gecko/services/sync/modules/stores.js

339 lines
9.0 KiB
JavaScript

/* ***** 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.
*
* The Original Code is Bookmarks Sync.
*
* The Initial Developer of the Original Code is Mozilla.
* Portions created by the Initial Developer are Copyright (C) 2007
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Dan Mills <thunder@mozilla.com>
*
* 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 ***** */
const EXPORTED_SYMBOLS = ['Store',
'SnapshotStore'];
const Cc = Components.classes;
const Ci = Components.interfaces;
const Cr = Components.results;
const Cu = Components.utils;
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://weave/log4moz.js");
Cu.import("resource://weave/constants.js");
Cu.import("resource://weave/util.js");
/*
* Data Stores
* These can wrap, serialize items and apply commands
*/
function Store() {
this._init();
}
Store.prototype = {
_logName: "BaseClass",
// set this property in child object's wrap()!
_lookup: null,
get cache() {
let cache = new Cache();
this.__defineGetter__("cache", function() cache);
return cache;
},
_init: function Store__init() {
this._log = Log4Moz.repository.getLogger("Store." + this._logName);
},
applyIncoming: function Store_applyIncoming(record) {
if (record.deleted)
this.remove(record);
else if (!this.itemExists(record.id))
this.create(record);
else
this.update(record);
},
// override these in derived objects
create: function Store_create(record) {
throw "override create in a subclass";
},
remove: function Store_remove(record) {
throw "override remove in a subclass";
},
update: function Store_update(record) {
throw "override update in a subclass";
},
itemExists: function Store_itemExists(id) {
throw "override itemExists in a subclass";
},
createRecord: function Store_createRecord(id) {
throw "override createRecord in a subclass";
},
// override if depth and/or depthindex are used
// should return all objects potentially affected by change of guid, in
// short form (no full content, only id, depth, sortindex)
createMetaRecords: function Store_createMetaRecords(guid, items) {
return {};
},
changeItemID: function Store_changeItemID(oldID, newID) {
throw "override changeItemID in a subclass";
},
getAllIDs: function Store_getAllIDs() {
throw "override getAllIDs in a subclass";
},
wipe: function Store_wipe() {
throw "override wipe in a subclass";
}
};
function Cache() {
this.count = 0;
this.maxItems = 100;
this.fifo = true;
this.enabled = true;
this._head = this._tail = null;
this._items = {};
}
Cache.prototype = {
remove: function Cache_remove(item) {
if (this.count <= 0 || this.count == 1) {
this.clear();
return;
}
item.next.prev = item.prev;
item.prev.next = item.next;
if (item == this._head)
this._head = item.next;
if (item == this._tail)
this._tail = item.prev;
item.next = null;
item.prev = null;
delete this._items[item.id];
this.count--;
},
pop: function Cache_pop() {
if (this.fifo)
this.remove(this._tail);
else
this.remove(this._head);
},
put: function Cache_put(id, item) {
if (!this.enabled)
return;
let wrapper = {id: id, item: item};
if (this._head === null) {
wrapper.next = wrapper;
wrapper.prev = wrapper;
this._head = wrapper;
this._tail = wrapper;
} else {
wrapper.next = this._tail;
wrapper.prev = this._head;
this._head.prev = wrapper;
this._tail.next = wrapper;
this._tail = wrapper;
}
this._items[wrapper.id] = wrapper;
this.count++;
if (this.count >= this.maxItems)
this.pop();
},
get: function Cache_get(id) {
if (id in this._items)
return this._items[id].item;
return undefined;
},
clear: function Cache_clear() {
this.count = 0;
this._head = null;
this._tail = null;
this._items = {};
}
};
function SnapshotStore(name) {
this._init(name);
}
SnapshotStore.prototype = {
_logName: "SnapStore",
_filename: null,
get filename() {
if (this._filename === null)
throw "filename is null";
return this._filename;
},
set filename(value) {
this._filename = value + ".json";
},
// Last synced tree, version, and GUID (to detect if the store has
// been completely replaced and invalidate the snapshot)
_data: {},
get data() { return this._data; },
set data(value) { this._data = value; },
_version: 0,
get version() { return this._version; },
set version(value) { this._version = value; },
_GUID: null,
get GUID() {
if (!this._GUID)
this._GUID = Utils.makeGUID();
return this._GUID;
},
set GUID(GUID) {
this._GUID = GUID;
},
_init: function SStore__init(name) {
this.filename = name;
this._log = Log4Moz.repository.getLogger("Service." + this._logName);
},
_createCommand: function SStore__createCommand(command) {
this._data[command.GUID] = Utils.deepCopy(command.data);
},
_removeCommand: function SStore__removeCommand(command) {
delete this._data[command.GUID];
},
_editCommand: function SStore__editCommand(command) {
if ("GUID" in command.data) {
// special-case guid changes
let newGUID = command.data.GUID,
oldGUID = command.GUID;
this._data[newGUID] = this._data[oldGUID];
delete this._data[oldGUID];
for (let GUID in this._data) {
if (("parentid" in this._data[GUID]) &&
(this._data[GUID].parentid == oldGUID))
this._data[GUID].parentid = newGUID;
}
}
for (let prop in command.data) {
if (prop == "GUID")
continue;
if (command.GUID in this._data)
this._data[command.GUID][prop] = command.data[prop];
else
this._log.warn("Warning! Edit command for unknown item: " + command.GUID);
}
},
save: function SStore_save() {
this._log.info("Saving snapshot to disk");
let file = Utils.getProfileFile(
{path: "weave/snapshots/" + this.filename,
autoCreate: true}
);
let out = {version: this.version,
GUID: this.GUID,
snapshot: this.data};
out = JSON.stringify(out);
let [fos] = Utils.open(file, ">");
fos.writeString(out);
fos.close();
},
load: function SStore_load() {
let file = Utils.getProfileFile("weave/snapshots/" + this.filename);
if (!file.exists())
return;
try {
let [is] = Utils.open(file, "<");
let json = Utils.readStream(is);
is.close();
json = JSON.parse(json);
if (json && 'snapshot' in json && 'version' in json && 'GUID' in json) {
this._log.debug("Read saved snapshot from disk");
this.data = json.snapshot;
this.version = json.version;
this.GUID = json.GUID;
}
} catch (e) {
this._log.warn("Could not parse saved snapshot; reverting to initial-sync state");
this._log.debug("Exception: " + e);
}
},
serialize: function SStore_serialize() {
let json = JSON.stringify(this.data);
json = json.replace(/:{type/g, ":\n\t{type");
json = json.replace(/}, /g, "},\n ");
json = json.replace(/, parentid/g, ",\n\t parentid");
json = json.replace(/, index/g, ",\n\t index");
json = json.replace(/, title/g, ",\n\t title");
json = json.replace(/, URI/g, ",\n\t URI");
json = json.replace(/, tags/g, ",\n\t tags");
json = json.replace(/, keyword/g, ",\n\t keyword");
return json;
},
wrap: function SStore_wrap() {
return this.data;
},
wipe: function SStore_wipe() {
this.data = {};
this.version = -1;
this.GUID = null;
this.save();
}
};
SnapshotStore.prototype.__proto__ = new Store();