more templates back into cli

middleman-cli/lib/middleman-templates/mobile/source/tools/wspl/gears_transaction.js

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+/*
+  Copyright 2009 Google Inc.
+
+  Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+*/
+
+/**
+ * @fileoverview A Gears implementation of dbwrapperapi Transaction.
+ */
+
+/**
+ * Creates a Gears Transaction object.
+ * @see google.wspl.ResultSet#ResultSet
+ *
+ * @constructor
+ * @extends google.wspl.Transaction
+ *
+ * @param {number} id The unique id for this transaction
+ * @param {google.wspl.gears.Database} db The Gears implementation of the
+ *    dbwrapperapi database
+ */
+google.wspl.gears.Transaction = function(id, db) {
+  google.wspl.Transaction.call(this);
+
+  /**
+   * The unique id for this transaction.
+   * @type {number}
+   * @private
+   */
+  this.id_ = id;
+
+  /**
+   * The Gears implementation of the dbwrapperapi database.
+   * @type {google.wspl.gears.Database}
+   * @private
+   */
+  this.db_ = db;
+
+  /**
+   * A map of statements, callback, and current statement.
+   * @type {Object}
+   * @private
+   */
+  this.activeExecutes_ = {};
+};
+google.inherits(google.wspl.gears.Transaction, google.wspl.Transaction);
+
+/**
+ * The number of active executes.
+ * @type {number}
+ * @private
+ */
+google.wspl.gears.Transaction.prototype.numActiveExecutes_ = 0;
+
+/**
+ * The id for the next call to execute.  Incremented after use.
+ * @type {number}
+ * @private
+ */
+google.wspl.gears.Transaction.prototype.nextCallbackId_ = 1;
+
+/**
+ * Whether the transaction should be rolled back or not. This property is set
+ * to true when a statement fails.
+ * @type {boolean}
+ * @private
+ */
+google.wspl.gears.Transaction.prototype.needsRollback_ = false;
+
+/**
+ * Begins a new transaction with the Gears database. Commits the transaction if
+ * all calls to executeAll for this transaction have finished receiving
+ * callbacks.  Rolls the transaction back if a statement failed.
+ *
+ * @see google.wspl.Transaction#executeAll
+ * @inheritDoc
+ */
+google.wspl.gears.Transaction.prototype.executeAll = function(statements,
+    opt_callback) {
+  if (statements.length == 0) {
+    throw Error('Possibly silly attempt to execute empty statement list.');
+  }
+  if (this.numActiveExecutes_ == 0) {
+    this.db_.doBegin(this.id_);
+  }
+
+  this.numActiveExecutes_++;
+  var callbackId = this.nextCallbackId_++;
+
+  var callback = opt_callback || {
+    onSuccess : function() {},
+    onFailure : function() {}
+  };
+
+  this.activeExecutes_[callbackId] = {
+    statements: statements,
+    currentStatement: 0,
+    callback: callback
+  };
+
+  this.db_.doExecute(statements, callbackId, this.id_);
+};
+
+/**
+ * Invokes onSuccess on the specified callback.
+ *
+ * @param {google.wspl.ResultSet} result The result of a successful statement
+ * @param {number} callbackId The callback to invoke
+ */
+google.wspl.gears.Transaction.prototype.success = function(result,
+                                                           callbackId) {
+  if (!this.needsRollback_) {
+    var activeExecute = this.activeExecutes_[callbackId];
+    activeExecute.callback.onSuccess(this, result);
+  }
+  this.endStatement_(callbackId);
+};
+
+/**
+ * Invokes onFailure on the specified callback.
+ *
+ * @param {Error} error The error of an unsuccessful statement
+ * @param {number} callbackId The callback to invoke
+ */
+google.wspl.gears.Transaction.prototype.failure = function(error,
+                                                           callbackId) {
+  if (!this.needsRollback_) {
+    this.needsRollback_ = true;
+    var activeExecute = this.activeExecutes_[callbackId];
+    activeExecute.callback.onFailure(error);
+  }
+  this.endStatement_(callbackId);
+};
+
+/**
+ * Handles clean up for the end of a single execution.
+ *
+ * @param {number} callbackId The callback to clean up.
+ * @private
+ */
+google.wspl.gears.Transaction.prototype.endStatement_ = function(callbackId) {
+  var activeExecute = this.activeExecutes_[callbackId];
+  var statements = activeExecute.statements;
+  var currentStatement = ++activeExecute.currentStatement;
+
+  if (currentStatement == statements.length) {
+    this.endExecute_(callbackId);
+  }
+};
+
+/**
+ * Handles clean up for the end of a call to executeAll.  Performs a commit or
+ * rollback if this is the last active execute to clean up.
+ *
+ * @param {number} callbackId The callback to clean up
+ * @private
+ */
+google.wspl.gears.Transaction.prototype.endExecute_ = function(callbackId) {
+  delete this.activeExecutes_[callbackId];
+  this.numActiveExecutes_--;
+  if (!this.isExecuting()) {
+    this.endTransaction_();
+  }
+};
+
+/**
+ * Instructs the worker to commit the transaction or roll it back if a failure
+ * occurred and a rollback is required.
+ *
+ * @private
+ */
+google.wspl.gears.Transaction.prototype.endTransaction_ = function() {
+  if (this.needsRollback_) {
+    this.db_.doRollback(this.id_);
+  } else {
+    this.db_.doCommit(this.id_);
+  }
+};
+
+/**
+ * @return {boolean} True if the transaction has statements executing, false
+ *     otherwise.
+ */
+google.wspl.gears.Transaction.prototype.isExecuting = function() {
+  return this.numActiveExecutes_ > 0;
+};