Merge pull request #77 from us-irs/update-spacepackets

Update spacepackets

Author: robamu

CHANGELOG.md

@@ -8,6 +8,27 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 # [unreleased]
 
+# [v0.24.0] 2024-04-23
+
+## Removed
+
+- Global configuration module for TC and TM APID was removed.
+
+## Changed
+
+- ECSS PUS telemetry time handling is now more generic and low level: Constructors expect
+  a simple `bytes` type while unpackers/readers expect the length of the timestamp. A helper
+  constant for the offset of the timestamp is exposed which can help with determining the
+  length of the timestamp.
+- `CdsShortTimestamp.from_now` renamed to `now`.
+- The ECSS TMTC APID field must not be set explicitely in the class constructors.
+
+## Added
+
+- `spacepackets.ecss.tm.PUS_TM_TIMESTAMP_OFFSET` constant which can be used as a look-ahead to
+  determine the timestamp length from a raw PUS TM packet.
+- `spacepackets.ccsds.CCSDS_HEADER_LEN` constant.
+
 # [v0.23.1] 2024-04-22
 
 ## Added

docs/api/ecss.rst

@@ -6,8 +6,13 @@ ECSS Package
    :undoc-members:
    :show-inheritance:
 
+.. automodule:: spacepackets.ecss.defs
+   :members:
+   :undoc-members:
+   :show-inheritance:
+
 ECSS PUS Telecommand Module
---------------------------------
+----------------------------
 
 :ref:`api/ecss_tc:ECSS Telecommand Module`
 
@@ -16,17 +21,6 @@ ECSS PUS Telemetry Module
 
 :ref:`api/ecss_tm:ECSS Telemetry Module`
 
-ECSS Configuration Submodule
-----------------------------------
-
-This module can be used to configure common default values so these don't have to be specified
-each time anymore when creating ECSS packets
-
-.. automodule:: spacepackets.ecss.conf
-   :members:
-   :undoc-members:
-   :show-inheritance:
-
 ECSS Fields Submodule
 ----------------------------------
 

docs/examples.rst

@@ -16,7 +16,7 @@ PUS ping telemetry reply without a timestamp.
     cmd_as_bytes = ping_cmd.pack()
     print(f"Ping telecommand [17,1] (hex): [{cmd_as_bytes.hex(sep=',')}]")
 
-    ping_reply = PusTm(service=17, subservice=2, apid=0x01, time_provider=None)
+    ping_reply = PusTm(service=17, subservice=2, apid=0x01, timestamp=bytes())
     tm_as_bytes = ping_reply.pack()
     print(f"Ping reply [17,2] (hex): [{tm_as_bytes.hex(sep=',')}]")
 

pyproject.toml

@@ -6,7 +6,7 @@ build-backend = "setuptools.build_meta"
 name = "spacepackets"
 description = "Various CCSDS and ECSS packet implementations"
 readme = "README.md"
-version = "0.23.1"
+version = "0.24.0"
 requires-python = ">=3.8"
 license = {text = "Apache-2.0"}
 authors = [

spacepackets/ccsds/spacepacket.py

@@ -10,10 +10,13 @@
 
 from spacepackets.exceptions import BytesTooShortError
 
-SPACE_PACKET_HEADER_SIZE: Final = 6
-SEQ_FLAG_MASK = 0xC000
-APID_MASK = 0x7FF
-PACKET_ID_MASK = 0x1FFF
+CCSDS_HEADER_LEN: Final[int] = 6
+SPACE_PACKET_HEADER_SIZE: Final[int] = CCSDS_HEADER_LEN
+SEQ_FLAG_MASK: Final[int] = 0xC000
+APID_MASK: Final[int] = 0x7FF
+PACKET_ID_MASK: Final[int] = 0x1FFF
+MAX_SEQ_COUNT: Final[int] = pow(2, 14) - 1
+MAX_APID: Final[int] = pow(2, 11) - 1
 
 
 class PacketType(enum.IntEnum):
@@ -34,7 +37,7 @@ class PacketSeqCtrl:
     """
 
     def __init__(self, seq_flags: SequenceFlags, seq_count: int):
-        if seq_count > pow(2, 14) - 1 or seq_count < 0:
+        if seq_count > MAX_SEQ_COUNT or seq_count < 0:
             raise ValueError(
                 f"Sequence count larger than allowed {pow(2, 14) - 1} or negative"
             )
@@ -205,7 +208,7 @@ def __init__(
         :param data_len: Contains a length count C that equals one fewer than the length of the
             packet data field. Should not be larger than 65535 bytes
         :param ccsds_version:
-        :param sec_header_flag: Secondary header flag, 1 or True by default
+        :param sec_header_flag: Secondary header flag, or False by default.
         :param seq_flags:
         :raises ValueError: On invalid parameters
         """
@@ -299,7 +302,7 @@ def seq_flags(self, value):
 
     @property
     def header_len(self) -> int:
-        return SPACE_PACKET_HEADER_SIZE
+        return CCSDS_HEADER_LEN
 
     @apid.setter
     def apid(self, apid):
@@ -311,7 +314,7 @@ def packet_len(self) -> int:
 
         :return: Size of the TM packet based on the space packet header data length field.
         """
-        return SPACE_PACKET_HEADER_SIZE + self.data_len + 1
+        return CCSDS_HEADER_LEN + self.data_len + 1
 
     @classmethod
     def unpack(cls, data: bytes) -> SpacePacketHeader:
@@ -500,7 +503,7 @@ def parse_space_packets(
     # Packet ID detected
     while True:
         # Can't even parse CCSDS header. Wait for more data to arrive.
-        if current_idx + SPACE_PACKET_HEADER_SIZE >= len(concatenated_packets):
+        if current_idx + CCSDS_HEADER_LEN >= len(concatenated_packets):
             break
         current_packet_id = (
             struct.unpack("!H", concatenated_packets[current_idx : current_idx + 2])[0]

spacepackets/ccsds/time/cds.py

@@ -84,11 +84,11 @@ def _calculate_unix_seconds(self):
 
     def _calculate_date_time(self):
         if self._unix_seconds < 0:
-            self._date_time = datetime.datetime(
+            self._datetime = datetime.datetime(
                 1970, 1, 1, tzinfo=datetime.timezone.utc
             ) + datetime.timedelta(seconds=self._unix_seconds)
         else:
-            self._date_time = datetime.datetime.fromtimestamp(
+            self._datetime = datetime.datetime.fromtimestamp(
                 self._unix_seconds, tz=datetime.timezone.utc
             )
 
@@ -108,7 +108,7 @@ def ccsds_days(self) -> int:
     def ms_of_day(self) -> int:
         return self._ms_of_day
 
-    def pack(self) -> bytearray:
+    def pack(self) -> bytes:
         cds_packet = bytearray()
         cds_packet.extend(self.__p_field)
         cds_packet.extend(struct.pack("!H", self._ccsds_days))
@@ -169,12 +169,14 @@ def __repr__(self):
         )
 
     def __str__(self):
-        return f"Date {self._date_time!r} with representation {self!r}"
+        return f"Date {self._datetime!r} with representation {self!r}"
 
-    def __eq__(self, other: CdsShortTimestamp):
-        return (self.ccsds_days == other.ccsds_days) and (
-            self.ms_of_day == other.ms_of_day
-        )
+    def __eq__(self, other: object):
+        if isinstance(other, CdsShortTimestamp):
+            return (self.ccsds_days == other.ccsds_days) and (
+                self.ms_of_day == other.ms_of_day
+            )
+        return False
 
     def __add__(self, timedelta: datetime.timedelta):
         """Allows adding timedelta to the CDS timestamp provider.
@@ -200,23 +202,33 @@ def __add__(self, timedelta: datetime.timedelta):
         return self
 
     @classmethod
-    def from_now(cls) -> CdsShortTimestamp:
+    def now(cls) -> CdsShortTimestamp:
         """Returns a seven byte CDS short timestamp with the current time."""
         return cls.from_date_time(datetime.datetime.now(tz=datetime.timezone.utc))
 
+    @classmethod
+    @deprecation.deprecated(
+        deprecated_in="0.24.0",
+        current_version=get_version(),
+        details="use now instead",
+    )
+    def from_now(cls) -> CdsShortTimestamp:
+        """Returns a seven byte CDS short timestamp with the current time."""
+        return cls.now()
+
     @classmethod
     @deprecation.deprecated(
         deprecated_in="0.14.0rc1",
         current_version=get_version(),
         details="use from_now instead",
     )
     def from_current_time(cls) -> CdsShortTimestamp:
-        return cls.from_now()
+        return cls.now()
 
     @classmethod
-    def from_date_time(cls, dt: datetime.datetime) -> CdsShortTimestamp:
+    def from_datetime(cls, dt: datetime.datetime) -> CdsShortTimestamp:
         instance = cls.empty(False)
-        instance._date_time = dt
+        instance._datetime = dt
         instance._unix_seconds = dt.timestamp()
         full_unix_secs = int(math.floor(instance._unix_seconds))
         subsec_millis = int((instance._unix_seconds - full_unix_secs) * 1000)
@@ -226,6 +238,15 @@ def from_date_time(cls, dt: datetime.datetime) -> CdsShortTimestamp:
         instance._ccsds_days = convert_unix_days_to_ccsds_days(unix_days)
         return instance
 
+    @classmethod
+    @deprecation.deprecated(
+        deprecated_in="0.24.0",
+        current_version=get_version(),
+        details="use from_datetime instead",
+    )
+    def from_date_time(cls, dt: datetime.datetime) -> CdsShortTimestamp:
+        return cls.from_datetime(dt)
+
     @staticmethod
     def ms_of_today(seconds_since_epoch: Optional[float] = None):
         if seconds_since_epoch is None:
@@ -238,5 +259,13 @@ def ms_of_today(seconds_since_epoch: Optional[float] = None):
     def as_unix_seconds(self) -> float:
         return self._unix_seconds
 
+    def as_datetime(self) -> datetime.datetime:
+        return self._datetime
+
+    @deprecation.deprecated(
+        deprecated_in="0.24.0",
+        current_version=get_version(),
+        details="use as_datetime instead",
+    )
     def as_date_time(self) -> datetime.datetime:
-        return self._date_time
+        return self.as_datetime()

spacepackets/ccsds/time/common.py

@@ -72,7 +72,7 @@ def len(self) -> int:
         return self.len_packed
 
     @abstractmethod
-    def pack(self) -> bytearray:
+    def pack(self) -> bytes:
         pass
 
     @abstractmethod

spacepackets/ecss/__init__.py

@@ -1,6 +1,6 @@
 from crcmod.predefined import mkPredefinedCrcFun
 
-from .tc import PusVersion, PusTelecommand, PusTc, PusTcDataFieldHeader
+from .tc import PusTc, PusTelecommand, PusTcDataFieldHeader
 from .tm import PusTm, PusTelemetry, PusTmSecondaryHeader
 from .fields import (
     PacketFieldEnum,
@@ -13,7 +13,7 @@
     PfcSigned,
     PfcUnsigned,
 )
-from .defs import PusService
+from .defs import PusService, PusVersion
 from .req_id import RequestId
 from .pus_verificator import PusVerificator
 

spacepackets/ecss/conf.py

@@ -1,6 +1,15 @@
 import enum
 
 
+class PusVersion(enum.IntEnum):
+    # ESA PSS-07-101. Not supported by this package!
+    ESA_PUS = 0
+    # ECSS-E-70-41A
+    PUS_A = 1
+    # ECSS-E-ST-70-41C
+    PUS_C = 2
+
+
 class PusService(enum.IntEnum):
     S1_VERIFICATION = 1
     S2_RAW_CMD = 2