dbm.c
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上传日期:2022-05-23
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- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1996-2002
- * Sleepycat Software. All rights reserved.
- */
- /*
- * Copyright (c) 1990, 1993
- * Margo Seltzer. All rights reserved.
- */
- /*
- * Copyright (c) 1990, 1993
- * The Regents of the University of California. All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Margo Seltzer.
- *
- * 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.
- */
- #include "db_config.h"
- #ifndef lint
- static const char revid[] = "$Id: dbm.c,v 11.14 2002/02/22 16:11:10 bostic Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #include <fcntl.h>
- #include <string.h>
- #endif
- #define DB_DBM_HSEARCH 1
- #include "db_int.h"
- /*
- *
- * This package provides dbm and ndbm compatible interfaces to DB.
- *
- * EXTERN: #if DB_DBM_HSEARCH != 0
- *
- * EXTERN: int __db_ndbm_clearerr __P((DBM *));
- * EXTERN: void __db_ndbm_close __P((DBM *));
- * EXTERN: int __db_ndbm_delete __P((DBM *, datum));
- * EXTERN: int __db_ndbm_dirfno __P((DBM *));
- * EXTERN: int __db_ndbm_error __P((DBM *));
- * EXTERN: datum __db_ndbm_fetch __P((DBM *, datum));
- * EXTERN: datum __db_ndbm_firstkey __P((DBM *));
- * EXTERN: datum __db_ndbm_nextkey __P((DBM *));
- * EXTERN: DBM *__db_ndbm_open __P((const char *, int, int));
- * EXTERN: int __db_ndbm_pagfno __P((DBM *));
- * EXTERN: int __db_ndbm_rdonly __P((DBM *));
- * EXTERN: int __db_ndbm_store __P((DBM *, datum, datum, int));
- *
- * EXTERN: int __db_dbm_close __P((void));
- * EXTERN: int __db_dbm_dbrdonly __P((void));
- * EXTERN: int __db_dbm_delete __P((datum));
- * EXTERN: int __db_dbm_dirf __P((void));
- * EXTERN: datum __db_dbm_fetch __P((datum));
- * EXTERN: datum __db_dbm_firstkey __P((void));
- * EXTERN: int __db_dbm_init __P((char *));
- * EXTERN: datum __db_dbm_nextkey __P((datum));
- * EXTERN: int __db_dbm_pagf __P((void));
- * EXTERN: int __db_dbm_store __P((datum, datum));
- *
- * EXTERN: #endif
- */
- /*
- * The DBM routines, which call the NDBM routines.
- */
- static DBM *__cur_db;
- static void __db_no_open __P((void));
- int
- __db_dbm_init(file)
- char *file;
- {
- if (__cur_db != NULL)
- (void)dbm_close(__cur_db);
- if ((__cur_db =
- dbm_open(file, O_CREAT | O_RDWR, __db_omode("rw----"))) != NULL)
- return (0);
- if ((__cur_db = dbm_open(file, O_RDONLY, 0)) != NULL)
- return (0);
- return (-1);
- }
- int
- __db_dbm_close()
- {
- if (__cur_db != NULL) {
- dbm_close(__cur_db);
- __cur_db = NULL;
- }
- return (0);
- }
- datum
- __db_dbm_fetch(key)
- datum key;
- {
- datum item;
- if (__cur_db == NULL) {
- __db_no_open();
- item.dptr = 0;
- return (item);
- }
- return (dbm_fetch(__cur_db, key));
- }
- datum
- __db_dbm_firstkey()
- {
- datum item;
- if (__cur_db == NULL) {
- __db_no_open();
- item.dptr = 0;
- return (item);
- }
- return (dbm_firstkey(__cur_db));
- }
- datum
- __db_dbm_nextkey(key)
- datum key;
- {
- datum item;
- COMPQUIET(key.dsize, 0);
- if (__cur_db == NULL) {
- __db_no_open();
- item.dptr = 0;
- return (item);
- }
- return (dbm_nextkey(__cur_db));
- }
- int
- __db_dbm_delete(key)
- datum key;
- {
- if (__cur_db == NULL) {
- __db_no_open();
- return (-1);
- }
- return (dbm_delete(__cur_db, key));
- }
- int
- __db_dbm_store(key, dat)
- datum key, dat;
- {
- if (__cur_db == NULL) {
- __db_no_open();
- return (-1);
- }
- return (dbm_store(__cur_db, key, dat, DBM_REPLACE));
- }
- static void
- __db_no_open()
- {
- (void)fprintf(stderr, "dbm: no open database.n");
- }
- /*
- * This package provides dbm and ndbm compatible interfaces to DB.
- *
- * The NDBM routines, which call the DB routines.
- */
- /*
- * Returns:
- * *DBM on success
- * NULL on failure
- */
- DBM *
- __db_ndbm_open(file, oflags, mode)
- const char *file;
- int oflags, mode;
- {
- DB *dbp;
- DBC *dbc;
- int ret;
- char path[MAXPATHLEN];
- /*
- * !!!
- * Don't use sprintf(3)/snprintf(3) -- the former is dangerous, and
- * the latter isn't standard, and we're manipulating strings handed
- * us by the application.
- */
- if (strlen(file) + strlen(DBM_SUFFIX) + 1 > sizeof(path)) {
- __os_set_errno(ENAMETOOLONG);
- return (NULL);
- }
- (void)strcpy(path, file);
- (void)strcat(path, DBM_SUFFIX);
- if ((ret = db_create(&dbp, NULL, 0)) != 0) {
- __os_set_errno(ret);
- return (NULL);
- }
- /*
- * !!!
- * The historic ndbm library corrected for opening O_WRONLY.
- */
- if (oflags & O_WRONLY) {
- oflags &= ~O_WRONLY;
- oflags |= O_RDWR;
- }
- if ((ret = dbp->set_pagesize(dbp, 4096)) != 0 ||
- (ret = dbp->set_h_ffactor(dbp, 40)) != 0 ||
- (ret = dbp->set_h_nelem(dbp, 1)) != 0 ||
- (ret = dbp->open(dbp, NULL,
- path, NULL, DB_HASH, __db_oflags(oflags), mode)) != 0) {
- __os_set_errno(ret);
- return (NULL);
- }
- if ((ret = dbp->cursor(dbp, NULL, &dbc, 0)) != 0) {
- (void)dbp->close(dbp, 0);
- __os_set_errno(ret);
- return (NULL);
- }
- return ((DBM *)dbc);
- }
- /*
- * Returns:
- * Nothing.
- */
- void
- __db_ndbm_close(dbm)
- DBM *dbm;
- {
- DBC *dbc;
- dbc = (DBC *)dbm;
- (void)dbc->dbp->close(dbc->dbp, 0);
- }
- /*
- * Returns:
- * DATUM on success
- * NULL on failure
- */
- datum
- __db_ndbm_fetch(dbm, key)
- DBM *dbm;
- datum key;
- {
- DBC *dbc;
- DBT _key, _data;
- datum data;
- int ret;
- dbc = (DBC *)dbm;
- memset(&_key, 0, sizeof(DBT));
- memset(&_data, 0, sizeof(DBT));
- _key.size = key.dsize;
- _key.data = key.dptr;
- /*
- * Note that we can't simply use the dbc we have to do a c_get/SET,
- * because that cursor is the one used for sequential iteration and
- * it has to remain stable in the face of intervening gets and puts.
- */
- if ((ret = dbc->dbp->get(dbc->dbp, NULL, &_key, &_data, 0)) == 0) {
- data.dptr = _data.data;
- data.dsize = _data.size;
- } else {
- data.dptr = NULL;
- data.dsize = 0;
- if (ret == DB_NOTFOUND)
- __os_set_errno(ENOENT);
- else {
- __os_set_errno(ret);
- F_SET(dbc->dbp, DB_AM_DBM_ERROR);
- }
- }
- return (data);
- }
- /*
- * Returns:
- * DATUM on success
- * NULL on failure
- */
- datum
- __db_ndbm_firstkey(dbm)
- DBM *dbm;
- {
- DBC *dbc;
- DBT _key, _data;
- datum key;
- int ret;
- dbc = (DBC *)dbm;
- memset(&_key, 0, sizeof(DBT));
- memset(&_data, 0, sizeof(DBT));
- if ((ret = dbc->c_get(dbc, &_key, &_data, DB_FIRST)) == 0) {
- key.dptr = _key.data;
- key.dsize = _key.size;
- } else {
- key.dptr = NULL;
- key.dsize = 0;
- if (ret == DB_NOTFOUND)
- __os_set_errno(ENOENT);
- else {
- __os_set_errno(ret);
- F_SET(dbc->dbp, DB_AM_DBM_ERROR);
- }
- }
- return (key);
- }
- /*
- * Returns:
- * DATUM on success
- * NULL on failure
- */
- datum
- __db_ndbm_nextkey(dbm)
- DBM *dbm;
- {
- DBC *dbc;
- DBT _key, _data;
- datum key;
- int ret;
- dbc = (DBC *)dbm;
- memset(&_key, 0, sizeof(DBT));
- memset(&_data, 0, sizeof(DBT));
- if ((ret = dbc->c_get(dbc, &_key, &_data, DB_NEXT)) == 0) {
- key.dptr = _key.data;
- key.dsize = _key.size;
- } else {
- key.dptr = NULL;
- key.dsize = 0;
- if (ret == DB_NOTFOUND)
- __os_set_errno(ENOENT);
- else {
- __os_set_errno(ret);
- F_SET(dbc->dbp, DB_AM_DBM_ERROR);
- }
- }
- return (key);
- }
- /*
- * Returns:
- * 0 on success
- * <0 failure
- */
- int
- __db_ndbm_delete(dbm, key)
- DBM *dbm;
- datum key;
- {
- DBC *dbc;
- DBT _key;
- int ret;
- dbc = (DBC *)dbm;
- memset(&_key, 0, sizeof(DBT));
- _key.data = key.dptr;
- _key.size = key.dsize;
- if ((ret = dbc->dbp->del(dbc->dbp, NULL, &_key, 0)) == 0)
- return (0);
- if (ret == DB_NOTFOUND)
- __os_set_errno(ENOENT);
- else {
- __os_set_errno(ret);
- F_SET(dbc->dbp, DB_AM_DBM_ERROR);
- }
- return (-1);
- }
- /*
- * Returns:
- * 0 on success
- * <0 failure
- * 1 if DBM_INSERT and entry exists
- */
- int
- __db_ndbm_store(dbm, key, data, flags)
- DBM *dbm;
- datum key, data;
- int flags;
- {
- DBC *dbc;
- DBT _key, _data;
- int ret;
- dbc = (DBC *)dbm;
- memset(&_key, 0, sizeof(DBT));
- _key.data = key.dptr;
- _key.size = key.dsize;
- memset(&_data, 0, sizeof(DBT));
- _data.data = data.dptr;
- _data.size = data.dsize;
- if ((ret = dbc->dbp->put(dbc->dbp, NULL,
- &_key, &_data, flags == DBM_INSERT ? DB_NOOVERWRITE : 0)) == 0)
- return (0);
- if (ret == DB_KEYEXIST)
- return (1);
- __os_set_errno(ret);
- F_SET(dbc->dbp, DB_AM_DBM_ERROR);
- return (-1);
- }
- int
- __db_ndbm_error(dbm)
- DBM *dbm;
- {
- DBC *dbc;
- dbc = (DBC *)dbm;
- return (F_ISSET(dbc->dbp, DB_AM_DBM_ERROR));
- }
- int
- __db_ndbm_clearerr(dbm)
- DBM *dbm;
- {
- DBC *dbc;
- dbc = (DBC *)dbm;
- F_CLR(dbc->dbp, DB_AM_DBM_ERROR);
- return (0);
- }
- /*
- * Returns:
- * 1 if read-only
- * 0 if not read-only
- */
- int
- __db_ndbm_rdonly(dbm)
- DBM *dbm;
- {
- DBC *dbc;
- dbc = (DBC *)dbm;
- return (F_ISSET(dbc->dbp, DB_AM_RDONLY) ? 1 : 0);
- }
- /*
- * XXX
- * We only have a single file descriptor that we can return, not two. Return
- * the same one for both files. Hopefully, the user is using it for locking
- * and picked one to use at random.
- */
- int
- __db_ndbm_dirfno(dbm)
- DBM *dbm;
- {
- return (dbm_pagfno(dbm));
- }
- int
- __db_ndbm_pagfno(dbm)
- DBM *dbm;
- {
- DBC *dbc;
- int fd;
- dbc = (DBC *)dbm;
- (void)dbc->dbp->fd(dbc->dbp, &fd);
- return (fd);
- }