p7zip-rar/CPP/7zip/Compress/LzmsDecoder.cpp
2017-10-11 12:40:22 +02:00

577 lines
13 KiB
C++

// LzmsDecoder.cpp
// The code is based on LZMS description from wimlib code
#include "StdAfx.h"
#include "../../../C/Alloc.h"
#include "LzmsDecoder.h"
namespace NCompress {
namespace NLzms {
static UInt32 g_PosBases[k_NumPosSyms /* + 1 */];
static Byte g_PosDirectBits[k_NumPosSyms];
static const Byte k_PosRuns[31] =
{
8, 0, 9, 7, 10, 15, 15, 20, 20, 30, 33, 40, 42, 45, 60, 73,
80, 85, 95, 105, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
};
static UInt32 g_LenBases[k_NumLenSyms];
static const Byte k_LenDirectBits[k_NumLenSyms] =
{
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2,
2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 6,
7, 8, 9, 10, 16, 30,
};
static struct CInit
{
CInit()
{
{
unsigned sum = 0;
for (unsigned i = 0; i < sizeof(k_PosRuns); i++)
{
unsigned t = k_PosRuns[i];
for (unsigned y = 0; y < t; y++)
g_PosDirectBits[sum + y] = (Byte)i;
sum += t;
}
}
{
UInt32 sum = 1;
for (unsigned i = 0; i < k_NumPosSyms; i++)
{
g_PosBases[i] = sum;
sum += (UInt32)1 << g_PosDirectBits[i];
}
// g_PosBases[k_NumPosSyms] = sum;
}
{
UInt32 sum = 1;
for (unsigned i = 0; i < k_NumLenSyms; i++)
{
g_LenBases[i] = sum;
sum += (UInt32)1 << k_LenDirectBits[i];
}
}
}
} g_Init;
static unsigned GetNumPosSlots(size_t size)
{
if (size < 2)
return 0;
size--;
if (size >= g_PosBases[k_NumPosSyms - 1])
return k_NumPosSyms;
unsigned left = 0;
unsigned right = k_NumPosSyms;
for (;;)
{
unsigned m = (left + right) / 2;
if (left == m)
return m + 1;
if (size >= g_PosBases[m])
left = m;
else
right = m;
}
}
static const Int32 k_x86_WindowSize = 65535;
static const Int32 k_x86_TransOffset = 1023;
static const size_t k_x86_HistorySize = (1 << 16);
static void x86_Filter(Byte *data, UInt32 size, Int32 *history)
{
if (size <= 17)
return;
Byte isCode[256];
memset(isCode, 0, 256);
isCode[0x48] = 1;
isCode[0x4C] = 1;
isCode[0xE8] = 1;
isCode[0xE9] = 1;
isCode[0xF0] = 1;
isCode[0xFF] = 1;
{
for (size_t i = 0; i < k_x86_HistorySize; i++)
history[i] = -(Int32)k_x86_WindowSize - 1;
}
size -= 16;
const unsigned kSave = 6;
const Byte savedByte = data[size + kSave];
data[size + kSave] = 0xE8;
Int32 last_x86_pos = -k_x86_TransOffset - 1;
// first byte is ignored
Int32 i = 0;
for (;;)
{
const Byte *p = data + (UInt32)i;
for (;;)
{
if (isCode[*(++p)]) break;
if (isCode[*(++p)]) break;
}
i = (Int32)(p - data);
if ((UInt32)i >= size)
break;
UInt32 codeLen;
Int32 maxTransOffset = k_x86_TransOffset;
Byte b = p[0];
if (b == 0x48)
{
if (p[1] == 0x8B)
{
if ((p[2] & 0xF7) != 0x5)
continue;
// MOV RAX / RCX, [RIP + disp32]
}
else if (p[1] == 0x8D) // LEA
{
if ((p[2] & 0x7) != 0x5)
continue;
// LEA R**, []
}
else
continue;
codeLen = 3;
}
else if (b == 0x4C)
{
if (p[1] != 0x8D || (p[2] & 0x7) != 0x5)
continue;
// LEA R*, []
codeLen = 3;
}
else if (b == 0xE8)
{
// CALL
codeLen = 1;
maxTransOffset /= 2;
}
else if (b == 0xE9)
{
// JUMP
i += 4;
continue;
}
else if (b == 0xF0)
{
if (p[1] != 0x83 || p[2] != 0x05)
continue;
// LOCK ADD [RIP + disp32], imm8
// LOCK ADD [disp32], imm8
codeLen = 3;
}
else
// if (b == 0xFF)
{
if (p[1] != 0x15)
continue;
// CALL [RIP + disp32];
// CALL [disp32];
codeLen = 2;
}
Int32 *target;
{
const Byte *p2 = p + codeLen;
UInt32 n = GetUi32(p2);
if (i - last_x86_pos <= maxTransOffset)
{
n -= i;
SetUi32(p2, n);
}
target = history + (((UInt32)i + n) & 0xFFFF);
}
i += codeLen + sizeof(UInt32) - 1;
if (i - *target <= k_x86_WindowSize)
last_x86_pos = i;
*target = i;
}
data[size + kSave] = savedByte;
}
static const int kLenIdNeedInit = -2;
CDecoder::CDecoder():
_x86_history(NULL)
{
}
CDecoder::~CDecoder()
{
::MidFree(_x86_history);
}
#define RIF(x) { if (!(x)) return false; }
#define LIMIT_CHECK if (_bs._buf < _rc.cur) return S_FALSE;
// #define LIMIT_CHECK
#define READ_BITS_CHECK(numDirectBits) \
if (_bs._buf < _rc.cur) return S_FALSE; \
if ((size_t)(_bs._buf - _rc.cur) < (numDirectBits >> 3)) return S_FALSE;
#define HUFF_DEC(sym, pp) \
sym = pp.DecodeFull(&_bs); \
pp.Freqs[sym]++; \
if (--pp.RebuildRem == 0) pp.Rebuild();
HRESULT CDecoder::CodeReal(const Byte *in, size_t inSize, Byte *_win, size_t outSize)
{
// size_t inSizeT = (size_t)(inSize);
// Byte *_win;
// size_t _pos;
_pos = 0;
CBitDecoder _bs;
CRangeDecoder _rc;
if (inSize < 8 || (inSize & 1) != 0)
return S_FALSE;
_rc.Init(in, inSize);
if (_rc.code >= _rc.range)
return S_FALSE;
_bs.Init(in, inSize);
{
{
{
for (unsigned i = 0 ; i < k_NumReps + 1; i++)
_reps[i] = i + 1;
}
{
for (unsigned i = 0 ; i < k_NumReps + 1; i++)
_deltaReps[i] = i + 1;
}
mainState = 0;
matchState = 0;
{ for (size_t i = 0; i < k_NumMainProbs; i++) mainProbs[i].Init(); }
{ for (size_t i = 0; i < k_NumMatchProbs; i++) matchProbs[i].Init(); }
{
for (size_t k = 0; k < k_NumReps; k++)
{
lzRepStates[k] = 0;
for (size_t i = 0; i < k_NumRepProbs; i++)
lzRepProbs[k][i].Init();
}
}
{
for (size_t k = 0; k < k_NumReps; k++)
{
deltaRepStates[k] = 0;
for (size_t i = 0; i < k_NumRepProbs; i++)
deltaRepProbs[k][i].Init();
}
}
m_LitDecoder.Init();
m_LenDecoder.Init();
m_PowerDecoder.Init();
unsigned numPosSyms = GetNumPosSlots(outSize);
if (numPosSyms < 2)
numPosSyms = 2;
m_PosDecoder.Init(numPosSyms);
m_DeltaDecoder.Init(numPosSyms);
}
}
{
unsigned prevType = 0;
while (_pos < outSize)
{
if (_rc.Decode(&mainState, k_NumMainProbs, mainProbs) == 0)
{
UInt32 number;
HUFF_DEC(number, m_LitDecoder);
LIMIT_CHECK
_win[_pos++] = (Byte)number;
prevType = 0;
}
else if (_rc.Decode(&matchState, k_NumMatchProbs, matchProbs) == 0)
{
UInt32 distance;
if (_rc.Decode(&lzRepStates[0], k_NumRepProbs, lzRepProbs[0]) == 0)
{
UInt32 number;
HUFF_DEC(number, m_PosDecoder);
LIMIT_CHECK
unsigned numDirectBits = g_PosDirectBits[number];
distance = g_PosBases[number];
READ_BITS_CHECK(numDirectBits);
distance += _bs.ReadBits32(numDirectBits);
// LIMIT_CHECK
_reps[3] = _reps[2];
_reps[2] = _reps[1];
_reps[1] = _reps[0];
_reps[0] = distance;
}
else
{
if (_rc.Decode(&lzRepStates[1], k_NumRepProbs, lzRepProbs[1]) == 0)
{
if (prevType != 1)
distance = _reps[0];
else
{
distance = _reps[1];
_reps[1] = _reps[0];
_reps[0] = distance;
}
}
else if (_rc.Decode(&lzRepStates[2], k_NumRepProbs, lzRepProbs[2]) == 0)
{
if (prevType != 1)
{
distance = _reps[1];
_reps[1] = _reps[0];
_reps[0] = distance;
}
else
{
distance = _reps[2];
_reps[2] = _reps[1];
_reps[1] = _reps[0];
_reps[0] = distance;
}
}
else
{
if (prevType != 1)
{
distance = _reps[2];
_reps[2] = _reps[1];
_reps[1] = _reps[0];
_reps[0] = distance;
}
else
{
distance = _reps[3];
_reps[3] = _reps[2];
_reps[2] = _reps[1];
_reps[1] = _reps[0];
_reps[0] = distance;
}
}
}
UInt32 lenSlot;
HUFF_DEC(lenSlot, m_LenDecoder);
LIMIT_CHECK
UInt32 len = g_LenBases[lenSlot];
{
unsigned numDirectBits = k_LenDirectBits[lenSlot];
READ_BITS_CHECK(numDirectBits);
len += _bs.ReadBits32(numDirectBits);
}
// LIMIT_CHECK
if (len > outSize - _pos)
return S_FALSE;
if (distance > _pos)
return S_FALSE;
Byte *dest = _win + _pos;
const Byte *src = dest - distance;
_pos += len;
do
*dest++ = *src++;
while (--len);
prevType = 1;
}
else
{
UInt64 distance;
UInt32 power;
UInt32 distance32;
if (_rc.Decode(&deltaRepStates[0], k_NumRepProbs, deltaRepProbs[0]) == 0)
{
HUFF_DEC(power, m_PowerDecoder);
LIMIT_CHECK
UInt32 number;
HUFF_DEC(number, m_DeltaDecoder);
LIMIT_CHECK
unsigned numDirectBits = g_PosDirectBits[number];
distance32 = g_PosBases[number];
READ_BITS_CHECK(numDirectBits);
distance32 += _bs.ReadBits32(numDirectBits);
// LIMIT_CHECK
distance = ((UInt64)power << 32) | distance32;
_deltaReps[3] = _deltaReps[2];
_deltaReps[2] = _deltaReps[1];
_deltaReps[1] = _deltaReps[0];
_deltaReps[0] = distance;
}
else
{
if (_rc.Decode(&deltaRepStates[1], k_NumRepProbs, deltaRepProbs[1]) == 0)
{
if (prevType != 2)
distance = _deltaReps[0];
else
{
distance = _deltaReps[1];
_deltaReps[1] = _deltaReps[0];
_deltaReps[0] = distance;
}
}
else if (_rc.Decode(&deltaRepStates[2], k_NumRepProbs, deltaRepProbs[2]) == 0)
{
if (prevType != 2)
{
distance = _deltaReps[1];
_deltaReps[1] = _deltaReps[0];
_deltaReps[0] = distance;
}
else
{
distance = _deltaReps[2];
_deltaReps[2] = _deltaReps[1];
_deltaReps[1] = _deltaReps[0];
_deltaReps[0] = distance;
}
}
else
{
if (prevType != 2)
{
distance = _deltaReps[2];
_deltaReps[2] = _deltaReps[1];
_deltaReps[1] = _deltaReps[0];
_deltaReps[0] = distance;
}
else
{
distance = _deltaReps[3];
_deltaReps[3] = _deltaReps[2];
_deltaReps[2] = _deltaReps[1];
_deltaReps[1] = _deltaReps[0];
_deltaReps[0] = distance;
}
}
distance32 = (UInt32)_deltaReps[0] & 0xFFFFFFFF;
power = (UInt32)(_deltaReps[0] >> 32);
}
UInt32 dist = (distance32 << power);
UInt32 lenSlot;
HUFF_DEC(lenSlot, m_LenDecoder);
LIMIT_CHECK
UInt32 len = g_LenBases[lenSlot];
{
unsigned numDirectBits = k_LenDirectBits[lenSlot];
READ_BITS_CHECK(numDirectBits);
len += _bs.ReadBits32(numDirectBits);
}
// LIMIT_CHECK
if (len > outSize - _pos)
return S_FALSE;
if (dist > _pos)
return S_FALSE;
size_t span = (size_t)1 << power;
Byte *dest = _win + _pos - span;
const Byte *src = dest - dist;
_pos += len;
do
{
*(dest + span) = (Byte)(*(dest) + *(src + span) - *(src));
src++;
dest++;
}
while (--len);
prevType = 2;
}
}
}
_rc.Normalize();
if (_rc.code != 0)
return S_FALSE;
if (_rc.cur > _bs._buf ||
_rc.cur == _bs._buf && _bs._bitPos != 0)
return S_FALSE;
/*
int delta = (int)(_bs._buf - _rc.cur);
if (_bs._bitPos != 0)
delta--;
if ((delta & 1))
delta--;
printf("%d ", delta);
*/
return S_OK;
}
HRESULT CDecoder::Code(const Byte *in, size_t inSize, Byte *out, size_t outSize)
{
if (!_x86_history)
{
_x86_history = (Int32 *)::MidAlloc(sizeof(Int32) * k_x86_HistorySize);
if (!_x86_history)
return E_OUTOFMEMORY;
}
HRESULT res;
// try
{
res = CodeReal(in, inSize, out, outSize);
}
// catch (...) { res = S_FALSE; }
x86_Filter(out, (UInt32)_pos, _x86_history);
return res;
}
}}