forked from mirror/ledisdb
60 lines
1.3 KiB
JavaScript
60 lines
1.3 KiB
JavaScript
// Queue class adapted from Tim Caswell's pattern library
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// http://github.com/creationix/pattern/blob/master/lib/pattern/queue.js
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function Queue() {
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this.tail = [];
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this.head = [];
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this.offset = 0;
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}
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Queue.prototype.shift = function () {
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if (this.offset === this.head.length) {
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var tmp = this.head;
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tmp.length = 0;
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this.head = this.tail;
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this.tail = tmp;
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this.offset = 0;
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if (this.head.length === 0) {
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return;
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}
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}
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return this.head[this.offset++]; // sorry, JSLint
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};
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Queue.prototype.push = function (item) {
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return this.tail.push(item);
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};
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Queue.prototype.forEach = function (fn, thisv) {
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var array = this.head.slice(this.offset), i, il;
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array.push.apply(array, this.tail);
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if (thisv) {
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for (i = 0, il = array.length; i < il; i += 1) {
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fn.call(thisv, array[i], i, array);
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}
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} else {
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for (i = 0, il = array.length; i < il; i += 1) {
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fn(array[i], i, array);
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}
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}
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return array;
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};
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Queue.prototype.getLength = function () {
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return this.head.length - this.offset + this.tail.length;
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};
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Object.defineProperty(Queue.prototype, "length", {
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get: function () {
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return this.getLength();
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}
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});
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if (typeof module !== "undefined" && module.exports) {
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module.exports = Queue;
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}
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