def key(self, obj):
"""Return a cache key (relative path to file in cache) for an object"""
if isnumpy(obj):
# Key is byte view sha1 hash with .h5 extension
byteview = obj.view(numpy.uint8)
key = str(hashlib.sha1(byteview).hexdigest()) + '.h5'
elif isurl(obj):
# key is URL filename with an appended hash (for uniqueness)
p = urlparse.urlsplit(obj)
urlquery = urlparse.urlunsplit([p[0],p[1],p[2],p[3],None])
urlpath = urlparse.urlunsplit([p[0],p[1],p[2],None,None])
urlhash = self._hash(obj)
(filename, ext) = splitextension(path.basename(urlpath))
key = str(urlhash) + str(ext)
elif os.path.isfile(obj):
# within cache?
filebase = obj.split(self.root(),1)
if len(filebase) == 2:
# key is subpath within cache
key = filebase[1][1:]
else:
# key is filename with unique appended hash
(head, tail) = os.path.split(obj)
(filename, ext) = splitextension(tail)
namehash = hashlib.sha1(tail).hexdigest()
key = filename + '_' + str(namehash[0:7]) + ext
elif (path.isfile(self.abspath(obj)) or path.isdir(self.abspath(obj))):
key = obj # Already a cache key
elif isstring(obj):
key = obj # Use arbitrary string if not file or url
else:
raise CacheError('[bobo.cache][ERROR]: Unsupported object for constructing key')
return key
def _hash(self, url, prettyhash=_prettyhash):
"""Compute a SHA1 hash of a url to generate a unique cache filename for a given url"""
p = urlparse.urlsplit(url)
urlquery = urlparse.urlunsplit([p[0],p[1],p[2],p[3],None])
urlpath = urlparse.urlunsplit([p[0],p[1],p[2],None,None])
(filename, ext) = splitextension(urlpath)
#urlopt = self._url_fragment_options(url)
urlhash = hashlib.sha1(urlquery).hexdigest()
if prettyhash:
return path.basename(filename) + '_' + urlhash[0:7]
else:
return urlhash
