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.
631 lines
20 KiB
631 lines
20 KiB
import asyncio
|
|
import collections
|
|
import warnings
|
|
from typing import List # noqa
|
|
from typing import Awaitable, Callable, Generic, Optional, Tuple, TypeVar
|
|
|
|
from .base_protocol import BaseProtocol
|
|
from .helpers import BaseTimerContext, set_exception, set_result
|
|
from .log import internal_logger
|
|
|
|
try: # pragma: no cover
|
|
from typing import Deque # noqa
|
|
except ImportError:
|
|
from typing_extensions import Deque # noqa
|
|
|
|
|
|
__all__ = (
|
|
'EMPTY_PAYLOAD', 'EofStream', 'StreamReader', 'DataQueue',
|
|
'FlowControlDataQueue')
|
|
|
|
DEFAULT_LIMIT = 2 ** 16
|
|
|
|
_T = TypeVar('_T')
|
|
|
|
|
|
class EofStream(Exception):
|
|
"""eof stream indication."""
|
|
|
|
|
|
class AsyncStreamIterator(Generic[_T]):
|
|
|
|
def __init__(self, read_func: Callable[[], Awaitable[_T]]) -> None:
|
|
self.read_func = read_func
|
|
|
|
def __aiter__(self) -> 'AsyncStreamIterator[_T]':
|
|
return self
|
|
|
|
async def __anext__(self) -> _T:
|
|
try:
|
|
rv = await self.read_func()
|
|
except EofStream:
|
|
raise StopAsyncIteration # NOQA
|
|
if rv == b'':
|
|
raise StopAsyncIteration # NOQA
|
|
return rv
|
|
|
|
|
|
class ChunkTupleAsyncStreamIterator:
|
|
|
|
def __init__(self, stream: 'StreamReader') -> None:
|
|
self._stream = stream
|
|
|
|
def __aiter__(self) -> 'ChunkTupleAsyncStreamIterator':
|
|
return self
|
|
|
|
async def __anext__(self) -> Tuple[bytes, bool]:
|
|
rv = await self._stream.readchunk()
|
|
if rv == (b'', False):
|
|
raise StopAsyncIteration # NOQA
|
|
return rv
|
|
|
|
|
|
class AsyncStreamReaderMixin:
|
|
|
|
def __aiter__(self) -> AsyncStreamIterator[bytes]:
|
|
return AsyncStreamIterator(self.readline) # type: ignore
|
|
|
|
def iter_chunked(self, n: int) -> AsyncStreamIterator[bytes]:
|
|
"""Returns an asynchronous iterator that yields chunks of size n.
|
|
|
|
Python-3.5 available for Python 3.5+ only
|
|
"""
|
|
return AsyncStreamIterator(lambda: self.read(n)) # type: ignore
|
|
|
|
def iter_any(self) -> AsyncStreamIterator[bytes]:
|
|
"""Returns an asynchronous iterator that yields all the available
|
|
data as soon as it is received
|
|
|
|
Python-3.5 available for Python 3.5+ only
|
|
"""
|
|
return AsyncStreamIterator(self.readany) # type: ignore
|
|
|
|
def iter_chunks(self) -> ChunkTupleAsyncStreamIterator:
|
|
"""Returns an asynchronous iterator that yields chunks of data
|
|
as they are received by the server. The yielded objects are tuples
|
|
of (bytes, bool) as returned by the StreamReader.readchunk method.
|
|
|
|
Python-3.5 available for Python 3.5+ only
|
|
"""
|
|
return ChunkTupleAsyncStreamIterator(self) # type: ignore
|
|
|
|
|
|
class StreamReader(AsyncStreamReaderMixin):
|
|
"""An enhancement of asyncio.StreamReader.
|
|
|
|
Supports asynchronous iteration by line, chunk or as available::
|
|
|
|
async for line in reader:
|
|
...
|
|
async for chunk in reader.iter_chunked(1024):
|
|
...
|
|
async for slice in reader.iter_any():
|
|
...
|
|
|
|
"""
|
|
|
|
total_bytes = 0
|
|
|
|
def __init__(self, protocol: BaseProtocol,
|
|
*, limit: int=DEFAULT_LIMIT,
|
|
timer: Optional[BaseTimerContext]=None,
|
|
loop: Optional[asyncio.AbstractEventLoop]=None) -> None:
|
|
self._protocol = protocol
|
|
self._low_water = limit
|
|
self._high_water = limit * 2
|
|
if loop is None:
|
|
loop = asyncio.get_event_loop()
|
|
self._loop = loop
|
|
self._size = 0
|
|
self._cursor = 0
|
|
self._http_chunk_splits = None # type: Optional[List[int]]
|
|
self._buffer = collections.deque() # type: Deque[bytes]
|
|
self._buffer_offset = 0
|
|
self._eof = False
|
|
self._waiter = None # type: Optional[asyncio.Future[bool]]
|
|
self._eof_waiter = None # type: Optional[asyncio.Future[bool]]
|
|
self._exception = None # type: Optional[BaseException]
|
|
self._timer = timer
|
|
self._eof_callbacks = [] # type: List[Callable[[], None]]
|
|
|
|
def __repr__(self) -> str:
|
|
info = [self.__class__.__name__]
|
|
if self._size:
|
|
info.append('%d bytes' % self._size)
|
|
if self._eof:
|
|
info.append('eof')
|
|
if self._low_water != DEFAULT_LIMIT:
|
|
info.append('low=%d high=%d' % (self._low_water, self._high_water))
|
|
if self._waiter:
|
|
info.append('w=%r' % self._waiter)
|
|
if self._exception:
|
|
info.append('e=%r' % self._exception)
|
|
return '<%s>' % ' '.join(info)
|
|
|
|
def exception(self) -> Optional[BaseException]:
|
|
return self._exception
|
|
|
|
def set_exception(self, exc: BaseException) -> None:
|
|
self._exception = exc
|
|
self._eof_callbacks.clear()
|
|
|
|
waiter = self._waiter
|
|
if waiter is not None:
|
|
self._waiter = None
|
|
set_exception(waiter, exc)
|
|
|
|
waiter = self._eof_waiter
|
|
if waiter is not None:
|
|
set_exception(waiter, exc)
|
|
self._eof_waiter = None
|
|
|
|
def on_eof(self, callback: Callable[[], None]) -> None:
|
|
if self._eof:
|
|
try:
|
|
callback()
|
|
except Exception:
|
|
internal_logger.exception('Exception in eof callback')
|
|
else:
|
|
self._eof_callbacks.append(callback)
|
|
|
|
def feed_eof(self) -> None:
|
|
self._eof = True
|
|
|
|
waiter = self._waiter
|
|
if waiter is not None:
|
|
self._waiter = None
|
|
set_result(waiter, True)
|
|
|
|
waiter = self._eof_waiter
|
|
if waiter is not None:
|
|
self._eof_waiter = None
|
|
set_result(waiter, True)
|
|
|
|
for cb in self._eof_callbacks:
|
|
try:
|
|
cb()
|
|
except Exception:
|
|
internal_logger.exception('Exception in eof callback')
|
|
|
|
self._eof_callbacks.clear()
|
|
|
|
def is_eof(self) -> bool:
|
|
"""Return True if 'feed_eof' was called."""
|
|
return self._eof
|
|
|
|
def at_eof(self) -> bool:
|
|
"""Return True if the buffer is empty and 'feed_eof' was called."""
|
|
return self._eof and not self._buffer
|
|
|
|
async def wait_eof(self) -> None:
|
|
if self._eof:
|
|
return
|
|
|
|
assert self._eof_waiter is None
|
|
self._eof_waiter = self._loop.create_future()
|
|
try:
|
|
await self._eof_waiter
|
|
finally:
|
|
self._eof_waiter = None
|
|
|
|
def unread_data(self, data: bytes) -> None:
|
|
""" rollback reading some data from stream, inserting it to buffer head.
|
|
"""
|
|
warnings.warn("unread_data() is deprecated "
|
|
"and will be removed in future releases (#3260)",
|
|
DeprecationWarning,
|
|
stacklevel=2)
|
|
if not data:
|
|
return
|
|
|
|
if self._buffer_offset:
|
|
self._buffer[0] = self._buffer[0][self._buffer_offset:]
|
|
self._buffer_offset = 0
|
|
self._size += len(data)
|
|
self._cursor -= len(data)
|
|
self._buffer.appendleft(data)
|
|
self._eof_counter = 0
|
|
|
|
# TODO: size is ignored, remove the param later
|
|
def feed_data(self, data: bytes, size: int=0) -> None:
|
|
assert not self._eof, 'feed_data after feed_eof'
|
|
|
|
if not data:
|
|
return
|
|
|
|
self._size += len(data)
|
|
self._buffer.append(data)
|
|
self.total_bytes += len(data)
|
|
|
|
waiter = self._waiter
|
|
if waiter is not None:
|
|
self._waiter = None
|
|
set_result(waiter, False)
|
|
|
|
if (self._size > self._high_water and
|
|
not self._protocol._reading_paused):
|
|
self._protocol.pause_reading()
|
|
|
|
def begin_http_chunk_receiving(self) -> None:
|
|
if self._http_chunk_splits is None:
|
|
if self.total_bytes:
|
|
raise RuntimeError("Called begin_http_chunk_receiving when"
|
|
"some data was already fed")
|
|
self._http_chunk_splits = []
|
|
|
|
def end_http_chunk_receiving(self) -> None:
|
|
if self._http_chunk_splits is None:
|
|
raise RuntimeError("Called end_chunk_receiving without calling "
|
|
"begin_chunk_receiving first")
|
|
|
|
# self._http_chunk_splits contains logical byte offsets from start of
|
|
# the body transfer. Each offset is the offset of the end of a chunk.
|
|
# "Logical" means bytes, accessible for a user.
|
|
# If no chunks containig logical data were received, current position
|
|
# is difinitely zero.
|
|
pos = self._http_chunk_splits[-1] if self._http_chunk_splits else 0
|
|
|
|
if self.total_bytes == pos:
|
|
# We should not add empty chunks here. So we check for that.
|
|
# Note, when chunked + gzip is used, we can receive a chunk
|
|
# of compressed data, but that data may not be enough for gzip FSM
|
|
# to yield any uncompressed data. That's why current position may
|
|
# not change after receiving a chunk.
|
|
return
|
|
|
|
self._http_chunk_splits.append(self.total_bytes)
|
|
|
|
# wake up readchunk when end of http chunk received
|
|
waiter = self._waiter
|
|
if waiter is not None:
|
|
self._waiter = None
|
|
set_result(waiter, False)
|
|
|
|
async def _wait(self, func_name: str) -> None:
|
|
# 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('%s() called while another coroutine is '
|
|
'already waiting for incoming data' % func_name)
|
|
|
|
waiter = self._waiter = self._loop.create_future()
|
|
try:
|
|
if self._timer:
|
|
with self._timer:
|
|
await waiter
|
|
else:
|
|
await waiter
|
|
finally:
|
|
self._waiter = None
|
|
|
|
async def readline(self) -> bytes:
|
|
if self._exception is not None:
|
|
raise self._exception
|
|
|
|
line = []
|
|
line_size = 0
|
|
not_enough = True
|
|
|
|
while not_enough:
|
|
while self._buffer and not_enough:
|
|
offset = self._buffer_offset
|
|
ichar = self._buffer[0].find(b'\n', offset) + 1
|
|
# Read from current offset to found b'\n' or to the end.
|
|
data = self._read_nowait_chunk(ichar - offset if ichar else -1)
|
|
line.append(data)
|
|
line_size += len(data)
|
|
if ichar:
|
|
not_enough = False
|
|
|
|
if line_size > self._high_water:
|
|
raise ValueError('Line is too long')
|
|
|
|
if self._eof:
|
|
break
|
|
|
|
if not_enough:
|
|
await self._wait('readline')
|
|
|
|
return b''.join(line)
|
|
|
|
async def read(self, n: int=-1) -> bytes:
|
|
if self._exception is not None:
|
|
raise self._exception
|
|
|
|
# migration problem; with DataQueue you have to catch
|
|
# EofStream exception, so common way is to run payload.read() inside
|
|
# infinite loop. what can cause real infinite loop with StreamReader
|
|
# lets keep this code one major release.
|
|
if __debug__:
|
|
if self._eof and not self._buffer:
|
|
self._eof_counter = getattr(self, '_eof_counter', 0) + 1
|
|
if self._eof_counter > 5:
|
|
internal_logger.warning(
|
|
'Multiple access to StreamReader in eof state, '
|
|
'might be infinite loop.', stack_info=True)
|
|
|
|
if not n:
|
|
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.readany() until EOF.
|
|
blocks = []
|
|
while True:
|
|
block = await self.readany()
|
|
if not block:
|
|
break
|
|
blocks.append(block)
|
|
return b''.join(blocks)
|
|
|
|
# TODO: should be `if` instead of `while`
|
|
# because waiter maybe triggered on chunk end,
|
|
# without feeding any data
|
|
while not self._buffer and not self._eof:
|
|
await self._wait('read')
|
|
|
|
return self._read_nowait(n)
|
|
|
|
async def readany(self) -> bytes:
|
|
if self._exception is not None:
|
|
raise self._exception
|
|
|
|
# TODO: should be `if` instead of `while`
|
|
# because waiter maybe triggered on chunk end,
|
|
# without feeding any data
|
|
while not self._buffer and not self._eof:
|
|
await self._wait('readany')
|
|
|
|
return self._read_nowait(-1)
|
|
|
|
async def readchunk(self) -> Tuple[bytes, bool]:
|
|
"""Returns a tuple of (data, end_of_http_chunk). When chunked transfer
|
|
encoding is used, end_of_http_chunk is a boolean indicating if the end
|
|
of the data corresponds to the end of a HTTP chunk , otherwise it is
|
|
always False.
|
|
"""
|
|
if self._exception is not None:
|
|
raise self._exception
|
|
|
|
if not self._buffer and not self._eof:
|
|
if (self._http_chunk_splits and
|
|
self._cursor == self._http_chunk_splits[0]):
|
|
# end of http chunk without available data
|
|
self._http_chunk_splits = self._http_chunk_splits[1:]
|
|
return (b"", True)
|
|
await self._wait('readchunk')
|
|
|
|
if not self._buffer and not self._http_chunk_splits:
|
|
# end of file
|
|
return (b"", False)
|
|
elif self._http_chunk_splits is not None:
|
|
while self._http_chunk_splits:
|
|
pos = self._http_chunk_splits[0]
|
|
self._http_chunk_splits = self._http_chunk_splits[1:]
|
|
if pos == self._cursor:
|
|
return (b"", True)
|
|
if pos > self._cursor:
|
|
return (self._read_nowait(pos-self._cursor), True)
|
|
return (self._read_nowait(-1), False)
|
|
else:
|
|
return (self._read_nowait_chunk(-1), False)
|
|
|
|
async def readexactly(self, n: int) -> bytes:
|
|
if self._exception is not None:
|
|
raise self._exception
|
|
|
|
blocks = [] # type: List[bytes]
|
|
while n > 0:
|
|
block = await self.read(n)
|
|
if not block:
|
|
partial = b''.join(blocks)
|
|
raise asyncio.streams.IncompleteReadError(
|
|
partial, len(partial) + n)
|
|
blocks.append(block)
|
|
n -= len(block)
|
|
|
|
return b''.join(blocks)
|
|
|
|
def read_nowait(self, n: int=-1) -> bytes:
|
|
# default was changed to be consistent with .read(-1)
|
|
#
|
|
# I believe the most users don't know about the method and
|
|
# they are not affected.
|
|
if self._exception is not None:
|
|
raise self._exception
|
|
|
|
if self._waiter and not self._waiter.done():
|
|
raise RuntimeError(
|
|
'Called while some coroutine is waiting for incoming data.')
|
|
|
|
return self._read_nowait(n)
|
|
|
|
def _read_nowait_chunk(self, n: int) -> bytes:
|
|
first_buffer = self._buffer[0]
|
|
offset = self._buffer_offset
|
|
if n != -1 and len(first_buffer) - offset > n:
|
|
data = first_buffer[offset:offset + n]
|
|
self._buffer_offset += n
|
|
|
|
elif offset:
|
|
self._buffer.popleft()
|
|
data = first_buffer[offset:]
|
|
self._buffer_offset = 0
|
|
|
|
else:
|
|
data = self._buffer.popleft()
|
|
|
|
self._size -= len(data)
|
|
self._cursor += len(data)
|
|
|
|
if self._size < self._low_water and self._protocol._reading_paused:
|
|
self._protocol.resume_reading()
|
|
return data
|
|
|
|
def _read_nowait(self, n: int) -> bytes:
|
|
chunks = []
|
|
|
|
while self._buffer:
|
|
chunk = self._read_nowait_chunk(n)
|
|
chunks.append(chunk)
|
|
if n != -1:
|
|
n -= len(chunk)
|
|
if n == 0:
|
|
break
|
|
|
|
return b''.join(chunks) if chunks else b''
|
|
|
|
|
|
class EmptyStreamReader(AsyncStreamReaderMixin):
|
|
|
|
def exception(self) -> Optional[BaseException]:
|
|
return None
|
|
|
|
def set_exception(self, exc: BaseException) -> None:
|
|
pass
|
|
|
|
def on_eof(self, callback: Callable[[], None]) -> None:
|
|
try:
|
|
callback()
|
|
except Exception:
|
|
internal_logger.exception('Exception in eof callback')
|
|
|
|
def feed_eof(self) -> None:
|
|
pass
|
|
|
|
def is_eof(self) -> bool:
|
|
return True
|
|
|
|
def at_eof(self) -> bool:
|
|
return True
|
|
|
|
async def wait_eof(self) -> None:
|
|
return
|
|
|
|
def feed_data(self, data: bytes, n: int=0) -> None:
|
|
pass
|
|
|
|
async def readline(self) -> bytes:
|
|
return b''
|
|
|
|
async def read(self, n: int=-1) -> bytes:
|
|
return b''
|
|
|
|
async def readany(self) -> bytes:
|
|
return b''
|
|
|
|
async def readchunk(self) -> Tuple[bytes, bool]:
|
|
return (b'', True)
|
|
|
|
async def readexactly(self, n: int) -> bytes:
|
|
raise asyncio.streams.IncompleteReadError(b'', n)
|
|
|
|
def read_nowait(self) -> bytes:
|
|
return b''
|
|
|
|
|
|
EMPTY_PAYLOAD = EmptyStreamReader()
|
|
|
|
|
|
class DataQueue(Generic[_T]):
|
|
"""DataQueue is a general-purpose blocking queue with one reader."""
|
|
|
|
def __init__(self, loop: asyncio.AbstractEventLoop) -> None:
|
|
self._loop = loop
|
|
self._eof = False
|
|
self._waiter = None # type: Optional[asyncio.Future[bool]]
|
|
self._exception = None # type: Optional[BaseException]
|
|
self._size = 0
|
|
self._buffer = collections.deque() # type: Deque[Tuple[_T, int]]
|
|
|
|
def __len__(self) -> int:
|
|
return len(self._buffer)
|
|
|
|
def is_eof(self) -> bool:
|
|
return self._eof
|
|
|
|
def at_eof(self) -> bool:
|
|
return self._eof and not self._buffer
|
|
|
|
def exception(self) -> Optional[BaseException]:
|
|
return self._exception
|
|
|
|
def set_exception(self, exc: BaseException) -> None:
|
|
self._eof = True
|
|
self._exception = exc
|
|
|
|
waiter = self._waiter
|
|
if waiter is not None:
|
|
set_exception(waiter, exc)
|
|
self._waiter = None
|
|
|
|
def feed_data(self, data: _T, size: int=0) -> None:
|
|
self._size += size
|
|
self._buffer.append((data, size))
|
|
|
|
waiter = self._waiter
|
|
if waiter is not None:
|
|
self._waiter = None
|
|
set_result(waiter, True)
|
|
|
|
def feed_eof(self) -> None:
|
|
self._eof = True
|
|
|
|
waiter = self._waiter
|
|
if waiter is not None:
|
|
self._waiter = None
|
|
set_result(waiter, False)
|
|
|
|
async def read(self) -> _T:
|
|
if not self._buffer and not self._eof:
|
|
assert not self._waiter
|
|
self._waiter = self._loop.create_future()
|
|
try:
|
|
await self._waiter
|
|
except (asyncio.CancelledError, asyncio.TimeoutError):
|
|
self._waiter = None
|
|
raise
|
|
|
|
if self._buffer:
|
|
data, size = self._buffer.popleft()
|
|
self._size -= size
|
|
return data
|
|
else:
|
|
if self._exception is not None:
|
|
raise self._exception
|
|
else:
|
|
raise EofStream
|
|
|
|
def __aiter__(self) -> AsyncStreamIterator[_T]:
|
|
return AsyncStreamIterator(self.read)
|
|
|
|
|
|
class FlowControlDataQueue(DataQueue[_T]):
|
|
"""FlowControlDataQueue resumes and pauses an underlying stream.
|
|
|
|
It is a destination for parsed data."""
|
|
|
|
def __init__(self, protocol: BaseProtocol, *,
|
|
limit: int=DEFAULT_LIMIT,
|
|
loop: asyncio.AbstractEventLoop) -> None:
|
|
super().__init__(loop=loop)
|
|
|
|
self._protocol = protocol
|
|
self._limit = limit * 2
|
|
|
|
def feed_data(self, data: _T, size: int=0) -> None:
|
|
super().feed_data(data, size)
|
|
|
|
if self._size > self._limit and not self._protocol._reading_paused:
|
|
self._protocol.pause_reading()
|
|
|
|
async def read(self) -> _T:
|
|
try:
|
|
return await super().read()
|
|
finally:
|
|
if self._size < self._limit and self._protocol._reading_paused:
|
|
self._protocol.resume_reading()
|