Merge pull request #2611 from delftswa2017/httpcachemiddleware_log

[MRG+1] [logging] HttpCacheMiddleware: log cache directory at instantiation

scrapy/extensions/httpcache.py

@@ -1,6 +1,7 @@
 from __future__ import print_function
 import os
 import gzip
+import logging
 from six.moves import cPickle as pickle
 from importlib import import_module
 from time import time
@@ -15,6 +16,9 @@ from scrapy.utils.httpobj import urlparse_cached
 from scrapy.utils.python import to_bytes, to_unicode
 
 
+logger = logging.getLogger(__name__)
+
+
 class DummyPolicy(object):
 
     def __init__(self, settings):
@@ -220,6 +224,8 @@ class DbmCacheStorage(object):
         dbpath = os.path.join(self.cachedir, '%s.db' % spider.name)
         self.db = self.dbmodule.open(dbpath, 'c')
 
+        logger.debug("Using DBM cache storage in %(cachepath)s" % {'cachepath': dbpath}, extra={'spider': spider})
+
     def close_spider(self, spider):
         self.db.close()
 
@@ -272,7 +278,8 @@ class FilesystemCacheStorage(object):
         self._open = gzip.open if self.use_gzip else open
 
     def open_spider(self, spider):
-        pass
+        logger.debug("Using filesystem cache storage in %(cachedir)s" % {'cachedir': self.cachedir},
+                     extra={'spider': spider})
 
     def close_spider(self, spider):
         pass
@@ -348,6 +355,8 @@ class LeveldbCacheStorage(object):
         dbpath = os.path.join(self.cachedir, '%s.leveldb' % spider.name)
         self.db = self._leveldb.LevelDB(dbpath)
 
+        logger.debug("Using LevelDB cache storage in %(cachepath)s" % {'cachepath': dbpath}, extra={'spider': spider})
+
     def close_spider(self, spider):
         # Do compactation each time to save space and also recreate files to
         # avoid them being removed in storages with timestamp-based autoremoval.