You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
117 lines
4.3 KiB
117 lines
4.3 KiB
from dataclasses import dataclass, field
|
|
from typing import Any, Callable, Mapping
|
|
|
|
from .. import ClosedResourceError, DelimiterNotFound, EndOfStream, IncompleteRead
|
|
from ..abc import AnyByteReceiveStream, ByteReceiveStream
|
|
|
|
|
|
@dataclass(eq=False)
|
|
class BufferedByteReceiveStream(ByteReceiveStream):
|
|
"""
|
|
Wraps any bytes-based receive stream and uses a buffer to provide sophisticated receiving
|
|
capabilities in the form of a byte stream.
|
|
"""
|
|
|
|
receive_stream: AnyByteReceiveStream
|
|
_buffer: bytearray = field(init=False, default_factory=bytearray)
|
|
_closed: bool = field(init=False, default=False)
|
|
|
|
async def aclose(self) -> None:
|
|
await self.receive_stream.aclose()
|
|
self._closed = True
|
|
|
|
@property
|
|
def buffer(self) -> bytes:
|
|
"""The bytes currently in the buffer."""
|
|
return bytes(self._buffer)
|
|
|
|
@property
|
|
def extra_attributes(self) -> Mapping[Any, Callable[[], Any]]:
|
|
return self.receive_stream.extra_attributes
|
|
|
|
async def receive(self, max_bytes: int = 65536) -> bytes:
|
|
if self._closed:
|
|
raise ClosedResourceError
|
|
|
|
if self._buffer:
|
|
chunk = bytes(self._buffer[:max_bytes])
|
|
del self._buffer[:max_bytes]
|
|
return chunk
|
|
elif isinstance(self.receive_stream, ByteReceiveStream):
|
|
return await self.receive_stream.receive(max_bytes)
|
|
else:
|
|
# With a bytes-oriented object stream, we need to handle any surplus bytes we get from
|
|
# the receive() call
|
|
chunk = await self.receive_stream.receive()
|
|
if len(chunk) > max_bytes:
|
|
# Save the surplus bytes in the buffer
|
|
self._buffer.extend(chunk[max_bytes:])
|
|
return chunk[:max_bytes]
|
|
else:
|
|
return chunk
|
|
|
|
async def receive_exactly(self, nbytes: int) -> bytes:
|
|
"""
|
|
Read exactly the given amount of bytes from the stream.
|
|
|
|
:param nbytes: the number of bytes to read
|
|
:return: the bytes read
|
|
:raises ~anyio.IncompleteRead: if the stream was closed before the requested
|
|
amount of bytes could be read from the stream
|
|
|
|
"""
|
|
while True:
|
|
remaining = nbytes - len(self._buffer)
|
|
if remaining <= 0:
|
|
retval = self._buffer[:nbytes]
|
|
del self._buffer[:nbytes]
|
|
return bytes(retval)
|
|
|
|
try:
|
|
if isinstance(self.receive_stream, ByteReceiveStream):
|
|
chunk = await self.receive_stream.receive(remaining)
|
|
else:
|
|
chunk = await self.receive_stream.receive()
|
|
except EndOfStream as exc:
|
|
raise IncompleteRead from exc
|
|
|
|
self._buffer.extend(chunk)
|
|
|
|
async def receive_until(self, delimiter: bytes, max_bytes: int) -> bytes:
|
|
"""
|
|
Read from the stream until the delimiter is found or max_bytes have been read.
|
|
|
|
:param delimiter: the marker to look for in the stream
|
|
:param max_bytes: maximum number of bytes that will be read before raising
|
|
:exc:`~anyio.DelimiterNotFound`
|
|
:return: the bytes read (not including the delimiter)
|
|
:raises ~anyio.IncompleteRead: if the stream was closed before the delimiter
|
|
was found
|
|
:raises ~anyio.DelimiterNotFound: if the delimiter is not found within the
|
|
bytes read up to the maximum allowed
|
|
|
|
"""
|
|
delimiter_size = len(delimiter)
|
|
offset = 0
|
|
while True:
|
|
# Check if the delimiter can be found in the current buffer
|
|
index = self._buffer.find(delimiter, offset)
|
|
if index >= 0:
|
|
found = self._buffer[:index]
|
|
del self._buffer[: index + len(delimiter) :]
|
|
return bytes(found)
|
|
|
|
# Check if the buffer is already at or over the limit
|
|
if len(self._buffer) >= max_bytes:
|
|
raise DelimiterNotFound(max_bytes)
|
|
|
|
# Read more data into the buffer from the socket
|
|
try:
|
|
data = await self.receive_stream.receive()
|
|
except EndOfStream as exc:
|
|
raise IncompleteRead from exc
|
|
|
|
# Move the offset forward and add the new data to the buffer
|
|
offset = max(len(self._buffer) - delimiter_size + 1, 0)
|
|
self._buffer.extend(data)
|