# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
# pylint: disable=missing-module-docstring, missing-function-docstring, global-statement
import asyncio
import logging
import threading
import httpcore
import httpx
from httpx_socks import AsyncProxyTransport
from python_socks import (
parse_proxy_url,
ProxyConnectionError,
ProxyTimeoutError,
ProxyError
)
from searx import logger
# Optional uvloop (support Python 3.6)
try:
import uvloop
except ImportError:
pass
else:
uvloop.install()
logger = logger.getChild('searx.http.client')
LOOP = None
SSLCONTEXTS = {}
TRANSPORT_KWARGS = {
'backend': 'asyncio',
'trust_env': False,
}
# pylint: disable=protected-access
async def close_connections_for_url(
connection_pool: httpcore.AsyncConnectionPool,
url: httpcore._utils.URL ):
origin = httpcore._utils.url_to_origin(url)
logger.debug('Drop connections for %r', origin)
connections_to_close = connection_pool._connections_for_origin(origin)
for connection in connections_to_close:
await connection_pool._remove_from_pool(connection)
try:
await connection.aclose()
except httpcore.NetworkError as e:
logger.warning('Error closing an existing connection', exc_info=e)
# pylint: enable=protected-access
def get_sslcontexts(proxy_url=None, cert=None, verify=True, trust_env=True, http2=False):
global SSLCONTEXTS
key = (proxy_url, cert, verify, trust_env, http2)
if key not in SSLCONTEXTS:
SSLCONTEXTS[key] = httpx.create_ssl_context(cert, verify, trust_env, http2)
return SSLCONTEXTS[key]
class AsyncHTTPTransportNoHttp(httpcore.AsyncHTTPTransport):
"""Block HTTP request"""
async def arequest(self, method, url, headers=None, stream=None, ext=None):
raise httpcore.UnsupportedProtocol("HTTP protocol is disabled")
class AsyncProxyTransportFixed(AsyncProxyTransport):
"""Fix httpx_socks.AsyncProxyTransport
Map python_socks exceptions to httpcore.ProxyError
Map socket.gaierror to httpcore.ConnectError
Note: keepalive_expiry is ignored, AsyncProxyTransport should call:
* self._keepalive_sweep()
* self._response_closed(self, connection)
Note: AsyncProxyTransport inherit from AsyncConnectionPool
Note: the API is going to change on httpx 0.18.0
see https://github.com/encode/httpx/pull/1522
"""
async def arequest(self, method, url, headers=None, stream=None, ext=None):
retry = 2
while retry > 0:
retry -= 1
try:
return await super().arequest(method, url, headers, stream, ext)
except (ProxyConnectionError, ProxyTimeoutError, ProxyError) as e:
raise httpcore.ProxyError(e)
except OSError as e:
# socket.gaierror when DNS resolution fails
raise httpcore.NetworkError(e)
except httpcore.RemoteProtocolError as e:
# in case of httpcore.RemoteProtocolError: Server disconnected
await close_connections_for_url(self, url)
logger.warning('httpcore.RemoteProtocolError: retry', exc_info=e)
# retry
except (httpcore.NetworkError, httpcore.ProtocolError) as e:
# httpcore.WriteError on HTTP/2 connection leaves a new opened stream
# then each new request creates a new stream and raise the same WriteError
await close_connections_for_url(self, url)
raise e
class AsyncHTTPTransportFixed(httpx.AsyncHTTPTransport):
"""Fix httpx.AsyncHTTPTransport"""
async def arequest(self, method, url, headers=None, stream=None, ext=None):
retry = 2
while retry > 0:
retry -= 1
try:
return await super().arequest(method, url, headers, stream, ext)
except OSError as e:
# socket.gaierror when DNS resolution fails
raise httpcore.ConnectError(e)
except httpcore.CloseError as e:
# httpcore.CloseError: [Errno 104] Connection reset by peer
# raised by _keepalive_sweep()
# from https://github.com/encode/httpcore/blob/4b662b5c42378a61e54d673b4c949420102379f5/httpcore/_backends/asyncio.py#L198 # pylint: disable=line-too-long
await close_connections_for_url(self._pool, url)
logger.warning('httpcore.CloseError: retry', exc_info=e)
# retry
except httpcore.RemoteProtocolError as e:
# in case of httpcore.RemoteProtocolError: Server disconnected
await close_connections_for_url(self._pool, url)
logger.warning('httpcore.RemoteProtocolError: retry', exc_info=e)
# retry
except (httpcore.ProtocolError, httpcore.NetworkError) as e:
await close_connections_for_url(self._pool, url)
raise e
def get_transport_for_socks_proxy(verify, http2, local_address, proxy_url, limit, retries):
global TRANSPORT_KWARGS
# support socks5h (requests compatibility):
# https://requests.readthedocs.io/en/master/user/advanced/#socks
# socks5:// hostname is resolved on client side
# socks5h:// hostname is resolved on proxy side
rdns = False
socks5h = 'socks5h://'
if proxy_url.startswith(socks5h):
proxy_url = 'socks5://' + proxy_url[len(socks5h):]
rdns = True
proxy_type, proxy_host, proxy_port, proxy_username, proxy_password = parse_proxy_url(proxy_url)
verify = get_sslcontexts(proxy_url, None, True, False, http2) if verify is True else verify
return AsyncProxyTransportFixed(
proxy_type=proxy_type, proxy_host=proxy_host, proxy_port=proxy_port,
username=proxy_username, password=proxy_password,
rdns=rdns,
loop=get_loop(),
verify=verify,
http2=http2,
local_address=local_address,
max_connections=limit.max_connections,
max_keepalive_connections=limit.max_keepalive_connections,
keepalive_expiry=limit.keepalive_expiry,
retries=retries,
**TRANSPORT_KWARGS
)
def get_transport(verify, http2, local_address, proxy_url, limit, retries):
global TRANSPORT_KWARGS
verify = get_sslcontexts(None, None, True, False, http2) if verify is True else verify
return AsyncHTTPTransportFixed(
# pylint: disable=protected-access
verify=verify,
http2=http2,
local_address=local_address,
proxy=httpx._config.Proxy(proxy_url) if proxy_url else None,
limits=limit,
retries=retries,
**TRANSPORT_KWARGS
)
def iter_proxies(proxies):
# https://www.python-httpx.org/compatibility/#proxy-keys
if isinstance(proxies, str):
yield 'all://', proxies
elif isinstance(proxies, dict):
for pattern, proxy_url in proxies.items():
yield pattern, proxy_url
def new_client(
# pylint: disable=too-many-arguments
enable_http, verify, enable_http2,
max_connections, max_keepalive_connections, keepalive_expiry,
proxies, local_address, retries, max_redirects ):
limit = httpx.Limits(
max_connections=max_connections,
max_keepalive_connections=max_keepalive_connections,
keepalive_expiry=keepalive_expiry
)
# See https://www.python-httpx.org/advanced/#routing
mounts = {}
for pattern, proxy_url in iter_proxies(proxies):
if not enable_http and (pattern == 'http' or pattern.startswith('http://')):
continue
if (proxy_url.startswith('socks4://')
or proxy_url.startswith('socks5://')
or proxy_url.startswith('socks5h://')
):
mounts[pattern] = get_transport_for_socks_proxy(
verify, enable_http2, local_address, proxy_url, limit, retries
)
else:
mounts[pattern] = get_transport(
verify, enable_http2, local_address, proxy_url, limit, retries
)
if not enable_http:
mounts['http://'] = AsyncHTTPTransportNoHttp()
transport = get_transport(verify, enable_http2, local_address, None, limit, retries)
return httpx.AsyncClient(transport=transport, mounts=mounts, max_redirects=max_redirects)
def get_loop():
global LOOP
return LOOP
def init():
# log
for logger_name in ('hpack.hpack', 'hpack.table'):
logging.getLogger(logger_name).setLevel(logging.WARNING)
# loop
def loop_thread():
global LOOP
LOOP = asyncio.new_event_loop()
LOOP.run_forever()
thread = threading.Thread(
target=loop_thread,
name='asyncio_loop',
daemon=True,
)
thread.start()
init()