FloatBuffer mergeSortIn()

in src/main/java/org/apache/datasketches/req/FloatBuffer.java [344:385]

• 42 lines of code
• 16 McCabe index (conditional complexity)

  FloatBuffer mergeSortIn(final FloatBuffer bufIn) {
    if (!sorted_ || !bufIn.isSorted()) {
      throw new SketchesArgumentException("Both buffers must be sorted.");
    }
    final float[] arrIn = bufIn.getArray(); //may be larger than its item count.
    final int bufInLen = bufIn.getCount();
    ensureSpace(bufInLen);
    final int totLen = count_ + bufInLen;
    if (spaceAtBottom_) { //scan up, insert at bottom
      final int tgtStart = capacity_ - totLen;
      int i = capacity_ - count_;
      int j = bufIn.capacity_ - bufIn.count_;
      for (int k = tgtStart; k < capacity_; k++) {
        if (i < capacity_ && j < bufIn.capacity_) { //both valid
          arr_[k] = arr_[i] <= arrIn[j] ? arr_[i++] : arrIn[j++];
        } else if (i < capacity_) { //i is valid
          arr_[k] = arr_[i++];
        } else if (j <  bufIn.capacity_) { //j is valid
          arr_[k] = arrIn[j++];
        } else {
          break;
        }
      }
    } else { //scan down, insert at top
      int i = count_ - 1;
      int j = bufInLen - 1;
      for (int k = totLen; k-- > 0; ) {
        if (i >= 0 && j >= 0) { //both valid
          arr_[k] = arr_[i] >= arrIn[j] ? arr_[i--] : arrIn[j--];
        } else if (i >= 0) { //i is valid
          arr_[k] = arr_[i--];
        } else if (j >= 0) { //j is valid
          arr_[k] = arrIn[j--];
        } else {
          break;
        }
      }
    }
    count_ += bufInLen;
    sorted_ = true;
    return this;
  }