Send Receive naming

changelog.md

@@ -0,0 +1,8 @@
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/)
+
+## [Unreleased] - 2026-09-14
+
+### Changed
+- Rename `DatagramWriteMemo` to **`DatagramSendMemo`** and `DatagramReadMemo` to **`DatagramReceiveMemo`** to distinguish meaning of read/write from the higher network layers (For example, in "DatagramWriteMemo" "Write" had two different meanings--one for port flow direction, one for request type, as it could be associated with a MemoryReadMemo. Now a MemoryReadMemo is associated with a "DatagramSendMemo" denoting it was requested by us but we may be still requesting a read such as in that case).

examples/example_cdi_access.py

@@ -91,7 +91,7 @@ def printDatagram(memo):
     """A call-back for when datagrams received
 
     Args:
-        DatagramReadMemo: The datagram object
+        DatagramReceiveMemo: The datagram object
 
     Returns:
         bool: Always False (True would mean we sent a reply to the datagram,

examples/example_datagram_transfer.py

@@ -28,7 +28,7 @@
 from openlcb.nodeid import NodeID  # noqa:E402
 from openlcb.datagramservice import (  # noqa:E402
     DatagramService,
-    DatagramWriteMemo,
+    DatagramSendMemo,
 )
 
 # specify connection information
@@ -74,15 +74,15 @@ def printMessage(message):
 
 
 # create a call-back for replies to write datagram
-def writeCallBackCheck(memo):
+def sendCallBackCheck(memo):
     print("Write complete call back")
 
 
 def datagramReceiver(memo):
     """A call-back for when datagrams received
 
     Args:
-        DatagramReadMemo: The datagram object
+        DatagramReceiveMemo: The datagram object
 
     Returns:
         bool: Always True (means we sent the reply to this datagram)
@@ -118,12 +118,12 @@ def datagramWrite():
     import time
     time.sleep(1)
 
-    writeMemo = DatagramWriteMemo(
+    sendMemo = DatagramSendMemo(
         NodeID(settings['farNodeID']),
         bytearray([0x20, 0x43, 0x00, 0x00, 0x00, 0x00, 0x14]),
-        writeCallBackCheck
+        sendCallBackCheck
     )
-    datagramService.sendDatagram(writeMemo)
+    datagramService.sendDatagram(sendMemo)
 
 
 thread = threading.Thread(target=datagramWrite)

examples/example_memory_length_query.py

@@ -26,8 +26,8 @@
 from openlcb.canbus.canlink import CanLink  # noqa: E402
 from openlcb.nodeid import NodeID  # noqa: E402
 from openlcb.datagramservice import (  # noqa: E402
-    # DatagramWriteMemo,
-    # DatagramReadMemo,
+    # DatagramSendMemo,
+    # DatagramReceiveMemo,
     DatagramService,
 )
 from openlcb.memoryservice import (  # noqa: E402
@@ -82,7 +82,7 @@ def printDatagram(memo):
     """create a call-back to print datagram contents when received
 
     Args:
-        memo (DatagramReadMemo): The datagram received
+        memo (DatagramReceiveMemo): The datagram received
 
     Returns:
         bool: Always False (True would mean we sent a reply to this datagram,

examples/example_memory_transfer.py

@@ -27,8 +27,8 @@
 from openlcb.canbus.canlink import CanLink  # noqa: E402
 from openlcb.nodeid import NodeID  # noqa: E402
 from openlcb.datagramservice import (  # noqa: E402
-    # DatagramWriteMemo,
-    # DatagramReadMemo,
+    # DatagramSendMemo,
+    # DatagramReceiveMemo,
     DatagramService,
 )
 from openlcb.memoryservice import (  # noqa: E402
@@ -83,7 +83,7 @@ def printDatagram(memo):
     """create a call-back to print datagram contents when received
 
     Args:
-        memo (DatagramReadMemo): The datagram received
+        memo (DatagramReceiveMemo): The datagram received
 
     Returns:
         bool: Always False (True would mean we sent a reply to this datagram,

examples/example_node_implementation.py

@@ -99,7 +99,7 @@ def printDatagram(memo):
     """create a call-back to print datagram contents when received
 
     Args:
-        memo (DatagramReadMemo): The datagram received
+        memo (DatagramReceiveMemo): The datagram received
 
     Returns:
         bool: Always False (True would mean we sent a reply to the datagram,

examples/example_node_memory_implementation.py

@@ -48,7 +48,7 @@
 )
 from openlcb.canbus.canlink import CanLink  # noqa: E402
 from openlcb.nodeid import NodeID  # noqa: E402
-from openlcb.datagramservice import DatagramReadMemo, DatagramService  # noqa: E402, E501
+from openlcb.datagramservice import DatagramReceiveMemo, DatagramService  # noqa: E402, E501
 from openlcb.memoryservice import MemoryService  # noqa: E402
 from openlcb.message import Message  # noqa: E402
 from openlcb.mti import MTI  # noqa: E402
@@ -151,11 +151,11 @@ def printMessage(message: Message):
 assert_xml(cdi)
 
 
-def handleDatagram(memo: DatagramReadMemo):
+def handleDatagram(memo: DatagramReceiveMemo):
     """create a call-back to print datagram contents when received
 
     Args:
-        memo (DatagramReadMemo): The datagram received
+        memo (DatagramReceiveMemo): The datagram received
 
     Returns:
         bool: Always False (True would mean we sent a reply to the datagram,

openlcb/datagramservice.py

@@ -6,7 +6,7 @@
 Provide a service interface for reading and writing Datagrams.
 
 Writes to remote node:
-- Create a ``DatagramWriteMemo`` and submit via ``sendDatagram(_:)``
+- Create a ``DatagramSendMemo`` and submit via ``sendDatagram(_:)``
 - Get an OK or NotOK callback
 
 Reads from remote node:
@@ -40,12 +40,12 @@
 
 
 def defaultIgnoreReply(memo: Union[Any, None]):
-    # ^ DatagramWriteMemo is the type, but that is not defined yet
+    # ^ DatagramSendMemo is the type, but that is not defined yet
     '''default handling of reply does nothing'''
     pass
 
 
-class DatagramWriteMemo:
+class DatagramSendMemo:
     '''Immutable memo carrying write request and two reply callbacks
     (In this context "Write" means sent to other node, even if
     associated with a MemoryReadMemo).
@@ -54,7 +54,7 @@ class DatagramWriteMemo:
     def __init__(self, destID: NodeID, data,
                  okReply=defaultIgnoreReply,
                  rejectedReply=defaultIgnoreReply):
-        # type: (NodeID, bytearray, Callable[[Union[DatagramWriteMemo, None]], None], Callable[[Union[DatagramWriteMemo, None]], None]) -> None  # noqa: E501
+        # type: (NodeID, bytearray, Callable[[Union[DatagramSendMemo, None]], None], Callable[[Union[DatagramSendMemo, None]], None]) -> None  # noqa: E501
         assert isinstance(destID, NodeID)
         self.destID = destID
         # NOTE: No srcID since always from this node ("Write" means send
@@ -63,8 +63,8 @@ def __init__(self, destID: NodeID, data,
             raise TypeError("Expected bytearray (formerly list[int]), got {}"
                             .format(type(data).__name__))
         self.data: bytearray = data
-        self.okReply: Callable[[Union[DatagramWriteMemo, None]], None] = okReply  # noqa: E501
-        self.rejectedReply: Callable[[Union[DatagramWriteMemo, None]], None] = rejectedReply  # noqa: E501
+        self.okReply: Callable[[Union[DatagramSendMemo, None]], None] = okReply  # noqa: E501
+        self.rejectedReply: Callable[[Union[DatagramSendMemo, None]], None] = rejectedReply  # noqa: E501
 
     def __eq__(lhs, rhs):
         if lhs.destID != rhs.destID:
@@ -74,7 +74,7 @@ def __eq__(lhs, rhs):
         return True
 
 
-class DatagramReadMemo:
+class DatagramReceiveMemo:
     '''Immutable memo carrying read result
     (In this context "Read" means received from other node,
     *not* associated with a MemoryReadMemo which, however, may be what
@@ -100,6 +100,16 @@ class DatagramService:
     Args:
         linkLayer (CanLink): Could actually be any link layer such as
             LinkMockLayer (for testing) or CanLink.
+
+    Attributes:
+        pendingSendMemos: (formerly pendingWriteMemos) These are written
+            to the port, but a MemorySendMemo may be associated with a
+            MemoryReadMemo since the device instantiating the service is
+            making the request; or may be used to send replies as well
+            (See where MemoryService instantiates any MemorySendMemo to
+            respond to space info request especially when the node
+            instantiating MemoryService is a node other than a
+            Configuration Tool).
     """
 
     class ProtocolID(Enum):
@@ -117,9 +127,9 @@ class ProtocolID(Enum):
     def __init__(self, linkLayer: LinkLayer):
         self.linkLayer: LinkLayer = linkLayer
         self.quiesced: bool = False
-        self.currentOutstandingMemo: Union[DatagramWriteMemo, None] = None  # noqa: E501
-        self.pendingWriteMemos: List[DatagramWriteMemo] = []
-        self._datagramReceivedListeners: List[Callable[[DatagramReadMemo], bool]] = []  # noqa: E501
+        self.currentOutstandingMemo: Union[DatagramSendMemo, None] = None  # noqa: E501
+        self.pendingSendMemos: List[DatagramSendMemo] = []
+        self._datagramReceivedListeners: List[Callable[[DatagramReceiveMemo], bool]] = []  # noqa: E501
 
     def datagramType(self, data: Union[bytearray, List[int]]):
         """Determine the protocol type of the content of the datagram.
@@ -154,42 +164,42 @@ def checkDestID(self, message, nodeID: NodeID):
         assert isinstance(nodeID, NodeID)
         return message.destination == nodeID
 
-    def sendDatagram(self, memo: DatagramWriteMemo):
-        '''Queue a ``DatagramWriteMemo`` to send a datagram to another node
+    def sendDatagram(self, memo: DatagramSendMemo):
+        '''Queue a ``DatagramSendMemo`` to send a datagram to another node
         on the network.
         '''
         # Make a record of memo for reply
-        self.pendingWriteMemos.append(memo)
+        self.pendingSendMemos.append(memo)
 
         # can only have one outstanding at a time, so check it there was
         # already one there.
-        if len(self.pendingWriteMemos) == 1:
+        if len(self.pendingSendMemos) == 1:
             self.sendDatagramMessage(memo)
 
-    def sendDatagramMessage(self, memo: DatagramWriteMemo):
+    def sendDatagramMessage(self, memo: DatagramSendMemo):
         '''Send datagram message'''
         message = Message(MTI.Datagram, self.linkLayer.localNodeID,
                           memo.destID, memo.data)
         self.linkLayer.sendMessage(message)
         self.currentOutstandingMemo = memo
 
     def registerDatagramReceivedListener(
-            self, listener: Callable[[DatagramReadMemo], bool]):
+            self, listener: Callable[[DatagramReceiveMemo], bool]):
         '''Register a listener to be notified when each datagram arrives.
 
         One and only one listener should reply positively or negatively to the
         datagram and return true.
 
         Args:
-            listener (Callable): A function that accepts a DatagramReadMemo
+            listener (Callable): A function that accepts a DatagramReceiveMemo
                 as an argument.
         '''
         logger.debug(
             "REGISTERING registerDatagramReceivedListener listener"
             f" {len(self._datagramReceivedListeners) + 1}")
         self._datagramReceivedListeners.append(listener)
 
-    def fireDatagramReceived(self, dg: DatagramReadMemo):  # internal for tests
+    def fireDatagramReceived(self, dg: DatagramReceiveMemo):  # internal for tests
         """Fire *datagram received* listeners."""
         logger.debug(
             f"FIRING listeners for datagram from {dg.srcID},"
@@ -236,15 +246,15 @@ def process(self, message: Message):
 
     def handleDatagram(self, message: Message):
         '''create a read memo and pass to listeners'''
-        memo = DatagramReadMemo(message.source, message.data)
+        memo = DatagramReceiveMemo(message.source, message.data)
         self.fireDatagramReceived(memo)
         # ^ destination listener calls back to
         #   positiveReplyToDatagram/negativeReplyToDatagram before returning
 
     def handleDatagramReceivedOK(self, message: Message):
         '''OK reply to write'''
         # match to the memo and remove from queue
-        memo = self.matchToWriteMemo(message)  # type: DatagramWriteMemo|None
+        memo = self.matchToWriteMemo(message)  # type: DatagramSendMemo|None
 
         # check for whether a match was found, indicating this was for us
         if memo is None:
@@ -307,16 +317,16 @@ def handleLinkRestarted(self, message: Message):
             return
         else:
             # are there any queued datagrams? If so, send first
-            if len(self.pendingWriteMemos) > 0:
+            if len(self.pendingSendMemos) > 0:
                 self.sendNextDatagramFromQueue()
 
     def matchToWriteMemo(self, message: Message):
-        for memo in self.pendingWriteMemos:
+        for memo in self.pendingSendMemos:
             if memo.destID != message.source:
                 continue  # keep looking
             # remove the found element - might need a try/except on this
-            index = self.pendingWriteMemos.index(memo)
-            del self.pendingWriteMemos[index]
+            index = self.pendingSendMemos.index(memo)
+            del self.pendingSendMemos[index]
 
             return memo
 
@@ -327,28 +337,28 @@ def matchToWriteMemo(self, message: Message):
 
     def sendNextDatagramFromQueue(self):
         # is there a next datagram request?
-        if len(self.pendingWriteMemos) > 0:
+        if len(self.pendingSendMemos) > 0:
             # yes, get it, process it
-            memo = self.pendingWriteMemos[0]
+            memo = self.pendingSendMemos[0]
             self.sendDatagramMessage(memo)
 
-    def positiveReplyToDatagram(self, dg: DatagramReadMemo, flags: int = 0):
+    def positiveReplyToDatagram(self, dg: DatagramReceiveMemo, flags: int = 0):
         """Send a positive reply to a received datagram.
 
         Args:
-            dg (DatagramReadMemo): Datagram memo being responded to.
+            dg (DatagramReceiveMemo): Datagram memo being responded to.
             flags (Optional[int]): Flag byte to be returned to sender, see
                 Datagram Standard & Technical Note for meaning. Defaults to 0.
         """
         message = Message(MTI.Datagram_Received_OK, self.linkLayer.localNodeID,
                           dg.srcID, bytearray([flags]))
         self.linkLayer.sendMessage(message)
 
-    def negativeReplyToDatagram(self, dg: DatagramReadMemo, err: int):
+    def negativeReplyToDatagram(self, dg: DatagramReceiveMemo, err: int):
         """Send a negative reply to a received datagram.
 
         Args:
-            dg (DatagramReadMemo): Datagram memo being responded to.
+            dg (DatagramReceiveMemo): Datagram memo being responded to.
             err (int): Error code(s) to be returned to sender,
                 see Datagram Standard & Technical Note for meaning.
         """