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/*-
* Public Domain 2014-2016 MongoDB, Inc.
* Public Domain 2008-2014 WiredTiger, Inc.
*
* This is free and unencumbered software released into the public domain.
*
* Anyone is free to copy, modify, publish, use, compile, sell, or
* distribute this software, either in source code form or as a compiled
* binary, for any purpose, commercial or non-commercial, and by any
* means.
*
* In jurisdictions that recognize copyright laws, the author or authors
* of this software dedicate any and all copyright interest in the
* software to the public domain. We make this dedication for the benefit
* of the public at large and to the detriment of our heirs and
* successors. We intend this dedication to be an overt act of
* relinquishment in perpetuity of all present and future rights to this
* software under copyright law.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
package com.wiredtiger.db;
import java.lang.String;
/**
* An internal helper class with utilities for packing and unpacking values.
*
* Applications should not need to use this class.
*/
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 from a value, counting from LSB == 0.
*
* \param x The value to extract bits from.
* \param start The first bit to extract.
* \param end The last bit to extract.
*/
public static byte GET_BITS(long x, int start, int end) {
return (byte)((x & ((1 << start) - 1)) >> end);
}
}
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