Issue #640 - extract database code to dedicated package

src/js/database/BackupDatabase.js

@@ -0,0 +1,179 @@
+(function () {
+  var ns = $.namespace('pskl.database');
+
+  var DB_NAME = 'PiskelSessionsDatabase';
+  var DB_VERSION = 1;
+
+  // Simple wrapper to promisify a request.
+  var _requestPromise = function (req) {
+    var deferred = Q.defer();
+    req.onsuccess = deferred.resolve.bind(deferred);
+    req.onerror = deferred.reject.bind(deferred);
+    return deferred.promise;
+  };
+
+  /**
+   * The BackupDatabase handles all the database interactions related
+   * to piskel snapshots continuously saved while during the usage of
+   * Piskel.
+   *
+   * @param {Object} options
+   *        - onUpgrade {Function} optional callback called when a DB
+   *        upgrade is performed.
+   */
+  ns.BackupDatabase = function (options) {
+    options = options || {};
+
+    this.db = null;
+    this.onUpgrade = options.onUpgrade;
+  };
+
+  /**
+   * Open and initialize the database.
+   */
+  ns.BackupDatabase.prototype.init = function () {
+    this.initDeferred_ = Q.defer();
+
+    var request = window.indexedDB.open(DB_NAME, DB_VERSION);
+
+    request.onerror = this.onRequestError_.bind(this);
+    request.onsuccess = this.onRequestSuccess_.bind(this);
+    request.onupgradeneeded = this.onUpgradeNeeded_.bind(this);
+
+    return this.initDeferred_.promise;
+  };
+
+  ns.BackupDatabase.prototype.onRequestError_ = function (event) {
+    console.log('Could not initialize the piskel backup database');
+    this.initDeferred_.reject();
+  };
+
+  ns.BackupDatabase.prototype.onRequestSuccess_ = function (event) {
+    this.db = event.target.result;
+    this.initDeferred_.resolve(this.db);
+  };
+
+  ns.BackupDatabase.prototype.onUpgradeNeeded_ = function (event) {
+    // Set this.db early to allow migration scripts to access it in oncomplete.
+    this.db = event.target.result;
+
+    // Create an object store "piskels" with the autoIncrement flag set as true.
+    var objectStore = this.db.createObjectStore('snapshots', { keyPath: 'id', autoIncrement : true });
+
+    objectStore.createIndex('session_id', 'session_id', { unique: false });
+    objectStore.createIndex('date', 'date', { unique: false });
+    objectStore.createIndex('session_id, date', ['session_id', 'date'], { unique: false });
+
+    objectStore.transaction.oncomplete = function(event) {
+      if (typeof this.onUpgrade == 'function') {
+        this.onUpgrade(this.db);
+      }
+    }.bind(this);
+  };
+
+  ns.BackupDatabase.prototype.openObjectStore_ = function () {
+    return this.db.transaction(['snapshots'], 'readwrite').objectStore('snapshots');
+  };
+
+  /**
+   * Send an add request for the provided snapshot.
+   * Returns a promise that resolves the request event.
+   */
+  ns.BackupDatabase.prototype.createSnapshot = function (snapshot) {
+    var objectStore = this.openObjectStore_();
+    var request = objectStore.add(snapshot);
+    return _requestPromise(request);
+  };
+
+  /**
+   * Send a put request for the provided snapshot.
+   * Returns a promise that resolves the request event.
+   */
+  ns.BackupDatabase.prototype.updateSnapshot = function (snapshot) {
+    var objectStore = this.openObjectStore_();
+    var request = objectStore.put(snapshot);
+    return _requestPromise(request);
+  };
+
+  /**
+   * Send a delete request for the provided snapshot.
+   * Returns a promise that resolves the request event.
+   */
+  ns.BackupDatabase.prototype.deleteSnapshot = function (snapshot) {
+    var objectStore = this.openObjectStore_();
+    var request = objectStore.delete(snapshot.id);
+    return _requestPromise(request);
+  };
+
+  /**
+   * Get the last (most recent) snapshot that satisfies the accept filter provided.
+   * Returns a promise that will resolve with the first matching snapshot (or null
+   * if no valid snapshot is found).
+   *
+   * @param {Function} accept:
+   *        Filter method that takes a snapshot as argument and should return true
+   *        if the snapshot is valid.
+   */
+  ns.BackupDatabase.prototype.findLastSnapshot = function (accept) {
+    // Create the backup promise.
+    var deferred = Q.defer();
+
+    // Open a transaction to the snapshots object store.
+    var objectStore = this.db.transaction(['snapshots']).objectStore('snapshots');
+
+    var index = objectStore.index('date');
+    var range = IDBKeyRange.upperBound(Infinity);
+    index.openCursor(range, 'prev').onsuccess = function(event) {
+      var cursor = event.target.result;
+      var snapshot = cursor && cursor.value;
+
+      // Resolve null if we couldn't find a matching snapshot.
+      if (!snapshot) {
+        deferred.resolve(null);
+      } else if (accept(snapshot)) {
+        deferred.resolve(snapshot);
+      } else {
+        cursor.continue();
+      }
+    };
+
+    return deferred.promise;
+  };
+
+  /**
+   * Retrieve all the snapshots for a given session id, sorted by descending date order.
+   * Returns a promise that resolves with an array of snapshots.
+   *
+   * @param {String} sessionId
+   *        The session id
+   */
+  ns.BackupDatabase.prototype.getSnapshotsBySessionId = function (sessionId) {
+    // Create the backup promise.
+    var deferred = Q.defer();
+
+    // Open a transaction to the snapshots object store.
+    var objectStore = this.db.transaction(['snapshots']).objectStore('snapshots');
+
+    // Loop on all the saved snapshots for the provided piskel id
+    var index = objectStore.index('session_id, date');
+    var keyRange = IDBKeyRange.bound(
+      [sessionId, 0],
+      [sessionId, Infinity]
+    );
+
+    var snapshots = [];
+    // Ordered by date in descending order.
+    index.openCursor(keyRange, 'prev').onsuccess = function(event) {
+      var cursor = event.target.result;
+      if (cursor) {
+        snapshots.push(cursor.value);
+        cursor.continue();
+      } else {
+        console.log('consumed all piskel snapshots');
+        deferred.resolve(snapshots);
+      }
+    };
+
+    return deferred.promise;
+  };
+})();

src/js/database/PiskelDatabase.js

@@ -0,0 +1,157 @@
+(function () {
+  var ns = $.namespace('pskl.database');
+
+  var DB_NAME = 'PiskelDatabase';
+  var DB_VERSION = 1;
+
+  // Simple wrapper to promisify a request.
+  var _requestPromise = function (req) {
+    var deferred = Q.defer();
+    req.onsuccess = deferred.resolve.bind(deferred);
+    req.onerror = deferred.reject.bind(deferred);
+    return deferred.promise;
+  };
+
+  /**
+   * The PiskelDatabase handles all the database interactions related
+   * to the local piskel saved that can be performed in-browser.
+   *
+   * @param {Object} options
+   *        - onUpgrade {Function} optional callback called when a DB
+   *        upgrade is performed.
+   */
+  ns.PiskelDatabase = function (options) {
+    options = options || {};
+
+    this.db = null;
+    this.onUpgrade = options.onUpgrade;
+  };
+
+  ns.PiskelDatabase.prototype.init = function () {
+    this.initDeferred_ = Q.defer();
+
+    var request = window.indexedDB.open(DB_NAME, DB_VERSION);
+
+    request.onerror = this.onRequestError_.bind(this);
+    request.onsuccess = this.onRequestSuccess_.bind(this);
+    request.onupgradeneeded = this.onUpgradeNeeded_.bind(this);
+
+    return this.initDeferred_.promise;
+  };
+
+  ns.PiskelDatabase.prototype.onRequestError_ = function (event) {
+    console.log('Failed to initialize IndexedDB, local browser saves will be unavailable.');
+    this.initDeferred_.reject();
+  };
+
+  ns.PiskelDatabase.prototype.onRequestSuccess_ = function (event) {
+    console.log('Successfully initialized IndexedDB, local browser saves are available.');
+    this.db = event.target.result;
+    this.initDeferred_.resolve(this.db);
+  };
+
+  ns.PiskelDatabase.prototype.onUpgradeNeeded_ = function (event) {
+    // Set this.db early to allow migration scripts to access it in oncomplete.
+    this.db = event.target.result;
+
+    // Create an object store "piskels" with the autoIncrement flag set as true.
+    var objectStore = this.db.createObjectStore('piskels', { keyPath : 'name' });
+    objectStore.transaction.oncomplete = function(event) {
+      if (typeof this.onUpgrade == 'function') {
+        this.onUpgrade(this.db);
+      }
+    }.bind(this);
+  };
+
+  ns.PiskelDatabase.prototype.openObjectStore_ = function () {
+    return this.db.transaction(['piskels'], 'readwrite').objectStore('piskels');
+  };
+
+  /**
+   * Send a get request for the provided name.
+   * Returns a promise that resolves the request event.
+   */
+  ns.PiskelDatabase.prototype.get = function (name) {
+    var objectStore = this.openObjectStore_();
+    return _requestPromise(objectStore.get(name));
+  };
+
+  /**
+   * List all locally saved piskels.
+   * Returns a promise that resolves an array of objects:
+   * - name: name of the piskel
+   * - description: description of the piskel
+   * - date: save date
+   *
+   * The sprite content is not contained in the object and
+   * needs to be retrieved with a separate get.
+   */
+  ns.PiskelDatabase.prototype.list = function () {
+    var deferred = Q.defer();
+
+    var piskels = [];
+    var objectStore = this.openObjectStore_();
+    var cursor = objectStore.openCursor();
+    cursor.onsuccess = function(event) {
+      var cursor = event.target.result;
+      if (cursor) {
+        piskels.push({
+          name: cursor.value.name,
+          date: cursor.value.date,
+          description: cursor.value.description
+        });
+        cursor.continue();
+      } else {
+        // Cursor consumed all availabled piskels
+        deferred.resolve(piskels);
+      }
+    };
+
+    cursor.onerror = function () {
+      deferred.reject();
+    };
+
+    return deferred.promise;
+  };
+
+  /**
+   * Send an put request for the provided args.
+   * Returns a promise that resolves the request event.
+   */
+  ns.PiskelDatabase.prototype.update = function (name, description, date, serialized) {
+    var data = {};
+
+    data.name = name;
+    data.serialized = serialized;
+    data.date = date;
+    data.description = description;
+
+    var objectStore = this.openObjectStore_();
+    return _requestPromise(objectStore.put(data));
+  };
+
+  /**
+   * Send an add request for the provided args.
+   * Returns a promise that resolves the request event.
+   */
+  ns.PiskelDatabase.prototype.create = function (name, description, date, serialized) {
+    var data = {};
+
+    data.name = name;
+    data.serialized = serialized;
+    data.date = date;
+    data.description = description;
+
+    var objectStore = this.openObjectStore_();
+    return _requestPromise(objectStore.add(data));
+  };
+
+  /**
+   * Delete a saved piskel for the provided name.
+   * Returns a promise that resolves the request event.
+   */
+  ns.PiskelDatabase.prototype.delete = function (name) {
+    var objectStore = this.openObjectStore_();
+    return _requestPromise(objectStore.delete(name));
+  };
+})();

src/js/service/BackupService.js

@@ -1,9 +1,6 @@
 (function () {
   var ns = $.namespace('pskl.service');
 
-  var DB_NAME = 'PiskelSessionsDatabase';
-  var DB_VERSION = 1;
-
   var ONE_SECOND = 1000;
   var ONE_MINUTE = 60 * ONE_SECOND;
 
@@ -14,104 +11,18 @@
   // Store up to 12 snapshots for a piskel session, min. 1 hour of work
   var MAX_SNAPSHOTS_PER_SESSION = 12;
 
-  var _requestPromise = function (req) {
-    var deferred = Q.defer();
-    req.onsuccess = deferred.resolve.bind(deferred);
-    req.onerror = deferred.reject.bind(deferred);
-    return deferred.promise;
-  };
-
   ns.BackupService = function (piskelController) {
     this.piskelController = piskelController;
     this.lastHash = null;
     this.nextSnapshotDate = -1;
+
+    this.backupDatabase = new pskl.database.BackupDatabase();
   };
 
   ns.BackupService.prototype.init = function () {
-    var request = window.indexedDB.open(DB_NAME, DB_VERSION);
-
-    request.onerror = this.onRequestError_.bind(this);
-    request.onupgradeneeded = this.onUpgradeNeeded_.bind(this);
-    request.onsuccess = this.onRequestSuccess_.bind(this);
-  };
-
-  ns.BackupService.prototype.onRequestError_ = function (event) {
-    console.log('Could not initialize the piskel backup database');
-  };
-
-  ns.BackupService.prototype.onUpgradeNeeded_ = function (event) {
-    // Set this.db early to allow migration scripts to access it in oncomplete.
-    this.db = event.target.result;
-
-    // Create an object store "piskels" with the autoIncrement flag set as true.
-    var objectStore = this.db.createObjectStore('snapshots', { keyPath: 'id', autoIncrement : true });
-
-    objectStore.createIndex('session_id', 'session_id', { unique: false });
-    objectStore.createIndex('date', 'date', { unique: false });
-    objectStore.createIndex('session_id, date', ['session_id', 'date'], { unique: false });
-
-    objectStore.transaction.oncomplete = function(event) {
-      // TODO: Migrate existing data from local storage?
-    };
-  };
-
-  ns.BackupService.prototype.onRequestSuccess_ = function (event) {
-    this.db = event.target.result;
+    this.backupDatabase.init().then(function () {
       window.setInterval(this.backup.bind(this), BACKUP_INTERVAL);
-  };
-
-  ns.BackupService.prototype.openObjectStore_ = function () {
-    return this.db.transaction(['snapshots'], 'readwrite').objectStore('snapshots');
-  };
-
-  ns.BackupService.prototype.createSnapshot = function (snapshot) {
-    var objectStore = this.openObjectStore_();
-    var request = objectStore.add(snapshot);
-    return _requestPromise(request);
-  };
-
-  ns.BackupService.prototype.replaceSnapshot = function (snapshot, replacedSnapshot) {
-    snapshot.id = replacedSnapshot.id;
-
-    var objectStore = this.openObjectStore_();
-    var request = objectStore.put(snapshot);
-    return _requestPromise(request);
-  };
-
-  ns.BackupService.prototype.deleteSnapshot = function (snapshot) {
-    var objectStore = this.openObjectStore_();
-    var request = objectStore.delete(snapshot.id);
-    return _requestPromise(request);
-  };
-
-  ns.BackupService.prototype.getSnapshotsBySessionId_ = function (sessionId) {
-    // Create the backup promise.
-    var deferred = Q.defer();
-
-    // Open a transaction to the snapshots object store.
-    var objectStore = this.db.transaction(['snapshots']).objectStore('snapshots');
-
-    // Loop on all the saved snapshots for the provided piskel id
-    var index = objectStore.index('session_id, date');
-    var keyRange = IDBKeyRange.bound(
-      [sessionId, 0],
-      [sessionId, Infinity]
-    );
-
-    var snapshots = [];
-    // Ordered by date in descending order.
-    index.openCursor(keyRange, 'prev').onsuccess = function(event) {
-      var cursor = event.target.result;
-      if (cursor) {
-        snapshots.push(cursor.value);
-        cursor.continue();
-      } else {
-        console.log('consumed all piskel snapshots');
-        deferred.resolve(snapshots);
-      }
-    };
-
-    return deferred.promise;
+    }.bind(this));
   };
 
   ns.BackupService.prototype.backup = function () {
@@ -138,19 +49,20 @@
       serialized: pskl.utils.serialization.Serializer.serialize(piskel)
     };
 
-    this.getSnapshotsBySessionId_(piskel.sessionId).then(function (snapshots) {
+    this.backupDatabase.getSnapshotsBySessionId(piskel.sessionId).then(function (snapshots) {
       var latest = snapshots[0];
 
       if (latest && date < this.nextSnapshotDate) {
         // update the latest snapshot
-        return this.replaceSnapshot(snapshot, latest);
+        snapshot.id = latest.id;
+        return this.backupDatabase.updateSnapshot(snapshot);
       } else {
         // add a new snapshot
         this.nextSnapshotDate = date + SNAPSHOT_INTERVAL;
-        return this.createSnapshot(snapshot).then(function () {
+        return this.backupDatabase.createSnapshot(snapshot).then(function () {
           if (snapshots.length >= MAX_SNAPSHOTS_PER_SESSION) {
             // remove oldest snapshot
-            return this.deleteSnapshot(snapshots[snapshots.length - 1]);
+            return this.backupDatabase.deleteSnapshot(snapshots[snapshots.length - 1]);
           }
         }.bind(this));
       }
@@ -161,27 +73,10 @@
   };
 
   ns.BackupService.prototype.getPreviousPiskelInfo = function () {
-    // Create the backup promise.
-    var deferred = Q.defer();
-
-    // Open a transaction to the snapshots object store.
-    var objectStore = this.db.transaction(['snapshots']).objectStore('snapshots');
-
     var sessionId = this.piskelController.getPiskel().sessionId;
-    var index = objectStore.index('date');
-    var range = IDBKeyRange.upperBound(Infinity);
-    index.openCursor(range, 'prev').onsuccess = function(event) {
-      var cursor = event.target.result;
-      var snapshot = cursor && cursor.value;
-      if (snapshot && snapshot.session_id === sessionId) {
-        // Skip snapshots for the current session.
-        cursor.continue();
-      } else {
-        deferred.resolve(snapshot);
-      }
-    };
-
-    return deferred.promise;
+    return this.backupDatabase.findLastSnapshot(function (snapshot) {
+      return snapshot.session_id !== sessionId;
+    });
   };
 
   ns.BackupService.prototype.load = function() {

src/js/service/storage/IndexedDbStorageService.js

@@ -5,14 +5,11 @@
 
   ns.IndexedDbStorageService = function (piskelController) {
     this.piskelController = piskelController;
+    this.piskelDatabase = new pskl.database.PiskelDatabase();
   };
 
   ns.IndexedDbStorageService.prototype.init = function () {
-    var request = window.indexedDB.open(DB_NAME, DB_VERSION);
-
-    request.onerror = this.onRequestError_.bind(this);
-    request.onupgradeneeded = this.onUpgradeNeeded_.bind(this);
-    request.onsuccess = this.onRequestSuccess_.bind(this);
+    this.piskelDatabase.init();
   };
 
   ns.IndexedDbStorageService.prototype.save = function (piskel) {
@@ -25,61 +22,18 @@
   };
 
   ns.IndexedDbStorageService.prototype.save_ = function (name, description, date, serialized) {
-    var deferred = Q.defer();
-    var objectStore = this.db.transaction(['piskels'], 'readwrite').objectStore('piskels');
-
-    var getRequest = objectStore.get(name);
-    getRequest.onsuccess = function (event) {
-      console.log('get request successful for name: ' + name);
+    return this.piskelDatabase.get(name).then(function (event) {
       var data = event.target.result;
       if (typeof data !== 'undefined') {
-
-        data.serialized = serialized;
-        data.date = date;
-        data.description = description;
-
-        var putRequest = objectStore.put(data);
-        putRequest.onerror = function(event) {
-          console.log('put request failed for name: ' + name);
-          deferred.reject();
-        };
-        putRequest.onsuccess = function(event) {
-          console.log('put request successful for name: ' + name);
-          deferred.resolve();
-        };
+        return this.piskelDatabase.update(name, description, date, serialized);
       } else {
-        var request = objectStore.add({
-          name: name,
-          description: description,
-          serialized: serialized,
-          date: date
-        });
-
-        request.onerror = function(event) {
-          console.log('Failed to save a piskel');
-          deferred.reject();
-        };
-        request.onsuccess = function(event) {
-          console.log('Successfully saved a piskel');
-          deferred.resolve();
-        };
+        return this.piskelDatabase.create(name, description, date, serialized);
       }
-    };
-
-    getRequest.onerror = function () {
-      console.log('get request failed for name: ' + name);
-      deferred.reject();
-    };
-
-    return deferred.promise;
+    }.bind(this));
   };
 
   ns.IndexedDbStorageService.prototype.load = function (name) {
-    var objectStore = this.db.transaction(['piskels'], 'readwrite').objectStore('piskels');
-
-    var getRequest = objectStore.get(name);
-    getRequest.onsuccess = function (event) {
-      console.log('get request successful for name: ' + name);
+    this.piskelDatabase.get(name).then(function (event) {
       var data = event.target.result;
       if (typeof data !== 'undefined') {
         var serialized = data.serialized;
@@ -92,80 +46,14 @@
       } else {
         console.log('no local browser save found for name: ' + name);
       }
-    };
-
-    getRequest.onerror = function () {
-      console.log('get request failed for name: ' + name);
-    };
+    });
   };
 
   ns.IndexedDbStorageService.prototype.remove = function (name) {
-    var objectStore = this.db.transaction(['piskels'], 'readwrite').objectStore('piskels');
-    var deleteRequest = objectStore.delete(name);
-    deleteRequest.onsuccess = function (event) {
-      console.log('successfully deleted local browser save for name: ' + name);
-    };
-
-    deleteRequest.onerror = function (event) {
-      console.log('failed to delete local browser save for name: ' + name);
-    };
-  };
-
-  ns.IndexedDbStorageService.prototype.list = function () {
-    var deferred = Q.defer();
-    var piskels = [];
-    var objectStore = this.db.transaction(['piskels']).objectStore('piskels');
-
-    var cursor = objectStore.openCursor();
-    cursor.onsuccess = function(event) {
-      var cursor = event.target.result;
-      if (cursor) {
-        piskels.push({
-          name: cursor.value.name,
-          date: cursor.value.date,
-          description: cursor.value.description
-        });
-        cursor.continue();
-      } else {
-        console.log('Cursor consumed all availabled piskels');
-        deferred.resolve(piskels);
-      }
-    };
-
-    cursor.onerror = function () {
-      deferred.reject();
-    };
-
-    return deferred.promise;
+    this.piskelDatabase.delete(name);
   };
 
   ns.IndexedDbStorageService.prototype.getKeys = function () {
-    return this.list();
-  };
-
-  ns.IndexedDbStorageService.prototype.onRequestError_ = function (event) {
-    console.log('Failed to initialize IndexedDB, local browser saves will be unavailable.');
-  };
-
-  ns.IndexedDbStorageService.prototype.onRequestSuccess_ = function (event) {
-    this.db = event.target.result;
-    console.log('Successfully initialized IndexedDB, local browser saves are available.');
-  };
-
-  ns.IndexedDbStorageService.prototype.onUpgradeNeeded_ = function (event) {
-    // Set this.db early to allow migration scripts to access it in oncomplete.
-    this.db = event.target.result;
-
-    // Create an object store "piskels" with the autoIncrement flag set as true.
-    var objectStore = this.db.createObjectStore('piskels', { keyPath : 'name' });
-    objectStore.transaction.oncomplete = function(event) {
-      // Migrate existing sprites from LocalStorage
-      pskl.service.storage.migrate.MigrateLocalStorageToIndexedDb.migrate().then(function () {
-        console.log('Successfully migrated local storage data to indexed db');
-      }).catch(function (e) {
-        console.log('Failed to migrate local storage data to indexed db');
-        console.error(e);
-      });
-    };
+    return this.piskelDatabase.list();
   };
 })();

src/piskel-script-list.js

@@ -79,6 +79,10 @@
   "js/model/Palette.js",
   "js/model/Piskel.js",
 
+  // Database (IndexedDB)
+  "js/database/BackupDatabase.js",
+  "js/database/PiskelDatabase.js",
+
   // Selection
   "js/selection/SelectionManager.js",
   "js/selection/BaseSelection.js",