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authorAndrew Tridgell <tridge@samba.org>2007-01-19 03:54:48 +0000
committerGerald (Jerry) Carter <jerry@samba.org>2007-10-10 14:43:46 -0500
commit5cb78383fafa15c2ff7a4ccd194cccd5cf5cd263 (patch)
tree050e2f47faf234685cd7f20ab7e4f37e6521f7a2 /source4/cluster/ctdb/common/ctdb_ltdb.c
parent8c3d15f6caa3f1ffda86755fa9b7ff9602cbb022 (diff)
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r20889: import ctdb cluster backend from bzr
it will be interesting to see how the build farm handles this (This used to be commit 53be449630bd67d649a9e70cc7e25a9799c0616b)
Diffstat (limited to 'source4/cluster/ctdb/common/ctdb_ltdb.c')
-rw-r--r--source4/cluster/ctdb/common/ctdb_ltdb.c139
1 files changed, 139 insertions, 0 deletions
diff --git a/source4/cluster/ctdb/common/ctdb_ltdb.c b/source4/cluster/ctdb/common/ctdb_ltdb.c
new file mode 100644
index 0000000000..bc15a3e898
--- /dev/null
+++ b/source4/cluster/ctdb/common/ctdb_ltdb.c
@@ -0,0 +1,139 @@
+/*
+ ctdb ltdb code
+
+ Copyright (C) Andrew Tridgell 2006
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2 of the License, or (at your option) any later version.
+
+ This library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include "includes.h"
+#include "lib/events/events.h"
+#include "lib/tdb/include/tdb.h"
+#include "system/network.h"
+#include "system/filesys.h"
+#include "cluster/ctdb/include/ctdb_private.h"
+
+/*
+ attach to a specific database
+*/
+int ctdb_attach(struct ctdb_context *ctdb, const char *name, int tdb_flags,
+ int open_flags, mode_t mode)
+{
+ /* when we have a separate daemon this will need to be a real
+ file, not a TDB_INTERNAL, so the parent can access it to
+ for ltdb bypass */
+ ctdb->ltdb = tdb_open(name, 0, /* tdb_flags */ TDB_INTERNAL, open_flags, mode);
+ if (ctdb->ltdb == NULL) {
+ ctdb_set_error(ctdb, "Failed to open tdb %s\n", name);
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ return the lmaster given a key
+*/
+uint32_t ctdb_lmaster(struct ctdb_context *ctdb, const TDB_DATA *key)
+{
+ return ctdb_hash(key) % ctdb->num_nodes;
+}
+
+
+/*
+ construct an initial header for a record with no ltdb header yet
+*/
+static void ltdb_initial_header(struct ctdb_context *ctdb,
+ TDB_DATA key,
+ struct ctdb_ltdb_header *header)
+{
+ header->rsn = 0;
+ /* initial dmaster is the lmaster */
+ header->dmaster = ctdb_lmaster(ctdb, &key);
+ header->laccessor = header->dmaster;
+ header->lacount = 0;
+}
+
+
+/*
+ fetch a record from the ltdb, separating out the header information
+ and returning the body of the record. A valid (initial) header is
+ returned if the record is not present
+*/
+int ctdb_ltdb_fetch(struct ctdb_context *ctdb,
+ TDB_DATA key, struct ctdb_ltdb_header *header, TDB_DATA *data)
+{
+ TDB_DATA rec;
+
+ rec = tdb_fetch(ctdb->ltdb, key);
+ if (rec.dsize < sizeof(*header)) {
+ /* return an initial header */
+ free(rec.dptr);
+ ltdb_initial_header(ctdb, key, header);
+ data->dptr = NULL;
+ data->dsize = 0;
+ return 0;
+ }
+
+ *header = *(struct ctdb_ltdb_header *)rec.dptr;
+
+ data->dsize = rec.dsize - sizeof(struct ctdb_ltdb_header);
+ data->dptr = talloc_memdup(ctdb, sizeof(struct ctdb_ltdb_header)+rec.dptr,
+ data->dsize);
+ free(rec.dptr);
+ CTDB_NO_MEMORY(ctdb, data->dptr);
+
+ {
+ int i, fd = open("/dev/null", O_WRONLY);
+ for (i=0;i<data->dsize;i++) {
+ write(fd, &data->dptr[i], 1);
+ }
+ close(fd);
+ }
+
+ return 0;
+}
+
+
+/*
+ fetch a record from the ltdb, separating out the header information
+ and returning the body of the record. A valid (initial) header is
+ returned if the record is not present
+*/
+int ctdb_ltdb_store(struct ctdb_context *ctdb, TDB_DATA key,
+ struct ctdb_ltdb_header *header, TDB_DATA data)
+{
+ TDB_DATA rec;
+ int ret;
+
+ rec.dsize = sizeof(*header) + data.dsize;
+ rec.dptr = talloc_size(ctdb, rec.dsize);
+ CTDB_NO_MEMORY(ctdb, rec.dptr);
+
+ memcpy(rec.dptr, header, sizeof(*header));
+ memcpy(rec.dptr + sizeof(*header), data.dptr, data.dsize);
+
+ {
+ int i, fd = open("/dev/null", O_WRONLY);
+ for (i=0;i<rec.dsize;i++) {
+ write(fd, &rec.dptr[i], 1);
+ }
+ close(fd);
+ }
+
+ ret = tdb_store(ctdb->ltdb, key, rec, TDB_REPLACE);
+ talloc_free(rec.dptr);
+
+ return ret;
+}