diff options
Diffstat (limited to 'source4/cluster/ctdb/common/ctdb_ltdb.c')
-rw-r--r-- | source4/cluster/ctdb/common/ctdb_ltdb.c | 139 |
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; +} |