87 lines
2.5 KiB
JavaScript
87 lines
2.5 KiB
JavaScript
// Copyright 2011 The Closure Library Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS-IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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/**
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* @fileoverview Interface for storing, retieving and scanning data using some
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* persistence mechanism.
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*
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*/
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goog.provide('goog.storage.mechanism.IterableMechanism');
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goog.require('goog.array');
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goog.require('goog.asserts');
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goog.require('goog.iter');
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goog.require('goog.iter.Iterator');
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goog.require('goog.storage.mechanism.Mechanism');
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/**
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* Interface for all iterable storage mechanisms.
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*
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* @constructor
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* @extends {goog.storage.mechanism.Mechanism}
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*/
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goog.storage.mechanism.IterableMechanism = function() {
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goog.base(this);
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};
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goog.inherits(goog.storage.mechanism.IterableMechanism,
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goog.storage.mechanism.Mechanism);
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/**
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* Get the number of stored key-value pairs.
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*
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* Could be overridden in a subclass, as the default implementation is not very
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* efficient - it iterates over all keys.
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*
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* @return {number} Number of stored elements.
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*/
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goog.storage.mechanism.IterableMechanism.prototype.getCount = function() {
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var count = 0;
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goog.iter.forEach(this.__iterator__(true), function(key) {
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goog.asserts.assertString(key);
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count++;
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});
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return count;
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};
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/**
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* Returns an iterator that iterates over the elements in the storage. Will
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* throw goog.iter.StopIteration after the last element.
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*
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* @param {boolean=} opt_keys True to iterate over the keys. False to iterate
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* over the values. The default value is false.
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* @return {!goog.iter.Iterator} The iterator.
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*/
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goog.storage.mechanism.IterableMechanism.prototype.__iterator__ =
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goog.abstractMethod;
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/**
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* Remove all key-value pairs.
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*
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* Could be overridden in a subclass, as the default implementation is not very
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* efficient - it iterates over all keys.
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*/
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goog.storage.mechanism.IterableMechanism.prototype.clear = function() {
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var keys = goog.iter.toArray(this.__iterator__(true));
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var selfObj = this;
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goog.array.forEach(keys, function(key) {
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selfObj.remove(key);
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});
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};
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