HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *outStream,
const UInt64 * /* inSize */, const UInt64 * /* outSize */, ICompressProgressInfo *progress)
{
NBitl::CBaseDecoder<CInBuffer> inBuffer;
COutBuffer outBuffer;
if (!inBuffer.Create(kBufferSize))
return E_OUTOFMEMORY;
inBuffer.SetStream(inStream);
inBuffer.Init();
if (!outBuffer.Create(kBufferSize))
return E_OUTOFMEMORY;
outBuffer.SetStream(outStream);
outBuffer.Init();
{
unsigned i;
for (i = 0; i < 257; i++)
_parents[i] = (UInt16)i;
for (; i < kNumItems; i++)
_parents[i] = kNumItems;
for (i = 0; i < kNumItems; i++)
_suffixes[i] = 0;
}
UInt64 prevPos = 0;
unsigned numBits = kNumMinBits;
unsigned head = 257;
int lastSym = -1;
Byte lastChar2 = 0;
for (;;)
{
UInt32 sym = inBuffer.ReadBits(numBits);
if (inBuffer.ExtraBitsWereRead())
break;
if (sym == 256)
{
sym = inBuffer.ReadBits(numBits);
if (sym == 1)
{
if (numBits >= kNumMaxBits)
return S_FALSE;
numBits++;
continue;
}
if (sym != 2)
return S_FALSE;
{
unsigned i;
for (i = 257; i < kNumItems; i++)
_stack[i] = 0;
for (i = 257; i < kNumItems; i++)
{
unsigned par = _parents[i];
if (par != kNumItems)
_stack[par] = 1;
}
for (i = 257; i < kNumItems; i++)
if (_stack[i] == 0)
_parents[i] = kNumItems;
head = 257;
continue;
}
}
bool needPrev = false;
if (head < kNumItems && lastSym >= 0)
{
while (head < kNumItems && _parents[head] != kNumItems)
head++;
if (head < kNumItems)
{
if (head == (unsigned)lastSym)
{
// we need to fix the code for that case
// _parents[head] is not allowed to link to itself
return E_NOTIMPL;
}
needPrev = true;
_parents[head] = (UInt16)lastSym;
_suffixes[head] = (Byte)lastChar2;
head++;
}
}
if (_parents[sym] == kNumItems)
return S_FALSE;
lastSym = sym;
unsigned cur = sym;
unsigned i = 0;
while (cur >= 256)
{
_stack[i++] = _suffixes[cur];
cur = _parents[cur];
}
_stack[i++] = (Byte)cur;
lastChar2 = (Byte)cur;
if (needPrev)
_suffixes[head - 1] = (Byte)cur;
do
outBuffer.WriteByte(_stack[--i]);
while (i);
if (progress)
{
const UInt64 nowPos = outBuffer.GetProcessedSize();
if (nowPos - prevPos >= (1 << 18))
{
prevPos = nowPos;
const UInt64 packSize = inBuffer.GetProcessedSize();
RINOK(progress->SetRatioInfo(&packSize, &nowPos));
}
}
}
return outBuffer.Flush();
}
HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *outStream,
const UInt64 * /* inSize */, const UInt64 * /* outSize */, ICompressProgressInfo *progress)
{
NBitl::CBaseDecoder<CInBuffer> inBuffer;
COutBuffer outBuffer;
if (!inBuffer.Create(kBufferSize))
return E_OUTOFMEMORY;
inBuffer.SetStream(inStream);
inBuffer.Init();
if (!outBuffer.Create(kBufferSize))
return E_OUTOFMEMORY;
outBuffer.SetStream(outStream);
outBuffer.Init();
UInt64 prevPos = 0;
int numBits = kNumMinBits;
UInt32 head = 257;
bool needPrev = false;
UInt32 lastSymbol = 0;
int i;
for (i = 0; i < kNumItems; i++)
_parents[i] = 0;
for (i = 0; i < kNumItems; i++)
_suffixes[i] = 0;
for (i = 0; i < 257; i++)
_isFree[i] = false;
for (; i < kNumItems; i++)
_isFree[i] = true;
for (;;)
{
UInt32 symbol = inBuffer.ReadBits(numBits);
if (inBuffer.ExtraBitsWereRead())
break;
if (_isFree[symbol])
return S_FALSE;
if (symbol == 256)
{
UInt32 symbol = inBuffer.ReadBits(numBits);
if (symbol == 1)
{
if (numBits < kNumMaxBits)
numBits++;
}
else if (symbol == 2)
{
if (needPrev)
_isFree[head - 1] = true;
for (i = 257; i < kNumItems; i++)
_isParent[i] = false;
for (i = 257; i < kNumItems; i++)
if (!_isFree[i])
_isParent[_parents[i]] = true;
for (i = 257; i < kNumItems; i++)
if (!_isParent[i])
_isFree[i] = true;
head = 257;
while (head < kNumItems && !_isFree[head])
head++;
if (head < kNumItems)
{
needPrev = true;
_isFree[head] = false;
_parents[head] = (UInt16)lastSymbol;
head++;
}
}
else
return S_FALSE;
continue;
}
UInt32 cur = symbol;
i = 0;
int corectionIndex = -1;
while (cur >= 256)
{
if (cur == head - 1)
corectionIndex = i;
_stack[i++] = _suffixes[cur];
cur = _parents[cur];
}
_stack[i++] = (Byte)cur;
if (needPrev)
{
_suffixes[head - 1] = (Byte)cur;
if (corectionIndex >= 0)
_stack[corectionIndex] = (Byte)cur;
}
while (i > 0)
outBuffer.WriteByte((_stack[--i]));
while (head < kNumItems && !_isFree[head])
head++;
if (head < kNumItems)
{
needPrev = true;
_isFree[head] = false;
_parents[head] = (UInt16)symbol;
head++;
}
else
needPrev = false;
lastSymbol = symbol;
UInt64 nowPos = outBuffer.GetProcessedSize();
if (progress != NULL && nowPos - prevPos > (1 << 18))
{
prevPos = nowPos;
UInt64 packSize = inBuffer.GetProcessedSize();
RINOK(progress->SetRatioInfo(&packSize, &nowPos));
}
}
return outBuffer.Flush();
}