mariadb/ft/quicklz.cc

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/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
#ident "$Id$"
#ident "Copyright (c) 2007-2012 Tokutek Inc. All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."
// 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.
// 1.5.0 final
#include "quicklz.h"
#if QLZ_VERSION_MAJOR != 1 || QLZ_VERSION_MINOR != 5 || QLZ_VERSION_REVISION != 0
#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 MINOFFSET 2
#define UNCONDITIONAL_MATCHLEN 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
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;
state->hash[i].offset[0] = 0;
#endif
}
}
static void reset_table_decompress(qlz_state_decompress *state)
{
(void)state;
#if QLZ_COMPRESSION_LEVEL == 2
for(int 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;
}
static
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 - UNCOMPRESSED_END;
ui32 fetch = 0;
unsigned int lits = 0;
(void) lits;
if(src <= last_matchstart)
fetch = fast_read(src, 3);
while(src <= last_matchstart)
{
if ((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))))
{
if(cached != 0)
{
#else
if (cached == 0 && o != OFFSET_BASE && (src - o > MINOFFSET || (src == o + 1 && lits >= 3 && src > source + 3 && same(src - 3, 6))))
{
if (*(o + 3) != *(src + 3))
{
#endif
hash <<= 4;
cword_val = (cword_val >> 1) | (1U << 31);
fast_write((3 - 2) | hash, dst, 2);
src += 3;
dst += 2;
}
else
{
const unsigned char *old_src = src;
size_t matchlen;
hash <<= 4;
cword_val = (cword_val >> 1) | (1U << 31);
src += 4;
if(*(o + (src - old_src)) == *src)
{
src++;
if(*(o + (src - old_src)) == *src)
{
size_t q = last_byte - UNCOMPRESSED_END - (src - 5) + 1;
size_t remaining = q > 255 ? 255 : q;
src++;
while(*(o + (src - old_src)) == *src && (size_t)(src - old_src) < remaining)
src++;
}
}
matchlen = src - old_src;
if (matchlen < 18)
{
fast_write((ui32)(matchlen - 2) | hash, dst, 2);
dst += 2;
}
else
{
fast_write((ui32)(matchlen << 16) | hash, dst, 3);
dst += 3;
}
}
fetch = fast_read(src, 3);
lits = 0;
}
else
{
lits++;
*dst = *src;
src++;
dst++;
cword_val = (cword_val >> 1);
#ifdef X86X64
fetch = fast_read(src, 3);
#else
fetch = (fetch >> 8 & 0xffff) | (*(src + 2) << 16);
#endif
}
}
#elif QLZ_COMPRESSION_LEVEL >= 2
{
const unsigned char *o, *offset2;
ui32 hash, matchlen, k, m, best_k = 0;
unsigned char c;
size_t remaining = (last_byte - UNCOMPRESSED_END - src + 1) > 255 ? 255 : (last_byte - UNCOMPRESSED_END - src + 1);
(void)best_k;
//hash = hashat(src);
fetch = fast_read(src, 3);
hash = hash_func(fetch);
c = state->hash_counter[hash];
offset2 = state->hash[hash].offset[0];
if(offset2 < src - MINOFFSET && c > 0 && ((fast_read(offset2, 3) ^ fetch) & 0xffffff) == 0)
{
matchlen = 3;
if(*(offset2 + matchlen) == *(src + matchlen))
{
matchlen = 4;
while(*(offset2 + matchlen) == *(src + matchlen) && matchlen < remaining)
matchlen++;
}
}
else
matchlen = 0;
for(k = 1; k < QLZ_POINTERS && c > k; k++)
{
o = state->hash[hash].offset[k];
#if QLZ_COMPRESSION_LEVEL == 3
if(((fast_read(o, 3) ^ fetch) & 0xffffff) == 0 && o < src - MINOFFSET)
#elif QLZ_COMPRESSION_LEVEL == 2
if(*(src + matchlen) == *(o + matchlen) && ((fast_read(o, 3) ^ fetch) & 0xffffff) == 0 && o < src - MINOFFSET)
#endif
{
m = 3;
while(*(o + m) == *(src + m) && m < remaining)
m++;
#if QLZ_COMPRESSION_LEVEL == 3
if ((m > matchlen) || (m == matchlen && o > offset2))
#elif QLZ_COMPRESSION_LEVEL == 2
if (m > matchlen)
#endif
{
offset2 = o;
matchlen = m;
best_k = k;
}
}
}
o = offset2;
state->hash[hash].offset[c & (QLZ_POINTERS - 1)] = src;
c++;
state->hash_counter[hash] = c;
#if QLZ_COMPRESSION_LEVEL == 3
if(matchlen > 2 && src - o < 131071)
{
ui32 u;
size_t offset = src - o;
for(u = 1; u < matchlen; u++)
{
hash = hashat(src + u);
c = state->hash_counter[hash]++;
state->hash[hash].offset[c & (QLZ_POINTERS - 1)] = src + u;
}
cword_val = (cword_val >> 1) | (1U << 31);
src += matchlen;
if(matchlen == 3 && offset <= 63)
{
*dst = (unsigned char)(offset << 2);
dst++;
}
else if (matchlen == 3 && offset <= 16383)
{
ui32 f = (ui32)((offset << 2) | 1);
fast_write(f, dst, 2);
dst += 2;
}
else if (matchlen <= 18 && offset <= 1023)
{
ui32 f = ((matchlen - 3) << 2) | ((ui32)offset << 6) | 2;
fast_write(f, dst, 2);
dst += 2;
}
else if(matchlen <= 33)
{
ui32 f = ((matchlen - 2) << 2) | ((ui32)offset << 7) | 3;
fast_write(f, dst, 3);
dst += 3;
}
else
{
ui32 f = ((matchlen - 3) << 7) | ((ui32)offset << 15) | 3;
fast_write(f, dst, 4);
dst += 4;
}
}
else
{
*dst = *src;
src++;
dst++;
cword_val = (cword_val >> 1);
}
#elif QLZ_COMPRESSION_LEVEL == 2
if(matchlen > 2)
{
cword_val = (cword_val >> 1) | (1U << 31);
src += matchlen;
if (matchlen < 10)
{
ui32 f = best_k | ((matchlen - 2) << 2) | (hash << 5);
fast_write(f, dst, 2);
dst += 2;
}
else
{
ui32 f = best_k | (matchlen << 16) | (hash << 5);
fast_write(f, dst, 3);
dst += 3;
}
}
else
{
*dst = *src;
src++;
dst++;
cword_val = (cword_val >> 1);
}
#endif
}
#endif
}
while (src <= last_byte)
{
if ((cword_val & 1) == 1)
{
fast_write((cword_val >> 1) | (1U << 31), cword_ptr, CWORD_LEN);
cword_ptr = dst;
dst += CWORD_LEN;
cword_val = 1U << 31;
}
#if QLZ_COMPRESSION_LEVEL < 3
if (src <= last_byte - 3)
{
#if QLZ_COMPRESSION_LEVEL == 1
ui32 hash, fetchv;
fetchv = fast_read(src, 3);
hash = hash_func(fetch);
state->hash[hash].offset = CAST(src - OFFSET_BASE);
state->hash[hash].cache = fetchv;
#elif QLZ_COMPRESSION_LEVEL == 2
ui32 hash;
unsigned char c;
hash = hashat(src);
c = state->hash_counter[hash];
state->hash[hash].offset[c & (QLZ_POINTERS - 1)] = src;
c++;
state->hash_counter[hash] = c;
#endif
}
#endif
*dst = *src;
src++;
dst++;
cword_val = (cword_val >> 1);
}
while((cword_val & 1) != 1)
cword_val = (cword_val >> 1);
fast_write((cword_val >> 1) | (1U << 31), cword_ptr, CWORD_LEN);
// min. size must be 9 bytes so that the qlz_size functions can take 9 bytes as argument
return dst - destination < 9 ? 9 : dst - destination;
}
static size_t qlz_decompress_core(const unsigned char *source, unsigned char *destination, size_t size, qlz_state_decompress *state, const unsigned char *history)
{
const unsigned char *src = source + qlz_size_header((const char *)source);
unsigned char *dst = destination;
const unsigned char *last_destination_byte = destination + size - 1;
ui32 cword_val = 1;
const unsigned char *last_matchstart = last_destination_byte - UNCONDITIONAL_MATCHLEN - UNCOMPRESSED_END;
unsigned char *last_hashed = destination - 1;
const unsigned char *last_source_byte = source + qlz_size_compressed((const char *)source) - 1;
static const ui32 bitlut[16] = {4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0};
(void) last_source_byte;
(void) last_hashed;
(void) state;
(void) history;
for(;;)
{
ui32 fetch;
if (cword_val == 1)
{
#ifdef QLZ_MEMORY_SAFE
if(src + CWORD_LEN - 1 > last_source_byte)
return 0;
#endif
cword_val = fast_read(src, CWORD_LEN);
src += CWORD_LEN;
}
#ifdef QLZ_MEMORY_SAFE
if(src + 4 - 1 > last_source_byte)
return 0;
#endif
fetch = fast_read(src, 4);
if ((cword_val & 1) == 1)
{
ui32 matchlen;
const unsigned char *offset2;
#if QLZ_COMPRESSION_LEVEL == 1
ui32 hash;
cword_val = cword_val >> 1;
hash = (fetch >> 4) & 0xfff;
offset2 = (const unsigned char *)(size_t)state->hash[hash].offset;
if((fetch & 0xf) != 0)
{
matchlen = (fetch & 0xf) + 2;
src += 2;
}
else
{
matchlen = *(src + 2);
src += 3;
}
#elif QLZ_COMPRESSION_LEVEL == 2
ui32 hash;
unsigned char c;
cword_val = cword_val >> 1;
hash = (fetch >> 5) & 0x7ff;
c = (unsigned char)(fetch & 0x3);
offset2 = state->hash[hash].offset[c];
if((fetch & (28)) != 0)
{
matchlen = ((fetch >> 2) & 0x7) + 2;
src += 2;
}
else
{
matchlen = *(src + 2);
src += 3;
}
#elif QLZ_COMPRESSION_LEVEL == 3
ui32 offset;
cword_val = cword_val >> 1;
if ((fetch & 3) == 0)
{
offset = (fetch & 0xff) >> 2;
matchlen = 3;
src++;
}
else if ((fetch & 2) == 0)
{
offset = (fetch & 0xffff) >> 2;
matchlen = 3;
src += 2;
}
else if ((fetch & 1) == 0)
{
offset = (fetch & 0xffff) >> 6;
matchlen = ((fetch >> 2) & 15) + 3;
src += 2;
}
else if ((fetch & 127) != 3)
{
offset = (fetch >> 7) & 0x1ffff;
matchlen = ((fetch >> 2) & 0x1f) + 2;
src += 3;
}
else
{
offset = (fetch >> 15);
matchlen = ((fetch >> 7) & 255) + 3;
src += 4;
}
offset2 = dst - offset;
#endif
#ifdef QLZ_MEMORY_SAFE
if(offset2 < history || offset2 > dst - MINOFFSET - 1)
return 0;
if(matchlen > (ui32)(last_destination_byte - dst - UNCOMPRESSED_END + 1))
return 0;
#endif
memcpy_up(dst, offset2, matchlen);
dst += matchlen;
#if QLZ_COMPRESSION_LEVEL <= 2
update_hash_upto(state, &last_hashed, dst - matchlen);
last_hashed = dst - 1;
#endif
}
else
{
if (dst < last_matchstart)
{
unsigned int n = bitlut[cword_val & 0xf];
#ifdef X86X64
*(ui32 *)dst = *(ui32 *)src;
#else
memcpy_up(dst, src, 4);
#endif
cword_val = cword_val >> n;
dst += n;
src += n;
#if QLZ_COMPRESSION_LEVEL <= 2
update_hash_upto(state, &last_hashed, dst - 3);
#endif
}
else
{
while(dst <= last_destination_byte)
{
if (cword_val == 1)
{
src += CWORD_LEN;
cword_val = 1U << 31;
}
#ifdef QLZ_MEMORY_SAFE
if(src >= last_source_byte + 1)
return 0;
#endif
*dst = *src;
dst++;
src++;
cword_val = cword_val >> 1;
}
#if QLZ_COMPRESSION_LEVEL <= 2
update_hash_upto(state, &last_hashed, last_destination_byte - 3); // todo, use constant
#endif
return size;
}
}
}
}
size_t qlz_compress(const void *source, char *destination, size_t size, qlz_state_compress *state)
{
size_t r;
ui32 compressed;
size_t base;
if(size == 0 || size > 0xffffffff - 400)
return 0;
if(size < 216)
base = 3;
else
base = 9;
#if QLZ_STREAMING_BUFFER > 0
if (state->stream_counter + size - 1 >= QLZ_STREAMING_BUFFER)
#endif
{
reset_table_compress(state);
r = base + qlz_compress_core((const unsigned char *)source, (unsigned char*)destination + base, size, state);
#if QLZ_STREAMING_BUFFER > 0
reset_table_compress(state);
#endif
if(r == base)
{
memcpy(destination + base, source, size);
r = size + base;
compressed = 0;
}
else
{
compressed = 1;
}
state->stream_counter = 0;
}
#if QLZ_STREAMING_BUFFER > 0
else
{
unsigned char *src = state->stream_buffer + state->stream_counter;
memcpy(src, source, size);
r = base + qlz_compress_core(src, (unsigned char*)destination + base, size, state);
if(r == base)
{
memcpy(destination + base, src, size);
r = size + base;
compressed = 0;
reset_table_compress(state);
}
else
{
compressed = 1;
}
state->stream_counter += size;
}
#endif
if(base == 3)
{
*destination = (unsigned char)(0 | compressed);
*(destination + 1) = (unsigned char)r;
*(destination + 2) = (unsigned char)size;
}
else
{
*destination = (unsigned char)(2 | compressed);
fast_write((ui32)r, destination + 1, 4);
fast_write((ui32)size, destination + 5, 4);
}
*destination |= (QLZ_COMPRESSION_LEVEL << 2);
*destination |= (1 << 6);
*destination |= ((QLZ_STREAMING_BUFFER == 0 ? 0 : (QLZ_STREAMING_BUFFER == 100000 ? 1 : (QLZ_STREAMING_BUFFER == 1000000 ? 2 : 3))) << 4);
// 76543210
// 01SSLLHC
return r;
}
size_t qlz_decompress(const char *source, void *destination, qlz_state_decompress *state)
{
size_t dsiz = qlz_size_decompressed(source);
#if QLZ_STREAMING_BUFFER > 0
if (state->stream_counter + qlz_size_decompressed(source) - 1 >= QLZ_STREAMING_BUFFER)
#endif
{
if((*source & 1) == 1)
{
reset_table_decompress(state);
dsiz = qlz_decompress_core((const unsigned char *)source, (unsigned char *)destination, dsiz, state, (const unsigned char *)destination);
}
else
{
memcpy(destination, source + qlz_size_header(source), dsiz);
}
state->stream_counter = 0;
reset_table_decompress(state);
}
#if QLZ_STREAMING_BUFFER > 0
else
{
unsigned char *dst = state->stream_buffer + state->stream_counter;
if((*source & 1) == 1)
{
dsiz = qlz_decompress_core((const unsigned char *)source, dst, dsiz, state, (const unsigned char *)state->stream_buffer);
}
else
{
memcpy(dst, source + qlz_size_header(source), dsiz);
reset_table_decompress(state);
}
memcpy(destination, dst, dsiz);
state->stream_counter += dsiz;
}
#endif
return dsiz;
}