Mercurial > libervia-backend
view sat/memory/cache.py @ 3101:ab7e8ade848a
plugin XEP-0045: added room statuses to metadata:
room statuses are now sent with other metadata on bridge signals, and saved in Room
instance. They give useful data on the room, for instance they can be used to know if a
full jid is used in this room.
author | Goffi <goffi@goffi.org> |
---|---|
date | Mon, 30 Dec 2019 20:44:02 +0100 |
parents | ab2696e34d29 |
children | 9d0df638c8b4 |
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#!/usr/bin/env python3 # -*- coding: utf-8 -*- # SAT: a jabber client # Copyright (C) 2009-2019 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 pickle as pickle import mimetypes import os.path import time DEFAULT_EXT = ".raw" class Cache(object): """generic file caching""" def __init__(self, host, profile): """ @param profile(unicode, None): ame of the profile to set the cache for if None, the cache will be common for all profiles """ self.profile = profile path_elts = [host.memory.getConfig("", "local_dir"), C.CACHE_DIR] if profile: path_elts.extend(["profiles", regex.pathEscape(profile)]) else: path_elts.append("common") self.cache_dir = os.path.join(*path_elts) 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 "/" in filename: log.error( "invalid char found in file name, hack attempt? name:{}".format(filename) ) raise exceptions.DataError("Invalid char found") return os.path.join(self.cache_dir, filename) def getMetadata(self, uid): """retrieve metadata for cached data @param uid(unicode): unique identifier of file @return (dict, None): metadata with following keys: see [cacheData] for data details, an additional "path" key is the full path to cached file. None if file is not in cache (or cache is invalid) """ uid = uid.strip() if not uid: raise exceptions.InternalError("uid must not be empty") 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("can't read cache at {}".format(cache_url)) return None except pickle.UnpicklingError: log.warning("invalid cache found at {}".format(cache_url)) return None try: eol = cache_data["eol"] except KeyError: log.warning("no End Of Life found for cached file {}".format(uid)) eol = 0 if eol < time.time(): log.debug( "removing expired cache (expired for {}s)".format(time.time() - eol) ) return None cache_data["path"] = self.getPath(cache_data["filename"]) return cache_data 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) """ metadata = self.getMetadata(uid) if metadata is not None: return metadata["path"] def cacheData(self, source, uid, mime_type=None, 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) """ cache_url = self.getPath(uid) if filename is None: if mime_type: ext = mimetypes.guess_extension(mime_type, strict=False) if ext is None: log.warning( "can't find extension for MIME type {}".format(mime_type) ) ext = DEFAULT_EXT elif ext == ".jpe": ext = ".jpg" else: ext = DEFAULT_EXT mime_type = 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")