static boolean equals()

in datasketches-memory-java8/src/main/java/org/apache/datasketches/memory/internal/CompareAndCopy.java [71:100]

• 26 lines of code
• 7 McCabe index (conditional complexity)

  static boolean equals(
      final ResourceImpl state1, final long offsetBytes1,
      final ResourceImpl state2, final long offsetBytes2, long lengthBytes) {
    state1.checkValid();
    ResourceImpl.checkBounds(offsetBytes1, lengthBytes, state1.getCapacity());
    state2.checkValid();
    ResourceImpl.checkBounds(offsetBytes2, lengthBytes, state2.getCapacity());
    long cumOff1 = state1.getCumulativeOffset(offsetBytes1);
    long cumOff2 = state2.getCumulativeOffset(offsetBytes2);
    final Object arr1 = state1.getUnsafeObject(); //could be null
    final Object arr2 = state2.getUnsafeObject(); //could be null
    if ((arr1 == arr2) && (cumOff1 == cumOff2)) { return true; }

    while (lengthBytes >= Long.BYTES) {
      final int chunk = (int) Math.min(lengthBytes, UNSAFE_COPY_THRESHOLD_BYTES);
      // int-counted loop to avoid safepoint polls (otherwise why we chunk by
      // UNSAFE_COPY_MEMORY_THRESHOLD)
      int i = 0;
      for (; i <= (chunk - Long.BYTES); i += Long.BYTES) {
        final long v1 = unsafe.getLong(arr1, cumOff1 + i);
        final long v2 = unsafe.getLong(arr2, cumOff2 + i);
        if (v1 != v2) { return false; }
      }
      lengthBytes -= i;
      cumOff1 += i;
      cumOff2 += i;
    }
    //check the remainder bytes, if any
    return (lengthBytes == 0) || equalsByBytes(arr1, cumOff1, arr2, cumOff2, (int) lengthBytes);
  }