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Direktori : /usr/lib/node_modules/pm2/node_modules/tx2/src/utils/probes/ |
Current File : //usr/lib/node_modules/pm2/node_modules/tx2/src/utils/probes/BinaryHeap.js |
// Based on http://en.wikipedia.org/wiki/Binary_Heap // as well as http://eloquentjavascript.net/appendix2.html module.exports = BinaryHeap; function BinaryHeap(options) { options = options || {}; this._elements = options.elements || []; this._score = options.score || this._score; } BinaryHeap.prototype.add = function(/* elements */) { for (var i = 0; i < arguments.length; i++) { var element = arguments[i]; this._elements.push(element); this._bubble(this._elements.length - 1); } }; BinaryHeap.prototype.first = function() { return this._elements[0]; }; BinaryHeap.prototype.removeFirst = function() { var root = this._elements[0]; var last = this._elements.pop(); if (this._elements.length > 0) { this._elements[0] = last; this._sink(0); } return root; }; BinaryHeap.prototype.clone = function() { return new BinaryHeap({ elements: this.toArray(), score: this._score, }); }; BinaryHeap.prototype.toSortedArray = function() { var array = []; var clone = this.clone(); while (true) { var element = clone.removeFirst(); if (element === undefined) break; array.push(element); } return array; }; BinaryHeap.prototype.toArray = function() { return [].concat(this._elements); }; BinaryHeap.prototype.size = function() { return this._elements.length; }; BinaryHeap.prototype._bubble = function(bubbleIndex) { var bubbleElement = this._elements[bubbleIndex]; var bubbleScore = this._score(bubbleElement); while (bubbleIndex > 0) { var parentIndex = this._parentIndex(bubbleIndex); var parentElement = this._elements[parentIndex]; var parentScore = this._score(parentElement); if (bubbleScore <= parentScore) break; this._elements[parentIndex] = bubbleElement; this._elements[bubbleIndex] = parentElement; bubbleIndex = parentIndex; } }; BinaryHeap.prototype._sink = function(sinkIndex) { var sinkElement = this._elements[sinkIndex]; var sinkScore = this._score(sinkElement); var length = this._elements.length; while (true) { var swapIndex = null; var swapScore = null; var swapElement = null; var childIndexes = this._childIndexes(sinkIndex); for (var i = 0; i < childIndexes.length; i++) { var childIndex = childIndexes[i]; if (childIndex >= length) break; var childElement = this._elements[childIndex]; var childScore = this._score(childElement); if (childScore > sinkScore) { if (swapScore === null || swapScore < childScore) { swapIndex = childIndex; swapScore = childScore; swapElement = childElement; } } } if (swapIndex === null) break; this._elements[swapIndex] = sinkElement; this._elements[sinkIndex] = swapElement; sinkIndex = swapIndex; } }; BinaryHeap.prototype._parentIndex = function(index) { return Math.floor((index - 1) / 2); }; BinaryHeap.prototype._childIndexes = function(index) { return [ 2 * index + 1, 2 * index + 2, ]; return ; }; BinaryHeap.prototype._score = function(element) { return element.valueOf(); };