Edit File: adapters.py
# -*- coding: utf-8 -*- """ requests.adapters ~~~~~~~~~~~~~~~~~ This module contains the transport adapters that Requests uses to define and maintain connections. """ import socket from .models import Response from urllib3.poolmanager import PoolManager, proxy_from_url from urllib3.response import HTTPResponse from urllib3.util import Timeout as TimeoutSauce from urllib3.util.retry import Retry from .compat import urlparse, basestring from .utils import (DEFAULT_CA_BUNDLE_PATH, get_encoding_from_headers, prepend_scheme_if_needed, get_auth_from_url, urldefragauth) from .structures import CaseInsensitiveDict from urllib3.exceptions import ConnectTimeoutError from urllib3.exceptions import HTTPError as _HTTPError from urllib3.exceptions import MaxRetryError from urllib3.exceptions import ProxyError as _ProxyError from urllib3.exceptions import ProtocolError from urllib3.exceptions import ReadTimeoutError from urllib3.exceptions import SSLError as _SSLError from urllib3.exceptions import ResponseError from .cookies import extract_cookies_to_jar from .exceptions import (ConnectionError, ConnectTimeout, ReadTimeout, SSLError, ProxyError, RetryError) from .auth import _basic_auth_str DEFAULT_POOLBLOCK = False DEFAULT_POOLSIZE = 10 DEFAULT_RETRIES = 0 class BaseAdapter(object): """The Base Transport Adapter""" def __init__(self): super(BaseAdapter, self).__init__() def send(self): raise NotImplementedError def close(self): raise NotImplementedError class HTTPAdapter(BaseAdapter): """The built-in HTTP Adapter for urllib3. Provides a general-case interface for Requests sessions to contact HTTP and HTTPS urls by implementing the Transport Adapter interface. This class will usually be created by the :class:`Session <Session>` class under the covers. :param pool_connections: The number of urllib3 connection pools to cache. :param pool_maxsize: The maximum number of connections to save in the pool. :param int max_retries: The maximum number of retries each connection should attempt. Note, this applies only to failed DNS lookups, socket connections and connection timeouts, never to requests where data has made it to the server. By default, Requests does not retry failed connections. If you need granular control over the conditions under which we retry a request, import urllib3's ``Retry`` class and pass that instead. :param pool_block: Whether the connection pool should block for connections. Usage:: >>> import requests >>> s = requests.Session() >>> a = requests.adapters.HTTPAdapter(max_retries=3) >>> s.mount('http://', a) """ __attrs__ = ['max_retries', 'config', '_pool_connections', '_pool_maxsize', '_pool_block'] def __init__(self, pool_connections=DEFAULT_POOLSIZE, pool_maxsize=DEFAULT_POOLSIZE, max_retries=DEFAULT_RETRIES, pool_block=DEFAULT_POOLBLOCK): if max_retries == DEFAULT_RETRIES: self.max_retries = Retry(0, read=False) else: self.max_retries = Retry.from_int(max_retries) self.config = {} self.proxy_manager = {} super(HTTPAdapter, self).__init__() self._pool_connections = pool_connections self._pool_maxsize = pool_maxsize self._pool_block = pool_block self.init_poolmanager(pool_connections, pool_maxsize, block=pool_block) def __getstate__(self): return dict((attr, getattr(self, attr, None)) for attr in self.__attrs__) def __setstate__(self, state): # Can't handle by adding 'proxy_manager' to self.__attrs__ because # because self.poolmanager uses a lambda function, which isn't pickleable. self.proxy_manager = {} self.config = {} for attr, value in state.items(): setattr(self, attr, value) self.init_poolmanager(self._pool_connections, self._pool_maxsize, block=self._pool_block) def init_poolmanager(self, connections, maxsize, block=DEFAULT_POOLBLOCK, **pool_kwargs): """Initializes a urllib3 PoolManager. This method should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. :param connections: The number of urllib3 connection pools to cache. :param maxsize: The maximum number of connections to save in the pool. :param block: Block when no free connections are available. :param pool_kwargs: Extra keyword arguments used to initialize the Pool Manager. """ # save these values for pickling self._pool_connections = connections self._pool_maxsize = maxsize self._pool_block = block self.poolmanager = PoolManager(num_pools=connections, maxsize=maxsize, block=block, strict=True, **pool_kwargs) def proxy_manager_for(self, proxy, **proxy_kwargs): """Return urllib3 ProxyManager for the given proxy. This method should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. :param proxy: The proxy to return a urllib3 ProxyManager for. :param proxy_kwargs: Extra keyword arguments used to configure the Proxy Manager. :returns: ProxyManager """ if not proxy in self.proxy_manager: proxy_headers = self.proxy_headers(proxy) self.proxy_manager[proxy] = proxy_from_url( proxy, proxy_headers=proxy_headers, num_pools=self._pool_connections, maxsize=self._pool_maxsize, block=self._pool_block, **proxy_kwargs) return self.proxy_manager[proxy] def cert_verify(self, conn, url, verify, cert): """Verify a SSL certificate. This method should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. :param conn: The urllib3 connection object associated with the cert. :param url: The requested URL. :param verify: Whether we should actually verify the certificate. :param cert: The SSL certificate to verify. """ if url.lower().startswith('https') and verify: cert_loc = None # Allow self-specified cert location. if verify is not True: cert_loc = verify if not cert_loc: cert_loc = DEFAULT_CA_BUNDLE_PATH if not cert_loc: raise Exception("Could not find a suitable SSL CA certificate bundle.") conn.cert_reqs = 'CERT_REQUIRED' conn.ca_certs = cert_loc else: conn.cert_reqs = 'CERT_NONE' conn.ca_certs = None if cert: if not isinstance(cert, basestring): conn.cert_file = cert[0] conn.key_file = cert[1] else: conn.cert_file = cert def build_response(self, req, resp): """Builds a :class:`Response <requests.Response>` object from a urllib3 response. This should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>` :param req: The :class:`PreparedRequest <PreparedRequest>` used to generate the response. :param resp: The urllib3 response object. """ response = Response() # Fallback to None if there's no status_code, for whatever reason. response.status_code = getattr(resp, 'status', None) # Make headers case-insensitive. response.headers = CaseInsensitiveDict(getattr(resp, 'headers', {})) # Set encoding. response.encoding = get_encoding_from_headers(response.headers) response.raw = resp response.reason = response.raw.reason if isinstance(req.url, bytes): response.url = req.url.decode('utf-8') else: response.url = req.url # Add new cookies from the server. extract_cookies_to_jar(response.cookies, req, resp) # Give the Response some context. response.request = req response.connection = self return response def get_connection(self, url, proxies=None): """Returns a urllib3 connection for the given URL. This should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. :param url: The URL to connect to. :param proxies: (optional) A Requests-style dictionary of proxies used on this request. """ proxies = proxies or {} proxy = proxies.get(urlparse(url.lower()).scheme) if proxy: proxy = prepend_scheme_if_needed(proxy, 'http') proxy_manager = self.proxy_manager_for(proxy) conn = proxy_manager.connection_from_url(url) else: # Only scheme should be lower case parsed = urlparse(url) url = parsed.geturl() conn = self.poolmanager.connection_from_url(url) return conn def close(self): """Disposes of any internal state. Currently, this just closes the PoolManager, which closes pooled connections. """ self.poolmanager.clear() def request_url(self, request, proxies): """Obtain the url to use when making the final request. If the message is being sent through a HTTP proxy, the full URL has to be used. Otherwise, we should only use the path portion of the URL. This should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. :param request: The :class:`PreparedRequest <PreparedRequest>` being sent. :param proxies: A dictionary of schemes to proxy URLs. """ proxies = proxies or {} scheme = urlparse(request.url).scheme proxy = proxies.get(scheme) if proxy and scheme != 'https': url = urldefragauth(request.url) else: url = request.path_url return url def add_headers(self, request, **kwargs): """Add any headers needed by the connection. As of v2.0 this does nothing by default, but is left for overriding by users that subclass the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. This should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. :param request: The :class:`PreparedRequest <PreparedRequest>` to add headers to. :param kwargs: The keyword arguments from the call to send(). """ pass def proxy_headers(self, proxy): """Returns a dictionary of the headers to add to any request sent through a proxy. This works with urllib3 magic to ensure that they are correctly sent to the proxy, rather than in a tunnelled request if CONNECT is being used. This should not be called from user code, and is only exposed for use when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`. :param proxies: The url of the proxy being used for this request. :param kwargs: Optional additional keyword arguments. """ headers = {} username, password = get_auth_from_url(proxy) if username and password: headers['Proxy-Authorization'] = _basic_auth_str(username, password) return headers def send(self, request, stream=False, timeout=None, verify=True, cert=None, proxies=None): """Sends PreparedRequest object. Returns Response object. :param request: The :class:`PreparedRequest <PreparedRequest>` being sent. :param stream: (optional) Whether to stream the request content. :param timeout: (optional) How long to wait for the server to send data before giving up, as a float, or a (`connect timeout, read timeout <user/advanced.html#timeouts>`_) tuple. :type timeout: float or tuple :param verify: (optional) Whether to verify SSL certificates. :param cert: (optional) Any user-provided SSL certificate to be trusted. :param proxies: (optional) The proxies dictionary to apply to the request. """ conn = self.get_connection(request.url, proxies) self.cert_verify(conn, request.url, verify, cert) url = self.request_url(request, proxies) self.add_headers(request) chunked = not (request.body is None or 'Content-Length' in request.headers) if isinstance(timeout, tuple): try: connect, read = timeout timeout = TimeoutSauce(connect=connect, read=read) except ValueError as e: # this may raise a string formatting error. err = ("Invalid timeout {0}. Pass a (connect, read) " "timeout tuple, or a single float to set " "both timeouts to the same value".format(timeout)) raise ValueError(err) else: timeout = TimeoutSauce(connect=timeout, read=timeout) try: if not chunked: resp = conn.urlopen( method=request.method, url=url, body=request.body, headers=request.headers, redirect=False, assert_same_host=False, preload_content=False, decode_content=False, retries=self.max_retries, timeout=timeout ) # Send the request. else: if hasattr(conn, 'proxy_pool'): conn = conn.proxy_pool low_conn = conn._get_conn(timeout=timeout) try: low_conn.putrequest(request.method, url, skip_accept_encoding=True) for header, value in request.headers.items(): low_conn.putheader(header, value) low_conn.endheaders() for i in request.body: low_conn.send(hex(len(i))[2:].encode('utf-8')) low_conn.send(b'\r\n') low_conn.send(i) low_conn.send(b'\r\n') low_conn.send(b'0\r\n\r\n') r = low_conn.getresponse() resp = HTTPResponse.from_httplib( r, pool=conn, connection=low_conn, preload_content=False, decode_content=False ) except: # If we hit any problems here, clean up the connection. # Then, reraise so that we can handle the actual exception. low_conn.close() raise else: # All is well, return the connection to the pool. conn._put_conn(low_conn) except (ProtocolError, socket.error) as err: raise ConnectionError(err, request=request) except MaxRetryError as e: if isinstance(e.reason, ConnectTimeoutError): raise ConnectTimeout(e, request=request) if isinstance(e.reason, ResponseError): raise RetryError(e, request=request) raise ConnectionError(e, request=request) except _ProxyError as e: raise ProxyError(e) except (_SSLError, _HTTPError) as e: if isinstance(e, _SSLError): raise SSLError(e, request=request) elif isinstance(e, ReadTimeoutError): raise ReadTimeout(e, request=request) else: raise return self.build_response(request, resp)