* Copyright 2014, Ingo Weinhold, ingo_weinhold@gmx.de.
* Distributed under the terms of the MIT License.
*/
#ifndef _COMPRESSION_ALGORITHM_H_
#define _COMPRESSION_ALGORITHM_H_
#include <DataIO.h>
#include <sys/uio.h>
class BCompressionParameters {
public:
BCompressionParameters();
virtual ~BCompressionParameters();
};
class BDecompressionParameters {
public:
BDecompressionParameters();
virtual ~BDecompressionParameters();
};
class BCompressionAlgorithm {
public:
BCompressionAlgorithm();
virtual ~BCompressionAlgorithm();
virtual status_t CreateCompressingInputStream(BDataIO* input,
const BCompressionParameters* parameters,
BDataIO*& _stream);
virtual status_t CreateCompressingOutputStream(BDataIO* output,
const BCompressionParameters* parameters,
BDataIO*& _stream);
virtual status_t CreateDecompressingInputStream(BDataIO* input,
const BDecompressionParameters* parameters,
BDataIO*& _stream);
virtual status_t CreateDecompressingOutputStream(BDataIO* output,
const BDecompressionParameters* parameters,
BDataIO*& _stream);
virtual status_t CompressBuffer(const iovec& input, iovec& output,
const BCompressionParameters* parameters = NULL,
iovec* scratch = NULL);
virtual status_t DecompressBuffer(const iovec& input, iovec& output,
const BDecompressionParameters* parameters = NULL,
iovec* scratch = NULL);
protected:
class BAbstractStream;
class BAbstractInputStream;
class BAbstractOutputStream;
};
class BCompressionAlgorithm::BAbstractStream : public BDataIO {
public:
BAbstractStream();
virtual ~BAbstractStream();
status_t Init(size_t bufferSize);
protected:
virtual status_t ProcessData(const void* input, size_t inputSize,
void* output, size_t outputSize,
size_t& bytesConsumed,
size_t& bytesProduced) = 0;
virtual status_t FlushPendingData(void* output,
size_t outputSize,
size_t& bytesProduced) = 0;
protected:
uint8* fBuffer;
size_t fBufferCapacity;
size_t fBufferOffset;
size_t fBufferSize;
};
class BCompressionAlgorithm::BAbstractInputStream : public BAbstractStream {
public:
BAbstractInputStream(BDataIO* input);
virtual ~BAbstractInputStream();
virtual ssize_t Read(void* buffer, size_t size);
private:
BDataIO* fInput;
bool fEndOfInput;
bool fNoMorePendingData;
};
class BCompressionAlgorithm::BAbstractOutputStream : public BAbstractStream {
public:
BAbstractOutputStream(BDataIO* output);
virtual ~BAbstractOutputStream();
virtual ssize_t Write(const void* buffer, size_t size);
virtual status_t Flush();
private:
ssize_t _Write(const void* buffer, size_t size,
bool flush);
private:
BDataIO* fOutput;
};
#endif
