// Fast data compression library
// Copyright (C) 2006-2011 Lasse Mikkel Reinhold
// lar@quicklz.com
//
// QuickLZ can be used for FREE under the GPL 1, 2 or 3 license (where anything
// released into public must be open source) or under a commercial license if such
// has been acquired (see http://www.quicklz.com/order.html). The commercial license
// does not cover derived or ported versions created by third parties under GPL.
// 1.5.1 BETA 7
#include "quicklz.h"
#if defined _MSC_VER
#include <intrin.h>
#endif
#if QLZ_VERSION_MAJOR != 1 || QLZ_VERSION_MINOR != 5 || QLZ_VERSION_REVISION != 1
#error quicklz.c and quicklz.h have different versions
#endif
#if (defined(__X86__) || defined(__i386__) || defined(i386) || defined(_M_IX86) || defined(__386__) || defined(__x86_64__) || defined(_M_X64))
#define X86X64
#endif
#define __inline
#define MINOFFSET 2
#define UNCONDITIONAL_MATCHLEN_COMPRESSOR 12
#define UNCONDITIONAL_MATCHLEN_DECOMPRESSOR 6
#define UNCOMPRESSED_END 4
#define CWORD_LEN 4
#if QLZ_COMPRESSION_LEVEL == 1 && defined QLZ_PTR_64 && QLZ_STREAMING_BUFFER == 0
#define OFFSET_BASE source
#define CAST (ui32)(size_t)
#else
#define OFFSET_BASE 0
#define CAST
#endif
#if defined(X86X64) && (defined(__GNUC__) || defined(__INTEL_COMPILER))
#define qlz_likely(x) __builtin_expect (x, 1)
#define qlz_unlikely(x) __builtin_expect (x, 0)
#else
#define qlz_likely(x) (x)
#define qlz_unlikely(x) (x)
#endif
int qlz_get_setting(int setting)
{
switch (setting)
{
case 0: return QLZ_COMPRESSION_LEVEL;
case 1: return sizeof(qlz_state_compress);
case 2: return sizeof(qlz_state_decompress);
case 3: return QLZ_STREAMING_BUFFER;
#ifdef QLZ_MEMORY_SAFE
case 6: return 1;
#else
case 6: return 0;
#endif
case 7: return QLZ_VERSION_MAJOR;
case 8: return QLZ_VERSION_MINOR;
case 9: return QLZ_VERSION_REVISION;
}
return -1;
}
#if QLZ_COMPRESSION_LEVEL == 1
static int same(const unsigned char *src, size_t n)
{
while(n > 0 && *(src + n) == *src)
n--;
return n == 0 ? 1 : 0;
}
#endif
static void reset_table_compress(qlz_state_compress *state)
{
int i;
for(i = 0; i < QLZ_HASH_VALUES; i++)
{
#if QLZ_COMPRESSION_LEVEL == 1
state->hash[i].offset = 0;
#else
state->hash_counter[i] = 0;
#endif
}
}
static void reset_table_decompress(qlz_state_decompress *state)
{
int i;
(void)state;
(void)i;
#if QLZ_COMPRESSION_LEVEL == 2
for(i = 0; i < QLZ_HASH_VALUES; i++)
{
state->hash_counter[i] = 0;
}
#endif
}
static __inline ui32 hash_func(ui32 i)
{
#if QLZ_COMPRESSION_LEVEL == 2
return ((i >> 9) ^ (i >> 13) ^ i) & (QLZ_HASH_VALUES - 1);
#else
return ((i >> 12) ^ i) & (QLZ_HASH_VALUES - 1);
#endif
}
static __inline ui32 fast_read(void const *src, ui32 bytes)
{
#ifndef X86X64
unsigned char *p = (unsigned char*)src;
switch (bytes)
{
case 4:
return(*p | *(p + 1) << 8 | *(p + 2) << 16 | *(p + 3) << 24);
case 3:
return(*p | *(p + 1) << 8 | *(p + 2) << 16);
case 2:
return(*p | *(p + 1) << 8);
case 1:
return(*p);
}
return 0;
#else
if (bytes >= 1 && bytes <= 4)
return *((ui32*)src);
else
return 0;
#endif
}
static __inline ui32 hashat(const unsigned char *src)
{
ui32 fetch, hash;
fetch = fast_read(src, 3);
hash = hash_func(fetch);
return hash;
}
static __inline void fast_write(ui32 f, void *dst, size_t bytes)
{
#ifndef X86X64
unsigned char *p = (unsigned char*)dst;
switch (bytes)
{
case 4:
*p = (unsigned char)f;
*(p + 1) = (unsigned char)(f >> 8);
*(p + 2) = (unsigned char)(f >> 16);
*(p + 3) = (unsigned char)(f >> 24);
return;
case 3:
*p = (unsigned char)f;
*(p + 1) = (unsigned char)(f >> 8);
*(p + 2) = (unsigned char)(f >> 16);
return;
case 2:
*p = (unsigned char)f;
*(p + 1) = (unsigned char)(f >> 8);
return;
case 1:
*p = (unsigned char)f;
return;
}
#else
switch (bytes)
{
case 4:
*((ui32*)dst) = f;
return;
case 3:
*((ui32*)dst) = f;
return;
case 2:
*((ui16 *)dst) = (ui16)f;
return;
case 1:
*((unsigned char*)dst) = (unsigned char)f;
return;
}
#endif
}
size_t qlz_size_decompressed(const char *source)
{
ui32 n, r;
n = (((*source) & 2) == 2) ? 4 : 1;
r = fast_read(source + 1 + n, n);
r = r & (0xffffffff >> ((4 - n)*8));
return r;
}
size_t qlz_size_compressed(const char *source)
{
ui32 n, r;
n = (((*source) & 2) == 2) ? 4 : 1;
r = fast_read(source + 1, n);
r = r & (0xffffffff >> ((4 - n)*8));
return r;
}
size_t qlz_size_header(const char *source)
{
size_t n = 2*((((*source) & 2) == 2) ? 4 : 1) + 1;
return n;
}
static __inline void memcpy_up(unsigned char *dst, const unsigned char *src, ui32 n)
{
// Caution if modifying memcpy_up! Overlap of dst and src must be special handled.
#ifndef X86X64
unsigned char *end = dst + n;
while(dst < end)
{
*dst = *src;
dst++;
src++;
}
#else
ui32 f = 0;
do
{
*(ui32 *)(dst + f) = *(ui32 *)(src + f);
f += MINOFFSET + 1;
}
while (f < n);
#endif
}
static __inline void update_hash(qlz_state_decompress *state, const unsigned char *s)
{
#if QLZ_COMPRESSION_LEVEL == 1
ui32 hash;
hash = hashat(s);
state->hash[hash].offset = s;
state->hash_counter[hash] = 1;
#elif QLZ_COMPRESSION_LEVEL == 2
ui32 hash;
unsigned char c;
hash = hashat(s);
c = state->hash_counter[hash];
state->hash[hash].offset[c & (QLZ_POINTERS - 1)] = s;
c++;
state->hash_counter[hash] = c;
#endif
(void)state;
(void)s;
}
#if QLZ_COMPRESSION_LEVEL <= 2
static void update_hash_upto(qlz_state_decompress *state, unsigned char **lh, const unsigned char *max)
{
while(*lh < max)
{
(*lh)++;
update_hash(state, *lh);
}
}
#endif
static size_t qlz_compress_core(const unsigned char *source, unsigned char *destination, size_t size, qlz_state_compress *state)
{
const unsigned char *last_byte = source + size - 1;
const unsigned char *src = source;
unsigned char *cword_ptr = destination;
unsigned char *dst = destination + CWORD_LEN;
ui32 cword_val = 1U << 31;
const unsigned char *last_matchstart = last_byte - UNCONDITIONAL_MATCHLEN_COMPRESSOR - UNCOMPRESSED_END;
ui32 fetch = 0;
unsigned int lits = 0;
(void) lits;
if(src <= last_matchstart)
fetch = fast_read(src, 3);
while(qlz_likely(src <= last_matchstart))
{
if (qlz_unlikely( (cword_val & 1) == 1))
{
// store uncompressed if compression ratio is too low
if (src > source + (size >> 1) && dst - destination > src - source - ((src - source) >> 5))
return 0;
fast_write((cword_val >> 1) | (1U << 31), cword_ptr, CWORD_LEN);
cword_ptr = dst;
dst += CWORD_LEN;
cword_val = 1U << 31;
fetch = fast_read(src, 3);
}
#if QLZ_COMPRESSION_LEVEL == 1
{
const unsigned char *o;
ui32 hash, cached;
hash = hash_func(fetch);
cached = fetch ^ state->hash[hash].cache;
state->hash[hash].cache = fetch;
o = state->hash[hash].offset + OFFSET_BASE;
state->hash[hash].offset = CAST(src - OFFSET_BASE);
#ifdef X86X64
if ((cached & 0xffffff) == 0 && o != OFFSET_BASE && (src - o > MINOFFSET || (src == o + 1 && lits >= 3 && src > source + 3 && same(src - 3, 6))))
{
#else
if (cached == 0 && o != OFFSET_BASE && (src - o > MINOFFSET || (src == o + 1 && lits >= 3 && src > source + 3 && same(src - 3, 6))))
{
#endif
size_t matchlen = 3;
hash <<= 4;
cword_val = (cword_val >> 1) | (1U << 31);
#if defined X86X64 && defined QLZ_PTR_64
{
#ifdef __GNUC__
unsigned long long a = *(unsigned long long *)(src + matchlen);
unsigned long long b = *(unsigned long long *)(o + matchlen);
unsigned long long c = a^b;
#else
unsigned int a = *(unsigned int *)(src + matchlen);
unsigned int b = *(unsigned int *)(o + matchlen);
unsigned int
