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: this.EXPORTED_SYMBOLS = [];
michael@0: 
michael@0: const DEBUG = false;
michael@0: function debug(s) { dump("-*- NotificationDB component: " + s + "\n"); }
michael@0: 
michael@0: const Cu = Components.utils;
michael@0: const Cc = Components.classes;
michael@0: const Ci = Components.interfaces;
michael@0: 
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: Cu.import("resource://gre/modules/osfile.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyServiceGetter(this, "ppmm",
michael@0:                                    "@mozilla.org/parentprocessmessagemanager;1",
michael@0:                                    "nsIMessageListenerManager");
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gEncoder", function() {
michael@0:   return new TextEncoder();
michael@0: });
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gDecoder", function() {
michael@0:   return new TextDecoder();
michael@0: });
michael@0: 
michael@0: 
michael@0: const NOTIFICATION_STORE_DIR = OS.Constants.Path.profileDir;
michael@0: const NOTIFICATION_STORE_PATH =
michael@0:         OS.Path.join(NOTIFICATION_STORE_DIR, "notificationstore.json");
michael@0: 
michael@0: let NotificationDB = {
michael@0:   init: function() {
michael@0:     this.notifications = {};
michael@0:     this.byTag = {};
michael@0:     this.loaded = false;
michael@0: 
michael@0:     this.tasks = []; // read/write operation queue
michael@0:     this.runningTask = false;
michael@0: 
michael@0:     ppmm.addMessageListener("Notification:Save", this);
michael@0:     ppmm.addMessageListener("Notification:Delete", this);
michael@0:     ppmm.addMessageListener("Notification:GetAll", this);
michael@0:   },
michael@0: 
michael@0:   // Attempt to read notification file, if it's not there we will create it.
michael@0:   load: function(callback) {
michael@0:     var promise = OS.File.read(NOTIFICATION_STORE_PATH);
michael@0:     promise.then(
michael@0:       function onSuccess(data) {
michael@0:         try {
michael@0:           this.notifications = JSON.parse(gDecoder.decode(data));
michael@0:         } catch (e) {
michael@0:           if (DEBUG) { debug("Unable to parse file data " + e); }
michael@0:         }
michael@0:         // populate the list of notifications by tag
michael@0:         if (this.notifications) {
michael@0:           for (var origin in this.notifications) {
michael@0:             this.byTag[origin] = {};
michael@0:             for (var id in this.notifications[origin]) {
michael@0:               var curNotification = this.notifications[origin][id];
michael@0:               if (curNotification.tag) {
michael@0:                 this.byTag[origin][curNotification.tag] = curNotification;
michael@0:               }
michael@0:             }
michael@0:           }
michael@0:         }
michael@0:         this.loaded = true;
michael@0:         callback && callback();
michael@0:       }.bind(this),
michael@0: 
michael@0:       // If read failed, we assume we have no notifications to load.
michael@0:       function onFailure(reason) {
michael@0:         this.loaded = true;
michael@0:         this.createStore(callback);
michael@0:       }.bind(this)
michael@0:     );
michael@0:   },
michael@0: 
michael@0:   // Creates the notification directory.
michael@0:   createStore: function(callback) {
michael@0:     var promise = OS.File.makeDir(NOTIFICATION_STORE_DIR, {
michael@0:       ignoreExisting: true
michael@0:     });
michael@0:     promise.then(
michael@0:       function onSuccess() {
michael@0:         this.createFile(callback);
michael@0:       }.bind(this),
michael@0: 
michael@0:       function onFailure(reason) {
michael@0:         if (DEBUG) { debug("Directory creation failed:" + reason); }
michael@0:         callback && callback();
michael@0:       }
michael@0:     );
michael@0:   },
michael@0: 
michael@0:   // Creates the notification file once the directory is created.
michael@0:   createFile: function(callback) {
michael@0:     var promise = OS.File.open(NOTIFICATION_STORE_PATH, {create: true});
michael@0:     promise.then(
michael@0:       function onSuccess(handle) {
michael@0:         handle.close();
michael@0:         callback && callback();
michael@0:       },
michael@0:       function onFailure(reason) {
michael@0:         if (DEBUG) { debug("File creation failed:" + reason); }
michael@0:         callback && callback();
michael@0:       }
michael@0:     );
michael@0:   },
michael@0: 
michael@0:   // Save current notifications to the file.
michael@0:   save: function(callback) {
michael@0:     var data = gEncoder.encode(JSON.stringify(this.notifications));
michael@0:     var promise = OS.File.writeAtomic(NOTIFICATION_STORE_PATH, data);
michael@0:     promise.then(
michael@0:       function onSuccess() {
michael@0:         callback && callback();
michael@0:       },
michael@0:       function onFailure(reason) {
michael@0:         if (DEBUG) { debug("Save failed:" + reason); }
michael@0:         callback && callback();
michael@0:       }
michael@0:     );
michael@0:   },
michael@0: 
michael@0:   // Helper function: callback will be called once file exists and/or is loaded.
michael@0:   ensureLoaded: function(callback) {
michael@0:     if (!this.loaded) {
michael@0:       this.load(callback);
michael@0:     } else {
michael@0:       callback();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   receiveMessage: function(message) {
michael@0:     if (DEBUG) { debug("Received message:" + message.name); }
michael@0: 
michael@0:     // sendAsyncMessage can fail if the child process exits during a
michael@0:     // notification storage operation, so always wrap it in a try/catch.
michael@0:     function returnMessage(name, data) {
michael@0:       try {
michael@0:         message.target.sendAsyncMessage(name, data);
michael@0:       } catch (e) {
michael@0:         if (DEBUG) { debug("Return message failed, " + name); }
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     switch (message.name) {
michael@0:       case "Notification:GetAll":
michael@0:         this.queueTask("getall", message.data, function(notifications) {
michael@0:           returnMessage("Notification:GetAll:Return:OK", {
michael@0:             requestID: message.data.requestID,
michael@0:             origin: message.data.origin,
michael@0:             notifications: notifications
michael@0:           });
michael@0:         });
michael@0:         break;
michael@0: 
michael@0:       case "Notification:Save":
michael@0:         this.queueTask("save", message.data, function() {
michael@0:           returnMessage("Notification:Save:Return:OK", {
michael@0:             requestID: message.data.requestID
michael@0:           });
michael@0:         });
michael@0:         break;
michael@0: 
michael@0:       case "Notification:Delete":
michael@0:         this.queueTask("delete", message.data, function() {
michael@0:           returnMessage("Notification:Delete:Return:OK", {
michael@0:             requestID: message.data.requestID
michael@0:           });
michael@0:         });
michael@0:         break;
michael@0: 
michael@0:       default:
michael@0:         if (DEBUG) { debug("Invalid message name" + message.name); }
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   // We need to make sure any read/write operations are atomic,
michael@0:   // so use a queue to run each operation sequentially.
michael@0:   queueTask: function(operation, data, callback) {
michael@0:     if (DEBUG) { debug("Queueing task: " + operation); }
michael@0:     this.tasks.push({
michael@0:       operation: operation,
michael@0:       data: data,
michael@0:       callback: callback
michael@0:     });
michael@0: 
michael@0:     // Only run immediately if we aren't currently running another task.
michael@0:     if (!this.runningTask) {
michael@0:       if (DEBUG) { dump("Task queue was not running, starting now..."); }
michael@0:       this.runNextTask();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   runNextTask: function() {
michael@0:     if (this.tasks.length === 0) {
michael@0:       if (DEBUG) { dump("No more tasks to run, queue depleted"); }
michael@0:       this.runningTask = false;
michael@0:       return;
michael@0:     }
michael@0:     this.runningTask = true;
michael@0: 
michael@0:     // Always make sure we are loaded before performing any read/write tasks.
michael@0:     this.ensureLoaded(function() {
michael@0:       var task = this.tasks.shift();
michael@0: 
michael@0:       // Wrap the task callback to make sure we immediately
michael@0:       // run the next task after running the original callback.
michael@0:       var wrappedCallback = function() {
michael@0:         if (DEBUG) { debug("Finishing task: " + task.operation); }
michael@0:         task.callback.apply(this, arguments);
michael@0:         this.runNextTask();
michael@0:       }.bind(this);
michael@0: 
michael@0:       switch (task.operation) {
michael@0:         case "getall":
michael@0:           this.taskGetAll(task.data, wrappedCallback);
michael@0:           break;
michael@0: 
michael@0:         case "save":
michael@0:           this.taskSave(task.data, wrappedCallback);
michael@0:           break;
michael@0: 
michael@0:         case "delete":
michael@0:           this.taskDelete(task.data, wrappedCallback);
michael@0:           break;
michael@0:       }
michael@0:     }.bind(this));
michael@0:   },
michael@0: 
michael@0:   taskGetAll: function(data, callback) {
michael@0:     if (DEBUG) { debug("Task, getting all"); }
michael@0:     var origin = data.origin;
michael@0:     var notifications = [];
michael@0:     // Grab only the notifications for specified origin.
michael@0:     for (var i in this.notifications[origin]) {
michael@0:       notifications.push(this.notifications[origin][i]);
michael@0:     }
michael@0:     callback(notifications);
michael@0:   },
michael@0: 
michael@0:   taskSave: function(data, callback) {
michael@0:     if (DEBUG) { debug("Task, saving"); }
michael@0:     var origin = data.origin;
michael@0:     var notification = data.notification;
michael@0:     if (!this.notifications[origin]) {
michael@0:       this.notifications[origin] = {};
michael@0:       this.byTag[origin] = {};
michael@0:     }
michael@0: 
michael@0:     // We might have existing notification with this tag,
michael@0:     // if so we need to remove it before saving the new one.
michael@0:     if (notification.tag && this.byTag[origin][notification.tag]) {
michael@0:       var oldNotification = this.byTag[origin][notification.tag];
michael@0:       delete this.notifications[origin][oldNotification.id];
michael@0:       this.byTag[origin][notification.tag] = notification;
michael@0:     }
michael@0: 
michael@0:     this.notifications[origin][notification.id] = notification;
michael@0:     this.save(callback);
michael@0:   },
michael@0: 
michael@0:   taskDelete: function(data, callback) {
michael@0:     if (DEBUG) { debug("Task, deleting"); }
michael@0:     var origin = data.origin;
michael@0:     var id = data.id;
michael@0:     if (!this.notifications[origin]) {
michael@0:       if (DEBUG) { debug("No notifications found for origin: " + origin); }
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     // Make sure we can find the notification to delete.
michael@0:     var oldNotification = this.notifications[origin][id];
michael@0:     if (!oldNotification) {
michael@0:       if (DEBUG) { debug("No notification found with id: " + id); }
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (oldNotification.tag) {
michael@0:       delete this.byTag[origin][oldNotification.tag];
michael@0:     }
michael@0:     delete this.notifications[origin][id];
michael@0:     this.save(callback);
michael@0:   }
michael@0: };
michael@0: 
michael@0: NotificationDB.init();