Source code for requests.adapters

# -*- coding: utf-8 -*-

"""
requests.adapters
~~~~~~~~~~~~~~~~~

This module contains the transport adapters that Requests uses to define
and maintain connections.
"""

import os.path
import socket

from .models import Response
from .packages.urllib3.poolmanager import PoolManager, proxy_from_url
from .packages.urllib3.response import HTTPResponse
from .packages.urllib3.util import Timeout as TimeoutSauce
from .packages.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,
                    select_proxy, to_native_string)
from .structures import CaseInsensitiveDict
from .packages.urllib3.exceptions import ClosedPoolError
from .packages.urllib3.exceptions import ConnectTimeoutError
from .packages.urllib3.exceptions import HTTPError as _HTTPError
from .packages.urllib3.exceptions import MaxRetryError
from .packages.urllib3.exceptions import NewConnectionError
from .packages.urllib3.exceptions import ProxyError as _ProxyError
from .packages.urllib3.exceptions import ProtocolError
from .packages.urllib3.exceptions import ReadTimeoutError
from .packages.urllib3.exceptions import SSLError as _SSLError
from .packages.urllib3.exceptions import ResponseError
from .cookies import extract_cookies_to_jar
from .exceptions import (ConnectionError, ConnectTimeout, ReadTimeout, SSLError,
                         ProxyError, RetryError, InvalidSchema)
from .auth import _basic_auth_str

try:
    from .packages.urllib3.contrib.socks import SOCKSProxyManager
except ImportError:
    def SOCKSProxyManager(*args, **kwargs):
        raise InvalidSchema("Missing dependencies for SOCKS support.")

DEFAULT_POOLBLOCK = False
DEFAULT_POOLSIZE = 10
DEFAULT_RETRIES = 0
DEFAULT_POOL_TIMEOUT = None


[docs]class BaseAdapter(object): """The Base Transport Adapter""" def __init__(self): super(BaseAdapter, self).__init__()
[docs] 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 :ref:`(connect timeout, read timeout) <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. """ raise NotImplementedError
[docs] def close(self): """Cleans up adapter specific items.""" raise NotImplementedError
[docs]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 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 # 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)
[docs] 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)
[docs] 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 :rtype: requests.packages.urllib3.ProxyManager """ if proxy in self.proxy_manager: manager = self.proxy_manager[proxy] elif proxy.lower().startswith('socks'): username, password = get_auth_from_url(proxy) manager = self.proxy_manager[proxy] = SOCKSProxyManager( proxy, username=username, password=password, num_pools=self._pool_connections, maxsize=self._pool_maxsize, block=self._pool_block, **proxy_kwargs ) else: proxy_headers = self.proxy_headers(proxy) manager = 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 manager
[docs] 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' if not os.path.isdir(cert_loc): conn.ca_certs = cert_loc else: conn.ca_cert_dir = cert_loc else: conn.cert_reqs = 'CERT_NONE' conn.ca_certs = None conn.ca_cert_dir = None if cert: if not isinstance(cert, basestring): conn.cert_file = cert[0] conn.key_file = cert[1] else: conn.cert_file = cert
[docs] 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. :rtype: requests.Response """ 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
[docs] 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. :rtype: requests.packages.urllib3.ConnectionPool """ proxy = select_proxy(url, proxies) 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
[docs] def close(self): """Disposes of any internal state. Currently, this closes the PoolManager and any active ProxyManager, which closes any pooled connections. """ self.poolmanager.clear() for proxy in self.proxy_manager.values(): proxy.clear()
[docs] 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 or schemes and hosts to proxy URLs. :rtype: str """ proxy = select_proxy(request.url, proxies) scheme = urlparse(request.url).scheme is_proxied_http_request = (proxy and scheme != 'https') using_socks_proxy = False if proxy: proxy_scheme = urlparse(proxy).scheme.lower() using_socks_proxy = proxy_scheme.startswith('socks') url = request.path_url if is_proxied_http_request and not using_socks_proxy: url = urldefragauth(request.url) return url
[docs] 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
[docs] 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. :rtype: dict """ headers = {} username, password = get_auth_from_url(proxy) if username: headers['Proxy-Authorization'] = _basic_auth_str(username, password) return headers
[docs] 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 :ref:`(connect timeout, read timeout) <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. :rtype: requests.Response """ 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=DEFAULT_POOL_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') # Receive the response from the server try: # For Python 2.7+ versions, use buffering of HTTP # responses r = low_conn.getresponse(buffering=True) except TypeError: # For compatibility with Python 2.6 versions and back 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 except (ProtocolError, socket.error) as err: raise ConnectionError(err, request=request) except MaxRetryError as e: if isinstance(e.reason, ConnectTimeoutError): # TODO: Remove this in 3.0.0: see #2811 if not isinstance(e.reason, NewConnectionError): raise ConnectTimeout(e, request=request) if isinstance(e.reason, ResponseError): raise RetryError(e, request=request) if isinstance(e.reason, _ProxyError): raise ProxyError(e, request=request) raise ConnectionError(e, request=request) except ClosedPoolError as e: 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)