michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: let DEBUG = 0;
michael@0: let debug;
michael@0: if (DEBUG) {
michael@0:   debug = function (s) { dump("-*- IndexedDBHelper: " + s + "\n"); }
michael@0: } else {
michael@0:   debug = function (s) {}
michael@0: }
michael@0: 
michael@0: const Cu = Components.utils;
michael@0: const Cc = Components.classes;
michael@0: const Ci = Components.interfaces;
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["IndexedDBHelper"];
michael@0: 
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: Cu.importGlobalProperties(["indexedDB"]);
michael@0: 
michael@0: this.IndexedDBHelper = function IndexedDBHelper() {}
michael@0: 
michael@0: IndexedDBHelper.prototype = {
michael@0: 
michael@0:   // Cache the database
michael@0:   _db: null,
michael@0: 
michael@0:   // Close the database
michael@0:   close: function close() {
michael@0:     if (this._db) {
michael@0:       this._db.close();
michael@0:       this._db = null;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Open a new database.
michael@0:    * User has to provide upgradeSchema.
michael@0:    *
michael@0:    * @param successCb
michael@0:    *        Success callback to call once database is open.
michael@0:    * @param failureCb
michael@0:    *        Error callback to call when an error is encountered.
michael@0:    */
michael@0:   open: function open(aSuccessCb, aFailureCb) {
michael@0:     let self = this;
michael@0:     if (DEBUG) debug("Try to open database:" + self.dbName + " " + self.dbVersion);
michael@0:     let req = indexedDB.open(this.dbName, this.dbVersion);
michael@0:     req.onsuccess = function (event) {
michael@0:       if (DEBUG) debug("Opened database:" + self.dbName + " " + self.dbVersion);
michael@0:       self._db = event.target.result;
michael@0:       self._db.onversionchange = function(event) {
michael@0:         if (DEBUG) debug("WARNING: DB modified from a different window.");
michael@0:       }
michael@0:       aSuccessCb && aSuccessCb();
michael@0:     };
michael@0: 
michael@0:     req.onupgradeneeded = function (aEvent) {
michael@0:       if (DEBUG) {
michael@0:         debug("Database needs upgrade:" + self.dbName + aEvent.oldVersion + aEvent.newVersion);
michael@0:         debug("Correct new database version:" + (aEvent.newVersion == this.dbVersion));
michael@0:       }
michael@0: 
michael@0:       let _db = aEvent.target.result;
michael@0:       self.upgradeSchema(req.transaction, _db, aEvent.oldVersion, aEvent.newVersion);
michael@0:     };
michael@0:     req.onerror = function (aEvent) {
michael@0:       if (DEBUG) debug("Failed to open database: " + self.dbName);
michael@0:       aFailureCb && aFailureCb(aEvent.target.error.name);
michael@0:     };
michael@0:     req.onblocked = function (aEvent) {
michael@0:       if (DEBUG) debug("Opening database request is blocked.");
michael@0:     };
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Use the cached DB or open a new one.
michael@0:    *
michael@0:    * @param successCb
michael@0:    *        Success callback to call.
michael@0:    * @param failureCb
michael@0:    *        Error callback to call when an error is encountered.
michael@0:    */
michael@0:   ensureDB: function ensureDB(aSuccessCb, aFailureCb) {
michael@0:     if (this._db) {
michael@0:       if (DEBUG) debug("ensureDB: already have a database, returning early.");
michael@0:       aSuccessCb && aSuccessCb();
michael@0:       return;
michael@0:     }
michael@0:     this.open(aSuccessCb, aFailureCb);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Start a new transaction.
michael@0:    *
michael@0:    * @param txn_type
michael@0:    *        Type of transaction (e.g. "readwrite")
michael@0:    * @param store_name
michael@0:    *        The object store you want to be passed to the callback
michael@0:    * @param callback
michael@0:    *        Function to call when the transaction is available. It will
michael@0:    *        be invoked with the transaction and the `store' object store.
michael@0:    * @param successCb
michael@0:    *        Success callback to call on a successful transaction commit.
michael@0:    *        The result is stored in txn.result.
michael@0:    * @param failureCb
michael@0:    *        Error callback to call when an error is encountered.
michael@0:    */
michael@0:   newTxn: function newTxn(txn_type, store_name, callback, successCb, failureCb) {
michael@0:     this.ensureDB(function () {
michael@0:       if (DEBUG) debug("Starting new transaction" + txn_type);
michael@0:       let txn = this._db.transaction(Array.isArray(store_name) ? store_name : this.dbStoreNames, txn_type);
michael@0:       if (DEBUG) debug("Retrieving object store", this.dbName);
michael@0:       let stores;
michael@0:       if (Array.isArray(store_name)) {
michael@0:         stores = [];
michael@0:         for (let i = 0; i < store_name.length; ++i) {
michael@0:           stores.push(txn.objectStore(store_name[i]));
michael@0:         }
michael@0:       } else {
michael@0:         stores = txn.objectStore(store_name);
michael@0:       }
michael@0: 
michael@0:       txn.oncomplete = function (event) {
michael@0:         if (DEBUG) debug("Transaction complete. Returning to callback.");
michael@0:         if (successCb) {
michael@0:           successCb(txn.result);
michael@0:         }
michael@0:       };
michael@0: 
michael@0:       txn.onabort = function (event) {
michael@0:         if (DEBUG) debug("Caught error on transaction");
michael@0:         /*
michael@0:          * event.target.error may be null
michael@0:          * if txn was aborted by calling txn.abort()
michael@0:          */
michael@0:         if (failureCb) {
michael@0:           if (event.target.error) {
michael@0:             failureCb(event.target.error.name);
michael@0:           } else {
michael@0:             failureCb("UnknownError");
michael@0:           }
michael@0:         }
michael@0:       };
michael@0:       callback(txn, stores);
michael@0:     }.bind(this), failureCb);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Initialize the DB. Does not call open.
michael@0:    *
michael@0:    * @param aDBName
michael@0:    *        DB name for the open call.
michael@0:    * @param aDBVersion
michael@0:    *        Current DB version. User has to implement upgradeSchema.
michael@0:    * @param aDBStoreName
michael@0:    *        ObjectStore that is used.
michael@0:    */
michael@0:   initDBHelper: function initDBHelper(aDBName, aDBVersion, aDBStoreNames) {
michael@0:     this.dbName = aDBName;
michael@0:     this.dbVersion = aDBVersion;
michael@0:     this.dbStoreNames = aDBStoreNames;
michael@0:   }
michael@0: }