1
0
mirror of https://github.com/vcmi/vcmi.git synced 2024-12-18 17:40:48 +02:00
vcmi/lib/Filesystem/CLodStream.h

115 lines
3.1 KiB
C++

/*
* CLodStream.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"
#include "CFileInputStream.h"
#include "CLodArchiveLoader.h"
/**
* A class which provides method definitions for reading a file from a LOD archive.
*/
class DLL_LINKAGE CLodStream : public CInputStream
{
public:
/**
* Default c-tor.
*/
CLodStream();
/**
* C-tor.
*
* @param loader The archive loader object which knows about the structure of the archive format.
* @param resourceName The resource name which says what resource should be loaded.
*
* @throws std::runtime_error if the archive entry wasn't found
*/
CLodStream(const CLodArchiveLoader * loader, const std::string & resourceName);
/**
* Opens a lod stream. It will close any currently opened file stream.
*
* @param loader The archive loader object which knows about the structure of the archive format.
* @param resourceName The resource name which says what resource should be loaded.
*
* @throws std::runtime_error if the archive entry wasn't found
*/
void open(const CLodArchiveLoader * loader, const std::string & resourceName);
/**
* Reads n bytes from the stream into the data buffer.
*
* Warning: You can't read just a part of the archive entry if it's a decompressed one. So reading the total size always is
* recommended unless you really know what you're doing e.g. reading from a video stream.
*
* @param data A pointer to the destination data array.
* @param size The number of bytes to read.
* @return the number of bytes read actually.
*
* @throws std::runtime_error if the file decompression was not successful
*/
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.
*/
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();
/**
* Closes the stream and releases any system resources associated with the stream explicitely.
*/
void close();
private:
/**
* Decompresses an archive entry.
*
* @param in A pointer to the compressed data array
* @param size The size of the compressed data array
* @param realSize The size of the decompressed real size of the entry
* @param out
*/
bool decompressFile(ui8 * in, int size, int realSize, ui8 * out);
/** The file stream for reading from the LOD archive. */
CFileInputStream fileStream;
/** The archive entry which specifies the length, offset,... of the entry. */
const ArchiveEntry * archiveEntry;
};