zstreambuf.h

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/* === S Y N F I G ========================================================= */
/* ========================================================================= */

/* === S T A R T =========================================================== */

#ifndef __SYNFIG_ZSTREAMBUF_H
#define __SYNFIG_ZSTREAMBUF_H

/* === H E A D E R S ======================================================= */

#include <streambuf>
#include <istream>
#include <ostream>
#include <vector>
#include <zlib.h>
#include "filesystem.h"

/* === M A C R O S ========================================================= */

/* === T Y P E D E F S ===================================================== */

/* === C L A S S E S & S T R U C T S ======================================= */

namespace synfig {

    class zstreambuf : public std::streambuf
    {
    public:
        enum {
            option_bufsize              = 4096,
            option_method               = Z_DEFLATED,
            option_compression_level    = 9,
            option_window_bits          = 16+MAX_WBITS,
            option_mem_level            = 9,
            option_strategy             = Z_DEFAULT_STRATEGY
        };

    private:
        std::streambuf *buf_;

        bool inflate_initialized;
        z_stream inflate_stream_;
        std::vector<char> read_buffer_;

        bool deflate_initialized;
        z_stream deflate_stream_;
        std::vector<char> write_buffer_;

        bool inflate_buf();
        bool deflate_buf(bool flush);

    public:
        explicit zstreambuf(std::streambuf *buf);
        virtual ~zstreambuf();

    protected:
        virtual int sync();
        virtual int underflow();
        virtual int overflow(int c = EOF);
    };

    class ZReadStream : public FileSystem::ReadStream
    {
    private:
        FileSystem::ReadStreamHandle stream_;
        zstreambuf buf_;
        std::istream istream_;

    protected:
        virtual size_t internal_read(void *buffer, size_t size)
            { return (size_t)istream_.read((char*)buffer, size).gcount(); }

    public:
        ZReadStream(FileSystem::ReadStreamHandle stream):
            FileSystem::ReadStream(stream->file_system()),
            stream_(stream),
            buf_(stream_->rdbuf()),
            istream_(&buf_)
        { }

    };

    class ZWriteStream : public FileSystem::WriteStream
    {
    private:
        FileSystem::WriteStreamHandle stream_;
        zstreambuf buf_;
        std::ostream ostream_;

    protected:
        virtual size_t internal_write(const void *buffer, size_t size)
        {
            for(size_t i = 0; i < size; i++)
                if (!ostream_.put(((const char*)buffer)[i]).good())
                    return i;
            return size;
        }

    public:
        ZWriteStream(FileSystem::WriteStreamHandle stream):
            FileSystem::WriteStream(stream->file_system()),
            stream_(stream),
            buf_(stream_->rdbuf()),
            ostream_(&buf_)
        { }
    };
}

/* === E N D =============================================================== */

#endif