import errno import md5 import os import tempfile import time class SafeHTTPCache(object): """Thread-safe replacement for httplib2.FileCache""" def __init__(self, path=None, max_age=None): self._dir = path if max_age is not None: try: self._clean(threshold=time.time() - max_age) except: pass def _clean(self, threshold=0): for ent in os.listdir(self._dir): fnm = os.path.join(self._dir, ent) if os.path.isdir(fnm) or not fnm.endswith('.tmp'): continue stat = os.lstat(fnm) if stat.st_mtime < threshold: try: os.unlink(fnm) except OSError as err: if err.errno != errno.ENOENT: raise def __str__(self): return self._dir def _filename(self, url): return os.path.join(self._dir, md5.new(url).hexdigest()+'.tmp') def get(self, url): filename = self._filename(url) try: with open(filename, 'rb') as f: return f.read() except IOError, OSError: return None def set(self, url, content): try: fd, tempname = tempfile.mkstemp(dir=self._dir) except: return None try: try: f = os.fdopen(fd, 'w') except: os.close(fd) raise try: f.write(content) finally: f.close() os.rename(tempname, self._filename(url)) tempname = None finally: if tempname: os.unlink(tempname) def delete(self, url): try: os.unlink(self._filename(url)) except OSError as err: if err.errno != errno.ENOENT: raise