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#ifndef LPC_COMPRESSED_H1108569807_INCLUDE_GUARD_
#define LPC_COMPRESSED_H1108569807_INCLUDE_GUARD_
/* This file is part of indexlib.
* Copyright (C) 2005 Luís Pedro Coelho <[email protected]>
*
* 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_ */
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