// This file is part of the AppIndicator/KStatusNotifierItem GNOME Shell extension
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
const GLib = imports.gi.GLib
const Lang = imports.lang
const Mainloop = imports.mainloop
const Util = imports.misc.extensionUtils.getCurrentExtension().imports.util;
// The icon cache caches icon objects in case they're reused shortly aftwerwards.
// This is necessary for some indicators like skype which rapidly switch between serveral icons.
// Without caching, the garbage collection would never be able to handle the amount of new icon data.
// If the lifetime of an icon is over, the cache will destroy the icon. (!)
// The presence of an inUse property set to true on the icon will extend the lifetime.
// how to use: see IconCache.add, IconCache.get
var IconCache = new Lang.Class({
Name: 'IconCache',
LIFETIME_TIMESPAN: 5000, //5s
GC_INTERVAL: 10000, //10s
_init: function() {
this._cache = {};
this._lifetime = {}; //we don't want to attach lifetime to the object
this._gc();
},
add: function(id, o) {
//Util.Logger.debug("IconCache: adding "+id);
if (!(o && id)) return null;
if (id in this._cache && this._cache[id] !== o)
this._remove(id);
this._cache[id] = o;
this._lifetime[id] = new Date().getTime() + this.LIFETIME_TIMESPAN;
return o;
},
_remove: function(id) {
//Util.Logger.debug('IconCache: removing '+id);
if ('destroy' in this._cache[id]) this._cache[id].destroy();
delete this._cache[id];
delete this._lifetime[id];
},
forceDestroy: function(id) {
this._remove(id);
},
// removes everything from the cache
clear: function() {
for (let id in this._cache)
this._remove(id)
},
// returns an object from the cache, or null if it can't be found.
get: function(id) {
if (id in this._cache) {
//Util.Logger.debug('IconCache: retrieving '+id);
this._lifetime[id] = new Date().getTime() + this.LIFETIME_TIMESPAN; //renew lifetime
return this._cache[id];
}
else return null;
},
_gc: function() {
var time = new Date().getTime();
for (var id in this._cache) {
if (this._cache[id].inUse) {
//Util.Logger.debug ("IconCache: " + id + " is in use.");
continue;
} else if (this._lifetime[id] < time) {
this._remove(id);
} else {
//Util.Logger.debug("IconCache: " + id + " survived this round.");
}
}
if (!this._stopGc) Mainloop.timeout_add(this.GC_INTERVAL, Lang.bind(this, this._gc));
return false; //we just added our timeout again.
},
destroy: function() {
this._stopGc = true;
this.clear();
}
});