Add a new control CTDB_GET_DB_SEQNUM - fetch a persistent db's sequence number.

[sahlberg/ctdb.git] / server / ctdb_persistent.c

diff --git a/server/ctdb_persistent.c b/server/ctdb_persistent.c
index c075a5d86a8bc9ebfcba3635eae374399d5e1f09..59ddadb042fe7eed63c01593139db4b3bf60ad4e 100644 (file)
--- a/server/ctdb_persistent.c
+++ b/server/ctdb_persistent.c
@@ -815,4 +815,70 @@ int32_t ctdb_control_persistent_store(struct ctdb_context *ctdb,
        return ctdb_control_trans2_commit(ctdb, c, ctdb_marshall_finish(m), async_reply);
 }
 
+static int32_t ctdb_get_db_seqnum(struct ctdb_context *ctdb,
+                                 uint32_t db_id,
+                                 uint64_t *seqnum)
+{
+       int32_t ret;
+       struct ctdb_db_context *ctdb_db;
+       const char *keyname = CTDB_DB_SEQNUM_KEY;
+       TDB_DATA key;
+       TDB_DATA data;
+       TALLOC_CTX *mem_ctx = talloc_new(ctdb);
+
+       ctdb_db = find_ctdb_db(ctdb, db_id);
+       if (!ctdb_db) {
+               DEBUG(DEBUG_ERR,(__location__ " Unknown db 0x%08x\n", db_id));
+               ret = -1;
+               goto done;
+       }
+
+       key.dptr = (uint8_t *)discard_const(keyname);
+       key.dsize = strlen(keyname) + 1;
+
+       ret = (int32_t)ctdb_ltdb_fetch(ctdb_db, key, NULL, mem_ctx, &data);
+       if (ret != 0) {
+               goto done;
+       }
+
+       if (data.dsize != sizeof(uint64_t)) {
+               *seqnum = 0;
+               goto done;
+       }
+
+       *seqnum = *(uint64_t *)data.dptr;
 
+done:
+       talloc_free(mem_ctx);
+       return ret;
+}
+
+/**
+ * Get the sequence number of a persistent database.
+ */
+int32_t ctdb_control_get_db_seqnum(struct ctdb_context *ctdb,
+                                  TDB_DATA indata,
+                                  TDB_DATA *outdata)
+{
+       uint32_t db_id;
+       int32_t ret;
+       uint64_t seqnum;
+
+       db_id = *(uint32_t *)indata.dptr;
+       ret = ctdb_get_db_seqnum(ctdb, db_id, &seqnum);
+       if (ret != 0) {
+               goto done;
+       }
+
+       outdata->dsize = sizeof(uint64_t);
+       outdata->dptr = (uint8_t *)talloc_zero(outdata, uint64_t);
+       if (outdata->dptr == NULL) {
+               ret = -1;
+               goto done;
+       }
+
+       *(outdata->dptr) = seqnum;
+
+done:
+       return ret;
+}