1 files changed, 407 insertions, 0 deletions
diff --git a/mobile/android/modules/HomeProvider.jsm b/mobile/android/modules/HomeProvider.jsm
new file mode 100644
index 000000000..bca8fa526
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+++ b/mobile/android/modules/HomeProvider.jsm
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+// -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = [ "HomeProvider" ];
+
+const { utils: Cu, classes: Cc, interfaces: Ci } = Components;
+
+Cu.import("resource://gre/modules/Messaging.jsm");
+Cu.import("resource://gre/modules/osfile.jsm");
+Cu.import("resource://gre/modules/Promise.jsm");
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Sqlite.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+/*
+ * SCHEMA_VERSION history:
+ *   1: Create HomeProvider (bug 942288)
+ *   2: Add filter column to items table (bug 942295/975841)
+ *   3: Add background_color and background_url columns (bug 1157539)
+ */
+const SCHEMA_VERSION = 3;
+
+// The maximum number of items you can attempt to save at once.
+const MAX_SAVE_COUNT = 100;
+
+XPCOMUtils.defineLazyGetter(this, "DB_PATH", function() {
+  return OS.Path.join(OS.Constants.Path.profileDir, "home.sqlite");
+});
+
+const PREF_STORAGE_LAST_SYNC_TIME_PREFIX = "home.storage.lastSyncTime.";
+const PREF_SYNC_UPDATE_MODE = "home.sync.updateMode";
+const PREF_SYNC_CHECK_INTERVAL_SECS = "home.sync.checkIntervalSecs";
+
+XPCOMUtils.defineLazyGetter(this, "gSyncCheckIntervalSecs", function() {
+  return Services.prefs.getIntPref(PREF_SYNC_CHECK_INTERVAL_SECS);
+});
+
+XPCOMUtils.defineLazyServiceGetter(this,
+  "gUpdateTimerManager", "@mozilla.org/updates/timer-manager;1", "nsIUpdateTimerManager");
+
+/**
+ * All SQL statements should be defined here.
+ */
+const SQL = {
+  createItemsTable:
+    "CREATE TABLE items (" +
+      "_id INTEGER PRIMARY KEY AUTOINCREMENT, " +
+      "dataset_id TEXT NOT NULL, " +
+      "url TEXT," +
+      "title TEXT," +
+      "description TEXT," +
+      "image_url TEXT," +
+      "background_color TEXT," +
+      "background_url TEXT," +
+      "filter TEXT," +
+      "created INTEGER" +
+    ")",
+
+  dropItemsTable:
+    "DROP TABLE items",
+
+  insertItem:
+    "INSERT INTO items (dataset_id, url, title, description, image_url, background_color, background_url, filter, created) " +
+      "VALUES (:dataset_id, :url, :title, :description, :image_url, :background_color, :background_url, :filter, :created)",
+
+  deleteFromDataset:
+    "DELETE FROM items WHERE dataset_id = :dataset_id",
+
+  addColumnBackgroundColor:
+    "ALTER TABLE items ADD COLUMN background_color TEXT",
+
+  addColumnBackgroundUrl:
+    "ALTER TABLE items ADD COLUMN background_url TEXT",
+}
+
+/**
+ * Technically this function checks to see if the user is on a local network,
+ * but we express this as "wifi" to the user.
+ */
+function isUsingWifi() {
+  let network = Cc["@mozilla.org/network/network-link-service;1"].getService(Ci.nsINetworkLinkService);
+  return (network.linkType === Ci.nsINetworkLinkService.LINK_TYPE_WIFI || network.linkType === Ci.nsINetworkLinkService.LINK_TYPE_ETHERNET);
+}
+
+function getNowInSeconds() {
+  return Math.round(Date.now() / 1000);
+}
+
+function getLastSyncPrefName(datasetId) {
+  return PREF_STORAGE_LAST_SYNC_TIME_PREFIX + datasetId;
+}
+
+// Whether or not we've registered an update timer.
+var gTimerRegistered = false;
+
+// Map of datasetId -> { interval: <integer>, callback: <function> }
+var gSyncCallbacks = {};
+
+/**
+ * nsITimerCallback implementation. Checks to see if it's time to sync any registered datasets.
+ *
+ * @param timer The timer which has expired.
+ */
+function syncTimerCallback(timer) {
+  for (let datasetId in gSyncCallbacks) {
+    let lastSyncTime = 0;
+    try {
+      lastSyncTime = Services.prefs.getIntPref(getLastSyncPrefName(datasetId));
+    } catch(e) { }
+
+    let now = getNowInSeconds();
+    let { interval: interval, callback: callback } = gSyncCallbacks[datasetId];
+
+    if (lastSyncTime < now - interval) {
+      let success = HomeProvider.requestSync(datasetId, callback);
+      if (success) {
+        Services.prefs.setIntPref(getLastSyncPrefName(datasetId), now);
+      }
+    }
+  }
+}
+
+this.HomeStorage = function(datasetId) {
+  this.datasetId = datasetId;
+};
+
+this.ValidationError = function(message) {
+  this.name = "ValidationError";
+  this.message = message;
+};
+ValidationError.prototype = new Error();
+ValidationError.prototype.constructor = ValidationError;
+
+this.HomeProvider = Object.freeze({
+  ValidationError: ValidationError,
+
+  /**
+   * Returns a storage associated with a given dataset identifer.
+   *
+   * @param datasetId
+   *        (string) Unique identifier for the dataset.
+   *
+   * @return HomeStorage
+   */
+  getStorage: function(datasetId) {
+    return new HomeStorage(datasetId);
+  },
+
+  /**
+   * Checks to see if it's an appropriate time to sync.
+   *
+   * @param datasetId Unique identifier for the dataset to sync.
+   * @param callback Function to call when it's time to sync, called with datasetId as a parameter.
+   *
+   * @return boolean Whether or not we were able to sync.
+   */
+  requestSync: function(datasetId, callback) {
+    // Make sure it's a good time to sync.
+    if ((Services.prefs.getIntPref(PREF_SYNC_UPDATE_MODE) === 1) && !isUsingWifi()) {
+      Cu.reportError("HomeProvider: Failed to sync because device is not on a local network");
+      return false;
+    }
+
+    callback(datasetId);
+    return true;
+  },
+
+  /**
+   * Specifies that a sync should be requested for the given dataset and update interval.
+   *
+   * @param datasetId Unique identifier for the dataset to sync.
+   * @param interval Update interval in seconds. By default, this is throttled to 3600 seconds (1 hour).
+   * @param callback Function to call when it's time to sync, called with datasetId as a parameter.
+   */
+  addPeriodicSync: function(datasetId, interval, callback) {
+    // Warn developers if they're expecting more frequent notifications that we allow.
+    if (interval < gSyncCheckIntervalSecs) {
+      Cu.reportError("HomeProvider: Warning for dataset " + datasetId +
+        " : Sync notifications are throttled to " + gSyncCheckIntervalSecs + " seconds");
+    }
+
+    gSyncCallbacks[datasetId] = {
+      interval: interval,
+      callback: callback
+    };
+
+    if (!gTimerRegistered) {
+      gUpdateTimerManager.registerTimer("home-provider-sync-timer", syncTimerCallback, gSyncCheckIntervalSecs);
+      gTimerRegistered = true;
+    }
+  },
+
+  /**
+   * Removes a periodic sync timer.
+   *
+   * @param datasetId Dataset to sync.
+   */
+  removePeriodicSync: function(datasetId) {
+    delete gSyncCallbacks[datasetId];
+    Services.prefs.clearUserPref(getLastSyncPrefName(datasetId));
+    // You can't unregister a update timer, so we don't try to do that.
+  }
+});
+
+var gDatabaseEnsured = false;
+
+/**
+ * Creates the database schema.
+ */
+function createDatabase(db) {
+  return Task.spawn(function create_database_task() {
+    yield db.execute(SQL.createItemsTable);
+  });
+}
+
+/**
+ * Migrates the database schema to a new version.
+ */
+function upgradeDatabase(db, oldVersion, newVersion) {
+  return Task.spawn(function upgrade_database_task() {
+    switch (oldVersion) {
+      case 1:
+        // Migration from v1 to latest:
+        // Recreate the items table discarding any
+        // existing data.
+        yield db.execute(SQL.dropItemsTable);
+        yield db.execute(SQL.createItemsTable);
+        break;
+
+      case 2:
+        // Migration from v2 to latest:
+        // Add new columns: background_color, background_url
+        yield db.execute(SQL.addColumnBackgroundColor);
+        yield db.execute(SQL.addColumnBackgroundUrl);
+        break;
+    }
+  });
+}
+
+/**
+ * Opens a database connection and makes sure that the database schema version
+ * is correct, performing migrations if necessary. Consumers should be sure
+ * to close any database connections they open.
+ *
+ * @return Promise
+ * @resolves Handle on an opened SQLite database.
+ */
+function getDatabaseConnection() {
+  return Task.spawn(function get_database_connection_task() {
+    let db = yield Sqlite.openConnection({ path: DB_PATH });
+    if (gDatabaseEnsured) {
+      throw new Task.Result(db);
+    }
+
+    try {
+      // Check to see if we need to perform any migrations.
+      let dbVersion = parseInt(yield db.getSchemaVersion());
+
+      // getSchemaVersion() returns a 0 int if the schema
+      // version is undefined.
+      if (dbVersion === 0) {
+        yield createDatabase(db);
+      } else if (dbVersion < SCHEMA_VERSION) {
+        yield upgradeDatabase(db, dbVersion, SCHEMA_VERSION);
+      }
+
+      yield db.setSchemaVersion(SCHEMA_VERSION);
+    } catch(e) {
+      // Close the DB connection before passing the exception to the consumer.
+      yield db.close();
+      throw e;
+    }
+
+    gDatabaseEnsured = true;
+    throw new Task.Result(db);
+  });
+}
+
+/**
+ * Validates an item to be saved to the DB.
+ *
+ * @param item
+ *        (object) item object to be validated.
+ */
+function validateItem(datasetId, item) {
+  if (!item.url) {
+    throw new ValidationError('HomeStorage: All rows must have an URL: datasetId = ' +
+                              datasetId);
+  }
+
+  if (!item.image_url && !item.title && !item.description) {
+    throw new ValidationError('HomeStorage: All rows must have at least an image URL, ' +
+                              'or a title or a description: datasetId = ' + datasetId);
+  }
+}
+
+var gRefreshTimers = {};
+
+/**
+ * Sends a message to Java to refresh the given dataset. Delays sending
+ * messages to avoid successive refreshes, which can result in flashing views.
+ */
+function refreshDataset(datasetId) {
+  // Bail if there's already a refresh timer waiting to fire
+  if (gRefreshTimers[datasetId]) {
+    return;
+  }
+
+  let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+  timer.initWithCallback(function(timer) {
+    delete gRefreshTimers[datasetId];
+
+    Messaging.sendRequest({
+      type: "HomePanels:RefreshDataset",
+      datasetId: datasetId
+    });
+  }, 100, Ci.nsITimer.TYPE_ONE_SHOT);
+
+  gRefreshTimers[datasetId] = timer;
+}
+
+HomeStorage.prototype = {
+  /**
+   * Saves data rows to the DB.
+   *
+   * @param data
+   *        An array of JS objects represnting row items to save.
+   *        Each object may have the following properties:
+   *        - url (string)
+   *        - title (string)
+   *        - description (string)
+   *        - image_url (string)
+   *        - filter (string)
+   * @param options
+   *        A JS object holding additional cofiguration properties.
+   *        The following properties are currently supported:
+   *        - replace (boolean): Whether or not to replace existing items.
+   *
+   * @return Promise
+   * @resolves When the operation has completed.
+   */
+  save: function(data, options) {
+    if (data && data.length > MAX_SAVE_COUNT) {
+      throw "save failed for dataset = " + this.datasetId +
+        ": you cannot save more than " + MAX_SAVE_COUNT + " items at once";
+    }
+
+    return Task.spawn(function save_task() {
+      let db = yield getDatabaseConnection();
+      try {
+        yield db.executeTransaction(function save_transaction() {
+          if (options && options.replace) {
+            yield db.executeCached(SQL.deleteFromDataset, { dataset_id: this.datasetId });
+          }
+
+          // Insert data into DB.
+          for (let item of data) {
+            validateItem(this.datasetId, item);
+
+            // XXX: Directly pass item as params? More validation for item?
+            let params = {
+              dataset_id: this.datasetId,
+              url: item.url,
+              title: item.title,
+              description: item.description,
+              image_url: item.image_url,
+              background_color: item.background_color,
+              background_url: item.background_url,
+              filter: item.filter,
+              created: Date.now()
+            };
+            yield db.executeCached(SQL.insertItem, params);
+          }
+        }.bind(this));
+      } finally {
+        yield db.close();
+      }
+
+      refreshDataset(this.datasetId);
+    }.bind(this));
+  },
+
+  /**
+   * Deletes all rows associated with this storage.
+   *
+   * @return Promise
+   * @resolves When the operation has completed.
+   */
+  deleteAll: function() {
+    return Task.spawn(function delete_all_task() {
+      let db = yield getDatabaseConnection();
+      try {
+        let params = { dataset_id: this.datasetId };
+        yield db.executeCached(SQL.deleteFromDataset, params);
+      } finally {
+        yield db.close();
+      }
+
+      refreshDataset(this.datasetId);
+    }.bind(this));
+  }
+};