WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance / 4.2.2

WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance v4.2.2

wp-optimize / js / queue.js

queue.js in WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance 4.2.2, at js/queue.js

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1	/**
2	Adapted and extended from the work of Stephen Morley - http://code.stephenmorley.org/javascript/queues/
3
4	Queue.js
5
6	A function to represent a queue
7
8	Created by Stephen Morley - http://code.stephenmorley.org/ - and released under
9	the terms of the CC0 1.0 Universal legal code:
10
11	http://creativecommons.org/publicdomain/zero/1.0/legalcode
12	*/
13
14	/**
15	* Creates a new queue. A queue is a first-in-first-out (FIFO) data structure -
16	* items are added to the end of the queue and removed from the front.
17	*
18	* @return {void}
19	*/
20	function Updraft_Queue() {
21
22	// Initialise the queue and offset.
23	var queue = [];
24	var offset = 0;
25	var locked = false;
26
27	/**
28	* Returns the length of the queue.
29	*
30	* @returns {number} - the length of the queue
31	*/
32	this.get_length = function () {
33	return (queue.length - offset);
34	}
35
36	/**
37	* Query whether the queue is empty or not
38	*
39	* @returns {boolean} - returns true if the queue is empty, and false otherwise.
40	*/
41	this.is_empty = function () {
42	return (queue.length == 0);
43	}
44
45	/**
46	* Enqueues the specified item. The parameter is:
47	*
48	* @param {*} item The item to enqueue
49	*
50	* @return {void}
51	*/
52	this.enqueue = function (item) {
53	queue.push(item);
54	}
55
56	/**
57	* Returns the queue lock status
58	*
59	* @returns {boolean} - whether the queue is locked or not
60	*/
61	this.is_locked = function () {
62	return locked;
63	}
64
65	/**
66	* Attempt to get the queue lock
67	*
68	* @returns {boolean} - whether the attempt succeeded or not
69	*/
70	this.get_lock = function () {
71	if (locked) { return false; }
72	this.lock();
73	return true;
74	}
75
76	/**
77	* Dequeues an item and returns it. If the queue is empty, the value
78	* 'undefined' is returned.
79	*
80	* @returns {*} - returns and removes the item at the front of the queue, or undefined if the queue is empty
81	*/
82	this.dequeue = function () {
83
84	// If the queue is empty, return immediately.
85	if (queue.length == 0) return undefined;
86
87	// Store the item at the front of the queue.
88	var item = queue[offset];
89
90	// Increment the offset and remove the free space if necessary.
91	if ((++offset * 2) >= queue.length) {
92	queue = queue.slice(offset);
93	offset = 0;
94	}
95
96	// Return the dequeued item.
97	return item;
98	}
99
100	/**
101	* Lock the queue
102	*
103	* @returns {void}
104	*/
105	this.lock = function () {
106	locked = true;
107	}
108
109	/**
110	* Unlock the queue
111	*
112	* @returns {void}
113	*/
114	this.unlock = function () {
115	locked = false;
116	}
117
118	/**
119	* Returns the item at the front of the queue (without dequeuing it). If the
120	* queue is empty then undefined is returned.
121	*
122	* @returns {*} - returns the item at the front of the queue, or undefined if the queue is empty
123	*/
124	this.peek = function () {
125	return (queue.length > 0 ? queue[offset] : undefined);
126	}
127
128	/**
129	* Replaces the item at the front of the queue (if any)
130	*
131	* @param {*} item The item to put at the front of the queue.
132	*
133	* @return {boolean} Whether or not the item was successfully replaced.
134	*/
135	this.replace_front = function (item) {
136	if (queue.length < 1) { return false; }
137	queue[offset] = item;
138	return true;
139	}
140
141	/**
142	* Checks if any queue object/element contains the ID
143	*
144	* @param {string} id The ID to search for.
145	*
146	* @return {boolean} Whether any queue object/element contains the ID.
147	*/
148	this.contains_id = function (id) {
149	return queue.some(function (ele) {
150	return ele.optimization_id === id;
151	});
152	}
153
154	}
155
156