| // Copyright 2011 The Closure Library Authors. All Rights Reserved. |
| // |
| // 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 Interface for storing, retieving and scanning data using some |
| * persistence mechanism. |
| * |
| */ |
| |
| goog.provide('goog.storage.mechanism.IterableMechanism'); |
| |
| goog.require('goog.array'); |
| goog.require('goog.asserts'); |
| goog.require('goog.iter'); |
| goog.require('goog.storage.mechanism.Mechanism'); |
| |
| |
| |
| /** |
| * Interface for all iterable storage mechanisms. |
| * |
| * @constructor |
| * @extends {goog.storage.mechanism.Mechanism} |
| */ |
| goog.storage.mechanism.IterableMechanism = function() { |
| goog.storage.mechanism.IterableMechanism.base(this, 'constructor'); |
| }; |
| goog.inherits(goog.storage.mechanism.IterableMechanism, |
| goog.storage.mechanism.Mechanism); |
| |
| |
| /** |
| * Get the number of stored key-value pairs. |
| * |
| * Could be overridden in a subclass, as the default implementation is not very |
| * efficient - it iterates over all keys. |
| * |
| * @return {number} Number of stored elements. |
| */ |
| goog.storage.mechanism.IterableMechanism.prototype.getCount = function() { |
| var count = 0; |
| goog.iter.forEach(this.__iterator__(true), function(key) { |
| goog.asserts.assertString(key); |
| count++; |
| }); |
| return count; |
| }; |
| |
| |
| /** |
| * Returns an iterator that iterates over the elements in the storage. Will |
| * throw goog.iter.StopIteration after the last element. |
| * |
| * @param {boolean=} opt_keys True to iterate over the keys. False to iterate |
| * over the values. The default value is false. |
| * @return {!goog.iter.Iterator} The iterator. |
| */ |
| goog.storage.mechanism.IterableMechanism.prototype.__iterator__ = |
| goog.abstractMethod; |
| |
| |
| /** |
| * Remove all key-value pairs. |
| * |
| * Could be overridden in a subclass, as the default implementation is not very |
| * efficient - it iterates over all keys. |
| */ |
| goog.storage.mechanism.IterableMechanism.prototype.clear = function() { |
| var keys = goog.iter.toArray(this.__iterator__(true)); |
| var selfObj = this; |
| goog.array.forEach(keys, function(key) { |
| selfObj.remove(key); |
| }); |
| }; |