static long decTwoBytePrimaryByOneStep(long basePrimary, boolean isCompressible, int step) {
        // Extract the second byte, minus the minimum byte value,
        // minus the step, modulo the number of usable byte values, plus the minimum.
        // Reserve the PRIMARY_COMPRESSION_LOW_BYTE and high byte if necessary.
        // Assume no further underflow for the first byte.
        assert(0 < step && step <= 0x7f);
        int byte2 = ((int)(basePrimary >> 16) & 0xff) - step;
        if(isCompressible) {
            if(byte2 < 4) {
                byte2 += 251;
                basePrimary -= 0x1000000;
            }
        } else {
            if(byte2 < 2) {
                byte2 += 254;
                basePrimary -= 0x1000000;
            }
        }
        return (basePrimary & 0xff000000L) | (byte2 << 16);
    }
static long decTwoBytePrimaryByOneStep ( long basePrimary , boolean isCompressible , int step ) { assert ( 0 < step && step <= 0x7f ) ; int byte2 = ( ( int ) ( basePrimary > > 16 ) & 0xff ) - step ; if ( isCompressible ) { if ( byte2 < 4 ) { byte2 += 251 ; basePrimary -= 0x1000000 ; } } else { if ( byte2 < 2 ) { byte2 += 254 ; basePrimary -= 0x1000000 ; } } return ( basePrimary & 0xff000000L ) | ( byte2 << 16 ) ; }
Decrements a 2-byte primary by one range step (1..0x7f).