Broaden receive data buffer types

pyproject.toml

@@ -65,7 +65,7 @@ testing = [
 
 linting = [
   "ruff>=0.8.0,<1",
-  "mypy>=1.13.0,<2",
+  "mypy>=1.16.0,<2",
   "typing_extensions>=4.12.2",
 ]
 
@@ -149,6 +149,7 @@ testpaths = [ "tests" ]
 [tool.coverage.run]
 branch = true
 source = [ "h2" ]
+omit = [ "*/h2/_typing.py" ]
 
 [tool.coverage.report]
 fail_under = 100
@@ -190,7 +191,7 @@ commands = [
 dependency_groups = ["linting"]
 commands = [
   ["ruff", "check", "src/"],
-  ["mypy", "src/"],
+  ["mypy", "--strict-bytes", "src/", "tests/typing/strict_bytes.py"],
 ]
 
 [tool.tox.env.docs]

src/h2/_typing.py

@@ -0,0 +1,21 @@
+"""
+h2/_typing
+~~~~~~~~~~
+
+Shared typing helpers.
+"""
+from __future__ import annotations
+
+from typing import Protocol
+
+
+class Buffer(Protocol):
+    """
+    An object implementing the PEP 688 buffer protocol.
+    """
+
+    def __buffer__(self, flags: int, /) -> memoryview:
+        """
+        Return a memoryview over this object's bytes.
+        """
+        ...

src/h2/connection.py

@@ -70,6 +70,8 @@
 
     from hpack.struct import Header, HeaderWeaklyTyped
 
+    from ._typing import Buffer
+
 
 class ConnectionState(Enum):
     IDLE = 0
@@ -1496,12 +1498,12 @@ def _inbound_flow_control_change_from_settings(self, old_value: int | None, new_
         for stream in self.streams.values():
             stream._inbound_flow_control_change_from_settings(delta)
 
-    def receive_data(self, data: bytes) -> list[Event]:
+    def receive_data(self, data: Buffer) -> list[Event]:
         """
         Pass some received HTTP/2 data to the connection for handling.
 
         :param data: The data received from the remote peer on the network.
-        :type data: ``bytes``
+        :type data: An object implementing the buffer protocol.
         :returns: A list of events that the remote peer triggered by sending
             this data.
         """

src/h2/frame_buffer.py

@@ -7,11 +7,16 @@
 """
 from __future__ import annotations
 
+from typing import TYPE_CHECKING
+
 from hyperframe.exceptions import InvalidDataError, InvalidFrameError
 from hyperframe.frame import ContinuationFrame, Frame, HeadersFrame, PushPromiseFrame
 
 from .exceptions import FrameDataMissingError, FrameTooLargeError, ProtocolError
 
+if TYPE_CHECKING:  # pragma: no cover
+    from ._typing import Buffer
+
 # To avoid a DOS attack based on sending loads of continuation frames, we limit
 # the maximum number we're prepared to receive. In this case, we'll set the
 # limit to 64, which means the largest encoded header block we can receive by
@@ -36,25 +41,27 @@ def __init__(self, server: bool = False) -> None:
         self._preamble_len = len(self._preamble)
         self._headers_buffer: list[HeadersFrame | ContinuationFrame | PushPromiseFrame] = []
 
-    def add_data(self, data: bytes) -> None:
+    def add_data(self, data: Buffer) -> None:
         """
         Add more data to the frame buffer.
 
         :param data: A bytestring containing the byte buffer.
         """
+        data_view = memoryview(data)
+
         if self._preamble_len:
-            data_len = len(data)
+            data_len = len(data_view)
             of_which_preamble = min(self._preamble_len, data_len)
 
-            if self._preamble[:of_which_preamble] != data[:of_which_preamble]:
+            if self._preamble[:of_which_preamble] != data_view[:of_which_preamble]:
                 msg = "Invalid HTTP/2 preamble."
                 raise ProtocolError(msg)
 
-            data = data[of_which_preamble:]
+            data_view = data_view[of_which_preamble:]
             self._preamble_len -= of_which_preamble
             self._preamble = self._preamble[of_which_preamble:]
 
-        self._data += data
+        self._data += data_view
 
     def _validate_frame_length(self, length: int) -> None:
         """

tests/typing/strict_bytes.py

@@ -0,0 +1,17 @@
+from __future__ import annotations
+
+from h2.connection import H2Connection
+from h2.frame_buffer import FrameBuffer
+
+
+def receive_data_accepts_buffer_types(
+    connection: H2Connection,
+    frame_buffer: FrameBuffer,
+) -> None:
+    bytearray_data = bytearray(b"")
+    memoryview_data = memoryview(b"")
+
+    connection.receive_data(bytearray_data)
+    connection.receive_data(memoryview_data)
+    frame_buffer.add_data(bytearray_data)
+    frame_buffer.add_data(memoryview_data)