Method memcmp

src/Bytes.java:536–547

memcmp in Java, hooray. @param a First non-null byte array to compare. @param b Second non-null byte array to compare. @return 0 if the two arrays are identical, otherwise the difference between the first two different bytes, otherwise the different between their lengths.

(final byte[] a, final byte[] b)

   * their lengths.
   */
  public static int memcmp(final byte[] a, final byte[] b) {
    final int length = Math.min(a.length, b.length);
    if (a == b) {  // Do this after accessing a.length and b.length
      return 0;    // in order to NPE if either a or b is null.
    }
    for (int i = 0; i < length; i++) {
      if (a[i] != b[i]) {
        return (a[i] & 0xFF) - (b[i] & 0xFF);  // "promote" to unsigned.
      }
    }
    return a.length - b.length;
  }

  /**
   * {@code memcmp(3)} with a given offset and length.