Upstream scrapy/scrapy state of the touched files before c9f94dc564

scrapy/downloadermiddlewares/robotstxt.py

@@ -0,0 +1,142 @@
+"""
+This is a middleware to respect robots.txt policies. To activate it you must
+enable this middleware and enable the ROBOTSTXT_OBEY setting.
+
+"""
+
+from __future__ import annotations
+
+import logging
+from typing import TYPE_CHECKING, Any, Self
+
+from twisted.internet.defer import Deferred
+
+from scrapy import signals
+from scrapy.exceptions import IgnoreRequest, NotConfigured
+from scrapy.http import Request, Response
+from scrapy.http.request import NO_CALLBACK
+from scrapy.utils.decorators import _warn_spider_arg
+from scrapy.utils.defer import maybe_deferred_to_future
+from scrapy.utils.httpobj import urlparse_cached
+from scrapy.utils.misc import build_from_crawler, load_object
+
+if TYPE_CHECKING:
+    from scrapy import Spider
+    from scrapy.crawler import Crawler
+    from scrapy.robotstxt import RobotParser
+    from scrapy.statscollectors import StatsCollector
+
+
+logger = logging.getLogger(__name__)
+
+
+class RobotsTxtMiddleware:
+    DOWNLOAD_PRIORITY: int = 1000
+
+    def __init__(self, crawler: Crawler):
+        if not crawler.settings.getbool("ROBOTSTXT_OBEY"):
+            raise NotConfigured
+        self._default_useragent: str = crawler.settings["USER_AGENT"]
+        self._robotstxt_useragent: str | None = crawler.settings["ROBOTSTXT_USER_AGENT"]
+        self.crawler: Crawler = crawler
+        self._stats: StatsCollector = crawler.stats
+        self._parsers: dict[str, RobotParser | Deferred[RobotParser | None] | None] = {}
+        self._parserimpl: type[RobotParser] = load_object(
+            crawler.settings.get("ROBOTSTXT_PARSER")
+        )
+
+        # check if parser dependencies are met, this should throw an error otherwise.
+        build_from_crawler(self._parserimpl, self.crawler, b"")
+
+    @classmethod
+    def from_crawler(cls, crawler: Crawler) -> Self:
+        return cls(crawler)
+
+    @_warn_spider_arg
+    async def process_request(
+        self, request: Request, spider: Spider | None = None
+    ) -> None:
+        if request.meta.get("dont_obey_robotstxt"):
+            return
+        if request.url.startswith("data:") or request.url.startswith("file:"):
+            return
+        rp = await self.robot_parser(request)
+        self.process_request_2(rp, request)
+
+    def process_request_2(self, rp: RobotParser | None, request: Request) -> None:
+        if rp is None:
+            return
+
+        useragent: str | bytes | None = self._robotstxt_useragent
+        if not useragent:
+            useragent = request.headers.get(b"User-Agent", self._default_useragent)
+            assert useragent is not None
+        if not rp.allowed(request.url, useragent):
+            logger.debug(
+                "Forbidden by robots.txt: %(request)s",
+                {"request": request},
+                extra={"spider": self.crawler.spider},
+            )
+            self._stats.inc_value("robotstxt/forbidden")
+            raise IgnoreRequest("Forbidden by robots.txt")
+
+    async def robot_parser(self, request: Request) -> RobotParser | None:
+        url = urlparse_cached(request)
+        netloc = url.netloc
+
+        if netloc not in self._parsers:
+            self._parsers[netloc] = Deferred()
+            robotsurl = f"{url.scheme}://{url.netloc}/robots.txt"
+            meta: dict[str, Any] = {
+                "dont_obey_robotstxt": True,
+                "is_robotstxt_request": True,
+            }
+            if "download_handler" in request.meta:
+                meta["download_handler"] = request.meta["download_handler"]
+            robotsreq = Request(
+                robotsurl,
+                priority=self.DOWNLOAD_PRIORITY,
+                meta=meta,
+                callback=NO_CALLBACK,
+            )
+            try:
+                resp = await self.crawler.engine.download_async(robotsreq)
+                await self._parse_robots(resp, netloc, request)
+            except Exception as e:
+                if not isinstance(e, IgnoreRequest):
+                    logger.exception(
+                        f"Error downloading {request}",
+                        extra={"spider": self.crawler.spider},
+                    )
+                self._robots_error(e, netloc)
+            self._stats.inc_value("robotstxt/request_count")
+
+        parser = self._parsers[netloc]
+        if isinstance(parser, Deferred):
+            return await maybe_deferred_to_future(parser)
+        return parser
+
+    async def _parse_robots(
+        self, response: Response, netloc: str, request: Request
+    ) -> None:
+        self._stats.inc_value("robotstxt/response_count")
+        self._stats.inc_value(f"robotstxt/response_status_count/{response.status}")
+        rp = build_from_crawler(self._parserimpl, self.crawler, response.body)
+        await self.crawler.signals.send_catch_log_async(
+            signal=signals.robots_parsed,
+            robotparser=rp,
+            request=request,
+        )
+        rp_dfd = self._parsers[netloc]
+        assert isinstance(rp_dfd, Deferred)
+        self._parsers[netloc] = rp
+        rp_dfd.callback(rp)
+
+    def _robots_error(self, exc: Exception, netloc: str) -> None:
+        if not isinstance(exc, IgnoreRequest):
+            key = f"robotstxt/exception_count/{type(exc)}"
+            self._stats.inc_value(key)
+        rp_dfd = self._parsers[netloc]
+        assert isinstance(rp_dfd, Deferred)
+        self._parsers[netloc] = None
+        rp_dfd.callback(None)