OpenSceneGraph/include/osgDB/Archive
2004-10-27 14:09:24 +00:00

148 lines
4.8 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#ifndef OSGDB_ARCHIVE
#define OSGDB_ARCHIVE 1
#include <osgDB/ReaderWriter>
#include <fstream>
#include <list>
namespace osgDB {
/** Base class for implementing database Archives. */
class OSGDB_EXPORT Archive : public ReaderWriter
{
public:
Archive();
virtual ~Archive();
virtual const char* libraryName() const { return "osgDB"; }
virtual const char* className() const { return "Archive"; }
virtual bool acceptsExtension(const std::string& /*extension*/) { return true; }
enum Status
{
READ,
WRITE
};
/** open the archive.*/
virtual void create(const std::string& filename, unsigned int indexBlockSize=4096);
/** open the archive.*/
virtual void open(const std::string& filename, Status status);
/** close the archive.*/
virtual void close();
/** return true if file exists in archive.*/
virtual bool fileExists(const std::string& filename) const;
virtual ReadResult readObject(const std::string& fileName,const Options* options=NULL);
virtual ReadResult readImage(const std::string& fileName,const Options* options=NULL);
virtual ReadResult readHeightField(const std::string& fileName,const Options* options=NULL);
virtual ReadResult readNode(const std::string& fileName,const Options* options=NULL);
virtual WriteResult writeObject(const osg::Object& obj,const std::string& fileName,const Options* options=NULL);
virtual WriteResult writeImage(const osg::Image& image,const std::string& fileName,const Options* options=NULL);
virtual WriteResult writeHeightField(const osg::HeightField& heightField,const std::string& fileName,const Options* options=NULL);
virtual WriteResult writeNode(const osg::Node& node,const std::string& fileName,const Options* options=NULL);
protected:
typedef std::istream::pos_type pos_type;
typedef std::map<std::string, pos_type> FileNamePositionMap;
class IndexBlock : public osg::Referenced
{
public:
IndexBlock(unsigned int blockSize=0);
inline pos_type getPosition() const { return _filePosition; }
inline unsigned int getBlockSize() const { return _blockSize; }
void setPositionNextIndexBlock(pos_type position);
inline pos_type getPositionNextIndexBlock() const { return _filePositionNextIndexBlock; }
void read(std::istream& in);
bool getFileReferences(FileNamePositionMap& indexMap);
inline bool requiresWrite() const { return _requiresWrite; }
void write(std::ostream& out);
inline bool spaceAvailable(pos_type position, const std::string& filename) const
{
unsigned requiredSize = sizeof(position)+sizeof(unsigned int)+filename.size();
return (_offsetOfNextAvailableSpace + requiredSize)<_blockSize;
}
bool addFileReference(pos_type position, const std::string& filename);
protected:
void allocateData(unsigned int blockSize);
virtual ~IndexBlock();
bool _requiresWrite;
pos_type _filePosition;
unsigned int _blockSize;
pos_type _filePositionNextIndexBlock;
unsigned int _offsetOfNextAvailableSpace;
unsigned char* _data;
};
typedef std::list< osg::ref_ptr<IndexBlock> > IndexBlockList;
void readIndexBlocks();
void writeIndexBlocks();
bool addFileReference(pos_type position, const std::string& fileName);
static float s_currentSupportedVersion;
float _version;
Status _status;
std::ifstream _input;
std::ofstream _output;
IndexBlockList _indexBlockList;
FileNamePositionMap _indexMap;
};
}
#endif // OSGDB_ARCHIVE