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vcmi/lib/Filesystem/CFileInputStream.h

100 lines
2.3 KiB
C++

/*
* CFileInputStream.h, part of VCMI engine
*
* Authors: listed in file AUTHORS in main folder
*
* License: GNU General Public License v2.0 or later
* Full text of license available in license.txt file, in main folder
*
*/
#pragma once
#include "CInputStream.h"
class CFileInfo;
/**
* A class which provides method definitions for reading a file from the filesystem.
*/
class DLL_LINKAGE CFileInputStream : public CInputStream
{
public:
/**
* C-tor. Opens the specified file.
*
* @see CFileInputStream::open
*/
CFileInputStream(const std::string & file, si64 start=0, si64 size=0);
/**
* C-tor. Opens the specified file.
*
* @see CFileInputStream::open
*/
CFileInputStream(const CFileInfo & file, si64 start=0, si64 size=0);
/**
* D-tor. Calls the close method implicitely, if the file is still opened.
*/
~CFileInputStream();
/**
* Reads n bytes from the stream into the data buffer.
*
* @param data A pointer to the destination data array.
* @param size The number of bytes to read.
* @return the number of bytes read actually.
*/
si64 read(ui8 * data, si64 size);
/**
* Seeks the internal read pointer to the specified position.
*
* @param position The read position from the beginning.
* @return the position actually moved to, -1 on error.
*/
si64 seek(si64 position);
/**
* Gets the current read position in the stream.
*
* @return the read position. -1 on failure or if the read pointer isn't in the valid range.
*/
si64 tell();
/**
* Skips delta numbers of bytes.
*
* @param delta The count of bytes to skip.
* @return the count of bytes skipped actually.
*/
si64 skip(si64 delta);
/**
* Gets the length in bytes of the stream.
*
* @return the length in bytes of the stream.
*/
si64 getSize();
private:
/**
* Opens a file. If a file is currently opened, it will be closed.
*
* @param file Path to the file.
* @param start - offset from file start where real data starts (e.g file on archive)
* @param size - size of real data in file (e.g file on archive) or 0 to use whole file
*
* @throws std::runtime_error if file wasn't found
*/
void open(const std::string & file, si64 start, si64 size);
si64 dataStart;
si64 dataSize;
/** Native c++ input file stream object. */
std::ifstream fileStream;
};