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TurboPFor-Integer-Compression/vint.h
2015-01-05 23:13:49 +01:00

89 lines
4.7 KiB
C

/**
Copyright (C) powturbo 2013-2014
GPL v2 License
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
- email : powturbo [AT] gmail.com
- github : https://github.com/powturbo
- homepage : https://sites.google.com/site/powturbo/
- twitter : https://twitter.com/powturbo
vint.h - "Integer Compression" variable byte
**/
#ifndef VINT_H
#define VINT_H
#include "conf.h"
#ifdef __cplusplus
extern "C" {
#endif
//-------------------------------------- variable byte : 32 bits ----------------------------------------------------------------
#define vbvlen(__x) vtab[(__x)&0xf]
#define vbputa(__op, __x, __act) {\
if(likely(__x < (1<< 7))) { *__op++ = __x << 1; __act;}\
else if(likely(__x < (1<<14))) { *(unsigned short *)__op = __x << 2 | 0x01; __op += 2; __act;}\
else if(likely(__x < (1<<21))) { *(unsigned short *)__op = __x << 3 | 0x03; __op += 2; *__op++ = __x >> 13; __act;}\
else if(likely(__x < (1<<28))) { *(unsigned *)__op = __x << 4 | 0x07; __op += 4; __act;}\
else { *(unsigned *)__op = __x << 4 | 0x0f; __op += 4; *__op++ = __x >> 28; __act;}\
}
#define vbgeta(__ip, __x, __act) do { __x = *__ip;\
if(!(__x & (1<<0))) { __x >>= 1; __ip++; __act;}\
else if(!(__x & (1<<1))) { __x = (*(unsigned short *)__ip) >> 2; __ip += 2; __act;}\
else if(!(__x & (1<<2))) { __x = (*(unsigned short *)__ip) >> 3 | *(__ip+2) << 13; __ip += 3; __act;}\
else if(!(__x & (1<<3))) { __x = (*(unsigned *)__ip) >> 4; __ip += 4; __act;}\
else { __x = (*(unsigned *)__ip) >> 4 | *(__ip+4) << 28; __ip += 5; __act;}\
} while(0)
//------------------------------------------------------------------------------------------------------------------------
//0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111
static unsigned char vtab[]= { 1, 2, 1, 3, 1, 2, 1, 4, 1, 2, 1, 3, 1, 2, 1, 5 };
// Length of uncompress value. Input __x is the compressed buffer start
// Length in bytes of compressed "__x" when using variable byte
#define vblen(__x) ({ unsigned _x = __x; _x > 0x7f?(_x > 0x3fff?(_x > 0x1fffff?(_x > 0x0fffffff?5:4):3):2):1; })
// compress single value
#define vbput(__op, __x) { unsigned _x__ = __x; vbputa(__op, _x__, ;); }
// decompress single value
#define vbget(__ip) ({ unsigned _x_; vbgeta(__ip, _x_, ;); _x_; })
// compress array with n unsigned (32 bits in[n]) values to the buffer out. Return value = end of compressed buffer out
static inline unsigned char *vbenc (unsigned *__restrict in, int n, unsigned char *__restrict out) { unsigned *in_ = in +n; while(in < in_) vbput(out, *in++); return out;}
// decompress buffer into an array of n unsigned values. Return value = end of decompressed buffer in
static inline unsigned char *vbdec (unsigned char *__restrict in, int n, unsigned *__restrict out) { unsigned *out_ = out+n,x; while(out < out_) vbgeta(in, x, *out++ = x); return in;}
//--------------------------------------- variable byte : 15 bits -------------------------------------------------------------------
#define vbput16(__op, __x) do { unsigned _x = __x; if(likely(_x < 0x80)) *__op++ = _x; else { *__op++ = (_x) >> 8 | 0x80; *__op++ = _x; } } while(0)
#define vbgeta16(__ip,__x, __act) do { if((__x = *__ip++) > 0x7f) __x = (__x & 0x7f) << 8 | *__ip++; __act; } while(0)
#define vblen16(__x) ((__x) > 0x7f?2:1)
#define vbget16(__ip) ({ unsigned _x; vbgeta16(__ip, _x, ;); _x; })
// like vbenc32 but for 16 bits values
static inline unsigned char *vbenc16(unsigned short *__restrict in, int n, unsigned char *__restrict out) { unsigned short *in_ = in +n; while(in < in_) vbput16(out, *in++); return out;}
// like vbdec32 but for 16 bits values
static inline unsigned char *vbdec16(unsigned char *__restrict in, int n, unsigned short *__restrict out) { unsigned short *out_ = out+n,x; while(out < out_) vgeta16(in, x, *out++ = x); return in; }
#ifdef __cplusplus
}
#endif
#endif