118 lines
2.0 KiB
C++
118 lines
2.0 KiB
C++
|
// Copyright (C) 2002-2007 Nikolaus Gebhardt
|
||
|
|
// This file is part of the "Irrlicht Engine".
|
||
|
|
// For conditions of distribution and use, see copyright notice in irrlicht.h
|
||
|
|
|
||
|
|
#include "CLimitReadFile.h"
|
||
|
|
#include "irrString.h"
|
||
|
|
|
||
|
|
namespace irr
|
||
|
|
{
|
||
|
|
namespace io
|
||
|
|
{
|
||
|
|
|
||
|
|
|
||
|
|
CLimitReadFile::CLimitReadFile(IReadFile* alreadyOpenedFile, s32 areaSize, const c8* name)
|
||
|
|
: Filename(name), AreaSize(areaSize), AreaStart(0), AreaEnd(0), File(alreadyOpenedFile)
|
||
|
|
{
|
||
|
|
#ifdef _DEBUG
|
||
|
|
setDebugName("CLimitReadFile");
|
||
|
|
#endif
|
||
|
|
|
||
|
|
if (File)
|
||
|
|
File->grab();
|
||
|
|
|
||
|
|
init();
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
void CLimitReadFile::init()
|
||
|
|
{
|
||
|
|
if (!File)
|
||
|
|
return;
|
||
|
|
|
||
|
|
AreaStart = File->getPos();
|
||
|
|
AreaEnd = AreaStart + AreaSize;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
CLimitReadFile::~CLimitReadFile()
|
||
|
|
{
|
||
|
|
if (File)
|
||
|
|
File->drop();
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
//! returns how much was read
|
||
|
|
s32 CLimitReadFile::read(void* buffer, u32 sizeToRead)
|
||
|
|
{
|
||
|
|
s32 pos = File->getPos();
|
||
|
|
|
||
|
|
if (pos >= AreaEnd)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (pos + (s32)sizeToRead >= AreaEnd)
|
||
|
|
sizeToRead = AreaEnd - pos;
|
||
|
|
|
||
|
|
return File->read(buffer, sizeToRead);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
//! changes position in file, returns true if successful
|
||
|
|
//! if relativeMovement==true, the pos is changed relative to current pos,
|
||
|
|
//! otherwise from begin of file
|
||
|
|
bool CLimitReadFile::seek(s32 finalPos, bool relativeMovement)
|
||
|
|
{
|
||
|
|
s32 pos = File->getPos();
|
||
|
|
|
||
|
|
if (relativeMovement)
|
||
|
|
{
|
||
|
|
if (pos + finalPos > AreaEnd)
|
||
|
|
finalPos = AreaEnd - pos;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
finalPos += AreaStart;
|
||
|
|
if ((s32)finalPos > AreaEnd)
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
return File->seek(finalPos, relativeMovement);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
//! returns size of file
|
||
|
|
s32 CLimitReadFile::getSize()
|
||
|
|
{
|
||
|
|
return AreaSize;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
//! returns where in the file we are.
|
||
|
|
s32 CLimitReadFile::getPos()
|
||
|
|
{
|
||
|
|
return File->getPos() - AreaStart;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
//! returns name of file
|
||
|
|
const c8* CLimitReadFile::getFileName()
|
||
|
|
{
|
||
|
|
return Filename.c_str();
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
IReadFile* createLimitReadFile(const c8* fileName, IReadFile* alreadyOpenedFile, s32 areaSize)
|
||
|
|
{
|
||
|
|
return new CLimitReadFile(alreadyOpenedFile, areaSize, fileName);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
} // end namespace io
|
||
|
|
} // end namespace irr
|