mirror of
https://github.com/bunny-lab-io/Borealis.git
synced 2025-07-28 04:58:29 -06:00
Removed the Requirement to Install Python and NodeJS (Now Bundled with Borealis)
This commit is contained in:
787
Dependencies/Python/Lib/asyncio/streams.py
vendored
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787
Dependencies/Python/Lib/asyncio/streams.py
vendored
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@ -0,0 +1,787 @@
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__all__ = (
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'StreamReader', 'StreamWriter', 'StreamReaderProtocol',
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'open_connection', 'start_server')
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import collections
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import socket
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import sys
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import warnings
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import weakref
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if hasattr(socket, 'AF_UNIX'):
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__all__ += ('open_unix_connection', 'start_unix_server')
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from . import coroutines
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from . import events
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from . import exceptions
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from . import format_helpers
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from . import protocols
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from .log import logger
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from .tasks import sleep
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_DEFAULT_LIMIT = 2 ** 16 # 64 KiB
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async def open_connection(host=None, port=None, *,
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limit=_DEFAULT_LIMIT, **kwds):
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"""A wrapper for create_connection() returning a (reader, writer) pair.
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The reader returned is a StreamReader instance; the writer is a
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StreamWriter instance.
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The arguments are all the usual arguments to create_connection()
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except protocol_factory; most common are positional host and port,
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with various optional keyword arguments following.
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Additional optional keyword arguments are loop (to set the event loop
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instance to use) and limit (to set the buffer limit passed to the
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StreamReader).
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(If you want to customize the StreamReader and/or
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StreamReaderProtocol classes, just copy the code -- there's
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really nothing special here except some convenience.)
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"""
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loop = events.get_running_loop()
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reader = StreamReader(limit=limit, loop=loop)
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protocol = StreamReaderProtocol(reader, loop=loop)
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transport, _ = await loop.create_connection(
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lambda: protocol, host, port, **kwds)
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writer = StreamWriter(transport, protocol, reader, loop)
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return reader, writer
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async def start_server(client_connected_cb, host=None, port=None, *,
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limit=_DEFAULT_LIMIT, **kwds):
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"""Start a socket server, call back for each client connected.
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The first parameter, `client_connected_cb`, takes two parameters:
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client_reader, client_writer. client_reader is a StreamReader
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object, while client_writer is a StreamWriter object. This
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parameter can either be a plain callback function or a coroutine;
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if it is a coroutine, it will be automatically converted into a
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Task.
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The rest of the arguments are all the usual arguments to
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loop.create_server() except protocol_factory; most common are
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positional host and port, with various optional keyword arguments
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following. The return value is the same as loop.create_server().
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Additional optional keyword argument is limit (to set the buffer
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limit passed to the StreamReader).
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The return value is the same as loop.create_server(), i.e. a
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Server object which can be used to stop the service.
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"""
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loop = events.get_running_loop()
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def factory():
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reader = StreamReader(limit=limit, loop=loop)
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protocol = StreamReaderProtocol(reader, client_connected_cb,
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loop=loop)
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return protocol
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return await loop.create_server(factory, host, port, **kwds)
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if hasattr(socket, 'AF_UNIX'):
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# UNIX Domain Sockets are supported on this platform
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async def open_unix_connection(path=None, *,
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limit=_DEFAULT_LIMIT, **kwds):
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"""Similar to `open_connection` but works with UNIX Domain Sockets."""
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loop = events.get_running_loop()
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reader = StreamReader(limit=limit, loop=loop)
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protocol = StreamReaderProtocol(reader, loop=loop)
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transport, _ = await loop.create_unix_connection(
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lambda: protocol, path, **kwds)
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writer = StreamWriter(transport, protocol, reader, loop)
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return reader, writer
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async def start_unix_server(client_connected_cb, path=None, *,
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limit=_DEFAULT_LIMIT, **kwds):
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"""Similar to `start_server` but works with UNIX Domain Sockets."""
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loop = events.get_running_loop()
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def factory():
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reader = StreamReader(limit=limit, loop=loop)
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protocol = StreamReaderProtocol(reader, client_connected_cb,
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loop=loop)
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return protocol
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return await loop.create_unix_server(factory, path, **kwds)
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class FlowControlMixin(protocols.Protocol):
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"""Reusable flow control logic for StreamWriter.drain().
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This implements the protocol methods pause_writing(),
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resume_writing() and connection_lost(). If the subclass overrides
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these it must call the super methods.
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StreamWriter.drain() must wait for _drain_helper() coroutine.
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"""
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def __init__(self, loop=None):
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if loop is None:
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self._loop = events.get_event_loop()
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else:
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self._loop = loop
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self._paused = False
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self._drain_waiters = collections.deque()
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self._connection_lost = False
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def pause_writing(self):
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assert not self._paused
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self._paused = True
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if self._loop.get_debug():
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logger.debug("%r pauses writing", self)
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def resume_writing(self):
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assert self._paused
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self._paused = False
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if self._loop.get_debug():
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logger.debug("%r resumes writing", self)
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for waiter in self._drain_waiters:
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if not waiter.done():
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waiter.set_result(None)
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def connection_lost(self, exc):
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self._connection_lost = True
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# Wake up the writer(s) if currently paused.
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if not self._paused:
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return
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for waiter in self._drain_waiters:
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if not waiter.done():
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if exc is None:
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waiter.set_result(None)
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else:
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waiter.set_exception(exc)
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async def _drain_helper(self):
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if self._connection_lost:
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raise ConnectionResetError('Connection lost')
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if not self._paused:
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return
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waiter = self._loop.create_future()
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self._drain_waiters.append(waiter)
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try:
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await waiter
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finally:
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self._drain_waiters.remove(waiter)
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def _get_close_waiter(self, stream):
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raise NotImplementedError
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class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
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"""Helper class to adapt between Protocol and StreamReader.
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(This is a helper class instead of making StreamReader itself a
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Protocol subclass, because the StreamReader has other potential
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uses, and to prevent the user of the StreamReader to accidentally
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call inappropriate methods of the protocol.)
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"""
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_source_traceback = None
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def __init__(self, stream_reader, client_connected_cb=None, loop=None):
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super().__init__(loop=loop)
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if stream_reader is not None:
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self._stream_reader_wr = weakref.ref(stream_reader)
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self._source_traceback = stream_reader._source_traceback
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else:
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self._stream_reader_wr = None
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if client_connected_cb is not None:
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# This is a stream created by the `create_server()` function.
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# Keep a strong reference to the reader until a connection
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# is established.
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self._strong_reader = stream_reader
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self._reject_connection = False
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self._task = None
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self._transport = None
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self._client_connected_cb = client_connected_cb
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self._over_ssl = False
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self._closed = self._loop.create_future()
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@property
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def _stream_reader(self):
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if self._stream_reader_wr is None:
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return None
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return self._stream_reader_wr()
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def _replace_transport(self, transport):
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loop = self._loop
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self._transport = transport
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self._over_ssl = transport.get_extra_info('sslcontext') is not None
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def connection_made(self, transport):
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if self._reject_connection:
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context = {
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'message': ('An open stream was garbage collected prior to '
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'establishing network connection; '
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'call "stream.close()" explicitly.')
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}
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if self._source_traceback:
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context['source_traceback'] = self._source_traceback
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self._loop.call_exception_handler(context)
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transport.abort()
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return
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self._transport = transport
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reader = self._stream_reader
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if reader is not None:
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reader.set_transport(transport)
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self._over_ssl = transport.get_extra_info('sslcontext') is not None
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if self._client_connected_cb is not None:
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writer = StreamWriter(transport, self, reader, self._loop)
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res = self._client_connected_cb(reader, writer)
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if coroutines.iscoroutine(res):
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def callback(task):
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if task.cancelled():
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transport.close()
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return
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exc = task.exception()
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if exc is not None:
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self._loop.call_exception_handler({
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'message': 'Unhandled exception in client_connected_cb',
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'exception': exc,
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'transport': transport,
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})
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transport.close()
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self._task = self._loop.create_task(res)
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self._task.add_done_callback(callback)
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self._strong_reader = None
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def connection_lost(self, exc):
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reader = self._stream_reader
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if reader is not None:
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if exc is None:
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reader.feed_eof()
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else:
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reader.set_exception(exc)
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if not self._closed.done():
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if exc is None:
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self._closed.set_result(None)
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else:
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self._closed.set_exception(exc)
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super().connection_lost(exc)
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self._stream_reader_wr = None
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self._stream_writer = None
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self._task = None
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self._transport = None
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def data_received(self, data):
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reader = self._stream_reader
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if reader is not None:
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reader.feed_data(data)
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def eof_received(self):
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reader = self._stream_reader
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if reader is not None:
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reader.feed_eof()
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if self._over_ssl:
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# Prevent a warning in SSLProtocol.eof_received:
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# "returning true from eof_received()
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# has no effect when using ssl"
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return False
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return True
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def _get_close_waiter(self, stream):
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return self._closed
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def __del__(self):
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# Prevent reports about unhandled exceptions.
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# Better than self._closed._log_traceback = False hack
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try:
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closed = self._closed
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except AttributeError:
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pass # failed constructor
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else:
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if closed.done() and not closed.cancelled():
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closed.exception()
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class StreamWriter:
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"""Wraps a Transport.
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This exposes write(), writelines(), [can_]write_eof(),
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get_extra_info() and close(). It adds drain() which returns an
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optional Future on which you can wait for flow control. It also
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adds a transport property which references the Transport
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directly.
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"""
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def __init__(self, transport, protocol, reader, loop):
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self._transport = transport
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self._protocol = protocol
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# drain() expects that the reader has an exception() method
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assert reader is None or isinstance(reader, StreamReader)
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self._reader = reader
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self._loop = loop
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self._complete_fut = self._loop.create_future()
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self._complete_fut.set_result(None)
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def __repr__(self):
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info = [self.__class__.__name__, f'transport={self._transport!r}']
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if self._reader is not None:
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info.append(f'reader={self._reader!r}')
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return '<{}>'.format(' '.join(info))
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@property
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def transport(self):
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return self._transport
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def write(self, data):
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self._transport.write(data)
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def writelines(self, data):
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self._transport.writelines(data)
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def write_eof(self):
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||||
return self._transport.write_eof()
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||||
def can_write_eof(self):
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||||
return self._transport.can_write_eof()
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||||
|
||||
def close(self):
|
||||
return self._transport.close()
|
||||
|
||||
def is_closing(self):
|
||||
return self._transport.is_closing()
|
||||
|
||||
async def wait_closed(self):
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||||
await self._protocol._get_close_waiter(self)
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||||
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||||
def get_extra_info(self, name, default=None):
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||||
return self._transport.get_extra_info(name, default)
|
||||
|
||||
async def drain(self):
|
||||
"""Flush the write buffer.
|
||||
|
||||
The intended use is to write
|
||||
|
||||
w.write(data)
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||||
await w.drain()
|
||||
"""
|
||||
if self._reader is not None:
|
||||
exc = self._reader.exception()
|
||||
if exc is not None:
|
||||
raise exc
|
||||
if self._transport.is_closing():
|
||||
# Wait for protocol.connection_lost() call
|
||||
# Raise connection closing error if any,
|
||||
# ConnectionResetError otherwise
|
||||
# Yield to the event loop so connection_lost() may be
|
||||
# called. Without this, _drain_helper() would return
|
||||
# immediately, and code that calls
|
||||
# write(...); await drain()
|
||||
# in a loop would never call connection_lost(), so it
|
||||
# would not see an error when the socket is closed.
|
||||
await sleep(0)
|
||||
await self._protocol._drain_helper()
|
||||
|
||||
async def start_tls(self, sslcontext, *,
|
||||
server_hostname=None,
|
||||
ssl_handshake_timeout=None,
|
||||
ssl_shutdown_timeout=None):
|
||||
"""Upgrade an existing stream-based connection to TLS."""
|
||||
server_side = self._protocol._client_connected_cb is not None
|
||||
protocol = self._protocol
|
||||
await self.drain()
|
||||
new_transport = await self._loop.start_tls( # type: ignore
|
||||
self._transport, protocol, sslcontext,
|
||||
server_side=server_side, server_hostname=server_hostname,
|
||||
ssl_handshake_timeout=ssl_handshake_timeout,
|
||||
ssl_shutdown_timeout=ssl_shutdown_timeout)
|
||||
self._transport = new_transport
|
||||
protocol._replace_transport(new_transport)
|
||||
|
||||
def __del__(self, warnings=warnings):
|
||||
if not self._transport.is_closing():
|
||||
if self._loop.is_closed():
|
||||
warnings.warn("loop is closed", ResourceWarning)
|
||||
else:
|
||||
self.close()
|
||||
warnings.warn(f"unclosed {self!r}", ResourceWarning)
|
||||
|
||||
class StreamReader:
|
||||
|
||||
_source_traceback = None
|
||||
|
||||
def __init__(self, limit=_DEFAULT_LIMIT, loop=None):
|
||||
# The line length limit is a security feature;
|
||||
# it also doubles as half the buffer limit.
|
||||
|
||||
if limit <= 0:
|
||||
raise ValueError('Limit cannot be <= 0')
|
||||
|
||||
self._limit = limit
|
||||
if loop is None:
|
||||
self._loop = events.get_event_loop()
|
||||
else:
|
||||
self._loop = loop
|
||||
self._buffer = bytearray()
|
||||
self._eof = False # Whether we're done.
|
||||
self._waiter = None # A future used by _wait_for_data()
|
||||
self._exception = None
|
||||
self._transport = None
|
||||
self._paused = False
|
||||
if self._loop.get_debug():
|
||||
self._source_traceback = format_helpers.extract_stack(
|
||||
sys._getframe(1))
|
||||
|
||||
def __repr__(self):
|
||||
info = ['StreamReader']
|
||||
if self._buffer:
|
||||
info.append(f'{len(self._buffer)} bytes')
|
||||
if self._eof:
|
||||
info.append('eof')
|
||||
if self._limit != _DEFAULT_LIMIT:
|
||||
info.append(f'limit={self._limit}')
|
||||
if self._waiter:
|
||||
info.append(f'waiter={self._waiter!r}')
|
||||
if self._exception:
|
||||
info.append(f'exception={self._exception!r}')
|
||||
if self._transport:
|
||||
info.append(f'transport={self._transport!r}')
|
||||
if self._paused:
|
||||
info.append('paused')
|
||||
return '<{}>'.format(' '.join(info))
|
||||
|
||||
def exception(self):
|
||||
return self._exception
|
||||
|
||||
def set_exception(self, exc):
|
||||
self._exception = exc
|
||||
|
||||
waiter = self._waiter
|
||||
if waiter is not None:
|
||||
self._waiter = None
|
||||
if not waiter.cancelled():
|
||||
waiter.set_exception(exc)
|
||||
|
||||
def _wakeup_waiter(self):
|
||||
"""Wakeup read*() functions waiting for data or EOF."""
|
||||
waiter = self._waiter
|
||||
if waiter is not None:
|
||||
self._waiter = None
|
||||
if not waiter.cancelled():
|
||||
waiter.set_result(None)
|
||||
|
||||
def set_transport(self, transport):
|
||||
assert self._transport is None, 'Transport already set'
|
||||
self._transport = transport
|
||||
|
||||
def _maybe_resume_transport(self):
|
||||
if self._paused and len(self._buffer) <= self._limit:
|
||||
self._paused = False
|
||||
self._transport.resume_reading()
|
||||
|
||||
def feed_eof(self):
|
||||
self._eof = True
|
||||
self._wakeup_waiter()
|
||||
|
||||
def at_eof(self):
|
||||
"""Return True if the buffer is empty and 'feed_eof' was called."""
|
||||
return self._eof and not self._buffer
|
||||
|
||||
def feed_data(self, data):
|
||||
assert not self._eof, 'feed_data after feed_eof'
|
||||
|
||||
if not data:
|
||||
return
|
||||
|
||||
self._buffer.extend(data)
|
||||
self._wakeup_waiter()
|
||||
|
||||
if (self._transport is not None and
|
||||
not self._paused and
|
||||
len(self._buffer) > 2 * self._limit):
|
||||
try:
|
||||
self._transport.pause_reading()
|
||||
except NotImplementedError:
|
||||
# The transport can't be paused.
|
||||
# We'll just have to buffer all data.
|
||||
# Forget the transport so we don't keep trying.
|
||||
self._transport = None
|
||||
else:
|
||||
self._paused = True
|
||||
|
||||
async def _wait_for_data(self, func_name):
|
||||
"""Wait until feed_data() or feed_eof() is called.
|
||||
|
||||
If stream was paused, automatically resume it.
|
||||
"""
|
||||
# StreamReader uses a future to link the protocol feed_data() method
|
||||
# to a read coroutine. Running two read coroutines at the same time
|
||||
# would have an unexpected behaviour. It would not possible to know
|
||||
# which coroutine would get the next data.
|
||||
if self._waiter is not None:
|
||||
raise RuntimeError(
|
||||
f'{func_name}() called while another coroutine is '
|
||||
f'already waiting for incoming data')
|
||||
|
||||
assert not self._eof, '_wait_for_data after EOF'
|
||||
|
||||
# Waiting for data while paused will make deadlock, so prevent it.
|
||||
# This is essential for readexactly(n) for case when n > self._limit.
|
||||
if self._paused:
|
||||
self._paused = False
|
||||
self._transport.resume_reading()
|
||||
|
||||
self._waiter = self._loop.create_future()
|
||||
try:
|
||||
await self._waiter
|
||||
finally:
|
||||
self._waiter = None
|
||||
|
||||
async def readline(self):
|
||||
"""Read chunk of data from the stream until newline (b'\n') is found.
|
||||
|
||||
On success, return chunk that ends with newline. If only partial
|
||||
line can be read due to EOF, return incomplete line without
|
||||
terminating newline. When EOF was reached while no bytes read, empty
|
||||
bytes object is returned.
|
||||
|
||||
If limit is reached, ValueError will be raised. In that case, if
|
||||
newline was found, complete line including newline will be removed
|
||||
from internal buffer. Else, internal buffer will be cleared. Limit is
|
||||
compared against part of the line without newline.
|
||||
|
||||
If stream was paused, this function will automatically resume it if
|
||||
needed.
|
||||
"""
|
||||
sep = b'\n'
|
||||
seplen = len(sep)
|
||||
try:
|
||||
line = await self.readuntil(sep)
|
||||
except exceptions.IncompleteReadError as e:
|
||||
return e.partial
|
||||
except exceptions.LimitOverrunError as e:
|
||||
if self._buffer.startswith(sep, e.consumed):
|
||||
del self._buffer[:e.consumed + seplen]
|
||||
else:
|
||||
self._buffer.clear()
|
||||
self._maybe_resume_transport()
|
||||
raise ValueError(e.args[0])
|
||||
return line
|
||||
|
||||
async def readuntil(self, separator=b'\n'):
|
||||
"""Read data from the stream until ``separator`` is found.
|
||||
|
||||
On success, the data and separator will be removed from the
|
||||
internal buffer (consumed). Returned data will include the
|
||||
separator at the end.
|
||||
|
||||
Configured stream limit is used to check result. Limit sets the
|
||||
maximal length of data that can be returned, not counting the
|
||||
separator.
|
||||
|
||||
If an EOF occurs and the complete separator is still not found,
|
||||
an IncompleteReadError exception will be raised, and the internal
|
||||
buffer will be reset. The IncompleteReadError.partial attribute
|
||||
may contain the separator partially.
|
||||
|
||||
If the data cannot be read because of over limit, a
|
||||
LimitOverrunError exception will be raised, and the data
|
||||
will be left in the internal buffer, so it can be read again.
|
||||
|
||||
The ``separator`` may also be a tuple of separators. In this
|
||||
case the return value will be the shortest possible that has any
|
||||
separator as the suffix. For the purposes of LimitOverrunError,
|
||||
the shortest possible separator is considered to be the one that
|
||||
matched.
|
||||
"""
|
||||
if isinstance(separator, tuple):
|
||||
# Makes sure shortest matches wins
|
||||
separator = sorted(separator, key=len)
|
||||
else:
|
||||
separator = [separator]
|
||||
if not separator:
|
||||
raise ValueError('Separator should contain at least one element')
|
||||
min_seplen = len(separator[0])
|
||||
max_seplen = len(separator[-1])
|
||||
if min_seplen == 0:
|
||||
raise ValueError('Separator should be at least one-byte string')
|
||||
|
||||
if self._exception is not None:
|
||||
raise self._exception
|
||||
|
||||
# Consume whole buffer except last bytes, which length is
|
||||
# one less than max_seplen. Let's check corner cases with
|
||||
# separator[-1]='SEPARATOR':
|
||||
# * we have received almost complete separator (without last
|
||||
# byte). i.e buffer='some textSEPARATO'. In this case we
|
||||
# can safely consume max_seplen - 1 bytes.
|
||||
# * last byte of buffer is first byte of separator, i.e.
|
||||
# buffer='abcdefghijklmnopqrS'. We may safely consume
|
||||
# everything except that last byte, but this require to
|
||||
# analyze bytes of buffer that match partial separator.
|
||||
# This is slow and/or require FSM. For this case our
|
||||
# implementation is not optimal, since require rescanning
|
||||
# of data that is known to not belong to separator. In
|
||||
# real world, separator will not be so long to notice
|
||||
# performance problems. Even when reading MIME-encoded
|
||||
# messages :)
|
||||
|
||||
# `offset` is the number of bytes from the beginning of the buffer
|
||||
# where there is no occurrence of any `separator`.
|
||||
offset = 0
|
||||
|
||||
# Loop until we find a `separator` in the buffer, exceed the buffer size,
|
||||
# or an EOF has happened.
|
||||
while True:
|
||||
buflen = len(self._buffer)
|
||||
|
||||
# Check if we now have enough data in the buffer for shortest
|
||||
# separator to fit.
|
||||
if buflen - offset >= min_seplen:
|
||||
match_start = None
|
||||
match_end = None
|
||||
for sep in separator:
|
||||
isep = self._buffer.find(sep, offset)
|
||||
|
||||
if isep != -1:
|
||||
# `separator` is in the buffer. `match_start` and
|
||||
# `match_end` will be used later to retrieve the
|
||||
# data.
|
||||
end = isep + len(sep)
|
||||
if match_end is None or end < match_end:
|
||||
match_end = end
|
||||
match_start = isep
|
||||
if match_end is not None:
|
||||
break
|
||||
|
||||
# see upper comment for explanation.
|
||||
offset = max(0, buflen + 1 - max_seplen)
|
||||
if offset > self._limit:
|
||||
raise exceptions.LimitOverrunError(
|
||||
'Separator is not found, and chunk exceed the limit',
|
||||
offset)
|
||||
|
||||
# Complete message (with full separator) may be present in buffer
|
||||
# even when EOF flag is set. This may happen when the last chunk
|
||||
# adds data which makes separator be found. That's why we check for
|
||||
# EOF *after* inspecting the buffer.
|
||||
if self._eof:
|
||||
chunk = bytes(self._buffer)
|
||||
self._buffer.clear()
|
||||
raise exceptions.IncompleteReadError(chunk, None)
|
||||
|
||||
# _wait_for_data() will resume reading if stream was paused.
|
||||
await self._wait_for_data('readuntil')
|
||||
|
||||
if match_start > self._limit:
|
||||
raise exceptions.LimitOverrunError(
|
||||
'Separator is found, but chunk is longer than limit', match_start)
|
||||
|
||||
chunk = self._buffer[:match_end]
|
||||
del self._buffer[:match_end]
|
||||
self._maybe_resume_transport()
|
||||
return bytes(chunk)
|
||||
|
||||
async def read(self, n=-1):
|
||||
"""Read up to `n` bytes from the stream.
|
||||
|
||||
If `n` is not provided or set to -1,
|
||||
read until EOF, then return all read bytes.
|
||||
If EOF was received and the internal buffer is empty,
|
||||
return an empty bytes object.
|
||||
|
||||
If `n` is 0, return an empty bytes object immediately.
|
||||
|
||||
If `n` is positive, return at most `n` available bytes
|
||||
as soon as at least 1 byte is available in the internal buffer.
|
||||
If EOF is received before any byte is read, return an empty
|
||||
bytes object.
|
||||
|
||||
Returned value is not limited with limit, configured at stream
|
||||
creation.
|
||||
|
||||
If stream was paused, this function will automatically resume it if
|
||||
needed.
|
||||
"""
|
||||
|
||||
if self._exception is not None:
|
||||
raise self._exception
|
||||
|
||||
if n == 0:
|
||||
return b''
|
||||
|
||||
if n < 0:
|
||||
# This used to just loop creating a new waiter hoping to
|
||||
# collect everything in self._buffer, but that would
|
||||
# deadlock if the subprocess sends more than self.limit
|
||||
# bytes. So just call self.read(self._limit) until EOF.
|
||||
blocks = []
|
||||
while True:
|
||||
block = await self.read(self._limit)
|
||||
if not block:
|
||||
break
|
||||
blocks.append(block)
|
||||
return b''.join(blocks)
|
||||
|
||||
if not self._buffer and not self._eof:
|
||||
await self._wait_for_data('read')
|
||||
|
||||
# This will work right even if buffer is less than n bytes
|
||||
data = bytes(memoryview(self._buffer)[:n])
|
||||
del self._buffer[:n]
|
||||
|
||||
self._maybe_resume_transport()
|
||||
return data
|
||||
|
||||
async def readexactly(self, n):
|
||||
"""Read exactly `n` bytes.
|
||||
|
||||
Raise an IncompleteReadError if EOF is reached before `n` bytes can be
|
||||
read. The IncompleteReadError.partial attribute of the exception will
|
||||
contain the partial read bytes.
|
||||
|
||||
if n is zero, return empty bytes object.
|
||||
|
||||
Returned value is not limited with limit, configured at stream
|
||||
creation.
|
||||
|
||||
If stream was paused, this function will automatically resume it if
|
||||
needed.
|
||||
"""
|
||||
if n < 0:
|
||||
raise ValueError('readexactly size can not be less than zero')
|
||||
|
||||
if self._exception is not None:
|
||||
raise self._exception
|
||||
|
||||
if n == 0:
|
||||
return b''
|
||||
|
||||
while len(self._buffer) < n:
|
||||
if self._eof:
|
||||
incomplete = bytes(self._buffer)
|
||||
self._buffer.clear()
|
||||
raise exceptions.IncompleteReadError(incomplete, n)
|
||||
|
||||
await self._wait_for_data('readexactly')
|
||||
|
||||
if len(self._buffer) == n:
|
||||
data = bytes(self._buffer)
|
||||
self._buffer.clear()
|
||||
else:
|
||||
data = bytes(memoryview(self._buffer)[:n])
|
||||
del self._buffer[:n]
|
||||
self._maybe_resume_transport()
|
||||
return data
|
||||
|
||||
def __aiter__(self):
|
||||
return self
|
||||
|
||||
async def __anext__(self):
|
||||
val = await self.readline()
|
||||
if val == b'':
|
||||
raise StopAsyncIteration
|
||||
return val
|
||||
Reference in New Issue
Block a user