Major example update

- Increased example modularization by moving the majority
  of app logic inside dedicated modules
- Added a new `dyn_tmtc` feature for the satrs-example which is used
  to configure the heap as the backing store for TMTC packages instead
  of static stores.
- Added dedicated satrs-example chapter in satrs-book

satrs-example/src/tm_funnel.rs

@@ -0,0 +1,145 @@
+use std::{
+    collections::HashMap,
+    sync::mpsc::{Receiver, Sender},
+};
+
+use satrs_core::{
+    pool::{PoolProviderMemInPlace, StoreAddr},
+    seq_count::{CcsdsSimpleSeqCountProvider, SequenceCountProviderCore},
+    spacepackets::{
+        ecss::{tm::PusTmZeroCopyWriter, PusPacket},
+        time::cds::MIN_CDS_FIELD_LEN,
+        CcsdsPacket,
+    },
+    tmtc::tm_helper::SharedTmStore,
+};
+
+use crate::tcp::SyncTcpTmSource;
+
+#[derive(Default)]
+pub struct CcsdsSeqCounterMap {
+    apid_seq_counter_map: HashMap<u16, CcsdsSimpleSeqCountProvider>,
+}
+impl CcsdsSeqCounterMap {
+    pub fn get_and_increment(&mut self, apid: u16) -> u16 {
+        self.apid_seq_counter_map
+            .entry(apid)
+            .or_default()
+            .get_and_increment()
+    }
+}
+
+pub struct TmFunnelCommon {
+    seq_counter_map: CcsdsSeqCounterMap,
+    msg_counter_map: HashMap<u8, u16>,
+    sync_tm_tcp_source: SyncTcpTmSource,
+}
+
+impl TmFunnelCommon {
+    pub fn new(sync_tm_tcp_source: SyncTcpTmSource) -> Self {
+        Self {
+            seq_counter_map: Default::default(),
+            msg_counter_map: Default::default(),
+            sync_tm_tcp_source,
+        }
+    }
+
+    // Applies common packet processing operations for PUS TM packets. This includes setting
+    // a sequence counter
+    fn apply_packet_processing(&mut self, mut zero_copy_writer: PusTmZeroCopyWriter) {
+        // zero_copy_writer.set_apid(PUS_APID);
+        zero_copy_writer.set_seq_count(
+            self.seq_counter_map
+                .get_and_increment(zero_copy_writer.apid()),
+        );
+        let entry = self
+            .msg_counter_map
+            .entry(zero_copy_writer.service())
+            .or_insert(0);
+        zero_copy_writer.set_msg_count(*entry);
+        if *entry == u16::MAX {
+            *entry = 0;
+        } else {
+            *entry += 1;
+        }
+
+        // This operation has to come last!
+        zero_copy_writer.finish();
+    }
+}
+
+pub struct TmFunnelStatic {
+    common: TmFunnelCommon,
+    shared_tm_store: SharedTmStore,
+    tm_funnel_rx: Receiver<StoreAddr>,
+    tm_server_tx: Sender<StoreAddr>,
+}
+
+impl TmFunnelStatic {
+    pub fn new(
+        shared_tm_store: SharedTmStore,
+        sync_tm_tcp_source: SyncTcpTmSource,
+        tm_funnel_rx: Receiver<StoreAddr>,
+        tm_server_tx: Sender<StoreAddr>,
+    ) -> Self {
+        Self {
+            common: TmFunnelCommon::new(sync_tm_tcp_source),
+            shared_tm_store,
+            tm_funnel_rx,
+            tm_server_tx,
+        }
+    }
+
+    pub fn operation(&mut self) {
+        if let Ok(addr) = self.tm_funnel_rx.recv() {
+            // Read the TM, set sequence counter and message counter, and finally update
+            // the CRC.
+            let shared_pool = self.shared_tm_store.clone_backing_pool();
+            let mut pool_guard = shared_pool.write().expect("Locking TM pool failed");
+            let tm_raw = pool_guard
+                .modify(&addr)
+                .expect("Reading TM from pool failed");
+            let zero_copy_writer = PusTmZeroCopyWriter::new(tm_raw, MIN_CDS_FIELD_LEN)
+                .expect("Creating TM zero copy writer failed");
+            self.common.apply_packet_processing(zero_copy_writer);
+            self.tm_server_tx
+                .send(addr)
+                .expect("Sending TM to server failed");
+            self.common.sync_tm_tcp_source.add_tm(tm_raw);
+        }
+    }
+}
+
+pub struct TmFunnelDynamic {
+    common: TmFunnelCommon,
+    tm_funnel_rx: Receiver<Vec<u8>>,
+    tm_server_tx: Sender<Vec<u8>>,
+}
+
+impl TmFunnelDynamic {
+    pub fn new(
+        sync_tm_tcp_source: SyncTcpTmSource,
+        tm_funnel_rx: Receiver<Vec<u8>>,
+        tm_server_tx: Sender<Vec<u8>>,
+    ) -> Self {
+        Self {
+            common: TmFunnelCommon::new(sync_tm_tcp_source),
+            tm_funnel_rx,
+            tm_server_tx,
+        }
+    }
+
+    pub fn operation(&mut self) {
+        if let Ok(mut tm) = self.tm_funnel_rx.recv() {
+            // Read the TM, set sequence counter and message counter, and finally update
+            // the CRC.
+            let zero_copy_writer = PusTmZeroCopyWriter::new(&mut tm, MIN_CDS_FIELD_LEN)
+                .expect("Creating TM zero copy writer failed");
+            self.common.apply_packet_processing(zero_copy_writer);
+            self.tm_server_tx
+                .send(tm.clone())
+                .expect("Sending TM to server failed");
+            self.common.sync_tm_tcp_source.add_tm(&tm);
+        }
+    }
+}