cache.py (view raw)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 |
import os
import json
import hashlib
import logging
import glob
class Cached(object):
def __init__(self, hash='', text='', stime=0):
if not os.path.isdir(glob.CACHE):
os.mkdir(glob.CACHE)
if hash:
self._hbase = hash
elif text:
self._hbase = hashlib.sha1(text.encode('utf-8')).hexdigest()
else:
print("No identifier passed for Cached")
raise
self._cpath = os.path.join(glob.CACHE, self._hbase)
self._stime = stime
if os.path.isfile(self._cpath):
self._ctime = os.stat(self._cpath)
else:
self._ctime = None
def get(self):
if not glob.CACHEENABLED:
return None
cached = ''
if os.path.isfile(self._cpath):
if self._stime and self._stime.st_mtime == self._ctime.st_mtime:
logging.debug("Cache exists at %s; using it" % (self._cpath ))
with open(self._cpath, 'r') as c:
cached = c.read()
c.close()
# invalidate old
elif self._stime and self._stime.st_mtime > self._ctime.st_mtime:
logging.debug("invalidating cache at %s" % (self._cpath ))
os.remove(self._cpath)
return cached
def set(self, content):
if not glob.CACHEENABLED:
return None
with open(self._cpath, "w") as c:
logging.debug("writing cache to %s" % (self._cpath ))
c.write(content)
c.close()
if self._stime:
os.utime(self._cpath, (self._stime.st_mtime, self._stime.st_mtime ))
|