Rename liberator/ to common/

common/modules/storage.jsm

@@ -0,0 +1,234 @@
+/***** BEGIN LICENSE BLOCK ***** {{{
+Version: MPL 1.1/GPL 2.0/LGPL 2.1
+
+The contents of this file are subject to the Mozilla Public License Version
+1.1 (the "License"); you may not use this file except in compliance with
+the License. You may obtain a copy of the License at
+http://www.mozilla.org/MPL/
+
+Software distributed under the License is distributed on an "AS IS" basis,
+WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+for the specific language governing rights and limitations under the
+License.
+
+ © 2008: Kris Maglione <maglione.k at Gmail>
+(c) 2006-2008: Martin Stubenschrott <stubenschrott@gmx.net>
+
+Alternatively, the contents of this file may be used under the terms of
+either the GNU General Public License Version 2 or later (the "GPL"), or
+the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+in which case the provisions of the GPL or the LGPL are applicable instead
+of those above. If you wish to allow use of your version of this file only
+under the terms of either the GPL or the LGPL, and not to allow others to
+use your version of this file under the terms of the MPL, indicate your
+decision by deleting the provisions above and replace them with the notice
+and other provisions required by the GPL or the LGPL. If you do not delete
+the provisions above, a recipient may use your version of this file under
+the terms of any one of the MPL, the GPL or the LGPL.
+}}} ***** END LICENSE BLOCK *****/
+
+var EXPORTED_SYMBOLS = ["storage"];
+
+var prefService = Components.classes["@mozilla.org/preferences-service;1"]
+                            .getService(Components.interfaces.nsIPrefService)
+                            .getBranch("extensions.liberator.datastore.");
+var json = Components.classes["@mozilla.org/dom/json;1"]
+                     .createInstance(Components.interfaces.nsIJSON);
+
+function getCharPref(name)
+{
+    try
+    {
+        return prefService.getComplexValue(name, Components.interfaces.nsISupportsString).data;
+    }
+    catch (e) {}
+}
+
+function setCharPref(name, value)
+{
+    var str = Components.classes['@mozilla.org/supports-string;1']
+                        .createInstance(Components.interfaces.nsISupportsString);
+    str.data = value;
+    return prefService.setComplexValue(name, Components.interfaces.nsISupportsString, str);
+}
+
+function loadPref(name, store, type)
+{
+    if (store)
+        var pref = getCharPref(name);
+    if (pref)
+        var result = json.decode(pref);
+    if (result instanceof type)
+        return result;
+}
+
+function savePref(obj)
+{
+    if (obj.store)
+        setCharPref(obj.name, obj.serial)
+}
+
+var prototype = {
+    fireEvent: function (event, arg) { storage.fireEvent(this.name, event, arg) },
+    save: function () { savePref(this) },
+};
+
+function ObjectStore(name, store, data)
+{
+    var object = data || {};
+
+    this.__defineGetter__("store", function () store);
+    this.__defineGetter__("name", function () name);
+    this.__defineGetter__("serial", function () json.encode(object));
+
+    this.set = function set(key, val)
+    {
+        var defined = key in object;
+        var orig = object[key];
+        object[key] = val;
+        if (!defined)
+            this.fireEvent("add", key);
+        else if (orig != val)
+            this.fireEvent("change", key);
+    };
+
+    this.remove = function remove(key)
+    {
+        var ret = object[key];
+        delete object[key];
+        this.fireEvent("remove", key);
+        return ret;
+    };
+
+    this.get = function get(val) object[val];
+
+    this.clear = function ()
+    {
+        object = {};
+    };
+
+    this.__iterator__ = function () Iterator(object);
+}
+ObjectStore.prototype = prototype;
+
+function ArrayStore(name, store, data)
+{
+    var array = data || [];
+
+    this.__defineGetter__("store",  function () store);
+    this.__defineGetter__("name",   function () name);
+    this.__defineGetter__("serial", function () json.encode(array));
+    this.__defineGetter__("length", function () array.length);
+
+    this.set = function set(index, value)
+    {
+        var orig = array[index];
+        array[index] = value;
+        this.fireEvent("change", index);
+    };
+
+    this.push = function push(value)
+    {
+        array.push(value);
+        this.fireEvent("push", array.length);
+    };
+
+    this.pop = function pop(value)
+    {
+        var ret = array.pop();
+        this.fireEvent("pop", array.length);
+        return ret;
+    };
+
+    this.truncate = function truncate(length, fromEnd)
+    {
+        var ret = array.length;
+        if (array.length > length)
+        {
+            if (fromEnd)
+                array.splice(0, array.length - length);
+            array.length = length;
+            this.fireEvent("truncate", length);
+        }
+        return ret;
+    };
+
+    // XXX: Awkward.
+    this.mutate = function mutate(aFuncName)
+    {
+        var funcName = aFuncName;
+        arguments[0] = array;
+        array = Array[funcName].apply(Array, arguments);
+    };
+
+    this.get = function get(index)
+    {
+        return index >= 0 ? array[index] : array[array.length + index];
+    };
+
+    this.__iterator__ = function () Iterator(array);
+}
+ArrayStore.prototype = prototype;
+
+var keys = {};
+var observers = {};
+
+var storage = {
+    newObject: function newObject(key, constructor, store, type, reload)
+    {
+        if (!(key in keys) || reload)
+        {
+            if (key in this && !reload)
+                throw Error;
+            keys[key] = new constructor(key, store, loadPref(key, store, type || Object));
+            this.__defineGetter__(key, function () keys[key]);
+        }
+        return keys[key];
+    },
+
+    newMap: function newMap(key, store)
+    {
+        return this.newObject(key, ObjectStore, store);
+    },
+
+    newArray: function newArray(key, store)
+    {
+        return this.newObject(key, ArrayStore, store, Array);
+    },
+
+    addObserver: function addObserver(key, callback)
+    {
+        if (!(key in observers))
+            observers[key] = [];
+        if (observers[key].indexOf(callback) == -1)
+            observers[key].push(callback);
+    },
+
+    removeObserver: function (key, callback)
+    {
+        if (!(key in observers))
+            return;
+        observers[key] = observers[key].filter(function (elem) elem != callback);
+        if (observers[key].length == 0)
+            delete obsevers[key];
+    },
+
+    fireEvent: function fireEvent(key, event, arg)
+    {
+        for each (callback in observers[key])
+            callback(key, event, arg);
+    },
+
+    save: function save(key)
+    {
+        savePref(keys[key]);
+    },
+
+    saveAll: function storeAll()
+    {
+        for each (obj in keys)
+            savePref(obj);
+    },
+};
+
+// vim: set fdm=marker sw=4 sts=4 et ft=javascript: