desk2/client/heapify.js

// translated by esbuild to js. original typescript source MIT licensed at https://github.com/luciopaiva/heapify

const ROOT_INDEX = 1;
class MinQueue {
  constructor(capacity = 64, keys = [], priorities = [], KeysBackingArrayType = Uint32Array, PrioritiesBackingArrayType = Uint32Array) {
    this._capacity = capacity;
    this._keys = new KeysBackingArrayType(capacity + ROOT_INDEX);
    this._priorities = new PrioritiesBackingArrayType(capacity + ROOT_INDEX);
    this._hasPoppedElement = false;
    if (keys.length !== priorities.length) {
      throw new Error("Number of keys does not match number of priorities provided.");
    }
    if (capacity < keys.length) {
      throw new Error("Capacity less than number of provided keys.");
    }
    for (let i = 0; i < keys.length; i++) {
      this._keys[i + ROOT_INDEX] = keys[i];
      this._priorities[i + ROOT_INDEX] = priorities[i];
    }
    this.length = keys.length;
    for (let i = keys.length >>> 1; i >= ROOT_INDEX; i--) {
      this.bubbleDown(i);
    }
  }
  get capacity() {
    return this._capacity;
  }
  clear() {
    this.length = 0;
    this._hasPoppedElement = false;
  }
  bubbleUp(index) {
    const key = this._keys[index];
    const priority = this._priorities[index];
    while (index > ROOT_INDEX) {
      const parentIndex = index >>> 1;
      if (this._priorities[parentIndex] <= priority) {
        break;
      }
      this._keys[index] = this._keys[parentIndex];
      this._priorities[index] = this._priorities[parentIndex];
      index = parentIndex;
    }
    this._keys[index] = key;
    this._priorities[index] = priority;
  }
  bubbleDown(index) {
    const key = this._keys[index];
    const priority = this._priorities[index];
    const halfLength = ROOT_INDEX + (this.length >>> 1);
    const lastIndex = this.length + ROOT_INDEX;
    while (index < halfLength) {
      const left = index << 1;
      let childPriority = this._priorities[left];
      let childKey = this._keys[left];
      let childIndex = left;
      const right = left + 1;
      if (right < lastIndex) {
        const rightPriority = this._priorities[right];
        if (rightPriority < childPriority) {
          childPriority = rightPriority;
          childKey = this._keys[right];
          childIndex = right;
        }
      }
      if (childPriority >= priority) {
        break;
      }
      this._keys[index] = childKey;
      this._priorities[index] = childPriority;
      index = childIndex;
    }
    this._keys[index] = key;
    this._priorities[index] = priority;
  }
  push(key, priority) {
    if (this.length === this._capacity) {
      throw new Error("Heap has reached capacity, can't push new items");
    }
    if (this._hasPoppedElement) {
      this._keys[ROOT_INDEX] = key;
      this._priorities[ROOT_INDEX] = priority;
      this.length++;
      this.bubbleDown(ROOT_INDEX);
      this._hasPoppedElement = false;
    } else {
      const pos = this.length + ROOT_INDEX;
      this._keys[pos] = key;
      this._priorities[pos] = priority;
      this.length++;
      this.bubbleUp(pos);
    }
  }
  pop() {
    if (this.length === 0) {
      return void 0;
    }
    this.removePoppedElement();
    this.length--;
    this._hasPoppedElement = true;
    return this._keys[ROOT_INDEX];
  }
  peekPriority() {
    this.removePoppedElement();
    return this._priorities[ROOT_INDEX];
  }
  peek() {
    this.removePoppedElement();
    return this._keys[ROOT_INDEX];
  }
  removePoppedElement() {
    if (this._hasPoppedElement) {
      this._keys[ROOT_INDEX] = this._keys[this.length + ROOT_INDEX];
      this._priorities[ROOT_INDEX] = this._priorities[this.length + ROOT_INDEX];
      this.bubbleDown(ROOT_INDEX);
      this._hasPoppedElement = false;
    }
  }
  get size() {
    return this.length;
  }
  dumpRawPriorities() {
    this.removePoppedElement();
    const result = Array(this.length - ROOT_INDEX);
    for (let i = 0; i < this.length; i++) {
      result[i] = this._priorities[i + ROOT_INDEX];
    }
    return `[${result.join(" ")}]`;
  }
}