From ecf2c0123bbeda951c5e7d9a832d20eaf99291ce Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 30 Oct 2011 13:46:23 +0000
Subject: [PATCH] yoweb-scrape: apply rate limiter per http:// site

---
 yoweb-scrape | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/yoweb-scrape b/yoweb-scrape
index cee5c17..717b539 100755
--- a/yoweb-scrape
+++ b/yoweb-scrape
@@ -131,12 +131,24 @@ class Fetcher:
 			if oe.errno != errno.EEXIST: raise
 		self._cache_scan(time.time())
 
-	def _cache_scan(self, now):
+	def _match_url_normalise(self, url):
+		without_scheme = regexp.sub('^[a-z]+://', '', url)
+		without_tail = regexp.sub('/.*', '', without_scheme)
+		return without_tail
+
+	def _cache_scan(self, now, match_url=None):
 		# returns list of ages, unsorted
+		if match_url is not None:
+			match_url = self._match_url_normalise(match_url)
 		ages = []
 		debug('Fetcher   scan_cache')
 		for leaf in os.listdir(self.cachedir):
 			if not leaf.startswith('#'): continue
+			if match_url is not None:
+				leaf_url = urllib.unquote_plus(leaf.strip('#'))
+				leaf_url = self._match_url_normalise(leaf_url)
+				if leaf_url != match_url:
+					continue
 			path = self.cachedir + '/' + leaf
 			try: s = os.stat(path)
 			except (OSError,IOError), oe:
@@ -152,8 +164,8 @@ class Fetcher:
 			ages.append(age)
 		return ages
 
-	def need_wait(self, now, imaginary=[]):
-		ages = self._cache_scan(now)
+	def need_wait(self, now, imaginary=[], next_url=None):
+		ages = self._cache_scan(now, match_url=next_url)
 		ages += imaginary
 		ages.sort()
 		debug('Fetcher   ages ' + `ages`)
@@ -169,8 +181,8 @@ class Fetcher:
 			need_wait += random.random() - 0.5
 		return need_wait
 
-	def _rate_limit_cache_clean(self, now):
-		need_wait = self.need_wait(now)
+	def _rate_limit_cache_clean(self, now, next_url=None):
+		need_wait = self.need_wait(now, next_url=next_url)
 		if need_wait > 0:
 			debug('Fetcher   wait %f' % need_wait)
 			sleep(need_wait)
@@ -198,7 +210,7 @@ class Fetcher:
 			return data
 
 		debug('Fetcher  fetch')
-		self._rate_limit_cache_clean(now)
+		self._rate_limit_cache_clean(now, next_url=url)
 
 		stream = urllib2.urlopen(url)
 		data = stream.read()
-- 
2.30.2