Method _buildIndex

src/Map.js:462–476

()

  // Builds and memoizes the secondary index. A plain object, not `Map` — which
  // in this module resolves to the *Immutable* Map, not the native one.
  _buildIndex() {
    const index = Object.create(null);
    const entries = this.entries;
    for (let ii = 0, len = entries.length; ii < len; ii++) {
      const secondaryHash = hashCollisionKey(entries[ii][0]);
      const positions = index[secondaryHash];
      if (positions !== undefined) {
        positions.push(ii);
      } else {
        index[secondaryHash] = [ii];
      }
    }
    this._index = index;
    return index;
  }

  get(shift, keyHash, key, notSetValue) {
    const idx = this._positionOf(key, true);