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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/*
* This file is part of the libvisio project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#include <string.h>
#include "VSDInternalStream.h"
VSDInternalStream::VSDInternalStream(librevenge::RVNGInputStream *input, unsigned long size, bool compressed) :
librevenge::RVNGInputStream(),
m_offset(0),
m_buffer()
{
unsigned long tmpNumBytesRead = 0;
const unsigned char *tmpBuffer = input->read(size, tmpNumBytesRead);
if (tmpNumBytesRead < 2)
return;
if (!compressed)
{
for (unsigned long i=0; i<tmpNumBytesRead; i++)
m_buffer.push_back(tmpBuffer[i]);
}
else
{
unsigned char buffer[4096] = { 0 };
unsigned pos = 0;
unsigned offset = 0;
while (offset < tmpNumBytesRead)
{
unsigned flag = tmpBuffer[offset++];
if (offset > tmpNumBytesRead-1)
break;
unsigned mask = 1;
for (unsigned bit = 0; bit < 8 && offset < tmpNumBytesRead; ++bit)
{
if (flag & mask)
{
buffer[pos&4095] = tmpBuffer[offset++];
m_buffer.push_back(buffer[pos&4095]);
pos++;
}
else
{
if (offset > tmpNumBytesRead-2)
break;
unsigned char addr1 = tmpBuffer[offset++];
unsigned char addr2 = tmpBuffer[offset++];
unsigned length = (addr2&15) + 3;
unsigned pointer = (((unsigned)addr2 & 0xF0) << 4) | addr1;
if (pointer > 4078)
pointer -= 4078;
else
pointer += 18;
for (unsigned j = 0; j < length; ++j)
{
buffer[(pos+j) & 4095] = buffer[(pointer+j) & 4095];
m_buffer.push_back(buffer[(pointer+j) & 4095]);
}
pos += length;
}
mask = mask << 1;
}
}
}
}
const unsigned char *VSDInternalStream::read(unsigned long numBytes, unsigned long &numBytesRead)
{
numBytesRead = 0;
if (numBytes == 0)
return 0;
int numBytesToRead;
if ((m_offset+numBytes) < m_buffer.size())
numBytesToRead = numBytes;
else
numBytesToRead = m_buffer.size() - m_offset;
numBytesRead = numBytesToRead; // about as paranoid as we can be..
if (numBytesToRead == 0)
return 0;
long oldOffset = m_offset;
m_offset += numBytesToRead;
return &m_buffer[oldOffset];
}
int VSDInternalStream::seek(long offset, librevenge::RVNG_SEEK_TYPE seekType)
{
if (seekType == librevenge::RVNG_SEEK_CUR)
m_offset += offset;
else if (seekType == librevenge::RVNG_SEEK_SET)
m_offset = offset;
if (m_offset < 0)
{
m_offset = 0;
return 1;
}
if ((long)m_offset > (long)m_buffer.size())
{
m_offset = m_buffer.size();
return 1;
}
return 0;
}
long VSDInternalStream::tell()
{
return m_offset;
}
bool VSDInternalStream::isEnd()
{
if ((long)m_offset >= (long)m_buffer.size())
return true;
return false;
}
/* vim:set shiftwidth=2 softtabstop=2 expandtab: */
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