minix/lib/libc/db/recno/rec_delete.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

197 lines
5.3 KiB
C

/* $NetBSD: rec_delete.c,v 1.17 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: rec_delete.c,v 1.17 2008/09/11 12:58:00 joerg Exp $");
#include "namespace.h"
#include <sys/types.h>
#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <db.h>
#include "recno.h"
static int rec_rdelete(BTREE *, recno_t);
/*
* __REC_DELETE -- Delete the item(s) referenced by a key.
*
* Parameters:
* dbp: pointer to access method
* key: key to delete
* flags: R_CURSOR if deleting what the cursor references
*
* Returns:
* RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
*/
int
__rec_delete(const DB *dbp, const DBT *key, u_int flags)
{
BTREE *t;
recno_t nrec;
int status;
t = dbp->internal;
/* Toss any page pinned across calls. */
if (t->bt_pinned != NULL) {
mpool_put(t->bt_mp, t->bt_pinned, 0);
t->bt_pinned = NULL;
}
switch(flags) {
case 0:
if ((nrec = *(recno_t *)key->data) == 0)
goto einval;
if (nrec > t->bt_nrecs)
return (RET_SPECIAL);
--nrec;
status = rec_rdelete(t, nrec);
break;
case R_CURSOR:
if (!F_ISSET(&t->bt_cursor, CURS_INIT))
goto einval;
if (t->bt_nrecs == 0)
return (RET_SPECIAL);
status = rec_rdelete(t, t->bt_cursor.rcursor - 1);
if (status == RET_SUCCESS)
--t->bt_cursor.rcursor;
break;
default:
einval: errno = EINVAL;
return (RET_ERROR);
}
if (status == RET_SUCCESS)
F_SET(t, B_MODIFIED | R_MODIFIED);
return (status);
}
/*
* REC_RDELETE -- Delete the data matching the specified key.
*
* Parameters:
* tree: tree
* nrec: record to delete
*
* Returns:
* RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
*/
static int
rec_rdelete(BTREE *t, recno_t nrec)
{
EPG *e;
PAGE *h;
int status;
/* Find the record; __rec_search pins the page. */
if ((e = __rec_search(t, nrec, SDELETE)) == NULL)
return (RET_ERROR);
/* Delete the record. */
h = e->page;
status = __rec_dleaf(t, h, (uint32_t)e->index);
if (status != RET_SUCCESS) {
mpool_put(t->bt_mp, h, 0);
return (status);
}
mpool_put(t->bt_mp, h, MPOOL_DIRTY);
return (RET_SUCCESS);
}
/*
* __REC_DLEAF -- Delete a single record from a recno leaf page.
*
* Parameters:
* t: tree
* index: index on current page to delete
*
* Returns:
* RET_SUCCESS, RET_ERROR.
*/
int
__rec_dleaf(BTREE *t, PAGE *h, uint32_t idx)
{
RLEAF *rl;
indx_t *ip, cnt, offset;
uint32_t nbytes;
char *from;
void *to;
size_t temp;
/*
* Delete a record from a recno leaf page. Internal records are never
* deleted from internal pages, regardless of the records that caused
* them to be added being deleted. Pages made empty by deletion are
* not reclaimed. They are, however, made available for reuse.
*
* Pack the remaining entries at the end of the page, shift the indices
* down, overwriting the deleted record and its index. If the record
* uses overflow pages, make them available for reuse.
*/
to = rl = GETRLEAF(h, idx);
if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR)
return (RET_ERROR);
nbytes = NRLEAF(rl);
/*
* Compress the key/data pairs. Compress and adjust the [BR]LEAF
* offsets. Reset the headers.
*/
from = (char *)(void *)h + h->upper;
memmove(from + nbytes, from, (size_t)((char *)to - from));
h->upper += nbytes;
offset = h->linp[idx];
temp = &h->linp[idx] - (ip = &h->linp[0]);
_DBFIT(temp, uint16_t);
for (cnt = (uint16_t)temp; cnt--; ++ip)
if (ip[0] < offset)
ip[0] += nbytes;
temp = &h->linp[NEXTINDEX(h)] - ip;
_DBFIT(temp, uint16_t);
for (cnt = (uint16_t)temp; --cnt; ++ip)
ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
h->lower -= sizeof(indx_t);
--t->bt_nrecs;
return (RET_SUCCESS);
}