bt_overflow.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
#pragma ident "%Z%%M% %I% %E% SMI"
/*-
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Mike Olson.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
static char sccsid[] = "@(#)bt_overflow.c 8.5 (Berkeley) 7/16/94";
#endif /* LIBC_SCCS and not lint */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "db-int.h"
#include "btree.h"
/*
*
* Big key and data entries are stored on linked lists of pages. The initial
* reference is byte string stored with the key or data and is the page number
* and size. The actual record is stored in a chain of pages linked by the
* nextpg field of the PAGE header.
*
* The first page of the chain has a special property. If the record is used
* by an internal page, it cannot be deleted and the P_PRESERVE bit will be set
* in the header.
*
* XXX
* A single DBT is written to each chain, so a lot of space on the last page
* is wasted. This is a fairly major bug for some data sets.
*/
/*
*
* Parameters:
* t: tree
* p: pointer to { db_pgno_t, u_int32_t }
* buf: storage address
* bufsz: storage size
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
BTREE *t;
void *p;
void **buf;
{
PAGE *h;
#ifdef DEBUG_DB
abort();
#endif
/* Make the buffer bigger as necessary. */
return (RET_ERROR);
}
/*
* Step through the linked list of pages, copying the data on each one
* into the buffer. Never copy more than the data's length.
*/
return (RET_ERROR);
break;
}
return (RET_SUCCESS);
}
/*
*
* Parameters:
* t: tree
* data: DBT to store
* pgno: storage page number
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
BTREE *t;
{
void *p;
/*
* number of the first page in the chain.
*/
return (RET_ERROR);
h->flags = P_OVERFLOW;
if (last) {
} else
break;
}
}
return (RET_SUCCESS);
}
/*
* __OVFL_DELETE -- Delete an overflow chain.
*
* Parameters:
* t: tree
* p: pointer to { db_pgno_t, u_int32_t }
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__ovfl_delete(t, p)
BTREE *t;
void *p;
{
PAGE *h;
#ifdef DEBUG_DB
abort();
#endif
return (RET_ERROR);
/* Don't delete chains used by internal pages. */
if (h->flags & P_PRESERVE) {
return (RET_SUCCESS);
}
/* Step through the chain, calling the free routine for each page. */
__bt_free(t, h);
break;
return (RET_ERROR);
}
return (RET_SUCCESS);
}