mirror of https://github.com/vitalif/zbackup
92 lines
2.6 KiB
C++
92 lines
2.6 KiB
C++
// Copyright (c) 2013 Benjamin Koch <bbbsnowball@gmail.com>
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// Copyright (c) 2012-2014 Konstantin Isakov <ikm@zbackup.org> and ZBackup contributors, see CONTRIBUTORS
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// Part of ZBackup. Licensed under GNU GPLv2 or later + OpenSSL, see LICENSE
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#ifndef COMPRESSION_HH_INCLUDED__
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#define COMPRESSION_HH_INCLUDED__
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#include "sptr.hh"
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#include "ex.hh"
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#include "nocopy.hh"
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namespace Compression {
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DEF_EX( Ex, "Compression exception", std::exception )
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DEF_EX_STR( exUnsupportedCompressionMethod, "Unsupported compression method: ", Ex )
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// used for encoding or decoding
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class EnDecoder: NoCopy
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{
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protected:
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EnDecoder();
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public:
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virtual ~EnDecoder();
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// encoder can read up to size bytes from data
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virtual void setInput ( const void* data, size_t size ) =0;
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// how many bytes of the last input haven't been used, yet?
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virtual size_t getAvailableInput() =0;
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// encoder can write up to size bytes to output
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virtual void setOutput( void* data, size_t size ) =0;
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// how many bytes of free space are remaining in the output buffer
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virtual size_t getAvailableOutput() =0;
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// process some bytes
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// finish: will you pass more data to the encoder via setOutput?
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// NOTE You must eventually set finish to true.
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// returns, whether all output bytes have been written
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virtual bool process( bool finish ) =0;
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};
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// compression method
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class CompressionMethod
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{
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public:
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virtual ~CompressionMethod();
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// returns name of compression method
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// This name is saved in the file header of the compressed file.
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virtual std::string getName() const =0;
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virtual sptr<EnDecoder> createEncoder() const =0;
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virtual sptr<EnDecoder> createDecoder() const =0;
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// find a compression by name
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// If optional is false, it will either return a valid CompressionMethod
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// object or abort the program. If optional is true, it will return
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// NULL, if it cannot find the a compression with that name.
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static const_sptr<CompressionMethod> findCompression(
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const std::string& name, bool optional = false );
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static const_sptr<CompressionMethod> defaultCompression;
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class iterator
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{
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friend class CompressionMethod;
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const const_sptr<CompressionMethod>* ptr;
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iterator( const const_sptr<CompressionMethod>* ptr );
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public:
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iterator( const iterator& it );
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iterator& operator =( const iterator& it );
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bool operator ==( const iterator& other ) const;
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bool operator !=( const iterator& other ) const;
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bool atEnd() const;
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iterator& operator ++();
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const_sptr<CompressionMethod> operator *();
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};
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static iterator begin();
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static iterator end();
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};
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}
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#endif
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