source: branches/samba-3.2.x/source/lib/dbwrap.c

/* 
   Unix SMB/CIFS implementation.
   Database interface wrapper
   Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2006

   Major code contributions from Aleksey Fedoseev (fedoseev@ru.ibm.com)
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#ifdef CLUSTER_SUPPORT
#include "ctdb_private.h"
#endif
/*
 * Fall back using fetch_locked if no genuine fetch operation is provided
 */

static int dbwrap_fallback_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
                                 TDB_DATA key, TDB_DATA *data)
{
        struct db_record *rec;

        if (!(rec = db->fetch_locked(db, mem_ctx, key))) {
                return -1;
        }

        data->dsize = rec->value.dsize;
        data->dptr = talloc_move(mem_ctx, &rec->value.dptr);
        TALLOC_FREE(rec);
        return 0;
}

bool db_is_local(const char *name)
{
#ifdef CLUSTER_SUPPORT
        const char *sockname = lp_ctdbd_socket();

        if(!sockname || !*sockname) {
                sockname = CTDB_PATH;
        }

        if (lp_clustering() && socket_exist(sockname)) {
                const char *partname;
                /* ctdb only wants the file part of the name */
                partname = strrchr(name, '/');
                if (partname) {
                        partname++;
                } else {
                        partname = name;
                }
                /* allow ctdb for individual databases to be disabled */
                if (lp_parm_bool(-1, "ctdb", partname, True)) {
                        return false;
                }
        }
#endif
        return true;
}

/**
 * If you need transaction support use db_open_trans()
 */
struct db_context *db_open(TALLOC_CTX *mem_ctx,
                           const char *name,
                           int hash_size, int tdb_flags,
                           int open_flags, mode_t mode)
{
        struct db_context *result = NULL;
#ifdef CLUSTER_SUPPORT
        const char *sockname = lp_ctdbd_socket();
#endif

#ifdef CLUSTER_SUPPORT
        if(!sockname || !*sockname) {
                sockname = CTDB_PATH;
        }

        if (lp_clustering() && socket_exist(sockname)) {
                const char *partname;
                /* ctdb only wants the file part of the name */
                partname = strrchr(name, '/');
                if (partname) {
                        partname++;
                } else {
                        partname = name;
                }
                /* allow ctdb for individual databases to be disabled */
                if (lp_parm_bool(-1, "ctdb", partname, True)) {
                        result = db_open_ctdb(mem_ctx, partname, hash_size,
                                              tdb_flags, open_flags, mode);
                        if (result == NULL) {
                                DEBUG(0,("failed to attach to ctdb %s\n",
                                         partname));
                                smb_panic("failed to attach to a ctdb "
                                          "database");
                        }
                }
        }

#endif

        if (result == NULL) {
                result = db_open_tdb(mem_ctx, name, hash_size,
                                     tdb_flags, open_flags, mode);
        }

        if ((result != NULL) && (result->fetch == NULL)) {
                result->fetch = dbwrap_fallback_fetch;
        }

        return result;
}

/**
 * If you use this you can only modify with a transaction
 */
struct db_context *db_open_trans(TALLOC_CTX *mem_ctx,
                                 const char *name,
                                 int hash_size, int tdb_flags,
                                 int open_flags, mode_t mode)
{
        bool use_tdb2 = lp_parm_bool(-1, "dbwrap", "use_tdb2", false);
#ifdef CLUSTER_SUPPORT
        const char *sockname = lp_ctdbd_socket();
#endif

        if (tdb_flags & TDB_CLEAR_IF_FIRST) {
                DEBUG(0,("db_open_trans: called with TDB_CLEAR_IF_FIRST: %s\n",
                         name));
                smb_panic("db_open_trans: called with TDB_CLEAR_IF_FIRST");
        }

#ifdef CLUSTER_SUPPORT
        if(!sockname || !*sockname) {
                sockname = CTDB_PATH;
        }

        if (lp_clustering() && socket_exist(sockname)) {
                const char *partname;
                /* ctdb only wants the file part of the name */
                partname = strrchr(name, '/');
                if (partname) {
                        partname++;
                } else {
                        partname = name;
                }
                /* allow ctdb for individual databases to be disabled */
                if (lp_parm_bool(-1, "ctdb", partname, true)) {
                        struct db_context *result = NULL;
                        result = db_open_ctdb(mem_ctx, partname, hash_size,
                                              tdb_flags, open_flags, mode);
                        if (result == NULL) {
                                DEBUG(0,("failed to attach to ctdb %s\n",
                                         partname));
                                smb_panic("failed to attach to a ctdb "
                                          "database");
                        }
                        return result;
                }
        }
#endif

        if (use_tdb2) {
                const char *partname;
                /* tdb2 only wants the file part of the name */
                partname = strrchr(name, '/');
                if (partname) {
                        partname++;
                } else {
                        partname = name;
                }
                /* allow ctdb for individual databases to be disabled */
                if (lp_parm_bool(-1, "tdb2", partname, true)) {
                        return db_open_tdb2(mem_ctx, partname, hash_size,
                                            tdb_flags, open_flags, mode);
                }
        }

        return db_open_tdb(mem_ctx, name, hash_size,
                           tdb_flags, open_flags, mode);
}

NTSTATUS dbwrap_delete_bystring(struct db_context *db, const char *key)
{
        struct db_record *rec;
        NTSTATUS status;

        rec = db->fetch_locked(db, talloc_tos(), string_term_tdb_data(key));
        if (rec == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        status = rec->delete_rec(rec);
        TALLOC_FREE(rec);
        return status;
}

NTSTATUS dbwrap_store_bystring(struct db_context *db, const char *key,
                               TDB_DATA data, int flags)
{
        struct db_record *rec;
        NTSTATUS status;

        rec = db->fetch_locked(db, talloc_tos(), string_term_tdb_data(key));
        if (rec == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        status = rec->store(rec, data, flags);
        TALLOC_FREE(rec);
        return status;
}

TDB_DATA dbwrap_fetch_bystring(struct db_context *db, TALLOC_CTX *mem_ctx,
                               const char *key)
{
        TDB_DATA result;

        if (db->fetch(db, mem_ctx, string_term_tdb_data(key), &result) == -1) {
                return make_tdb_data(NULL, 0);
        }

        return result;
}