使用现有套接字连接的Python"请求"

Question

Python"请求"库目前风靡一时,因为它提供了用于发出HTTP请求的漂亮界面 - 但在它下面似乎有很多层间接 - 会话,HTTP适配器,最后是urllib3的机制.

如果我已经拥有一个打开的套接字,并希望使用"请求"在该套接字下发送HTTP响应并收到回复,那么在这个抽象堆栈中哪里是干预的正确位置？

如果没有某种干预(或自定义？),堆栈将尝试为我创建一个新的TCP/IP套接字,但在我的特定应用程序中,我的代码在代表我已建立连接之前不会被调用,所以我会如果我想能够使用请求的功能,需要说服请求在现有套接字上进行通话.

请求库:

http://pypi.python.org/pypi/requests

https://github.com/kennethreitz/requests

Answer 1

以下代码需要来自git(特别是requests.packages.urllib3.poolmanager.PoolManager._new_pool())的请求

我用它来测试它 ncat -v -l 127.0.0.1 8000

问题在于,连接不是由urllib3打开,而是由标准库中的httplib打开.

import socket
import requests
from requests.adapters import HTTPAdapter
from requests.packages.urllib3 import PoolManager, HTTPConnectionPool

try:
    from http.client import HTTPConnection
except ImportError:
    from httplib import HTTPConnection


class MyAdapter(HTTPAdapter):
    def init_poolmanager(self, connections, maxsize):
        self.poolmanager = MyPoolManager(num_pools=connections,
                                         maxsize=maxsize)


class MyPoolManager(PoolManager):
    def _new_pool(self, scheme, host, port):
        # Important!
        if scheme == 'http' and host == my_host and port == my_port:
            return MyHTTPConnectionPool(host, port, **self.connection_pool_kw)
        return super(PoolManager, self)._new_pool(self, scheme, host, port)


class MyHTTPConnectionPool(HTTPConnectionPool):
    def _new_conn(self):
        self.num_connections += 1
        return MyHTTPConnection(host=self.host,
                            port=self.port,
                            strict=self.strict)


class MyHTTPConnection(HTTPConnection):
    def connect(self):
        """Connect to the host and port specified in __init__."""
        # Original
        # self.sock = socket.create_connection((self.host, self.port),
        #                                    self.timeout, self.source_address)
        # Important!
        self.sock = my_socket
        if self._tunnel_host:
            self._tunnel()


if __name__ == '__main__':
    import time

    my_host = '127.0.0.1'
    my_port = 8000

    my_socket = socket.create_connection((my_host, my_port))
    time.sleep(4)
    s = requests.Session()
    s.mount('http://', MyAdapter())
    s.get('http://127.0.0.1:8000/foo')

编辑:

或直接monkeypatching连接池:

class MyHTTPConnection(HTTPConnection):
    def connect(self):
        self.sock = my_socket
        if self._tunnel_host:
            self._tunnel()

requests.packages.urllib3.connectionpool.HTTPConnection = MyHTTPConnection

if __name__ == '__main__':
    my_host = '127.0.0.1'
    my_port = 8000

    my_socket = socket.create_connection((my_host, my_port))
    requests.get('http://127.0.0.1:8000/foo')

Answer 2

直接去图书馆urllib3；urllib3.connectionpool它在模块中拥有一个连接池。

您可以更换池或通过破解poolmanager模块来调整它。