Edit: poolmanager.py
from __future__ import annotations import functools import logging import typing import warnings from types import TracebackType from urllib.parse import urljoin from ._collections import HTTPHeaderDict, RecentlyUsedContainer from ._request_methods import RequestMethods from .connection import ProxyConfig from .connectionpool import HTTPConnectionPool, HTTPSConnectionPool, port_by_scheme from .exceptions import ( LocationValueError, MaxRetryError, ProxySchemeUnknown, URLSchemeUnknown, ) from .response import BaseHTTPResponse from .util.connection import _TYPE_SOCKET_OPTIONS from .util.proxy import connection_requires_http_tunnel from .util.retry import Retry from .util.timeout import Timeout from .util.url import Url, parse_url if typing.TYPE_CHECKING: import ssl from typing_extensions import Self __all__ = ["PoolManager", "ProxyManager", "proxy_from_url"] log = logging.getLogger(__name__) SSL_KEYWORDS = ( "key_file", "cert_file", "cert_reqs", "ca_certs", "ca_cert_data", "ssl_version", "ssl_minimum_version", "ssl_maximum_version", "ca_cert_dir", "ssl_context", "key_password", "server_hostname", ) # Default value for `blocksize` - a new parameter introduced to # http.client.HTTPConnection & http.client.HTTPSConnection in Python 3.7 _DEFAULT_BLOCKSIZE = 16384 class PoolKey(typing.NamedTuple): """ All known keyword arguments that could be provided to the pool manager, its pools, or the underlying connections. All custom key schemes should include the fields in this key at a minimum. """ key_scheme: str key_host: str key_port: int | None key_timeout: Timeout | float | int | None key_retries: Retry | bool | int | None key_block: bool | None key_source_address: tuple[str, int] | None key_key_file: str | None key_key_password: str | None key_cert_file: str | None key_cert_reqs: str | None key_ca_certs: str | None key_ca_cert_data: str | bytes | None key_ssl_version: int | str | None key_ssl_minimum_version: ssl.TLSVersion | None key_ssl_maximum_version: ssl.TLSVersion | None key_ca_cert_dir: str | None key_ssl_context: ssl.SSLContext | None key_maxsize: int | None key_headers: frozenset[tuple[str, str]] | None key__proxy: Url | None key__proxy_headers: frozenset[tuple[str, str]] | None key__proxy_config: ProxyConfig | None key_socket_options: _TYPE_SOCKET_OPTIONS | None key__socks_options: frozenset[tuple[str, str]] | None key_assert_hostname: bool | str | None key_assert_fingerprint: str | None key_server_hostname: str | None key_blocksize: int | None def _default_key_normalizer( key_class: type[PoolKey], request_context: dict[str, typing.Any] ) -> PoolKey: """ Create a pool key out of a request context dictionary. According to RFC 3986, both the scheme and host are case-insensitive. Therefore, this function normalizes both before constructing the pool key for an HTTPS request. If you wish to change this behaviour, provide alternate callables to ``key_fn_by_scheme``. :param key_class: The class to use when constructing the key. This should be a namedtuple with the ``scheme`` and ``host`` keys at a minimum. :type key_class: namedtuple :param request_context: A dictionary-like object that contain the context for a request. :type request_context: dict :return: A namedtuple that can be used as a connection pool key. :rtype: PoolKey """ # Since we mutate the dictionary, make a copy first context = request_context.copy() context["scheme"] = context["scheme"].lower() context["host"] = context["host"].lower() # These are both dictionaries and need to be transformed into frozensets for key in ("headers", "_proxy_headers", "_socks_options"): if key in context and context[key] is not None: context[key] = frozenset(context[key].items()) # The socket_options key may be a list and needs to be transformed into a # tuple. socket_opts = context.get("socket_options") if socket_opts is not None: context["socket_options"] = tuple(socket_opts) # Map the kwargs to the names in the namedtuple - this is necessary since # namedtuples can't have fields starting with '_'. for key in list(context.keys()): context["key_" + key] = context.pop(key) # Default to ``None`` for keys missing from the context for field in key_class._fields: if field not in context: context[field] = None # Default key_blocksize to _DEFAULT_BLOCKSIZE if missing from the context if context.get("key_blocksize") is None: context["key_blocksize"] = _DEFAULT_BLOCKSIZE return key_class(**context) #: A dictionary that maps a scheme to a callable that creates a pool key. #: This can be used to alter the way pool keys are constructed, if desired. #: Each PoolManager makes a copy of this dictionary so they can be configured #: globally here, or individually on the instance. key_fn_by_scheme = { "http": functools.partial(_default_key_normalizer, PoolKey), "https": functools.partial(_default_key_normalizer, PoolKey), } pool_classes_by_scheme = {"http": HTTPConnectionPool, "https": HTTPSConnectionPool} class PoolManager(RequestMethods): """ Allows for arbitrary requests while transparently keeping track of necessary connection pools for you. :param num_pools: Number of connection pools to cache before discarding the least recently used pool. :param headers: Headers to include with all requests, unless other headers are given explicitly. :param \\**connection_pool_kw: Additional parameters are used to create fresh :class:`urllib3.connectionpool.ConnectionPool` instances. Example: .. code-block:: python import urllib3 http = urllib3.PoolManager(num_pools=2) resp1 = http.request("GET", "https://google.com/") resp2 = http.request("GET", "https://google.com/mail") resp3 = http.request("GET", "https://yahoo.com/") print(len(http.pools)) # 2 """ proxy: Url | None = None proxy_config: ProxyConfig | None = None def __init__( self, num_pools: int = 10, headers: typing.Mapping[str, str] | None = None, **connection_pool_kw: typing.Any, ) -> None: super().__init__(headers) self.connection_pool_kw = connection_pool_kw self.pools: RecentlyUsedContainer[PoolKey, HTTPConnectionPool] self.pools = RecentlyUsedContainer(num_pools) # Locally set the pool classes and keys so other PoolManagers can # override them. self.pool_classes_by_scheme = pool_classes_by_scheme self.key_fn_by_scheme = key_fn_by_scheme.copy() def __enter__(self) -> Self: return self def __exit__( self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None, ) -> typing.Literal[False]: self.clear() # Return False to re-raise any potential exceptions return False def _new_pool( self, scheme: str, host: str, port: int, request_context: dict[str, typing.Any] | None = None, ) -> HTTPConnectionPool: """ Create a new :class:`urllib3.connectionpool.ConnectionPool` based on host, port, scheme, and any additional pool keyword arguments. If ``request_context`` is provided, it is provided as keyword arguments to the pool class used. This method is used to actually create the connection pools handed out by :meth:`connection_from_url` and companion methods. It is intended to be overridden for customization. """ pool_cls: type[HTTPConnectionPool] = self.pool_classes_by_scheme[scheme] if request_context is None: request_context = self.connection_pool_kw.copy() # Default blocksize to _DEFAULT_BLOCKSIZE if missing or explicitly # set to 'None' in the request_context. if request_context.get("blocksize") is None: request_context["blocksize"] = _DEFAULT_BLOCKSIZE # Although the context has everything necessary to create the pool, # this function has historically only used the scheme, host, and port # in the positional args. When an API change is acceptable these can # be removed. for key in ("scheme", "host", "port"): request_context.pop(key, None) if scheme == "http": for kw in SSL_KEYWORDS: request_context.pop(kw, None) return pool_cls(host, port, **request_context) def clear(self) -> None: """ Empty our store of pools and direct them all to close. This will not affect in-flight connections, but they will not be re-used after completion. """ self.pools.clear() def connection_from_host( self, host: str | None, port: int | None = None, scheme: str | None = "http", pool_kwargs: dict[str, typing.Any] | None = None, ) -> HTTPConnectionPool: """ Get a :class:`urllib3.connectionpool.ConnectionPool` based on the host, port, and scheme. If ``port`` isn't given, it will be derived from the ``scheme`` using ``urllib3.connectionpool.port_by_scheme``. If ``pool_kwargs`` is provided, it is merged with the instance's ``connection_pool_kw`` variable and used to create the new connection pool, if one is needed. """ if not host: raise LocationValueError("No host specified.") request_context = self._merge_pool_kwargs(pool_kwargs) request_context["scheme"] = scheme or "http" if not port: port = port_by_scheme.get(request_context["scheme"].lower(), 80) request_context["port"] = port request_context["host"] = host return self.connection_from_context(request_context) def connection_from_context( self, request_context: dict[str, typing.Any] ) -> HTTPConnectionPool: """ Get a :class:`urllib3.connectionpool.ConnectionPool` based on the request context. ``request_context`` must at least contain the ``scheme`` key and its value must be a key in ``key_fn_by_scheme`` instance variable. """ if "strict" in request_context: warnings.warn( "The 'strict' parameter is no longer needed on Python 3+. " "This will raise an error in urllib3 v2.1.0.", DeprecationWarning, ) request_context.pop("strict") scheme = request_context["scheme"].lower() pool_key_constructor = self.key_fn_by_scheme.get(scheme) if not pool_key_constructor: raise URLSchemeUnknown(scheme) pool_key = pool_key_constructor(request_context) return self.connection_from_pool_key(pool_key, request_context=request_context) def connection_from_pool_key( self, pool_key: PoolKey, request_context: dict[str, typing.Any] ) -> HTTPConnectionPool: """ Get a :class:`urllib3.connectionpool.ConnectionPool` based on the provided pool key. ``pool_key`` should be a namedtuple that only contains immutable objects. At a minimum it must have the ``scheme``, ``host``, and ``port`` fields. """ with self.pools.lock: # If the scheme, host, or port doesn't match existing open # connections, open a new ConnectionPool. pool = self.pools.get(pool_key) if pool: return pool # Make a fresh ConnectionPool of the desired type scheme = request_context["scheme"] host = request_context["host"] port = request_context["port"] pool = self._new_pool(scheme, host, port, request_context=request_context) self.pools[pool_key] = pool return pool def connection_from_url( self, url: str, pool_kwargs: dict[str, typing.Any] | None = None ) -> HTTPConnectionPool: """ Similar to :func:`urllib3.connectionpool.connection_from_url`. If ``pool_kwargs`` is not provided and a new pool needs to be constructed, ``self.connection_pool_kw`` is used to initialize the :class:`urllib3.connectionpool.ConnectionPool`. If ``pool_kwargs`` is provided, it is used instead. Note that if a new pool does not need to be created for the request, the provided ``pool_kwargs`` are not used. """ u = parse_url(url) return self.connection_from_host( u.host, port=u.port, scheme=u.scheme, pool_kwargs=pool_kwargs ) def _merge_pool_kwargs( self, override: dict[str, typing.Any] | None ) -> dict[str, typing.Any]: """ Merge a dictionary of override values for self.connection_pool_kw. This does not modify self.connection_pool_kw and returns a new dict. Any keys in the override dictionary with a value of ``None`` are removed from the merged dictionary. """ base_pool_kwargs = self.connection_pool_kw.copy() if override: for key, value in override.items(): if value is None: try: del base_pool_kwargs[key] except KeyError: pass else: base_pool_kwargs[key] = value return base_pool_kwargs def _proxy_requires_url_absolute_form(self, parsed_url: Url) -> bool: """ Indicates if the proxy requires the complete destination URL in the request. Normally this is only needed when not using an HTTP CONNECT tunnel. """ if self.proxy is None: return False return not connection_requires_http_tunnel( self.proxy, self.proxy_config, parsed_url.scheme ) def urlopen( # type: ignore[override] self, method: str, url: str, redirect: bool = True, **kw: typing.Any ) -> BaseHTTPResponse: """ Same as :meth:`urllib3.HTTPConnectionPool.urlopen` with custom cross-host redirect logic and only sends the request-uri portion of the ``url``. The given ``url`` parameter must be absolute, such that an appropriate :class:`urllib3.connectionpool.ConnectionPool` can be chosen for it. """ u = parse_url(url) if u.scheme is None: warnings.warn( "URLs without a scheme (ie 'https://') are deprecated and will raise an error " "in a future version of urllib3. To avoid this DeprecationWarning ensure all URLs " "start with 'https://' or 'http://'. Read more in this issue: " "https://github.com/urllib3/urllib3/issues/2920", category=DeprecationWarning, stacklevel=2, ) conn = self.connection_from_host(u.host, port=u.port, scheme=u.scheme) kw["assert_same_host"] = False kw["redirect"] = False if "headers" not in kw: kw["headers"] = self.headers if self._proxy_requires_url_absolute_form(u): response = conn.urlopen(method, url, **kw) else: response = conn.urlopen(method, u.request_uri, **kw) redirect_location = redirect and response.get_redirect_location() if not redirect_location: return response # Support relative URLs for redirecting. redirect_location = urljoin(url, redirect_location) if response.status == 303: # Change the method according to RFC 9110, Section 15.4.4. method = "GET" # And lose the body not to transfer anything sensitive. kw["body"] = None kw["headers"] = HTTPHeaderDict(kw["headers"])._prepare_for_method_change() retries = kw.get("retries") if not isinstance(retries, Retry): retries = Retry.from_int(retries, redirect=redirect) # Strip headers marked as unsafe to forward to the redirected location. # Check remove_headers_on_redirect to avoid a potential network call within # conn.is_same_host() which may use socket.gethostbyname() in the future. if retries.remove_headers_on_redirect and not conn.is_same_host( redirect_location ): new_headers = kw["headers"].copy() for header in kw["headers"]: if header.lower() in retries.remove_headers_on_redirect: new_headers.pop(header, None) kw["headers"] = new_headers try: retries = retries.increment(method, url, response=response, _pool=conn) except MaxRetryError: if retries.raise_on_redirect: response.drain_conn() raise return response kw["retries"] = retries kw["redirect"] = redirect log.info("Redirecting %s -> %s", url, redirect_location) response.drain_conn() return self.urlopen(method, redirect_location, **kw) class ProxyManager(PoolManager): """ Behaves just like :class:`PoolManager`, but sends all requests through the defined proxy, using the CONNECT method for HTTPS URLs. :param proxy_url: The URL of the proxy to be used. :param proxy_headers: A dictionary containing headers that will be sent to the proxy. In case of HTTP they are being sent with each request, while in the HTTPS/CONNECT case they are sent only once. Could be used for proxy authentication. :param proxy_ssl_context: The proxy SSL context is used to establish the TLS connection to the proxy when using HTTPS proxies. :param use_forwarding_for_https: (Defaults to False) If set to True will forward requests to the HTTPS proxy to be made on behalf of the client instead of creating a TLS tunnel via the CONNECT method. **Enabling this flag means that request and response headers and content will be visible from the HTTPS proxy** whereas tunneling keeps request and response headers and content private. IP address, target hostname, SNI, and port are always visible to an HTTPS proxy even when this flag is disabled. :param proxy_assert_hostname: The hostname of the certificate to verify against. :param proxy_assert_fingerprint: The fingerprint of the certificate to verify against. Example: .. code-block:: python import urllib3 proxy = urllib3.ProxyManager("https://localhost:3128/") resp1 = proxy.request("GET", "https://google.com/") resp2 = proxy.request("GET", "https://httpbin.org/") print(len(proxy.pools)) # 1 resp3 = proxy.request("GET", "https://httpbin.org/") resp4 = proxy.request("GET", "https://twitter.com/") print(len(proxy.pools)) # 3 """ def __init__( self, proxy_url: str, num_pools: int = 10, headers: typing.Mapping[str, str] | None = None, proxy_headers: typing.Mapping[str, str] | None = None, proxy_ssl_context: ssl.SSLContext | None = None, use_forwarding_for_https: bool = False, proxy_assert_hostname: None | str | typing.Literal[False] = None, proxy_assert_fingerprint: str | None = None, **connection_pool_kw: typing.Any, ) -> None: if isinstance(proxy_url, HTTPConnectionPool): str_proxy_url = f"{proxy_url.scheme}://{proxy_url.host}:{proxy_url.port}" else: str_proxy_url = proxy_url proxy = parse_url(str_proxy_url) if proxy.scheme not in ("http", "https"): raise ProxySchemeUnknown(proxy.scheme) if not proxy.port: port = port_by_scheme.get(proxy.scheme, 80) proxy = proxy._replace(port=port) self.proxy = proxy self.proxy_headers = proxy_headers or {} self.proxy_ssl_context = proxy_ssl_context self.proxy_config = ProxyConfig( proxy_ssl_context, use_forwarding_for_https, proxy_assert_hostname, proxy_assert_fingerprint, ) connection_pool_kw["_proxy"] = self.proxy connection_pool_kw["_proxy_headers"] = self.proxy_headers connection_pool_kw["_proxy_config"] = self.proxy_config super().__init__(num_pools, headers, **connection_pool_kw) def connection_from_host( self, host: str | None, port: int | None = None, scheme: str | None = "http", pool_kwargs: dict[str, typing.Any] | None = None, ) -> HTTPConnectionPool: if scheme == "https": return super().connection_from_host( host, port, scheme, pool_kwargs=pool_kwargs ) return super().connection_from_host( self.proxy.host, self.proxy.port, self.proxy.scheme, pool_kwargs=pool_kwargs # type: ignore[union-attr] ) def _set_proxy_headers( self, url: str, headers: typing.Mapping[str, str] | None = None ) -> typing.Mapping[str, str]: """ Sets headers needed by proxies: specifically, the Accept and Host headers. Only sets headers not provided by the user. """ headers_ = {"Accept": "*/*"} netloc = parse_url(url).netloc if netloc: headers_["Host"] = netloc if headers: headers_.update(headers) return headers_ def urlopen( # type: ignore[override] self, method: str, url: str, redirect: bool = True, **kw: typing.Any ) -> BaseHTTPResponse: "Same as HTTP(S)ConnectionPool.urlopen, ``url`` must be absolute." u = parse_url(url) if not connection_requires_http_tunnel(self.proxy, self.proxy_config, u.scheme): # For connections using HTTP CONNECT, httplib sets the necessary # headers on the CONNECT to the proxy. If we're not using CONNECT, # we'll definitely need to set 'Host' at the very least. headers = kw.get("headers", self.headers) kw["headers"] = self._set_proxy_headers(url, headers) return super().urlopen(method, url, redirect=redirect, **kw) def proxy_from_url(url: str, **kw: typing.Any) -> ProxyManager: return ProxyManager(proxy_url=url, **kw)
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