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cdesktop/cde/programs/dtinfo/DtMmdb/storage/page.h
2018-04-28 12:30:20 -06:00

164 lines
4.8 KiB
C++

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/*
* $XConsortium: page.h /main/10 1996/07/18 14:54:33 drk $
*
* Copyright (c) 1992 HaL Computer Systems, Inc. All rights reserved.
* UNPUBLISHED -- rights reserved under the Copyright Laws of the United
* States. Use of a copyright notice is precautionary only and does not
* imply publication or disclosure.
*
* This software contains confidential information and trade secrets of HaL
* Computer Systems, Inc. Use, disclosure, or reproduction is prohibited
* without the prior express written permission of HaL Computer Systems, Inc.
*
* RESTRICTED RIGHTS LEGEND
* Use, duplication, or disclosure by the Government is subject to
* restrictions as set forth in subparagraph (c)(l)(ii) of the Rights in
* Technical Data and Computer Software clause at DFARS 252.227-7013.
* HaL Computer Systems, Inc.
* 1315 Dell Avenue, Campbell, CA 95008
*
*/
#ifndef _page_h
#define _page_h 1
#include "utility/config.h"
#include "utility/funcs.h"
#include "utility/buffer.h"
#include "storage/rep_cell.h"
#include "storage/spointer.h"
// do not change to short! (for alignment reason)
typedef int count_t;
class page : private buffer
{
public:
page(int buf_sz = PAGSIZ, int pid = 0, Boolean swap_order = false);
virtual ~page() ;
// wipe the page clean
void clean_all();
// get and put functions
Boolean get( int slot_num, buffer& target,
int offset = 0, int bytes_to_read = 0
) const;
// get the byte string at slot 'slot_num' from buf.
Boolean put( int& slot_num, buffer& source );
// put buf into the page into next
// available slot. the index of the slot
// is returned in slot_num.
Boolean alloc_slot( int& slot_num, int size, char*& string_ptr );
Boolean del_slot( int slot_num );
// delete the slot at postiion 'slot_num'
Boolean update_slot( int slot_num, buffer& source, int offset = 0 );
Boolean get_str_ptr( int slot_num, char*& str, int& len );
virtual void reset() { buffer::reset(); };
spointer_t* get_spointer(int slot_num) const;
// return the number of objects on the page
int count() const { return *((count_t*)v_base); } ;
int page_id() { return pageid; };// page id
int free_bytes() const; // free bytes on the page
int free_slots() const; // free slots on the page
char* page_base() { return v_base; };
// iteration functions
// go over all strings on the page
int first() const { return ( count() <= 1 ) ? 0 : 1; };
void next(int &) const;
void prev(int &) const;
// new operator
void* operator new( size_t );
void operator delete( void*, size_t );
// IO function and friend class
friend ostream& operator<<(ostream&, page&);
friend class page_storage;
friend class page_cache_global_part;
friend class dyn_hash;
protected:
// slot management funcs
void set_count(int i) {
count_t& count = *(count_t*)(v_base);
count = i; // reset count
};
Boolean _alloc_slot( int slot_num, int size, char*& string_ptr );
void _swap_order(Boolean swap_count_field_first);
protected:
unsigned int pageid ; // page id
Boolean dirty ; // = false: page has not been written;
int num_locks; // no. of locks
int v_memalign_offset; // align offset of the memory
// chunk for this page
Boolean v_swap_order;
};
typedef page* pagePtr;
class page_storage;
class lru_page : public page, public rep_cell
{
public:
lru_page(page_storage* st, int buf_sz = PAGSIZ,
int pid = 0, Boolean swap_order = false
) :
page(buf_sz, pid, swap_order), f_store(st) {};
virtual ~lru_page() {};
page_storage* f_store;
};
typedef lru_page* lru_pagePtr;
#endif