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Diffstat (limited to 'requests/adapters.py')
| -rw-r--r-- | requests/adapters.py | 396 |
1 files changed, 396 insertions, 0 deletions
diff --git a/requests/adapters.py b/requests/adapters.py new file mode 100644 index 0000000..dd10e95 --- /dev/null +++ b/requests/adapters.py @@ -0,0 +1,396 @@ +# -*- 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 .packages.urllib3.poolmanager import PoolManager, proxy_from_url +from .packages.urllib3.response import HTTPResponse +from .packages.urllib3.util import Timeout as TimeoutSauce +from .compat import urlparse, basestring, urldefrag, unquote +from .utils import (DEFAULT_CA_BUNDLE_PATH, get_encoding_from_headers, + except_on_missing_scheme, get_auth_from_url) +from .structures import CaseInsensitiveDict +from .packages.urllib3.exceptions import MaxRetryError +from .packages.urllib3.exceptions import TimeoutError +from .packages.urllib3.exceptions import SSLError as _SSLError +from .packages.urllib3.exceptions import HTTPError as _HTTPError +from .packages.urllib3.exceptions import ProxyError as _ProxyError +from .cookies import extract_cookies_to_jar +from .exceptions import ConnectionError, Timeout, SSLError, ProxyError +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 connections and + timeouts, never to requests where the server returns a response. + :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): + self.max_retries = 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): + """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. + """ + # 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) + + 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: + except_on_missing_scheme(proxy) + proxy_headers = self.proxy_headers(proxy) + + if not proxy in self.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) + + conn = self.proxy_manager[proxy].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, _ = urldefrag(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) The timeout on the request. + :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 stream: + timeout = TimeoutSauce(connect=timeout) + 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 socket.error as sockerr: + raise ConnectionError(sockerr) + + except MaxRetryError as e: + raise ConnectionError(e) + + except _ProxyError as e: + raise ProxyError(e) + + except (_SSLError, _HTTPError) as e: + if isinstance(e, _SSLError): + raise SSLError(e) + elif isinstance(e, TimeoutError): + raise Timeout(e) + else: + raise + + r = self.build_response(request, resp) + + if not stream: + r.content + + return r |