pcompress/utils.h
Moinak Ghosh 7ff2cb74c4 Increase the small size slabs a bit.
Move 64Bit integer hashing function to common file for use in other places.
2012-07-29 15:02:51 +05:30

159 lines
4.2 KiB
C

/*
* This file is a part of Pcompress, a chunked parallel multi-
* algorithm lossless compression and decompression program.
*
* Copyright (C) 2012 Moinak Ghosh. All rights reserved.
* Use is subject to license terms.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 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
* Lesser General Public License for more details.
*
* moinakg@belenix.org, http://moinakg.wordpress.com/
*
* This program includes partly-modified public domain source
* code from the LZMA SDK: http://www.7-zip.org/sdk.html
*/
#ifndef _UTILS_H
#define _UTILS_H
#include <arpa/nameser_compat.h>
#include <sys/types.h>
#ifdef __cplusplus
extern "C" {
#endif
#define DATA_TEXT 1
#define DATA_BINARY 2
#if !defined(sun) && !defined(__sun)
#define ulong_t u_long
#define uchar_t u_char
#define uint8_t u_char
#define uint64_t u_int64_t
#define uint32_t u_int32_t
#endif
#if ULONG_MAX == 4294967295UL
# ifndef UINT64_C
# define UINT64_C(n) n ## ULL
# endif
#else
# ifndef UINT64_C
# define UINT64_C(n) n ## UL
# endif
#endif
typedef unsigned long uintptr_t;
typedef ssize_t bsize_t;
#undef WORDS_BIGENDIAN
#if BYTE_ORDER == BIG_ENDIAN
# define WORDS_BIGENDIAN
# ifndef htonll
# define htonll(x) (x)
# endif
# ifndef ntonll
# define ntohll(x) (x)
# endif
#else
# if !defined(sun) && !defined (__sun)
# ifndef htonll
# define htonll(x) __bswap_64(x)
# endif
# ifndef ntohll
# define ntohll(x) __bswap_64(x)
# endif
# endif
#endif
// These allow helping the compiler in some often-executed branches, whose
// result is almost always the same.
#ifdef __GNUC__
# define likely(expr) __builtin_expect(expr, 1)
# define unlikely(expr) __builtin_expect(expr, 0)
# define ATOMIC_ADD(var, val) __sync_fetch_and_add(&var, val)
# define ATOMIC_SUB(var, val) __sync_fetch_and_sub(&var, val)
#else
# define likely(expr) (expr)
# define unlikely(expr) (expr)
# if defined(sun) || defined (__sun)
# include <atomic.h>
# define ATOMIC_ADD(var, val) atomic_add_int(&var, val)
# define ATOMIC_SUB(var, val) atomic_add_int(&var, -val)
# else
// Dunno what to do
# define ATOMIC_ADD(var, val) var += val
# define ATOMIC_SUB(var, val) var -= val
# endif
#endif
#define ISP2(x) ((x != 0) && ((x & (~x + 1)) == x))
extern void err_exit(int show_errno, const char *format, ...);
extern const char *get_execname(const char *);
extern int parse_numeric(ssize_t *val, const char *str);
extern char *bytes_to_size(uint64_t bytes);
extern ssize_t Read(int fd, void *buf, size_t count);
extern ssize_t Read_Adjusted(int fd, uchar_t *buf, size_t count,
ssize_t *rabin_count, void *ctx);
extern ssize_t Write(int fd, const void *buf, size_t count);
/* Pointer type for compress and decompress functions. */
typedef int (*compress_func_ptr)(void *src, size_t srclen, void *dst,
size_t *destlen, int level, uchar_t chdr, void *data);
/* Pointer type for algo specific init/deinit/stats functions. */
typedef int (*init_func_ptr)(void **data, int *level, ssize_t chunksize);
typedef int (*deinit_func_ptr)(void **data);
typedef void (*stats_func_ptr)(int show);
/*
* Roundup v to the nearest power of 2. From Bit Twiddling Hacks:
* http://graphics.stanford.edu/~seander/bithacks.html
*/
static inline unsigned int
roundup_pow_two(unsigned int v) {
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
v++;
return (v);
}
/*
* Hash function for 64Bit pointers/numbers that generates
* a 32Bit hash value.
* Taken from Thomas Wang's Integer hashing paper:
* http://www.cris.com/~Ttwang/tech/inthash.htm
*/
static uint32_t
hash6432shift(uint64_t key)
{
key = (~key) + (key << 18); // key = (key << 18) - key - 1;
key = key ^ (key >> 31);
key = key * 21; // key = (key + (key << 2)) + (key << 4);
key = key ^ (key >> 11);
key = key + (key << 6);
key = key ^ (key >> 22);
return (uint32_t) key;
}
#ifdef __cplusplus
}
#endif
#endif