mongo/lang/java/src/com/wiredtiger/db/PackUtil.java

package com.wiredtiger.db;

import java.lang.String;

/*
 * Package-private - not part of the public API.
 */
class PackUtil {
    /* Contants. */
    final static byte NEG_MULTI_MARKER = (byte)0x10;
    final static byte NEG_2BYTE_MARKER = (byte)0x20;
    final static byte NEG_1BYTE_MARKER = (byte)0x40;
    final static byte POS_1BYTE_MARKER = (byte)0x80;
    final static byte POS_2BYTE_MARKER = (byte)0xc0;
    final static byte POS_MULTI_MARKER = (byte)0xe0;

    final static int NEG_1BYTE_MIN = ((-1) << 6);
    final static int NEG_2BYTE_MIN = (((-1) << 13) + NEG_1BYTE_MIN);
    final static int POS_1BYTE_MAX = ((1 << 6) - 1);
    final static int POS_2BYTE_MAX = ((1 << 13) + POS_1BYTE_MAX);

    // See: http://docs.python.org/2/library/struct.html for an explanation
    // of what these special characters mean.
    // TODO: Care about byte ordering and padding in packed formats.
    final static String PackSpecialCharacters = "@=<>!x";

    final static int SIZEOF_LONG = 8;

    /*
     * Extract bits <start> to <end> from a value (counting from LSB == 0).
     */
    public static byte GET_BITS(long x, int start, int end) {
        return (byte)((x & ((1 << start) - 1)) >> end);
    }


}