Mercurial > libervia-backend
view src/memory/cache.py @ 2309:c7a72b75232b
jp (shell): shell command (REPL mode), first draft:
This command launch jp in REPL mode, allowing do normal jp commands with some facilities.
Command can be selected with "cmd" (e.g. "cmd blog").
An argument can be fixed with "use" (e.g. "use output fancy").
Command is launched with "do", or directly with its name if it doesn't conflict with a shell command.
Arguments completion is still TODO (only shell commands are completed so far).
author | Goffi <goffi@goffi.org> |
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date | Thu, 06 Jul 2017 20:28:25 +0200 |
parents | 1b3fbb76984b |
children | 8b37a62336c3 |
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#!/usr/bin/env python2 # -*- coding: utf-8 -*- # SAT: a jabber client # Copyright (C) 2009-2016 Jérôme Poisson (goffi@goffi.org) # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU Affero General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU Affero General Public License for more details. # You should have received a copy of the GNU Affero General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. from sat.core.log import getLogger log = getLogger(__name__) from sat.tools.common import regex from sat.core import exceptions from sat.core.constants import Const as C import cPickle as pickle import mimetypes import os.path import time class Cache(object): """generic file caching""" def __init__(self, host, profile=None): host = host self.profile = profile self.cache_dir = os.path.join( host.memory.getConfig('', 'local_dir'), C.CACHE_DIR, regex.pathEscape(profile or '')) if not os.path.exists(self.cache_dir): os.makedirs(self.cache_dir) def getPath(self, filename): """return cached file URL @param filename(unicode): cached file name (cache data or actual file) """ if not filename or u'/' in filename: log.error(u"invalid char found in file name, hack attempt? name:{}".format(filename)) raise exceptions.DataError(u"Invalid char found") return os.path.join(self.cache_dir, filename) def getFilePath(self, uid): """retrieve absolute path to file @param uid(unicode): unique identifier of file @return (unicode, None): absolute path to cached file None if file is not in cache (or cache is invalid) """ uid = uid.strip() if not uid: return None cache_url = self.getPath(uid) if not os.path.exists(cache_url): return None try: with open(cache_url, 'rb') as f: cache_data = pickle.load(f) except IOError: log.warning(u"can't read cache at {}".format(cache_url)) return None except pickle.UnpicklingError: log.warning(u'invalid cache found at {}'.format(cache_url)) return None try: eol = cache_data['eol'] except KeyError: log.warning(u'no End Of Life found for cached file {}'.format(uid)) eol = 0 if eol < time.time(): log.debug(u"removing expired cache (expired for {}s)".format( time.time() - eol)) return None return self.getPath(cache_data['filename']) def cacheData(self, source, uid, mime_type=u'', max_age=None, filename=None): """create cache metadata and file object to use for actual data @param source(unicode): source of the cache (should be plugin's import_name) @param uid(unicode): an identifier of the file which must be unique @param mime_type(unicode): MIME type of the file to cache it will be used notably to guess file extension @param max_age(int, None): maximum age in seconds the cache metadata will have an "eol" (end of life) None to use default value 0 to ignore cache (file will be re-downloaded on each access) @param filename: if not None, will be used as filename else one will be generated from uid and guessed extension @return(file): file object opened in write mode you have to close it yourself (hint: use with statement) """ # FIXME: is it needed to use a separate thread? # probably not with the little data expected with BoB cache_url = self.getPath(uid) ext = mimetypes.guess_extension(mime_type, strict=False) if ext is None: log.warning(u"can't find extension for MIME type {}".format(mime_type)) ext = '.dump' if filename is None: filename = uid + ext if max_age is None: max_age = C.DEFAULT_MAX_AGE cache_data = {'source': source, 'filename': filename, 'eol': int(time.time()) + max_age, 'mime_type': mime_type, } file_path = self.getPath(filename) with open(cache_url, 'wb') as f: pickle.dump(cache_data, f, protocol=2) return open(file_path, 'wb')