public static TDigestDouble heapify()

in src/main/java/org/apache/datasketches/tdigest/TDigestDouble.java [393:445]
53 lines of code
16 McCabe index (conditional complexity)

  public static TDigestDouble heapify(final Memory mem, final boolean isFloat) {
    final Buffer buff = mem.asBuffer();
    final byte preambleLongs = buff.getByte();
    final byte serialVersion = buff.getByte();
    final byte sketchType = buff.getByte();
    if (sketchType != (byte) Family.TDIGEST.getID()) {
      if (preambleLongs == 0 && serialVersion == 0 && sketchType == 0) { return heapifyCompat(mem); }
      throw new SketchesArgumentException("Sketch type mismatch: expected " + Family.TDIGEST.getID() + ", actual " + sketchType);
    }
    if (serialVersion != SERIAL_VERSION) {
      throw new SketchesArgumentException("Serial version mismatch: expected " + SERIAL_VERSION + ", actual " + serialVersion);
    }
    final short k = buff.getShort();
    final byte flagsByte = buff.getByte();
    final boolean isEmpty = (flagsByte & (1 << Flags.IS_EMPTY.ordinal())) > 0;
    final boolean isSingleValue = (flagsByte & (1 << Flags.IS_SINGLE_VALUE.ordinal())) > 0;
    final byte expectedPreambleLongs = isEmpty || isSingleValue ? PREAMBLE_LONGS_EMPTY_OR_SINGLE : PREAMBLE_LONGS_MULTIPLE;
    if (preambleLongs != expectedPreambleLongs) {
      throw new SketchesArgumentException("Preamble longs mismatch: expected " + expectedPreambleLongs + ", actual " + preambleLongs);
    }
    buff.getShort(); // unused
    if (isEmpty) { return new TDigestDouble(k); }
    final boolean reverseMerge = (flagsByte & (1 << Flags.REVERSE_MERGE.ordinal())) > 0;
    if (isSingleValue) {
      final double value;
      if (isFloat) {
        value = buff.getFloat();
      } else {
        value = buff.getDouble();
      }
      return new TDigestDouble(reverseMerge, k, value, value, new double[] {value}, new long[] {1}, 1, null);
    }
    final int numCentroids = buff.getInt();
    buff.getInt(); // unused
    final double min;
    final double max;
    if (isFloat) {
      min = buff.getFloat();
      max = buff.getFloat();
    } else {
      min = buff.getDouble();
      max = buff.getDouble();
    }
    final double[] means = new double[numCentroids];
    final long[] weights = new long[numCentroids];
    long totalWeight = 0;
    for (int i = 0; i < numCentroids; i++) {
      means[i] = isFloat ? buff.getFloat() : buff.getDouble();
      weights[i] = isFloat ? buff.getInt() : buff.getLong();
      totalWeight += weights[i];
    }
    return new TDigestDouble(reverseMerge, k, min, max, means, weights, totalWeight, null);
  }