Remove BufferedReceiver class

This class is only used by the Broadcast channel and the interface is
really intended for channel implementations, because the users are not
supposed to enqueue messages to receiver but just receive from them.

Signed-off-by: Leandro Lucarella <[email protected]>

Author: llucax

RELEASE_NOTES.md

@@ -28,7 +28,6 @@ time.
   * `frequenz.channels.Bidirectional`
   * `frequenz.channels.BidirectionalHandle`
   * `frequenz.channels.Broadcast`
-  * `frequenz.channels.BufferedReceiver`
   * `frequenz.channels.Peekable`
   * `frequenz.channels.Receiver`
   * `frequenz.channels.Sender`
@@ -38,6 +37,11 @@ time.
   * `frequenz.channels.util.Select`
   * `frequenz.channels.util.Timer`
 
+* The class `BufferedReceiver` was removed because the interface was really
+  intended for channel implementations. Users are not supposed to enqueue
+  messages to receiver but just receive from them. If you used it you can
+  implement it yourself.
+
 ## New Features
 
 <!-- Here goes the main new features and examples or instructions on how to use them -->

src/frequenz/channels/__init__.py

@@ -48,7 +48,6 @@
 from . import util
 from ._anycast import Anycast
 from ._base_classes import (
-    BufferedReceiver,
     ChannelClosedError,
     ChannelError,
     Peekable,
@@ -63,7 +62,6 @@
     "Bidirectional",
     "BidirectionalHandle",
     "Broadcast",
-    "BufferedReceiver",
     "ChannelClosedError",
     "ChannelError",
     "Peekable",

src/frequenz/channels/_base_classes.py

@@ -164,18 +164,6 @@ def peek(self) -> Optional[T]:
         """
 
 
-class BufferedReceiver(Receiver[T]):
-    """A channel receiver with a buffer."""
-
-    @abstractmethod
-    def enqueue(self, msg: T) -> None:
-        """Put a message into this buffered receiver's queue.
-
-        Args:
-            msg: The message to be added to the queue.
-        """
-
-
 class _Map(Receiver[U], Generic[T, U]):
     """Apply a transform function on a channel receiver.
 

src/frequenz/channels/_broadcast.py

@@ -12,8 +12,9 @@
 from typing import Deque, Dict, Generic, Optional
 from uuid import UUID, uuid4
 
-from ._base_classes import BufferedReceiver, ChannelClosedError
+from ._base_classes import ChannelClosedError
 from ._base_classes import Peekable as BasePeekable
+from ._base_classes import Receiver as BaseReceiver
 from ._base_classes import Sender as BaseSender
 from ._base_classes import T
 
@@ -192,7 +193,7 @@ async def send(self, msg: T) -> bool:
         return True
 
 
-class Receiver(BufferedReceiver[T]):
+class Receiver(BaseReceiver[T]):
     """A receiver to receive messages from the broadcast channel.
 
     Should not be created directly, but through the