    #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
-    pub fn from_now() -> Result<Self, SystemTimeError> {
-        let now = SystemTime::now().duration_since(SystemTime::UNIX_EPOCH)?;
-        let epoch = now.as_secs();
-        Ok(UnixTimestamp {
-            unix_seconds: epoch as i64,
-            subsecond_millis: Some(now.subsec_millis() as u16),
-        })
-    }
-
-    #[inline]
-    pub fn unix_seconds_f64(&self) -> f64 {
-        let mut secs = self.unix_seconds as f64;
-        if let Some(subsec_millis) = self.subsecond_millis {
-            secs += subsec_millis as f64 / 1000.0;
-        }
-        secs
-    }
-
-    pub fn as_date_time(&self) -> LocalResult<DateTime<Utc>> {
-        Utc.timestamp_opt(
-            self.unix_seconds,
-            self.subsecond_millis.unwrap_or(0) as u32 * 10_u32.pow(6),
-        )
-    }
-}
-
-impl From<DateTime<Utc>> for UnixTimestamp {
-    fn from(value: DateTime<Utc>) -> Self {
-        Self {
-            unix_seconds: value.timestamp(),
-            subsecond_millis: Some(value.timestamp_subsec_millis() as u16),
-        }
-    }
-}
-
 #[cfg(all(test, feature = "std"))]
 mod tests {
     use super::*;
@@ -332,30 +234,10 @@ mod tests {
             .duration_since(SystemTime::UNIX_EPOCH)
             .unwrap();
         let unix_epoch = now.as_secs();
-        let ccsds_epoch = unix_epoch_to_ccsds_epoch(now.as_secs() as i64) as u64;
+        let ccsds_epoch = unix_epoch_to_ccsds_epoch(now.as_secs());
         assert!(ccsds_epoch > unix_epoch);
         assert_eq!((ccsds_epoch - unix_epoch) % SECONDS_PER_DAY as u64, 0);
         let days_diff = (ccsds_epoch - unix_epoch) / SECONDS_PER_DAY as u64;
         assert_eq!(days_diff, -DAYS_CCSDS_TO_UNIX as u64);
     }
-
-    #[test]
-    fn basic_unix_stamp_test() {
-        let stamp = UnixTimestamp::new_only_seconds(-200);
-        assert_eq!(stamp.unix_seconds, -200);
-        assert!(stamp.subsecond_millis().is_none());
-        let stamp = UnixTimestamp::new_only_seconds(250);
-        assert_eq!(stamp.unix_seconds, 250);
-        assert!(stamp.subsecond_millis().is_none());
-    }
-
-    #[test]
-    fn basic_float_unix_stamp_test() {
-        let stamp = UnixTimestamp::new(500, 600).unwrap();
-        assert!(stamp.subsecond_millis.is_some());
-        assert_eq!(stamp.unix_seconds, 500);
-        let subsec_millis = stamp.subsecond_millis().unwrap();
-        assert_eq!(subsec_millis, 600);
-        assert!((500.6 - stamp.unix_seconds_f64()).abs() < 0.0001);
-    }
 }

src/tm.rs

@@ -48,7 +48,7 @@ pub mod zc {
 
     pub struct PusTmSecHeader<'slice> {
         pub(crate) zc_header: PusTmSecHeaderWithoutTimestamp,
-        pub(crate) timestamp: Option<&'slice [u8]>,
+        pub(crate) timestamp: &'slice [u8],
     }
 
     impl TryFrom<crate::tm::PusTmSecondaryHeader<'_>> for PusTmSecHeaderWithoutTimestamp {
@@ -108,24 +108,27 @@ pub mod zc {
 
 #[derive(PartialEq, Eq, Copy, Clone, Debug)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub struct PusTmSecondaryHeader<'stamp> {
+pub struct PusTmSecondaryHeader<'slice> {
     pus_version: PusVersion,
     pub sc_time_ref_status: u8,
     pub service: u8,
     pub subservice: u8,
     pub msg_counter: u16,
     pub dest_id: u16,
-    pub timestamp: Option<&'stamp [u8]>,
+    pub time_stamp: &'slice [u8],
 }
 
-impl<'stamp> PusTmSecondaryHeader<'stamp> {
-    pub fn new_simple(service: u8, subservice: u8, timestamp: &'stamp [u8]) -> Self {
-        Self::new(service, subservice, 0, 0, Some(timestamp))
-    }
-
-    /// Like [Self::new_simple] but without a timestamp.
-    pub fn new_simple_no_timestamp(service: u8, subservice: u8) -> Self {
-        Self::new(service, subservice, 0, 0, None)
+impl<'slice> PusTmSecondaryHeader<'slice> {
+    pub fn new_simple(service: u8, subservice: u8, time_stamp: &'slice [u8]) -> Self {
+        PusTmSecondaryHeader {
+            pus_version: PusVersion::PusC,
+            sc_time_ref_status: 0,
+            service,
+            subservice,
+            msg_counter: 0,
+            dest_id: 0,
+            time_stamp,
+        }
     }
 
     pub fn new(
@@ -133,7 +136,7 @@ impl<'stamp> PusTmSecondaryHeader<'stamp> {
         subservice: u8,
         msg_counter: u16,
         dest_id: u16,
-        timestamp: Option<&'stamp [u8]>,
+        time_stamp: &'slice [u8],
     ) -> Self {
         PusTmSecondaryHeader {
             pus_version: PusVersion::PusC,
@@ -142,7 +145,7 @@ impl<'stamp> PusTmSecondaryHeader<'stamp> {
             subservice,
             msg_counter,
             dest_id,
-            timestamp,
+            time_stamp,
         }
     }
 }
@@ -184,7 +187,7 @@ 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(),
-            timestamp: sec_header.timestamp,
+            time_stamp: sec_header.timestamp,
         })
     }
 }
@@ -198,26 +201,21 @@ impl<'slice> TryFrom<zc::PusTmSecHeader<'slice>> for PusTmSecondaryHeader<'slice
 /// provider like [postcard](https://docs.rs/postcard/latest/postcard/).
 ///
 /// There is no spare bytes support yet.
-///
-/// # Lifetimes
-///
-/// * `'src_data` - Life time of a buffer where the user provided time stamp and source data will
-///    be serialized into.
 #[derive(PartialEq, Eq, Debug, Copy, Clone)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-pub struct PusTm<'src_data> {
+pub struct PusTm<'slice> {
     pub sp_header: SpHeader,
-    pub sec_header: PusTmSecondaryHeader<'src_data>,
+    pub sec_header: PusTmSecondaryHeader<'slice>,
     /// If this is set to false, a manual call to [PusTm::calc_own_crc16] or
     /// [PusTm::update_packet_fields] is necessary for the serialized or cached CRC16 to be valid.
     pub calc_crc_on_serialization: bool,
     #[cfg_attr(feature = "serde", serde(skip))]
-    raw_data: Option<&'src_data [u8]>,
-    source_data: Option<&'src_data [u8]>,
+    raw_data: Option<&'slice [u8]>,
+    source_data: Option<&'slice [u8]>,
     crc16: Option<u16>,
 }
 
-impl<'src_data> PusTm<'src_data> {
+impl<'slice> PusTm<'slice> {
     /// Generates a new struct instance.
     ///
     /// # Arguments
@@ -232,8 +230,8 @@ impl<'src_data> PusTm<'src_data> {
     ///     the correct value to this field manually
     pub fn new(
         sp_header: &mut SpHeader,
-        sec_header: PusTmSecondaryHeader<'src_data>,
-        source_data: Option<&'src_data [u8]>,
+        sec_header: PusTmSecondaryHeader<'slice>,
+        source_data: Option<&'slice [u8]>,
         set_ccsds_len: bool,
     ) -> Self {
         sp_header.set_packet_type(PacketType::Tm);
@@ -254,20 +252,18 @@ impl<'src_data> PusTm<'src_data> {
 
     pub fn len_packed(&self) -> usize {
         let mut length = PUS_TM_MIN_LEN_WITHOUT_SOURCE_DATA;
-        if let Some(timestamp) = self.sec_header.timestamp {
-            length += timestamp.len();
-        }
+        length += self.sec_header.time_stamp.len();
         if let Some(src_data) = self.source_data {
             length += src_data.len();
         }
         length
     }
 
-    pub fn timestamp(&self) -> Option<&'src_data [u8]> {
-        self.sec_header.timestamp
+    pub fn time_stamp(&self) -> &'slice [u8] {
+        self.sec_header.time_stamp
     }
 
-    pub fn source_data(&self) -> Option<&'src_data [u8]> {
+    pub fn source_data(&self) -> Option<&'slice [u8]> {
         self.source_data
     }
 
@@ -303,9 +299,7 @@ impl<'src_data> PusTm<'src_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());
-        if let Some(stamp) = self.sec_header.timestamp {
-            digest.update(stamp);
-        }
+        digest.update(self.sec_header.time_stamp);
         if let Some(src_data) = self.source_data {
             digest.update(src_data);
         }
@@ -338,11 +332,9 @@ impl<'src_data> PusTm<'src_data> {
             .write_to_bytes(&mut slice[curr_idx..curr_idx + sec_header_len])
             .ok_or(ByteConversionError::ZeroCopyToError)?;
         curr_idx += sec_header_len;
-        if let Some(timestamp) = self.sec_header.timestamp {
-            let timestamp_len = timestamp.len();
-            slice[curr_idx..curr_idx + timestamp_len].copy_from_slice(timestamp);
-            curr_idx += timestamp_len;
-        }
+        let timestamp_len = self.sec_header.time_stamp.len();
+        slice[curr_idx..curr_idx + timestamp_len].copy_from_slice(self.sec_header.time_stamp);
+        curr_idx += timestamp_len;
         if let Some(src_data) = self.source_data {
             slice[curr_idx..curr_idx + src_data.len()].copy_from_slice(src_data);
             curr_idx += src_data.len();
@@ -364,10 +356,8 @@ impl<'src_data> PusTm<'src_data> {
     #[cfg_attr(doc_cfg, doc(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 = PUS_TM_MIN_LEN_WITHOUT_SOURCE_DATA;
-        if let Some(timestamp) = self.sec_header.timestamp {
-            appended_len += timestamp.len();
-        }
+        let mut appended_len =
+            PUS_TM_MIN_LEN_WITHOUT_SOURCE_DATA + self.sec_header.time_stamp.len();
         if let Some(src_data) = self.source_data {
             appended_len += src_data.len();
         };
@@ -379,10 +369,8 @@ impl<'src_data> PusTm<'src_data> {
         let sec_header = zc::PusTmSecHeaderWithoutTimestamp::try_from(self.sec_header).unwrap();
         vec.extend_from_slice(sec_header.as_bytes());
         ser_len += sec_header.as_bytes().len();
-        if let Some(timestamp) = self.sec_header.timestamp {
-            ser_len += timestamp.len();
-            vec.extend_from_slice(timestamp);
-        }
+        vec.extend_from_slice(self.sec_header.time_stamp);
+        ser_len += self.sec_header.time_stamp.len();
         if let Some(src_data) = self.source_data {
             vec.extend_from_slice(src_data);
             ser_len += src_data.len();
@@ -402,7 +390,7 @@ impl<'src_data> PusTm<'src_data> {
     /// the instance and the found byte length of the packet. The timestamp length needs to be
     /// known beforehand.
     pub fn from_bytes(
-        slice: &'src_data [u8],
+        slice: &'slice [u8],
         timestamp_len: usize,
     ) -> Result<(Self, usize), PusError> {
         let raw_data_len = slice.len();
@@ -421,13 +409,9 @@ impl<'src_data> PusTm<'src_data> {
         )
         .ok_or(ByteConversionError::ZeroCopyFromError)?;
         current_idx += PUC_TM_MIN_SEC_HEADER_LEN;
-        let mut timestamp = None;
-        if timestamp_len > 0 {
-            timestamp = Some(&slice[current_idx..current_idx + timestamp_len]);
-        }
         let zc_sec_header_wrapper = zc::PusTmSecHeader {
             zc_header: sec_header_zc,
-            timestamp,
+            timestamp: &slice[current_idx..current_idx + timestamp_len],
         };
         current_idx += timestamp_len;
         let raw_data = &slice[0..total_len];
@@ -484,33 +468,33 @@ mod tests {
     use crate::ecss::PusVersion::PusC;
     use crate::SpHeader;
 
-    fn base_ping_reply_full_ctor(timestamp: &[u8]) -> PusTm {
+    fn base_ping_reply_full_ctor(time_stamp: &[u8]) -> PusTm {
         let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
-        let tc_header = PusTmSecondaryHeader::new_simple(17, 2, &timestamp);
+        let tc_header = PusTmSecondaryHeader::new_simple(17, 2, &time_stamp);
         PusTm::new(&mut sph, tc_header, None, true)
     }
 
-    fn base_hk_reply<'a>(timestamp: &'a [u8], src_data: &'a [u8]) -> PusTm<'a> {
+    fn base_hk_reply<'a>(time_stamp: &'a [u8], src_data: &'a [u8]) -> PusTm<'a> {
         let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
-        let tc_header = PusTmSecondaryHeader::new_simple(3, 5, &timestamp);
+        let tc_header = PusTmSecondaryHeader::new_simple(3, 5, &time_stamp);
         PusTm::new(&mut sph, tc_header, Some(src_data), true)
     }
 
-    fn dummy_timestamp() -> &'static [u8] {
+    fn dummy_time_stamp() -> &'static [u8] {
         return &[0, 1, 2, 3, 4, 5, 6];
     }
 
     #[test]
     fn test_basic() {
-        let timestamp = dummy_timestamp();
-        let pus_tm = base_ping_reply_full_ctor(&timestamp);
-        verify_ping_reply(&pus_tm, false, 22, dummy_timestamp());
+        let time_stamp = dummy_time_stamp();
+        let pus_tm = base_ping_reply_full_ctor(&time_stamp);
+        verify_ping_reply(&pus_tm, false, 22, dummy_time_stamp());
     }
 
     #[test]
     fn test_serialization_no_source_data() {
-        let timestamp = dummy_timestamp();
-        let pus_tm = base_ping_reply_full_ctor(&timestamp);
+        let time_stamp = dummy_time_stamp();
+        let pus_tm = base_ping_reply_full_ctor(&time_stamp);
         let mut buf: [u8; 32] = [0; 32];
         let ser_len = pus_tm
             .write_to_bytes(&mut buf)
@@ -522,7 +506,7 @@ mod tests {
     #[test]
     fn test_serialization_with_source_data() {
         let src_data = [1, 2, 3];
-        let hk_reply = base_hk_reply(dummy_timestamp(), &src_data);
+        let hk_reply = base_hk_reply(dummy_time_stamp(), &src_data);
         let mut buf: [u8; 32] = [0; 32];
         let ser_len = hk_reply
             .write_to_bytes(&mut buf)
@@ -535,8 +519,8 @@ mod tests {
 
     #[test]
     fn test_setters() {
-        let timestamp = dummy_timestamp();
-        let mut pus_tm = base_ping_reply_full_ctor(&timestamp);
+        let time_stamp = dummy_time_stamp();
+        let mut pus_tm = base_ping_reply_full_ctor(&time_stamp);
         pus_tm.set_sc_time_ref_status(0b1010);
         pus_tm.set_dest_id(0x7fff);
         pus_tm.set_msg_counter(0x1f1f);
@@ -549,8 +533,8 @@ mod tests {
 
     #[test]
     fn test_deserialization_no_source_data() {
-        let timestamp = dummy_timestamp();
-        let pus_tm = base_ping_reply_full_ctor(&timestamp);
+        let time_stamp = dummy_time_stamp();
+        let pus_tm = base_ping_reply_full_ctor(&time_stamp);
         let mut buf: [u8; 32] = [0; 32];
         let ser_len = pus_tm
             .write_to_bytes(&mut buf)
@@ -558,13 +542,13 @@ mod tests {
         assert_eq!(ser_len, 22);
         let (tm_deserialized, size) = PusTm::from_bytes(&buf, 7).expect("Deserialization failed");
         assert_eq!(ser_len, size);
-        verify_ping_reply(&tm_deserialized, false, 22, dummy_timestamp());
+        verify_ping_reply(&tm_deserialized, false, 22, dummy_time_stamp());
     }
 
     #[test]
     fn test_manual_field_update() {
         let mut sph = SpHeader::tm_unseg(0x123, 0x234, 0).unwrap();
-        let tc_header = PusTmSecondaryHeader::new_simple(17, 2, dummy_timestamp());
+        let tc_header = PusTmSecondaryHeader::new_simple(17, 2, dummy_time_stamp());
         let mut tm = PusTm::new(&mut sph, tc_header, None, false);
         tm.calc_crc_on_serialization = false;
         assert_eq!(tm.data_len(), 0x00);
@@ -584,8 +568,8 @@ mod tests {
 
     #[test]
     fn test_target_buf_too_small() {
-        let timestamp = dummy_timestamp();
-        let pus_tm = base_ping_reply_full_ctor(&timestamp);
+        let time_stamp = dummy_time_stamp();
+        let pus_tm = base_ping_reply_full_ctor(&time_stamp);
         let mut buf: [u8; 16] = [0; 16];
         let res = pus_tm.write_to_bytes(&mut buf);
         assert!(res.is_err());
@@ -608,8 +592,8 @@ mod tests {
     #[test]
     #[cfg(feature = "alloc")]
     fn test_append_to_vec() {
-        let timestamp = dummy_timestamp();
-        let pus_tm = base_ping_reply_full_ctor(&timestamp);
+        let time_stamp = dummy_time_stamp();
+        let pus_tm = base_ping_reply_full_ctor(&time_stamp);
         let mut vec = Vec::new();
         let res = pus_tm.append_to_vec(&mut vec);
         assert!(res.is_ok());
@@ -621,7 +605,7 @@ mod tests {
     #[cfg(feature = "alloc")]
     fn test_append_to_vec_with_src_data() {
         let src_data = [1, 2, 3];
-        let hk_reply = base_hk_reply(dummy_timestamp(), &src_data);
+        let hk_reply = base_hk_reply(dummy_time_stamp(), &src_data);
         let mut vec = Vec::new();
         vec.push(4);
         let res = hk_reply.append_to_vec(&mut vec);
@@ -650,7 +634,7 @@ mod tests {
         assert_eq!(buf[11], 0x00);
         assert_eq!(buf[12], 0x00);
         // Timestamp
-        assert_eq!(&buf[13..20], dummy_timestamp());
+        assert_eq!(&buf[13..20], dummy_time_stamp());
         let mut digest = CRC_CCITT_FALSE.digest();
         digest.update(&buf[0..20]);
         let crc16 = digest.finalize();
@@ -662,14 +646,14 @@ mod tests {
         tm: &PusTm,
         has_user_data: bool,
         exp_full_len: usize,
-        exp_timestamp: &[u8],
+        exp_time_stamp: &[u8],
     ) {
         assert!(tm.is_tm());
         assert_eq!(PusPacket::service(tm), 17);
         assert_eq!(PusPacket::subservice(tm), 2);
         assert!(tm.sec_header_flag());
         assert_eq!(tm.len_packed(), exp_full_len);
-        assert_eq!(tm.timestamp().unwrap(), exp_timestamp);
+        assert_eq!(tm.time_stamp(), exp_time_stamp);
         if has_user_data {
             assert!(!tm.user_data().is_none());
         }