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Diffstat (limited to 'indexlib/compressed.h')
| -rw-r--r-- | indexlib/compressed.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/indexlib/compressed.h b/indexlib/compressed.h new file mode 100644 index 00000000..7397c821 --- /dev/null +++ b/indexlib/compressed.h @@ -0,0 +1,127 @@ +#ifndef LPC_COMPRESSED_H1108569807_INCLUDE_GUARD_ +#define LPC_COMPRESSED_H1108569807_INCLUDE_GUARD_ + +/* This file is part of indexlib. + * Copyright (C) 2005 Luís Pedro Coelho <luis@luispedro.org> + * + * Indexlib is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation and available as file + * GPL_V2 which is distributed along with indexlib. + * + * Indexlib 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 GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + * MA 02110-1301, USA + * + * In addition, as a special exception, the copyright holders give + * permission to link the code of this program with any edition of + * the Qt library by Trolltech AS, Norway (or with modified versions + * of Qt that use the same license as Qt), and distribute linked + * combinations including the two. You must obey the GNU General + * Public License in all respects for all of the code used other than + * Qt. If you modify this file, you may extend this exception to + * your version of the file, but you are not obligated to do so. If + * you do not wish to do so, delete this exception statement from + * your version. + */ + +#include <string> +#include <vector> +#include <memory> +#include <iostream> +#include "memvector.h" +#include "manager.h" +#include "mempool.h" +#include "thing.h" +#include "pointer.h" +#include "format.h" + +void set_compression_manager( memory_manager* ); +memory_manager* get_comp_p(); + +START_THING( compressed_page, thing<thing_manager<get_comp_p> > ) + public: // private: + MEMBER( uint8_t, capacity, 0 ) + enum { header_size = 1 }; + MY_BASE( header_size ) + public: + static void init( pointer<compressed_page> p ) { + p->set_capacity( 4 ); + } + void * data() { return my_base(); } + const void * data() const { return my_base(); } + void grow_to_size( const unsigned size ) { + unsigned cur = ( 1 << capacity() ) - header_size; + if ( size <= cur ) return; + set_capacity( capacity() + 1 ); + grow_to_size( size ); + } + void print( std::ostream& out ) { + out << format( "\tsized %s\n" ) % ( 1 << capacity() ); + } +END_THING( compressed_page ) +DO_POINTER_SPECS( compressed_page ) + +struct compressed_page_traits { + typedef compressed_page value_type; + typedef compressed_pageptr pointer; + + static bool is_free( pointer p ) { return p->capacity() == 0; } + static void mark_free( pointer p ) { p->set_capacity( 0 ); } + static unsigned size_of( pointer p ) { return 1 << p->capacity(); } + + static unsigned type_offset() { return compressed_page::header_size; } + + static unsigned min_size() { return 16; } // zlib needs minimum 12 bytes + static unsigned max_size() { return 1024 * 4; } + + static void set_manager( memory_manager* m ) { set_compression_manager( m ); } + static void print( std::ostream& out, pointer p ) { out << '[' << p << "] compressed_page:\n"; p->print( out ); } +}; + +class compressed_file : public memory_manager { + struct page; + friend struct page; + public: + compressed_file( std::string ); + ~compressed_file(); + const unsigned char* ronly_base( unsigned idx ) const; + unsigned char* rw_base( unsigned idx ) const; + unsigned size() const; + void resize( unsigned ); + void print( std::ostream& ) const; + static void remove( std::string base ); + private: + + void write_back(); + void zlibchecktrue( bool ) const; + void zlibcheck( int err, int expected = 0 ) const; + + enum { page_bits = 12, page_bytes = 1 << page_bits, compress_buffer_size = page_bytes + 12 + page_bytes/50 }; + static unsigned pageidx( unsigned idx ) { return idx >> page_bits; } + static unsigned inpageidx( unsigned idx ) { return idx & ( ( 1 << page_bits ) - 1 ); } + struct page { + explicit page( bool d = false ): + dirty_( d ) { + } + compressed_pageptr origin_; + bool dirty_; + unsigned char data_[ compressed_file::page_bytes ]; + }; + mutable std::vector<page*> pages_; + mutable memvector<uint32_t> auxdata_; + memory_reference<uint32_t> compressed_data_for( unsigned idx ) const { + return auxdata_[ idx + 1 ]; + } + mempool<compressed_page_traits> data_; +}; + + + +#endif /* LPC_COMPRESSED_H1108569807_INCLUDE_GUARD_ */ |