mirror of
https://github.com/Unitech/pm2.git
synced 2025-12-08 20:35:53 +00:00
136 lines
3.2 KiB
JavaScript
136 lines
3.2 KiB
JavaScript
|
|
// Hacked https://github.com/felixge/node-measured
|
|
|
|
// 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();
|
|
};
|