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// Archive/GZipIn.cpp
#include "StdAfx.h"
#include "GZipIn.h"
#include "Common/Defs.h"
#include "Common/MyCom.h"
#include "Windows/Defs.h"
namespace NArchive {
namespace NGZip {
HRESULT CInArchive::ReadBytes(ISequentialInStream *inStream, void *data, UInt32 size)
{
UInt32 realProcessedSize;
RINOK(inStream->Read(data, size, &realProcessedSize));
m_Position += realProcessedSize;
if(realProcessedSize != size)
return S_FALSE;
return S_OK;
}
HRESULT CInArchive::ReadByte(ISequentialInStream *inStream, Byte &value)
{
return ReadBytes(inStream, &value, 1);
}
HRESULT CInArchive::ReadUInt16(ISequentialInStream *inStream, UInt16 &value)
{
value = 0;
for (int i = 0; i < 2; i++)
{
Byte b;
RINOK(ReadByte(inStream, b));
value |= (UInt16(b) << (8 * i));
}
return S_OK;
}
HRESULT CInArchive::ReadUInt32(ISequentialInStream *inStream, UInt32 &value)
{
value = 0;
for (int i = 0; i < 4; i++)
{
Byte b;
RINOK(ReadByte(inStream, b));
value |= (UInt32(b) << (8 * i));
}
return S_OK;
}
HRESULT CInArchive::ReadZeroTerminatedString(ISequentialInStream *inStream, AString &resString, CCRC &crc)
{
resString.Empty();
while(true)
{
Byte c;
RINOK(ReadByte(inStream, c));
crc.UpdateByte(c);
if (c == 0)
return S_OK;
resString += char(c);
}
}
HRESULT CInArchive::ReadHeader(ISequentialInStream *inStream, CItem &item)
{
item.Clear();
m_Position = 0;
UInt16 signature;
RINOK(ReadUInt16(inStream, signature));
if (signature != kSignature)
return S_FALSE;
RINOK(ReadByte(inStream, item.CompressionMethod));
RINOK(ReadByte(inStream, item.Flags));
RINOK(ReadUInt32(inStream, item.Time));
RINOK(ReadByte(inStream, item.ExtraFlags));
RINOK(ReadByte(inStream, item.HostOS));
CCRC crc;
crc.Update(&signature, 2);
crc.UpdateByte(item.CompressionMethod);
crc.UpdateByte(item.Flags);
crc.UpdateUInt32(item.Time);
crc.UpdateByte(item.ExtraFlags);
crc.UpdateByte(item.HostOS);
if (item.ExtraFieldIsPresent())
{
UInt16 extraSize;
RINOK(ReadUInt16(inStream, extraSize));
crc.UpdateUInt16(extraSize);
item.Extra.SetCapacity(extraSize);
RINOK(ReadBytes(inStream, item.Extra, extraSize));
crc.Update(item.Extra, extraSize);
}
if (item.NameIsPresent())
RINOK(ReadZeroTerminatedString(inStream, item.Name, crc));
if (item.CommentIsPresent())
RINOK(ReadZeroTerminatedString(inStream, item.Comment, crc));
if (item.HeaderCRCIsPresent())
{
UInt16 headerCRC;
RINOK(ReadUInt16(inStream, headerCRC));
if ((UInt16)crc.GetDigest() != headerCRC)
return S_FALSE;
}
return S_OK;
}
HRESULT CInArchive::ReadPostHeader(ISequentialInStream *inStream, CItem &item)
{
RINOK(ReadUInt32(inStream, item.FileCRC));
return ReadUInt32(inStream, item.UnPackSize32);
}
}}
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