Source code for

"""The CheckExternalLinksBuilder class."""

from __future__ import annotations

import contextlib
import json
import re
import socket
import time
import warnings
from html.parser import HTMLParser
from os import path
from queue import PriorityQueue, Queue
from threading import Thread
from typing import TYPE_CHECKING, NamedTuple, cast
from urllib.parse import quote, unquote, urlparse, urlsplit, urlunparse

from docutils import nodes
from requests.exceptions import ConnectionError, HTTPError, SSLError, TooManyRedirects
from requests.exceptions import Timeout as RequestTimeout

from import DummyBuilder
from sphinx.deprecation import RemovedInSphinx80Warning
from sphinx.locale import __
from sphinx.transforms.post_transforms import SphinxPostTransform
from sphinx.util import encode_uri, logging, requests
from sphinx.util.console import darkgray, darkgreen, purple, red, turquoise
from sphinx.util.http_date import rfc1123_to_epoch
from sphinx.util.nodes import get_node_line

    from import Iterator
    from typing import Any, Callable

    from requests import Response

    from sphinx.application import Sphinx
    from sphinx.config import Config
    from sphinx.util.typing import ExtensionMetadata

logger = logging.getLogger(__name__)

uri_re = re.compile('([a-z]+:)?//')  # matches to foo:// and // (a protocol relative URL)

    'Accept': 'text/html,application/xhtml+xml;q=0.9,*/*;q=0.8',

[docs] class CheckExternalLinksBuilder(DummyBuilder): """ Checks for broken external links. """ name = 'linkcheck' epilog = __('Look for any errors in the above output or in ' '%(outdir)s/output.txt') def init(self) -> None: self.broken_hyperlinks = 0 self.timed_out_hyperlinks = 0 self.hyperlinks: dict[str, Hyperlink] = {} # set a timeout for non-responding servers socket.setdefaulttimeout(5.0) if not self.config.linkcheck_allow_unauthorized: deprecation_msg = ( "The default value for 'linkcheck_allow_unauthorized' will change " "from `True` in Sphinx 7.3+ to `False`, meaning that HTTP 401 " "unauthorized responses will be reported as broken by default. " "See for details." ) warnings.warn(deprecation_msg, RemovedInSphinx80Warning, stacklevel=1) if self.config.linkcheck_report_timeouts_as_broken: deprecation_msg = ( "The default value for 'linkcheck_report_timeouts_as_broken' will change " 'to False in Sphinx 8, meaning that request timeouts ' "will be reported with a new 'timeout' status, instead of as 'broken'. " 'This is intended to provide more detail as to the failure mode. ' 'See for details.' ) warnings.warn(deprecation_msg, RemovedInSphinx80Warning, stacklevel=1) def finish(self) -> None: checker = HyperlinkAvailabilityChecker(self.config)'') output_text = path.join(self.outdir, 'output.txt') output_json = path.join(self.outdir, 'output.json') with open(output_text, 'w', encoding='utf-8') as self.txt_outfile, \ open(output_json, 'w', encoding='utf-8') as self.json_outfile: for result in checker.check(self.hyperlinks): self.process_result(result) if self.broken_hyperlinks or self.timed_out_hyperlinks: = 1 def process_result(self, result: CheckResult) -> None: filename = self.env.doc2path(result.docname, False) linkstat = {'filename': filename, 'lineno': result.lineno, 'status': result.status, 'code': result.code, 'uri': result.uri, 'info': result.message} self.write_linkstat(linkstat) if result.status == 'unchecked': return if result.status == 'working' and result.message == 'old': return if result.lineno:'(%16s: line %4d) ', result.docname, result.lineno, nonl=True) if result.status == 'ignored': if result.message:'-ignored- ') + result.uri + ': ' + result.message) else:'-ignored- ') + result.uri) elif result.status == 'local':'-local- ') + result.uri) self.write_entry('local', result.docname, filename, result.lineno, result.uri) elif result.status == 'working':'ok ') + result.uri + result.message) elif result.status == 'timeout': if or logger.warning('timeout ' + result.uri + result.message, location=(result.docname, result.lineno)) else:'timeout ') + result.uri + red(' - ' + result.message)) self.write_entry('timeout', result.docname, filename, result.lineno, result.uri + ': ' + result.message) self.timed_out_hyperlinks += 1 elif result.status == 'broken': if or logger.warning(__('broken link: %s (%s)'), result.uri, result.message, location=(result.docname, result.lineno)) else:'broken ') + result.uri + red(' - ' + result.message)) self.write_entry('broken', result.docname, filename, result.lineno, result.uri + ': ' + result.message) self.broken_hyperlinks += 1 elif result.status == 'redirected': try: text, color = { 301: ('permanently', purple), 302: ('with Found', purple), 303: ('with See Other', purple), 307: ('temporarily', turquoise), 308: ('permanently', purple), }[result.code] except KeyError: text, color = ('with unknown code', purple) linkstat['text'] = text if self.config.linkcheck_allowed_redirects: logger.warning('redirect ' + result.uri + ' - ' + text + ' to ' + result.message, location=(result.docname, result.lineno)) else:'redirect ') + result.uri + color(' - ' + text + ' to ' + result.message)) self.write_entry('redirected ' + text, result.docname, filename, result.lineno, result.uri + ' to ' + result.message) else: raise ValueError('Unknown status %s.' % result.status) def write_linkstat(self, data: dict) -> None: self.json_outfile.write(json.dumps(data)) self.json_outfile.write('\n') def write_entry(self, what: str, docname: str, filename: str, line: int, uri: str) -> None: self.txt_outfile.write(f'{filename}:{line}: [{what}] {uri}\n')
class HyperlinkCollector(SphinxPostTransform): builders = ('linkcheck',) default_priority = 800 def run(self, **kwargs: Any) -> None: for node in self.document.findall(): if uri := self.find_uri(node): self._add_uri(uri, node) def find_uri(self, node: nodes.Element) -> str | None: """Find a URI for a given node. This call can be used to retrieve a URI from a provided node. If no URI exists for a provided node, this call will return ``None``. This method can be useful for extension developers who wish to easily inject hyperlinks into a builder by only needing to override this method. :param node: A node class :returns: URI of the node """ # reference nodes if isinstance(node, nodes.reference): if 'refuri' in node: return node['refuri'] # image nodes if isinstance(node, nodes.image): uri = node['candidates'].get('?') if uri and '://' in uri: return uri # raw nodes if isinstance(node, nodes.raw): uri = node.get('source') if uri and '://' in uri: return uri return None def _add_uri(self, uri: str, node: nodes.Element) -> None: """Registers a node's URI into a builder's collection of hyperlinks. Provides the ability to register a URI value determined from a node into the linkcheck's builder. URI's processed through this call can be manipulated through a ``linkcheck-process-uri`` event before the builder attempts to validate. :param uri: URI to add :param node: A node class where the URI was found """ builder = cast(CheckExternalLinksBuilder, hyperlinks = builder.hyperlinks docname = self.env.docname if newuri :='linkcheck-process-uri', uri): uri = newuri try: lineno = get_node_line(node) except ValueError: lineno = -1 if uri not in hyperlinks: hyperlinks[uri] = Hyperlink(uri, docname, self.env.doc2path(docname), lineno) class Hyperlink(NamedTuple): uri: str docname: str docpath: str lineno: int class HyperlinkAvailabilityChecker: def __init__(self, config: Config) -> None: self.config = config self.rate_limits: dict[str, RateLimit] = {} self.rqueue: Queue[CheckResult] = Queue() self.workers: list[Thread] = [] self.wqueue: PriorityQueue[CheckRequest] = PriorityQueue() self.num_workers: int = config.linkcheck_workers self.to_ignore: list[re.Pattern[str]] = list(map(re.compile, self.config.linkcheck_ignore)) def check(self, hyperlinks: dict[str, Hyperlink]) -> Iterator[CheckResult]: self.invoke_threads() total_links = 0 for hyperlink in hyperlinks.values(): if self.is_ignored_uri(hyperlink.uri): yield CheckResult(hyperlink.uri, hyperlink.docname, hyperlink.lineno, 'ignored', '', 0) else: self.wqueue.put(CheckRequest(CHECK_IMMEDIATELY, hyperlink), False) total_links += 1 done = 0 while done < total_links: yield self.rqueue.get() done += 1 self.shutdown_threads() def invoke_threads(self) -> None: for _i in range(self.num_workers): thread = HyperlinkAvailabilityCheckWorker(self.config, self.rqueue, self.wqueue, self.rate_limits) thread.start() self.workers.append(thread) def shutdown_threads(self) -> None: self.wqueue.join() for _worker in self.workers: self.wqueue.put(CheckRequest(CHECK_IMMEDIATELY, None), False) def is_ignored_uri(self, uri: str) -> bool: return any(pat.match(uri) for pat in self.to_ignore) class CheckRequest(NamedTuple): next_check: float hyperlink: Hyperlink | None class CheckResult(NamedTuple): uri: str docname: str lineno: int status: str message: str code: int class HyperlinkAvailabilityCheckWorker(Thread): """A worker class for checking the availability of hyperlinks.""" def __init__(self, config: Config, rqueue: Queue[CheckResult], wqueue: Queue[CheckRequest], rate_limits: dict[str, RateLimit]) -> None: self.rate_limits = rate_limits self.rqueue = rqueue self.wqueue = wqueue self.anchors_ignore: list[re.Pattern[str]] = list( map(re.compile, config.linkcheck_anchors_ignore)) self.anchors_ignore_for_url: list[re.Pattern[str]] = list( map(re.compile, config.linkcheck_anchors_ignore_for_url)) self.documents_exclude: list[re.Pattern[str]] = list( map(re.compile, config.linkcheck_exclude_documents)) self.auth = [(re.compile(pattern), auth_info) for pattern, auth_info in config.linkcheck_auth] self.timeout: int | float | None = config.linkcheck_timeout self.request_headers: dict[str, dict[str, str]] = config.linkcheck_request_headers self.check_anchors: bool = config.linkcheck_anchors self.allowed_redirects: dict[re.Pattern[str], re.Pattern[str]] self.allowed_redirects = config.linkcheck_allowed_redirects self.retries: int = config.linkcheck_retries self.rate_limit_timeout = config.linkcheck_rate_limit_timeout self._allow_unauthorized = config.linkcheck_allow_unauthorized if config.linkcheck_report_timeouts_as_broken: self._timeout_status = 'broken' else: self._timeout_status = 'timeout' self.user_agent = config.user_agent self.tls_verify = config.tls_verify self.tls_cacerts = config.tls_cacerts self._session = requests._Session() super().__init__(daemon=True) def run(self) -> None: while True: next_check, hyperlink = self.wqueue.get() if hyperlink is None: # An empty hyperlink is a signal to shutdown the worker; cleanup resources here self._session.close() break uri, docname, _docpath, lineno = hyperlink if uri is None: break netloc = urlsplit(uri).netloc with contextlib.suppress(KeyError): # Refresh rate limit. # When there are many links in the queue, workers are all stuck waiting # for responses, but the builder keeps queuing. Links in the queue may # have been queued before rate limits were discovered. next_check = self.rate_limits[netloc].next_check if next_check > time.time(): # Sleep before putting message back in the queue to avoid # waking up other threads. time.sleep(QUEUE_POLL_SECS) self.wqueue.put(CheckRequest(next_check, hyperlink), False) self.wqueue.task_done() continue status, info, code = self._check(docname, uri, hyperlink) if status == 'rate-limited':'-rate limited- ') + uri + darkgray(' | sleeping...')) else: self.rqueue.put(CheckResult(uri, docname, lineno, status, info, code)) self.wqueue.task_done() def _check(self, docname: str, uri: str, hyperlink: Hyperlink) -> tuple[str, str, int]: # check for various conditions without bothering the network for doc_matcher in self.documents_exclude: if doc_matcher.match(docname): info = ( f'{docname} matched {doc_matcher.pattern} from ' 'linkcheck_exclude_documents' ) return 'ignored', info, 0 if len(uri) == 0 or uri.startswith(('#', 'mailto:', 'tel:')): return 'unchecked', '', 0 if not uri.startswith(('http:', 'https:')): if uri_re.match(uri): # Non-supported URI schemes (ex. ftp) return 'unchecked', '', 0 src_dir = path.dirname(hyperlink.docpath) if path.exists(path.join(src_dir, uri)): return 'working', '', 0 return 'broken', '', 0 # need to actually check the URI status, info, code = '', '', 0 for _ in range(self.retries): status, info, code = self._check_uri(uri, hyperlink) if status != 'broken': break return status, info, code def _retrieval_methods(self, check_anchors: bool, anchor: str) -> Iterator[tuple[Callable, dict]]: if not check_anchors or not anchor: yield self._session.head, {'allow_redirects': True} yield self._session.get, {'stream': True} def _check_uri(self, uri: str, hyperlink: Hyperlink) -> tuple[str, str, int]: req_url, delimiter, anchor = uri.partition('#') if delimiter and anchor: for rex in self.anchors_ignore: if rex.match(anchor): anchor = '' break else: for rex in self.anchors_ignore_for_url: if rex.match(req_url): anchor = '' break anchor = unquote(anchor) # handle non-ASCII URIs try: req_url.encode('ascii') except UnicodeError: req_url = encode_uri(req_url) # Get auth info, if any for pattern, auth_info in self.auth: # NoQA: B007 (false positive) if pattern.match(uri): break else: auth_info = None # update request headers for the URL headers = _get_request_headers(uri, self.request_headers) # Linkcheck HTTP request logic: # # - Attempt HTTP HEAD before HTTP GET unless page content is required. # - Follow server-issued HTTP redirects. # - Respect server-issued HTTP 429 back-offs. error_message = '' status_code = -1 response_url = retry_after = '' for retrieval_method, kwargs in self._retrieval_methods(self.check_anchors, anchor): try: with retrieval_method( url=req_url, auth=auth_info, headers=headers, timeout=self.timeout, **kwargs, _user_agent=self.user_agent, _tls_info=(self.tls_verify, self.tls_cacerts), ) as response: if (self.check_anchors and response.ok and anchor and not contains_anchor(response, anchor)): raise Exception(__(f'Anchor {quote(anchor)!r} not found')) # Copy data we need from the (closed) response status_code = response.status_code redirect_status_code = response.history[-1].status_code if response.history else None # NoQA: E501 retry_after = response.headers.get('Retry-After') response_url = f'{response.url}' response.raise_for_status() del response break except RequestTimeout as err: return self._timeout_status, str(err), 0 except SSLError as err: # SSL failure; report that the link is broken. return 'broken', str(err), 0 except (ConnectionError, TooManyRedirects) as err: # Servers drop the connection on HEAD requests, causing # ConnectionError. error_message = str(err) continue except HTTPError as err: error_message = str(err) # Unauthorized: the client did not provide required credentials if status_code == 401: if self._allow_unauthorized: deprecation_msg = ( "\n---\n" "The linkcheck builder encountered an HTTP 401 " "(unauthorized) response, and will report it as " "'working' in this version of Sphinx to maintain " "backwards-compatibility." "\n" "This logic will change in Sphinx 8.0 which will " "report the hyperlink as 'broken'." "\n" "To explicitly continue treating unauthorized " "hyperlink responses as 'working', set the " "'linkcheck_allow_unauthorized' config option to " "``True``." "\n" "See " "for details." "\n---" ) warnings.warn(deprecation_msg, RemovedInSphinx80Warning, stacklevel=1) status = 'working' if self._allow_unauthorized else 'broken' return status, 'unauthorized', 0 # Rate limiting; back-off if allowed, or report failure otherwise if status_code == 429: if next_check := self.limit_rate(response_url, retry_after): self.wqueue.put(CheckRequest(next_check, hyperlink), False) return 'rate-limited', '', 0 return 'broken', error_message, 0 # Don't claim success/failure during server-side outages if status_code == 503: return 'ignored', 'service unavailable', 0 # For most HTTP failures, continue attempting alternate retrieval methods continue except Exception as err: # Unhandled exception (intermittent or permanent); report that # the link is broken. return 'broken', str(err), 0 else: # All available retrieval methods have been exhausted; report # that the link is broken. return 'broken', error_message, 0 # Success; clear rate limits for the origin netloc = urlsplit(req_url).netloc self.rate_limits.pop(netloc, None) if ((response_url.rstrip('/') == req_url.rstrip('/')) or _allowed_redirect(req_url, response_url, self.allowed_redirects)): return 'working', '', 0 elif redirect_status_code is not None: return 'redirected', response_url, redirect_status_code else: return 'redirected', response_url, 0 def limit_rate(self, response_url: str, retry_after: str | None) -> float | None: delay = DEFAULT_DELAY next_check = None if retry_after: try: # Integer: time to wait before next attempt. delay = float(retry_after) except ValueError: try: # An HTTP-date: time of next attempt. next_check = rfc1123_to_epoch(retry_after) except (ValueError, TypeError): # TypeError: Invalid date format. # ValueError: Invalid date, e.g. Oct 52th. pass else: delay = next_check - time.time() else: next_check = time.time() + delay netloc = urlsplit(response_url).netloc if next_check is None: max_delay = self.rate_limit_timeout try: rate_limit = self.rate_limits[netloc] except KeyError: delay = DEFAULT_DELAY else: last_wait_time = rate_limit.delay delay = 2.0 * last_wait_time if delay > max_delay > last_wait_time: delay = max_delay if delay > max_delay: return None next_check = time.time() + delay self.rate_limits[netloc] = RateLimit(delay, next_check) return next_check def _get_request_headers( uri: str, request_headers: dict[str, dict[str, str]], ) -> dict[str, str]: url = urlsplit(uri) candidates = (f'{url.scheme}://{url.netloc}', f'{url.scheme}://{url.netloc}/', uri, '*') for u in candidates: if u in request_headers: return {**DEFAULT_REQUEST_HEADERS, **request_headers[u]} return {} def contains_anchor(response: Response, anchor: str) -> bool: """Determine if an anchor is contained within an HTTP response.""" parser = AnchorCheckParser(anchor) # Read file in chunks. If we find a matching anchor, we break # the loop early in hopes not to have to download the whole thing. for chunk in response.iter_content(chunk_size=4096, decode_unicode=True): if isinstance(chunk, bytes): # requests failed to decode chunk = chunk.decode() # manually try to decode it parser.feed(chunk) if parser.found: break parser.close() return parser.found class AnchorCheckParser(HTMLParser): """Specialised HTML parser that looks for a specific anchor.""" def __init__(self, search_anchor: str) -> None: super().__init__() self.search_anchor = search_anchor self.found = False def handle_starttag(self, tag: Any, attrs: Any) -> None: for key, value in attrs: if key in ('id', 'name') and value == self.search_anchor: self.found = True break def _allowed_redirect(url: str, new_url: str, allowed_redirects: dict[re.Pattern[str], re.Pattern[str]]) -> bool: return any( from_url.match(url) and to_url.match(new_url) for from_url, to_url in allowed_redirects.items() ) class RateLimit(NamedTuple): delay: float next_check: float def rewrite_github_anchor(app: Sphinx, uri: str) -> str | None: """Rewrite anchor name of the hyperlink to The hyperlink anchors in are dynamically generated. This rewrites them before checking and makes them comparable. """ parsed = urlparse(uri) if parsed.hostname == '' and parsed.fragment: prefixed = parsed.fragment.startswith('user-content-') if not prefixed: fragment = f'user-content-{parsed.fragment}' return urlunparse(parsed._replace(fragment=fragment)) return None def compile_linkcheck_allowed_redirects(app: Sphinx, config: Config) -> None: """Compile patterns in linkcheck_allowed_redirects to the regexp objects.""" for url, pattern in list(app.config.linkcheck_allowed_redirects.items()): try: app.config.linkcheck_allowed_redirects[re.compile(url)] = re.compile(pattern) except re.error as exc: logger.warning(__('Failed to compile regex in linkcheck_allowed_redirects: %r %s'), exc.pattern, exc.msg) finally: # Remove the original regexp-string app.config.linkcheck_allowed_redirects.pop(url) def setup(app: Sphinx) -> ExtensionMetadata: app.add_builder(CheckExternalLinksBuilder) app.add_post_transform(HyperlinkCollector) app.add_config_value('linkcheck_ignore', [], '') app.add_config_value('linkcheck_exclude_documents', [], '') app.add_config_value('linkcheck_allowed_redirects', {}, '') app.add_config_value('linkcheck_auth', [], '') app.add_config_value('linkcheck_request_headers', {}, '') app.add_config_value('linkcheck_retries', 1, '') app.add_config_value('linkcheck_timeout', 30, '', (int, float)) app.add_config_value('linkcheck_workers', 5, '') app.add_config_value('linkcheck_anchors', True, '') # Anchors starting with ! are ignored since they are # commonly used for dynamic pages app.add_config_value('linkcheck_anchors_ignore', ['^!'], '') app.add_config_value('linkcheck_anchors_ignore_for_url', (), '', (tuple, list)) app.add_config_value('linkcheck_rate_limit_timeout', 300.0, '') app.add_config_value('linkcheck_allow_unauthorized', True, '') app.add_config_value('linkcheck_report_timeouts_as_broken', True, '', bool) app.add_event('linkcheck-process-uri') app.connect('config-inited', compile_linkcheck_allowed_redirects, priority=800) # FIXME: Disable URL rewrite handler for temporarily. # ref: # app.connect('linkcheck-process-uri', rewrite_github_anchor) return { 'version': 'builtin', 'parallel_read_safe': True, 'parallel_write_safe': True, }