@thi.ng/vector-pools/alist.js

Data structures for managing & working with strided, memory mapped vectors

import { wrap } from "./wrap.js";
class AVecList {
  buffer;
  factory;
  start;
  capacity;
  curr;
  size;
  estride;
  cstride;
  freeIDs;
  /**
   *
   * @param buffer -
   * @param capacity -
   * @param size -
   * @param start -
   * @param cstride -
   * @param estride -
   * @param factory -
   */
  constructor(buffer, capacity, size, start = 0, cstride = 1, estride = size, factory = wrap) {
    this.buffer = buffer || new Float32Array(size * capacity);
    this.size = size;
    this.factory = factory;
    this.cstride = cstride;
    this.estride = estride;
    this.start = this.curr = start;
    this.capacity = capacity;
    this.freeIDs = [];
  }
  indices(res = [], i = 0, local = true) {
    const { start, estride } = this;
    if (local) {
      for (let v of this) {
        res[i++] = (v.offset - start) / estride;
      }
    } else {
      for (let v of this) {
        res[i++] = v.offset;
      }
    }
    return res;
  }
  alloc() {
    let idx;
    if (this.freeIDs.length > 0) {
      idx = this.freeIDs.pop();
    } else if (this.length >= this.capacity) {
      return;
    } else {
      idx = this.curr;
      this.curr += this.estride;
    }
    return this.factory(this.buffer, this.size, idx, this.cstride);
  }
}
export {
  AVecList
};