Method calculateDistanceAlphabetLimit

java/org/brotli/dec/Decode.java:183–191

(State s, int maxDistance, int npostfix, int ndirect)

  // TODO(eustas): add a correctness test for this function when
  //               large-window and dictionary are implemented.
  private static int calculateDistanceAlphabetLimit(State s, int maxDistance, int npostfix, int ndirect) {
    if (maxDistance < ndirect + (2 << npostfix)) {
      return Utils.makeError(s, BROTLI_PANIC_MAX_DISTANCE_TOO_SMALL);
    }
    final int offset = ((maxDistance - ndirect) >> npostfix) + 4;
    final int ndistbits = log2floor(offset) - 1;
    final int group = ((ndistbits - 1) << 1) | ((offset >> ndistbits) & 1);
    return ((group - 1) << npostfix) + (1 << npostfix) + ndirect + NUM_DISTANCE_SHORT_CODES;
  }

  private static void unpackCommandLookupTable(short[] cmdLookup) {
    final int[] insertLengthOffsets = new int[24];