我正在尝试使用aiohttp来制作某种高级反向代理。
我想获取HTTP请求的内容并将其传递给新的HTTP请求,而不将其拉到内存中。尽管只有上游,但任务相当容易:aiohttp服务器以StreamReader
的形式返回请求内容,而aiohttp客户端可以接受StreamReader
作为请求主体。
问题是我想将原始请求发送到几个上游,或者例如,同时将内容发送到上游并将其写入磁盘。
是否有一些仪器可以播放StreamReader
的内容?
我尝试制作一些天真的广播器,但在大型物体上失败。我该怎么办?
class StreamBroadcast:
async def __do_broadcast(self):
while True:
chunk = await self.__source.read(self.__n)
if not chunk:
break
for output in self.__sinks:
output.feed_data(chunk)
for output in self.__sinks:
output.feed_eof()
def __init__(self, source: StreamReader, sinks_count: int, n: int = -1):
self.__source = source
self.__n = n
self.__sinks = [StreamReader() for i in range(sinks_count)]
self.__task = asyncio.create_task(self.__do_broadcast())
@property
def sinks(self) -> Iterable[StreamReader]:
return self.__sinks
@property
def ready(self) -> Task:
return self.__task
嗯,我浏览了asyncio
源,发现我应该使用Transport
在流上泵送数据。这是我的解决方案。
import asyncio
from asyncio import StreamReader, StreamWriter, ReadTransport, StreamReaderProtocol
from typing import Iterable
class _BroadcastReadTransport(ReadTransport):
"""
Internal class, is not meant to be instantiated manually
"""
def __init__(self, source: StreamReader, sinks: Iterable[StreamReader]):
super().__init__()
self.__source = source
self.__sinks = tuple(StreamReaderProtocol(s) for s in sinks)
for sink in sinks:
sink.set_transport(self)
self.__waiting_for_data = len(self.__sinks)
asyncio.create_task(self.__broadcast_next_chunk(), name='initial-chunk-broadcast')
def is_reading(self):
return self.__waiting_for_data == len(self.__sinks)
def pause_reading(self):
self.__waiting_for_data -= 1
async def __broadcast_next_chunk(self):
data = await self.__source.read()
if data:
for sink in self.__sinks:
sink.data_received(data)
if self.is_reading():
asyncio.create_task(self.__broadcast_next_chunk())
else:
for sink in self.__sinks:
sink.eof_received()
def resume_reading(self):
self.__waiting_for_data += 1
if self.__waiting_for_data == len(self.__sinks):
asyncio.create_task(self.__broadcast_next_chunk(), name='chunk-broadcast')
@property
def is_completed(self):
return self.__source.at_eof()
class StreamBroadcast:
def __init__(self, source: StreamReader, sinks_count: int):
self.__source = source
self.__sinks = tuple(StreamReader() for _ in range(sinks_count))
self.__transport = _BroadcastReadTransport(self.__source, self.__sinks)
@property
def sinks(self) -> Iterable[StreamReader]:
return self.__sinks
@property
def is_completed(self):
return self.__transport.is_completed
async def copy(reader: StreamReader, writer: StreamWriter, n: int = -1):
while True:
chunk = await reader.read(n)
if not chunk:
break
writer.write(chunk)
await writer.drain()
writer.close()
希望将其包装到pip模块中。