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This commit is contained in:
Igor Pavlov
2018-01-11 22:16:32 +01:00
committed by Kornel
parent b5dc853b24
commit da28077952
44 changed files with 853 additions and 366 deletions
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77
CPP/7zip/Compress/ShrinkDecoder.cpp
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@@ -13,6 +13,7 @@
namespace NCompress {
namespace NShrink {
static const UInt32 kEmpty = 256; // kNumItems;
static const UInt32 kBufferSize = (1 << 18);
static const unsigned kNumMinBits = 9;
@@ -34,20 +35,15 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
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;
for (unsigned i = 0; i < kNumItems; i++)
_parents[i] = kEmpty;
}
UInt64 prevPos = 0, inPrev = 0;
UInt64 outPrev = 0, inPrev = 0;
unsigned numBits = kNumMinBits;
unsigned head = 257;
int lastSym = -1;
Byte lastChar2 = 0;
Byte lastChar = 0;
bool moreOut = false;
HRESULT res = S_FALSE;
@@ -67,18 +63,22 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
break;
}
eofCheck = true;
// Is specSym(=256) allowed after end of stream
// Do we need to read it here
// Is specSym(=256) allowed after end of stream ?
// Do we need to read it here ?
}
if (progress)
{
if (nowPos - prevPos >= (1 << 18)
|| _inProcessed - inPrev >= (1 << 20))
if (nowPos - outPrev >= (1 << 20) || _inProcessed - inPrev >= (1 << 20))
{
prevPos = nowPos;
outPrev = nowPos;
inPrev = _inProcessed;
RINOK(progress->SetRatioInfo(&_inProcessed, &nowPos));
res = progress->SetRatioInfo(&_inProcessed, &nowPos);
if (res != SZ_OK)
{
// break;
return res;
}
}
}
@@ -105,23 +105,30 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
continue;
}
if (sym != 2)
break;
{
break;
// continue; // info-zip just ignores such code
}
{
/*
---------- Free leaf nodes ----------
Note : that code can mark _parents[lastSym] as free, and next
inserted node will be Orphan in that case.
*/
unsigned i;
for (i = 257; i < kNumItems; i++)
for (i = 256; i < kNumItems; i++)
_stack[i] = 0;
for (i = 257; i < kNumItems; i++)
{
unsigned par = _parents[i];
if (par != kNumItems)
if (par != kEmpty)
_stack[par] = 1;
}
for (i = 257; i < kNumItems; i++)
if (_stack[i] == 0)
_parents[i] = kNumItems;
_parents[i] = kEmpty;
head = 257;
continue;
}
}
@@ -137,27 +144,22 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
bool needPrev = false;
if (head < kNumItems && lastSym >= 0)
{
while (head < kNumItems && _parents[head] != kNumItems)
while (head < kNumItems && _parents[head] != kEmpty)
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
res = E_NOTIMPL;
break;
}
/*
if (head == lastSym), it updates Orphan to self-linked Orphan and creates two problems:
1) we must check _stack[i++] overflow in code that walks tree nodes.
2) self-linked node can not be removed. So such self-linked nodes can occupy all _parents items.
*/
needPrev = true;
_parents[head] = (UInt16)lastSym;
_suffixes[head] = (Byte)lastChar2;
_suffixes[head] = (Byte)lastChar;
head++;
}
}
if (_parents[sym] == kNumItems)
break;
lastSym = sym;
unsigned cur = sym;
unsigned i = 0;
@@ -166,10 +168,17 @@ HRESULT CDecoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *
{
_stack[i++] = _suffixes[cur];
cur = _parents[cur];
// don't change that code:
// Orphan Check and self-linked Orphan check (_stack overflow check);
if (cur == kEmpty || i >= kNumItems)
break;
}
if (cur == kEmpty || i >= kNumItems)
break;
_stack[i++] = (Byte)cur;
lastChar2 = (Byte)cur;
lastChar = (Byte)cur;
if (needPrev)
_suffixes[(size_t)head - 1] = (Byte)cur;