static final long nativeOverlap()

in src/main/java/org/apache/datasketches/memory/internal/ResourceImpl.java [516:533]

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

  static final long nativeOverlap(final MemorySegment segA, final MemorySegment segB) { //used in test
    if (!segA.isNative() || !segB.isNative()) { return 0; } //both segments must be native
    //Assume that memory addresses increase from left to right.
    //Identify the left and right edges of two regions, A and B in memory.
    final long bytesA = segA.byteSize();
    final long bytesB = segB.byteSize();
    final long lA = segA.address(); //left A
    final long lB = segB.address(); //left B
    final long rA = lA + bytesA; //right A
    final long rB = lB + bytesB; //right B
    if ((rA <= lB) || (rB <= lA)) { return 0; } //Eliminate the totally disjoint case:

    final long result = (bytesA == bytesB) //Two major cases: equal and not equal in size
        ? nativeOverlapEqualSizes(lA, rA, lB, rB)
        : nativeOverlapNotEqualSizes(lA, rA, lB, rB);

    return (lB < lA) ? -result : result; //if lB is lower in memory than lA, we return a negative result
  }