searxng/searx/network/__init__.py
2021-09-07 13:34:35 +02:00

223 lines
6 KiB
Python

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
# pylint: disable=missing-module-docstring, global-statement
import asyncio
import threading
import concurrent.futures
from types import MethodType
from timeit import default_timer
import httpx
import h2.exceptions
from .network import get_network, initialize
from .client import get_loop
from .raise_for_httperror import raise_for_httperror
# queue.SimpleQueue: Support Python 3.6
try:
from queue import SimpleQueue
except ImportError:
from queue import Empty
from collections import deque
class SimpleQueue:
"""Minimal backport of queue.SimpleQueue"""
def __init__(self):
self._queue = deque()
self._count = threading.Semaphore(0)
def put(self, item):
self._queue.append(item)
self._count.release()
def get(self):
if not self._count.acquire(True): #pylint: disable=consider-using-with
raise Empty
return self._queue.popleft()
THREADLOCAL = threading.local()
"""Thread-local data is data for thread specific values."""
def reset_time_for_thread():
global THREADLOCAL
THREADLOCAL.total_time = 0
def get_time_for_thread():
"""returns thread's total time or None"""
global THREADLOCAL
return THREADLOCAL.__dict__.get('total_time')
def set_timeout_for_thread(timeout, start_time=None):
global THREADLOCAL
THREADLOCAL.timeout = timeout
THREADLOCAL.start_time = start_time
def set_context_network_name(network_name):
global THREADLOCAL
THREADLOCAL.network = get_network(network_name)
def get_context_network():
"""If set return thread's network.
If unset, return value from :py:obj:`get_network`.
"""
global THREADLOCAL
return THREADLOCAL.__dict__.get('network') or get_network()
def request(method, url, **kwargs):
"""same as requests/requests/api.py request(...)"""
global THREADLOCAL
time_before_request = default_timer()
# timeout (httpx)
if 'timeout' in kwargs:
timeout = kwargs['timeout']
else:
timeout = getattr(THREADLOCAL, 'timeout', None)
if timeout is not None:
kwargs['timeout'] = timeout
# 2 minutes timeout for the requests without timeout
timeout = timeout or 120
# ajdust actual timeout
timeout += 0.2 # overhead
start_time = getattr(THREADLOCAL, 'start_time', time_before_request)
if start_time:
timeout -= default_timer() - start_time
# raise_for_error
check_for_httperror = True
if 'raise_for_httperror' in kwargs:
check_for_httperror = kwargs['raise_for_httperror']
del kwargs['raise_for_httperror']
# requests compatibility
if isinstance(url, bytes):
url = url.decode()
# network
network = get_context_network()
# do request
future = asyncio.run_coroutine_threadsafe(network.request(method, url, **kwargs), get_loop())
try:
response = future.result(timeout)
except concurrent.futures.TimeoutError as e:
raise httpx.TimeoutException('Timeout', request=None) from e
# requests compatibility
# see also https://www.python-httpx.org/compatibility/#checking-for-4xx5xx-responses
response.ok = not response.is_error
# update total_time.
# See get_time_for_thread() and reset_time_for_thread()
if hasattr(THREADLOCAL, 'total_time'):
time_after_request = default_timer()
THREADLOCAL.total_time += time_after_request - time_before_request
# raise an exception
if check_for_httperror:
raise_for_httperror(response)
return response
def get(url, **kwargs):
kwargs.setdefault('allow_redirects', True)
return request('get', url, **kwargs)
def options(url, **kwargs):
kwargs.setdefault('allow_redirects', True)
return request('options', url, **kwargs)
def head(url, **kwargs):
kwargs.setdefault('allow_redirects', False)
return request('head', url, **kwargs)
def post(url, data=None, **kwargs):
return request('post', url, data=data, **kwargs)
def put(url, data=None, **kwargs):
return request('put', url, data=data, **kwargs)
def patch(url, data=None, **kwargs):
return request('patch', url, data=data, **kwargs)
def delete(url, **kwargs):
return request('delete', url, **kwargs)
async def stream_chunk_to_queue(network, queue, method, url, **kwargs):
try:
async with network.stream(method, url, **kwargs) as response:
queue.put(response)
# aiter_raw: access the raw bytes on the response without applying any HTTP content decoding
# https://www.python-httpx.org/quickstart/#streaming-responses
async for chunk in response.aiter_raw(65536):
if len(chunk) > 0:
queue.put(chunk)
except httpx.ResponseClosed:
# the response was closed
pass
except (httpx.HTTPError, OSError, h2.exceptions.ProtocolError) as e:
queue.put(e)
finally:
queue.put(None)
def _close_response_method(self):
asyncio.run_coroutine_threadsafe(
self.aclose(),
get_loop()
)
def stream(method, url, **kwargs):
"""Replace httpx.stream.
Usage:
stream = poolrequests.stream(...)
response = next(stream)
for chunk in stream:
...
httpx.Client.stream requires to write the httpx.HTTPTransport version of the
the httpx.AsyncHTTPTransport declared above.
"""
queue = SimpleQueue()
future = asyncio.run_coroutine_threadsafe(
stream_chunk_to_queue(get_network(), queue, method, url, **kwargs),
get_loop()
)
# yield response
response = queue.get()
if isinstance(response, Exception):
raise response
response.close = MethodType(_close_response_method, response)
yield response
# yield chunks
chunk_or_exception = queue.get()
while chunk_or_exception is not None:
if isinstance(chunk_or_exception, Exception):
raise chunk_or_exception
yield chunk_or_exception
chunk_or_exception = queue.get()
future.result()