public void update()

in src/main/java/org/apache/commons/codec/digest/PureJavaCrc32.java [599:630]

• 25 lines of code
• 9 McCabe index (conditional complexity)

  public void update(final byte[] b, final int offset, final int len) {
    int localCrc = crc;

    final int remainder = len & 0x7;
    int i = offset;
    for(final int end = offset + len - remainder; i < end; i += 8) {
      final int x = localCrc ^
          ((((b[i  ] << 24) >>> 24) + ((b[i+1] << 24) >>> 16)) +
          (((b[i+2] << 24) >>> 8 ) +  (b[i+3] << 24)));

      localCrc = ((T[((x << 24) >>> 24) + 0x700] ^ T[((x << 16) >>> 24) + 0x600]) ^
                 (T[((x <<  8) >>> 24) + 0x500] ^ T[ (x        >>> 24) + 0x400])) ^
                 ((T[((b[i+4] << 24) >>> 24) + 0x300] ^ T[((b[i+5] << 24) >>> 24) + 0x200]) ^
                 (T[((b[i+6] << 24) >>> 24) + 0x100] ^ T[((b[i+7] << 24) >>> 24)]));
    }

    /* loop unroll - duff's device style */
    switch(remainder) {
      case 7: localCrc = (localCrc >>> 8) ^ T[((localCrc ^ b[i++]) << 24) >>> 24];
      case 6: localCrc = (localCrc >>> 8) ^ T[((localCrc ^ b[i++]) << 24) >>> 24];
      case 5: localCrc = (localCrc >>> 8) ^ T[((localCrc ^ b[i++]) << 24) >>> 24];
      case 4: localCrc = (localCrc >>> 8) ^ T[((localCrc ^ b[i++]) << 24) >>> 24];
      case 3: localCrc = (localCrc >>> 8) ^ T[((localCrc ^ b[i++]) << 24) >>> 24];
      case 2: localCrc = (localCrc >>> 8) ^ T[((localCrc ^ b[i++]) << 24) >>> 24];
      case 1: localCrc = (localCrc >>> 8) ^ T[((localCrc ^ b[i++]) << 24) >>> 24];
      default:
        /* nothing */
    }

    // Publish crc out to object
    crc = localCrc;
  }