freebsd-dev/contrib/global/lib/dbio.c

329 lines
7.5 KiB
C

/*
* Copyright (c) 1996, 1997 Shigio Yamaguchi. All rights reserved.
*
* Redilogibution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redilogibutions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redilogibutions 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 dilogibution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Shigio Yamaguchi.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* dbio.c 14-Dec-97
*
*/
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "dbio.h"
#include "die.h"
#include "test.h"
DBT key; /* key of record */
DBT dat; /* data of record */
/*
* db_open: open db database.
*
* i) dbname database name
* i) mode 0: read only, 1: write only, 2: read & write
* i) perm file permission
* i) flags
* DBIO_DUP: allow duplicate records.
* DBIO_REMOVE: remove on closed.
* r) descripter for db_xxx()
*
* db_open leaves database permission 0600. please chmod(2) to make public.
*/
DBIO *
db_open(dbname, mode, perm, flags)
char *dbname;
int mode;
int perm;
int flags;
{
DB *db;
int rw;
BTREEINFO info;
DBIO *dbio;
/*
* setup argments.
*/
if (mode == 0)
rw = O_RDONLY;
else if (mode == 1)
rw = O_RDWR|O_CREAT|O_TRUNC;
else if (mode == 2)
rw = O_RDWR;
else
die("db_open illegal mode.");
info.flags = (flags & DBIO_DUP) ? R_DUP : 0;
info.cachesize = 500000;
info.maxkeypage = 0;
info.minkeypage = 0;
info.psize = 0;
info.compare = NULL;
info.prefix = NULL;
info.lorder = LITTLE_ENDIAN;
/*
* if unlink do job normally, those who already open tag file can use
* it until closing.
*/
if (mode == 1 && test("f", dbname))
(void)unlink(dbname);
db = dbopen(dbname, rw, 0600, DB_BTREE, &info);
if (!db)
die1("db_open failed (dbname = %s).", dbname);
if (!(dbio = (DBIO *)malloc(sizeof(DBIO))))
die("short of memory.");
strcpy(dbio->dbname, dbname);
dbio->db = db;
dbio->openflags = flags;
dbio->perm = (mode == 1) ? perm : 0;
dbio->lastkey = (char *)0;
dbio->lastdat = (char *)0;
return dbio;
}
/*
* db_get: get data by a key.
*
* i) dbio descripter
* i) k key
* r) pointer to data
*/
char *
db_get(dbio, k)
DBIO *dbio;
char *k;
{
DB *db = dbio->db;
int status;
key.data = k;
key.size = strlen(k)+1;
status = (*db->get)(db, &key, &dat, 0);
dbio->lastkey = (char *)key.data;
dbio->lastdat = (char *)dat.data;
switch (status) {
case RET_SUCCESS:
break;
case RET_ERROR:
die("db_get failed.");
case RET_SPECIAL:
return((char *)0);
}
return((char *)dat.data);
}
/*
* db_put: put data by a key.
*
* i) dbio descripter
* i) k key
* i) d data
*/
void
db_put(dbio, k, d)
DBIO *dbio;
char *k;
char *d;
{
DB *db = dbio->db;
int status;
if (strlen(k) > MAXKEYLEN)
die("primary key too long.");
key.data = k;
key.size = strlen(k)+1;
dat.data = d;
dat.size = strlen(d)+1;
status = (*db->put)(db, &key, &dat, 0);
switch (status) {
case RET_SUCCESS:
break;
case RET_ERROR:
case RET_SPECIAL:
die("db_put failed.");
}
}
/*
* db_del: delete record by a key.
*
* i) dbio descripter
* i) k key
*/
void
db_del(dbio, k)
DBIO *dbio;
char *k;
{
DB *db = dbio->db;
int status;
if (k) {
key.data = k;
key.size = strlen(k)+1;
status = (*db->del)(db, &key, 0);
} else
status = (*db->del)(db, &key, R_CURSOR);
if (status == RET_ERROR)
die("db_del failed.");
}
/*
* db_first: get first record.
*
* i) dbio dbio descripter
* i) k key
* !=NULL: indexed read by key
* ==NULL: sequential read
* i) flags following db_next call take over this.
* DBIO_KEY read key part
* DBIO_PREFIX prefix read
* DBIO_SKIPMETA skip META record
* only valied when sequential read
* r) data
*/
char *
db_first(dbio, k, flags)
DBIO *dbio;
char *k;
int flags;
{
DB *db = dbio->db;
int status;
if (flags & DBIO_PREFIX && !k)
flags &= ~DBIO_PREFIX;
if (flags & DBIO_SKIPMETA && k)
flags &= ~DBIO_SKIPMETA;
if (k) {
if (strlen(k) > MAXKEYLEN)
die("primary key too long.");
strcpy(dbio->key, k);
key.data = k;
key.size = strlen(k);
/*
* includes NULL character unless prefix read.
*/
if (!(flags & DBIO_PREFIX))
key.size++;
dbio->keylen = key.size;
status = (*db->seq)(db, &key, &dat, R_CURSOR);
} else {
dbio->keylen = dbio->key[0] = 0;
for (status = (*db->seq)(db, &key, &dat, R_FIRST);
status == RET_SUCCESS &&
flags & DBIO_SKIPMETA &&
*((char *)dat.data) == ' ';
status = (*db->seq)(db, &key, &dat, R_NEXT))
;
}
dbio->lastkey = (char *)key.data;
dbio->lastdat = (char *)dat.data;
switch (status) {
case RET_SUCCESS:
break;
case RET_ERROR:
die("db_first failed.");
case RET_SPECIAL:
return ((char *)0);
}
dbio->ioflags = flags;
if (flags & DBIO_PREFIX) {
if (strncmp((char *)key.data, dbio->key, dbio->keylen))
return (char *)0;
} else if (dbio->keylen) {
if (strcmp((char *)key.data, dbio->key))
return (char *)0;
}
if (flags & DBIO_KEY) {
strcpy(dbio->prev, (char *)key.data);
return (char *)key.data;
}
return ((char *)dat.data);
}
/*
* db_next: get next record.
*
* i) dbio dbio descripter
* r) data
*/
char *
db_next(dbio)
DBIO *dbio;
{
DB *db = dbio->db;
int flags = dbio->ioflags;
int status;
while ((status = (*db->seq)(db, &key, &dat, R_NEXT)) == RET_SUCCESS) {
if (flags & DBIO_SKIPMETA) {
if (*((char *)dat.data) == ' ')
continue;
}
if (flags & DBIO_KEY) {
if (!strcmp(dbio->prev, (char *)key.data))
continue;
if (strlen((char *)key.data) > MAXKEYLEN)
die("primary key too long.");
strcpy(dbio->prev, (char *)key.data);
}
dbio->lastkey = (char *)key.data;
dbio->lastdat = (char *)dat.data;
if (flags & DBIO_PREFIX) {
if (strncmp((char *)key.data, dbio->key, dbio->keylen))
return (char *)0;
} else if (dbio->keylen) {
if (strcmp((char *)key.data, dbio->key))
return (char *)0;
}
return (flags & DBIO_KEY) ? (char *)key.data : (char *)dat.data;
}
if (status == RET_ERROR)
die("db_next failed.");
return (char *)0;
}
/*
* db_close: close db
*
* i) dbio dbio descripter
*/
void
db_close(dbio)
DBIO *dbio;
{
DB *db = dbio->db;
(void)db->close(db);
if (dbio->openflags & DBIO_REMOVE)
(void)unlink(dbio->dbname);
else if (dbio->perm && chmod(dbio->dbname, dbio->perm) < 0)
die("cannot change file mode.");
(void)free(dbio);
}