minix/lib/libc/db/btree/bt_overflow.c
Ben Gras 2fe8fb192f Full switch to clang/ELF. Drop ack. Simplify.
There is important information about booting non-ack images in
docs/UPDATING. ack/aout-format images can't be built any more, and
booting clang/ELF-format ones is a little different. Updating to the
new boot monitor is recommended.

Changes in this commit:

	. drop boot monitor -> allowing dropping ack support
	. facility to copy ELF boot files to /boot so that old boot monitor
	  can still boot fairly easily, see UPDATING
	. no more ack-format libraries -> single-case libraries
	. some cleanup of OBJECT_FMT, COMPILER_TYPE, etc cases
	. drop several ack toolchain commands, but not all support
	  commands (e.g. aal is gone but acksize is not yet).
	. a few libc files moved to netbsd libc dir
	. new /bin/date as minix date used code in libc/
	. test compile fix
	. harmonize includes
	. /usr/lib is no longer special: without ack, /usr/lib plays no
	  kind of special bootstrapping role any more and bootstrapping
	  is done exclusively through packages, so releases depend even
	  less on the state of the machine making them now.
	. rename nbsd_lib* to lib*
	. reduce mtree
2012-02-14 14:52:02 +01:00

232 lines
5.9 KiB
C

/* $NetBSD: bt_overflow.c,v 1.16 2008/09/11 12:58:00 joerg Exp $ */
/*-
* 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
* documentation and/or other materials provided with the distribution.
* 3. 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.
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
__RCSID("$NetBSD: bt_overflow.c,v 1.16 2008/09/11 12:58:00 joerg Exp $");
#include "namespace.h"
#include <sys/param.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <db.h>
#include "btree.h"
/*
* Big key/data code.
*
* 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.
*/
/*
* __OVFL_GET -- Get an overflow key/data item.
*
* Parameters:
* t: tree
* p: pointer to { pgno_t, uint32_t }
* buf: storage address
* bufsz: storage size
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__ovfl_get(BTREE *t, void *p, size_t *ssz, void **buf, size_t *bufsz)
{
PAGE *h;
pgno_t pg;
uint32_t sz, nb, plen;
size_t temp;
memmove(&pg, p, sizeof(pgno_t));
memmove(&sz, (char *)p + sizeof(pgno_t), sizeof(uint32_t));
*ssz = sz;
#ifdef DEBUG
if (pg == P_INVALID || sz == 0)
abort();
#endif
/* Make the buffer bigger as necessary. */
if (*bufsz < sz) {
*buf = (char *)(*buf == NULL ? malloc(sz) : realloc(*buf, sz));
if (*buf == NULL)
return (RET_ERROR);
*bufsz = sz;
}
/*
* Step through the linked list of pages, copying the data on each one
* into the buffer. Never copy more than the data's length.
*/
temp = t->bt_psize - BTDATAOFF;
_DBFIT(temp, uint32_t);
plen = (uint32_t)temp;
for (p = *buf;; p = (char *)p + nb, pg = h->nextpg) {
if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
return (RET_ERROR);
nb = MIN(sz, plen);
memmove(p, (char *)(void *)h + BTDATAOFF, nb);
mpool_put(t->bt_mp, h, 0);
if ((sz -= nb) == 0)
break;
}
return (RET_SUCCESS);
}
/*
* __OVFL_PUT -- Store an overflow key/data item.
*
* Parameters:
* t: tree
* data: DBT to store
* pgno: storage page number
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__ovfl_put(BTREE *t, const DBT *dbt, pgno_t *pg)
{
PAGE *h, *last;
void *p;
pgno_t npg;
uint32_t sz, nb, plen;
size_t temp;
/*
* Allocate pages and copy the key/data record into them. Store the
* number of the first page in the chain.
*/
temp = t->bt_psize - BTDATAOFF;
_DBFIT(temp, uint32_t);
plen = (uint32_t)temp;
last = NULL;
p = dbt->data;
temp = dbt->size;
_DBFIT(temp, uint32_t);
sz = temp;
for (;; p = (char *)p + plen, last = h) {
if ((h = __bt_new(t, &npg)) == NULL)
return (RET_ERROR);
h->pgno = npg;
h->nextpg = h->prevpg = P_INVALID;
h->flags = P_OVERFLOW;
h->lower = h->upper = 0;
nb = MIN(sz, plen);
(void)memmove((char *)(void *)h + BTDATAOFF, p, (size_t)nb);
if (last) {
last->nextpg = h->pgno;
mpool_put(t->bt_mp, last, MPOOL_DIRTY);
} else
*pg = h->pgno;
if ((sz -= nb) == 0) {
mpool_put(t->bt_mp, h, MPOOL_DIRTY);
break;
}
}
return (RET_SUCCESS);
}
/*
* __OVFL_DELETE -- Delete an overflow chain.
*
* Parameters:
* t: tree
* p: pointer to { pgno_t, uint32_t }
*
* Returns:
* RET_ERROR, RET_SUCCESS
*/
int
__ovfl_delete(BTREE *t, void *p)
{
PAGE *h;
pgno_t pg;
uint32_t sz, plen;
size_t temp;
(void)memmove(&pg, p, sizeof(pgno_t));
(void)memmove(&sz, (char *)p + sizeof(pgno_t), sizeof(uint32_t));
#ifdef DEBUG
if (pg == P_INVALID || sz == 0)
abort();
#endif
if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
return (RET_ERROR);
/* Don't delete chains used by internal pages. */
if (h->flags & P_PRESERVE) {
mpool_put(t->bt_mp, h, 0);
return (RET_SUCCESS);
}
/* Step through the chain, calling the free routine for each page. */
temp = t->bt_psize - BTDATAOFF;
_DBFIT(temp, uint32_t);
plen = (uint32_t)temp;
for (;; sz -= plen) {
pg = h->nextpg;
__bt_free(t, h);
if (sz <= plen)
break;
if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
return (RET_ERROR);
}
return (RET_SUCCESS);
}