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"""Http related parsers and protocol."""
import asyncio
import zlib
from typing import Any, Awaitable, Callable, NamedTuple, Optional, Union # noqa
from multidict import CIMultiDict
from .abc import AbstractStreamWriter
from .base_protocol import BaseProtocol
from .helpers import NO_EXTENSIONS
__all__ = ("StreamWriter", "HttpVersion", "HttpVersion10", "HttpVersion11")
class HttpVersion(NamedTuple):
major: int
minor: int
HttpVersion10 = HttpVersion(1, 0)
HttpVersion11 = HttpVersion(1, 1)
_T_OnChunkSent = Optional[Callable[[bytes], Awaitable[None]]]
_T_OnHeadersSent = Optional[Callable[["CIMultiDict[str]"], Awaitable[None]]]
class StreamWriter(AbstractStreamWriter):
def __init__(
self,
protocol: BaseProtocol,
loop: asyncio.AbstractEventLoop,
on_chunk_sent: _T_OnChunkSent = None,
on_headers_sent: _T_OnHeadersSent = None,
) -> None:
self._protocol = protocol
self.loop = loop
self.length = None
self.chunked = False
self.buffer_size = 0
self.output_size = 0
self._eof = False
self._compress: Any = None
self._drain_waiter = None
self._on_chunk_sent: _T_OnChunkSent = on_chunk_sent
self._on_headers_sent: _T_OnHeadersSent = on_headers_sent
@property
def transport(self) -> Optional[asyncio.Transport]:
return self._protocol.transport
@property
def protocol(self) -> BaseProtocol:
return self._protocol
def enable_chunking(self) -> None:
self.chunked = True
def enable_compression(
self, encoding: str = "deflate", strategy: int = zlib.Z_DEFAULT_STRATEGY
) -> None:
zlib_mode = 16 + zlib.MAX_WBITS if encoding == "gzip" else zlib.MAX_WBITS
self._compress = zlib.compressobj(wbits=zlib_mode, strategy=strategy)
def _write(self, chunk: bytes) -> None:
size = len(chunk)
self.buffer_size += size
self.output_size += size
transport = self.transport
if not self._protocol.connected or transport is None or transport.is_closing():
raise ConnectionResetError("Cannot write to closing transport")
transport.write(chunk)
async def write(
self, chunk: bytes, *, drain: bool = True, LIMIT: int = 0x10000
) -> None:
"""Writes chunk of data to a stream.
write_eof() indicates end of stream.
writer can't be used after write_eof() method being called.
write() return drain future.
"""
if self._on_chunk_sent is not None:
await self._on_chunk_sent(chunk)
if isinstance(chunk, memoryview):
if chunk.nbytes != len(chunk):
# just reshape it
chunk = chunk.cast("c")
if self._compress is not None:
chunk = self._compress.compress(chunk)
if not chunk:
return
if self.length is not None:
chunk_len = len(chunk)
if self.length >= chunk_len:
self.length = self.length - chunk_len
else:
chunk = chunk[: self.length]
self.length = 0
if not chunk:
return
if chunk:
if self.chunked:
chunk_len_pre = ("%x\r\n" % len(chunk)).encode("ascii")
chunk = chunk_len_pre + chunk + b"\r\n"
self._write(chunk)
if self.buffer_size > LIMIT and drain:
self.buffer_size = 0
await self.drain()
async def write_headers(
self, status_line: str, headers: "CIMultiDict[str]"
) -> None:
"""Write request/response status and headers."""
if self._on_headers_sent is not None:
await self._on_headers_sent(headers)
# status + headers
buf = _serialize_headers(status_line, headers)
self._write(buf)
async def write_eof(self, chunk: bytes = b"") -> None:
if self._eof:
return
if chunk and self._on_chunk_sent is not None:
await self._on_chunk_sent(chunk)
if self._compress:
if chunk:
chunk = self._compress.compress(chunk)
chunk = chunk + self._compress.flush()
if chunk and self.chunked:
chunk_len = ("%x\r\n" % len(chunk)).encode("ascii")
chunk = chunk_len + chunk + b"\r\n0\r\n\r\n"
else:
if self.chunked:
if chunk:
chunk_len = ("%x\r\n" % len(chunk)).encode("ascii")
chunk = chunk_len + chunk + b"\r\n0\r\n\r\n"
else:
chunk = b"0\r\n\r\n"
if chunk:
self._write(chunk)
await self.drain()
self._eof = True
async def drain(self) -> None:
"""Flush the write buffer.
The intended use is to write
await w.write(data)
await w.drain()
"""
if self._protocol.transport is not None:
await self._protocol._drain_helper()
def _safe_header(string: str) -> str:
if "\r" in string or "\n" in string:
raise ValueError(
"Newline or carriage return detected in headers. "
"Potential header injection attack."
)
return string
def _py_serialize_headers(status_line: str, headers: "CIMultiDict[str]") -> bytes:
headers_gen = (_safe_header(k) + ": " + _safe_header(v) for k, v in headers.items())
line = status_line + "\r\n" + "\r\n".join(headers_gen) + "\r\n\r\n"
return line.encode("utf-8")
_serialize_headers = _py_serialize_headers
try:
import aiohttp._http_writer as _http_writer # type: ignore[import]
_c_serialize_headers = _http_writer._serialize_headers
if not NO_EXTENSIONS:
_serialize_headers = _c_serialize_headers
except ImportError:
pass