Pool uses a js array as a queue

[isaacl]

Probably doesn't matter most of the time, but arrays are poorly suited as a queue. shift() is an O(n) operation. Better would be a simple structure which has amortized O(1) operations:

class Queue {
  constructor() {
    this._pushQueue = [];
    this._removeQueue = []
  }

  pop() {
    if (this._removeQueue.length === 0 && this._pushQueue.length > 0) {
      this._removeQueue = this._pushQueue.reverse();
      this._pushQueue = [];
    }
    return this._removeQueue.pop();
  }

  push(...args) {
    this._pushQueue.push(...args)
  }

  length() {
    return this._pushQueue.length + this._removeQueue.length;
  }
}

[charmander]

Do you know if that implementation is published as a package anywhere?

I wonder how this compares to double-ended-queue for pg’s purposes. It’s probably a bit slower, but that’s minor compared to everything else pg does, plus it’s simpler and the arrays shrink automatically. A clear winner?

[isaacl]

I wrote that for this bug. Yes its is probably a bit slower than a double ended queue (or a circular buffer).