tweak for SP parser

CHANGELOG.md

@@ -8,6 +8,11 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 # [unreleased]
 
+## Changed
+
+- The `parse_space_packets` function analysis queue argument is now expected to be filled
+  on the right side.
+
 # [v0.18.0rc1] 2023-09-04
 
 ## Added

spacepackets/ccsds/spacepacket.py

@@ -2,6 +2,7 @@
 of all CCSDS packets."""
 from __future__ import annotations
 
+import logging
 from abc import abstractmethod, ABC
 import enum
 import struct
@@ -418,9 +419,10 @@ def get_total_space_packet_len_from_len_field(len_field: int):
 def parse_space_packets(
     analysis_queue: Deque[bytearray], packet_ids: Sequence[PacketId]
 ) -> List[bytearray]:
-    """Given a deque of bytearrays, parse for space packets. Any broken headers will be removed.
-    If a split packet with a valid header is detected, broken tail packets will be reinserted
-    in the given deque.
+    """Given a deque of bytearrays, parse for space packets. This funtion expects the deque
+    to be filled on the right side, for example with :py:meth:`collections.deque.append`.
+    If a split packet with a valid header is detected, this function will re-insert the header into
+    the given deque on the right side.
 
     :param analysis_queue:
     :param packet_ids:
@@ -433,7 +435,7 @@ def parse_space_packets(
         return tm_list
     while analysis_queue:
         # Put it all in one buffer
-        concatenated_packets.extend(analysis_queue.pop())
+        concatenated_packets.extend(analysis_queue.popleft())
     current_idx = 0
     if len(concatenated_packets) < 6:
         return tm_list
@@ -472,6 +474,8 @@ def __handle_packet_id_match(
     )
     # Might be part of packet. Put back into analysis queue as whole
     if current_idx + total_packet_len > len(concatenated_packets):
+        # Clear the queue first. We are done with parsing
+        analysis_queue.clear()
         analysis_queue.append(concatenated_packets[current_idx:])
         return -1, current_idx
     else:

tests/ccsds/test_sp_parser.py

@@ -33,9 +33,9 @@ def test_sp_parser_crap_data_is_skipped(self):
             time_provider=CdsShortTimestamp.empty(),
         )
         other_larger_packet_raw = other_larger_packet.pack()
-        self.packet_deque.appendleft(self.tm_packet_raw)
-        self.packet_deque.appendleft(bytearray(8))
-        self.packet_deque.appendleft(other_larger_packet_raw)
+        self.packet_deque.append(self.tm_packet_raw)
+        self.packet_deque.append(bytearray(8))
+        self.packet_deque.append(other_larger_packet_raw)
         sp_list = parse_space_packets(
             analysis_queue=self.packet_deque, packet_ids=self.packet_ids
         )
@@ -64,7 +64,7 @@ def test_broken_packet(self):
         )
         self.assertEqual(len(sp_list), 0)
         self.assertEqual(len(self.packet_deque), 1)
-        self.packet_deque.appendleft(tm_packet_second_half)
+        self.packet_deque.append(tm_packet_second_half)
         sp_list = parse_space_packets(
             analysis_queue=self.packet_deque, packet_ids=self.packet_ids
         )
@@ -73,10 +73,10 @@ def test_broken_packet(self):
         self.assertEqual(sp_list[0], self.tm_packet_raw)
 
     def test_broken_packet_at_end(self):
-        self.packet_deque.appendleft(self.tm_packet_raw)
+        self.packet_deque.append(self.tm_packet_raw)
         # slice TM packet in half
         tm_packet_first_half = self.tm_packet_raw[:10]
-        self.packet_deque.appendleft(tm_packet_first_half)
+        self.packet_deque.append(tm_packet_first_half)
         sp_list = parse_space_packets(
             analysis_queue=self.packet_deque, packet_ids=self.packet_ids
         )