from __future__ import annotations
from typing import TYPE_CHECKING, Dict, Union
from twisted.web import http
from scrapy import Request, Spider
from scrapy.crawler import Crawler
from scrapy.exceptions import NotConfigured
from scrapy.http import Response
from scrapy.statscollectors import StatsCollector
from scrapy.utils.python import global_object_name, to_bytes
from scrapy.utils.request import request_httprepr
if TYPE_CHECKING:
# typing.Self requires Python 3.11
from typing_extensions import Self
def get_header_size(headers: Dict[str, Union[list, tuple]]) -> int:
size = 0
for key, value in headers.items():
if isinstance(value, (list, tuple)):
for v in value:
size += len(b": ") + len(key) + len(v)
return size + len(b"\r\n") * (len(headers.keys()) - 1)
def get_status_size(response_status: int) -> int:
return len(to_bytes(http.RESPONSES.get(response_status, b""))) + 15
# resp.status + b"\r\n" + b"HTTP/1.1 <100-599> "
[docs]class DownloaderStats:
def __init__(self, stats: StatsCollector):
self.stats: StatsCollector = stats
@classmethod
def from_crawler(cls, crawler: Crawler) -> Self:
if not crawler.settings.getbool("DOWNLOADER_STATS"):
raise NotConfigured
assert crawler.stats
return cls(crawler.stats)
def process_request(
self, request: Request, spider: Spider
) -> Union[Request, Response, None]:
self.stats.inc_value("downloader/request_count", spider=spider)
self.stats.inc_value(
f"downloader/request_method_count/{request.method}", spider=spider
)
reqlen = len(request_httprepr(request))
self.stats.inc_value("downloader/request_bytes", reqlen, spider=spider)
return None
def process_response(
self, request: Request, response: Response, spider: Spider
) -> Union[Request, Response]:
self.stats.inc_value("downloader/response_count", spider=spider)
self.stats.inc_value(
f"downloader/response_status_count/{response.status}", spider=spider
)
reslen = (
len(response.body)
+ get_header_size(response.headers)
+ get_status_size(response.status)
+ 4
)
# response.body + b"\r\n"+ response.header + b"\r\n" + response.status
self.stats.inc_value("downloader/response_bytes", reslen, spider=spider)
return response
def process_exception(
self, request: Request, exception: Exception, spider: Spider
) -> Union[Request, Response, None]:
ex_class = global_object_name(exception.__class__)
self.stats.inc_value("downloader/exception_count", spider=spider)
self.stats.inc_value(
f"downloader/exception_type_count/{ex_class}", spider=spider
)
return None