stream.h

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#ifndef ROSBAG_STREAM_H
#define ROSBAG_STREAM_H

#include <ios>
#include <stdint.h>
#include <string>

#include <boost/shared_ptr.hpp>

#include <bzlib.h>

#include <roslz4/lz4s.h>

#include "rosbag/exceptions.h"
#include "rosbag/macros.h"

namespace rosbag {

namespace compression
{
    enum CompressionType
    {
        Uncompressed = 0,
        BZ2          = 1,
        LZ4          = 2,
    };
}
typedef compression::CompressionType CompressionType;

class ChunkedFile;

class ROSBAG_DECL Stream
{
public:
    Stream(ChunkedFile* file);
    virtual ~Stream();

    virtual CompressionType getCompressionType() const = 0;

    virtual void write(void* ptr, size_t size) = 0;
    virtual void read (void* ptr, size_t size) = 0;

    virtual void decompress(uint8_t* dest, unsigned int dest_len, uint8_t* source, unsigned int source_len) = 0;

    virtual void startWrite();
    virtual void stopWrite();

    virtual void startRead();
    virtual void stopRead();

protected:
    FILE*    getFilePointer();
    uint64_t getCompressedIn();
    void     setCompressedIn(uint64_t nbytes);
    void     advanceOffset(uint64_t nbytes);
    char*    getUnused();
    int      getUnusedLength();
    void     setUnused(char* unused);
    void     setUnusedLength(int nUnused);
    void     clearUnused();

protected:
    ChunkedFile* file_;
};

class ROSBAG_DECL StreamFactory
{
public:
    StreamFactory(ChunkedFile* file);

    boost::shared_ptr<Stream> getStream(CompressionType type) const;

private:
    boost::shared_ptr<Stream> uncompressed_stream_;
    boost::shared_ptr<Stream> bz2_stream_;
    boost::shared_ptr<Stream> lz4_stream_;
};

class ROSBAG_DECL UncompressedStream : public Stream
{
public:
    UncompressedStream(ChunkedFile* file);

    CompressionType getCompressionType() const;

    void write(void* ptr, size_t size);
    void read(void* ptr, size_t size);

    void decompress(uint8_t* dest, unsigned int dest_len, uint8_t* source, unsigned int source_len);
};

class ROSBAG_DECL BZ2Stream : public Stream
{
public:
    BZ2Stream(ChunkedFile* file);

    CompressionType getCompressionType() const;

    void startWrite();
    void write(void* ptr, size_t size);
    void stopWrite();

    void startRead();
    void read(void* ptr, size_t size);
    void stopRead();

    void decompress(uint8_t* dest, unsigned int dest_len, uint8_t* source, unsigned int source_len);

private:
    int     verbosity_;        
    int     block_size_100k_;  
    int     work_factor_;      

    BZFILE* bzfile_;           
    int     bzerror_;          
};

// LZ4Stream reads/writes compressed datat in the LZ4 format
// https://code.google.com/p/lz4/
class ROSBAG_DECL LZ4Stream : public Stream
{
public:
    LZ4Stream(ChunkedFile* file);
    ~LZ4Stream();

    CompressionType getCompressionType() const;

    void startWrite();
    void write(void* ptr, size_t size);
    void stopWrite();

    void startRead();
    void read(void* ptr, size_t size);
    void stopRead();

    void decompress(uint8_t* dest, unsigned int dest_len, uint8_t* source, unsigned int source_len);

private:
    void writeStream(int action);

    char *buff_;
    int buff_size_;
    int block_size_id_;
    roslz4_stream lz4s_;
};



} // namespace rosbag

#endif