aoc/node_modules/jest-worker/build/PriorityQueue.js

138 lines
3.9 KiB
JavaScript

'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
exports.default = void 0;
/**
* Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
/**
* Priority queue that processes tasks in natural ordering (lower priority first)
* according to the priority computed by the function passed in the constructor.
*
* FIFO ordering isn't guaranteed for tasks with the same priority.
*
* Worker specific tasks with the same priority as a non-worker specific task
* are always processed first.
*/
class PriorityQueue {
_queue = [];
_sharedQueue = new MinHeap();
constructor(_computePriority) {
this._computePriority = _computePriority;
}
enqueue(task, workerId) {
if (workerId == null) {
this._enqueue(task, this._sharedQueue);
} else {
const queue = this._getWorkerQueue(workerId);
this._enqueue(task, queue);
}
}
_enqueue(task, queue) {
const item = {
priority: this._computePriority(task.request[2], ...task.request[3]),
task
};
queue.add(item);
}
dequeue(workerId) {
const workerQueue = this._getWorkerQueue(workerId);
const workerTop = workerQueue.peek();
const sharedTop = this._sharedQueue.peek();
// use the task from the worker queue if there's no task in the shared queue
// or if the priority of the worker queue is smaller or equal to the
// priority of the top task in the shared queue. The tasks of the
// worker specific queue are preferred because no other worker can pick this
// specific task up.
if (
sharedTop == null ||
(workerTop != null && workerTop.priority <= sharedTop.priority)
) {
return workerQueue.poll()?.task ?? null;
}
return this._sharedQueue.poll().task;
}
_getWorkerQueue(workerId) {
let queue = this._queue[workerId];
if (queue == null) {
queue = this._queue[workerId] = new MinHeap();
}
return queue;
}
}
exports.default = PriorityQueue;
class MinHeap {
_heap = [];
peek() {
return this._heap[0] ?? null;
}
add(item) {
const nodes = this._heap;
nodes.push(item);
if (nodes.length === 1) {
return;
}
let currentIndex = nodes.length - 1;
// Bubble up the added node as long as the parent is bigger
while (currentIndex > 0) {
const parentIndex = Math.floor((currentIndex + 1) / 2) - 1;
const parent = nodes[parentIndex];
if (parent.priority <= item.priority) {
break;
}
nodes[currentIndex] = parent;
nodes[parentIndex] = item;
currentIndex = parentIndex;
}
}
poll() {
const nodes = this._heap;
const result = nodes[0];
const lastElement = nodes.pop();
// heap was empty or removed the last element
if (result == null || nodes.length === 0) {
return result ?? null;
}
let index = 0;
nodes[0] = lastElement ?? null;
const element = nodes[0];
while (true) {
let swapIndex = null;
const rightChildIndex = (index + 1) * 2;
const leftChildIndex = rightChildIndex - 1;
const rightChild = nodes[rightChildIndex];
const leftChild = nodes[leftChildIndex];
// if the left child is smaller, swap with the left
if (leftChild != null && leftChild.priority < element.priority) {
swapIndex = leftChildIndex;
}
// If the right child is smaller or the right child is smaller than the left
// then swap with the right child
if (
rightChild != null &&
rightChild.priority < (swapIndex == null ? element : leftChild).priority
) {
swapIndex = rightChildIndex;
}
if (swapIndex == null) {
break;
}
nodes[index] = nodes[swapIndex];
nodes[swapIndex] = element;
index = swapIndex;
}
return result;
}
}