Ejemplo n.º 1
0
  @Override
  public final long getJoinPosition(BlockCursor... cursors) {
    int pos = ((int) Murmur3.hash64(hashCursor(cursors))) & mask;

    while (key[pos] != -1) {
      if (positionEqualsCurrentRow(key[pos], cursors)) {
        return key[pos];
      }
      // increment position and mask to handler wrap around
      pos = (pos + 1) & mask;
    }
    return -1;
  }
Ejemplo n.º 2
0
  public InMemoryJoinHash(
      LongArrayList addresses,
      PagesHashStrategy pagesHashStrategy,
      OperatorContext operatorContext) {
    this.addresses = checkNotNull(addresses, "addresses is null");
    this.pagesHashStrategy = checkNotNull(pagesHashStrategy, "pagesHashStrategy is null");
    this.channelCount = pagesHashStrategy.getChannelCount();

    checkNotNull(operatorContext, "operatorContext is null");

    // reserve memory for the arrays
    int hashSize = HashCommon.arraySize(addresses.size(), 0.75f);
    operatorContext.reserveMemory(sizeOfIntArray(hashSize) + sizeOfIntArray(addresses.size()));

    mask = hashSize - 1;
    key = new int[hashSize];
    Arrays.fill(key, -1);

    this.positionLinks = new int[addresses.size()];
    Arrays.fill(positionLinks, -1);

    // index pages
    for (int position = 0; position < addresses.size(); position++) {
      int pos = ((int) Murmur3.hash64(hashPosition(position))) & mask;

      // look for an empty slot or a slot containing this key
      while (key[pos] != -1) {
        int currentKey = key[pos];
        if (positionEqualsPosition(currentKey, position)) {
          // found a slot for this key
          // link the new key position to the current key position
          positionLinks[position] = currentKey;

          // key[pos] updated outside of this loop
          break;
        }
        // increment position and mask to handler wrap around
        pos = (pos + 1) & mask;
      }

      key[pos] = position;
    }
  }