From 5cb78383fafa15c2ff7a4ccd194cccd5cf5cd263 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Fri, 19 Jan 2007 03:54:48 +0000
Subject: 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)
---
 source4/cluster/ctdb/common/ctdb_ltdb.c | 139 ++++++++++++++++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100644 source4/cluster/ctdb/common/ctdb_ltdb.c

(limited to 'source4/cluster/ctdb/common/ctdb_ltdb.c')

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;
+}
-- 
cgit