From 4c185a6077322ba64231d23dda25a6b6d44d0b12 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Thu, 10 May 2007 10:42:13 +0000 Subject: r22775: For the cluster code I've developed a wrapper around tdb to put different database backends in place dynamically. The main abstractions are db_context and db_record, it should be mainly self-describing, see include/dbwrap.h. You open the db just as you would open a tdb, this time with db_open(). If you want to fetch a record, just do the db->fetch() call, if you want to do operations on it, you need to get it with fetch_locked(). I added dbwrap_file.c (not heavily tested lately) as an example for what can be done with that abstraction, uses a file per key. So if anybody is willing to shape that up, we might have a chance on reiserfs again.... :-) This abstraction works fine for brlock.tdb, locking.tdb, connections.tdb and sessionid.tdb. It should work fine for the others as well, I just did not yet get around to convert them. If nobody loudly screams NO, then I will import the code that uses this soon. Volker (This used to be commit e9d7484ca246cfca4a1fd23be35edc2783136ebe) --- source3/lib/dbwrap.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 source3/lib/dbwrap.c (limited to 'source3/lib/dbwrap.c') diff --git a/source3/lib/dbwrap.c b/source3/lib/dbwrap.c new file mode 100644 index 0000000000..9f74a9eb48 --- /dev/null +++ b/source3/lib/dbwrap.c @@ -0,0 +1,61 @@ +/* + Unix SMB/CIFS implementation. + Database interface wrapper + Copyright (C) Jim McDonough 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 2 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, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include "includes.h" + +/* + * 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; +} + +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; + + 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; +} -- cgit