LibCTDB: add get persistent db seqnum control

(This used to be ctdb commit 6e96a62494bbb2c7b0682ebf0c2115dd2f44f7af)

ctdb/include/ctdb.h

@@ -509,6 +509,35 @@ bool ctdb_getpnn_recv(struct ctdb_connection *ctdb,
 		      struct ctdb_request *req, uint32_t *pnn);
 
 
+/**
+ * ctdb_getdbseqnum_send - read the sequence number off a db
+ * @ctdb: the ctdb_connection from ctdb_connect.
+ * @destnode: the destination node (see below)
+ * @dbid: database id
+ * @callback: the callback when ctdb replies to our message (typesafe)
+ * @cbdata: the argument to callback()
+ *
+ * There are several special values for destnode, detailed in
+ * ctdb_protocol.h, particularly CTDB_CURRENT_NODE which means the
+ * local ctdbd.
+ */
+struct ctdb_request *
+ctdb_getdbseqnum_send(struct ctdb_connection *ctdb,
+		 uint32_t destnode,
+		 uint32_t dbid,
+		 ctdb_callback_t callback,
+		 void *cbdata);
+/**
+ * ctdb_getdbseqnum_recv - read the sequence number off a database
+ * @ctdb: the ctdb_connection from ctdb_connect.
+ * @req: the completed request.
+ * @seqnum: a pointer to the seqnum to fill in
+ *
+ * This returns false if something went wrong, or otherwise fills in pnn.
+ */
+bool ctdb_getdbseqnum_recv(struct ctdb_connection *ctdb,
+		      struct ctdb_request *req, uint64_t *seqnum);
+
 /**
  * ctdb_getnodemap_send - read the nodemap number from a node.
  * @ctdb: the ctdb_connection from ctdb_connect.
@@ -737,6 +766,25 @@ bool ctdb_getpnn(struct ctdb_connection *ctdb,
 		 uint32_t destnode,
 		 uint32_t *pnn);
 
+/**
+ * ctdb_getdbseqnum - read the seqnum of a database
+ * @ctdb: the ctdb_connection from ctdb_connect.
+ * @destnode: the destination node (see below)
+ * @dbid: database id
+ * @seqnum: sequence number for the database
+ *
+ * There are several special values for destnode, detailed in
+ * ctdb_protocol.h, particularly CTDB_CURRENT_NODE which means the
+ * local ctdbd.
+ *
+ * Returns true and fills in *pnn on success.
+ */
+bool
+ctdb_getdbseqnum(struct ctdb_connection *ctdb,
+		 uint32_t destnode,
+		 uint32_t dbid,
+		 uint64_t *seqnum);
+
 /**
  * ctdb_getrecmaster - read the recovery master of a node (synchronous)
  * @ctdb: the ctdb_connection from ctdb_connect.
@@ -890,4 +938,8 @@ void ctdb_free_publicips(struct ctdb_all_public_ips *ips);
 	ctdb_getpublicips_send((ctdb), (destnode),			\
 			 ctdb_sendcb((cb), (cbdata)), (cbdata))
 
+#define ctdb_getdbseqnum_send(ctdb, destnode, dbid, cb, cbdata)		\
+	ctdb_getdbseqnum_send((ctdb), (destnode), (dbid),		\
+			 ctdb_sendcb((cb), (cbdata)), (cbdata))
+
 #endif

ctdb/libctdb/control.c

@@ -27,6 +27,7 @@
 #undef ctdb_getpnn_send
 #undef ctdb_getnodemap_send
 #undef ctdb_getpublicips_send
+#undef ctdb_getdbseqnum_send
 
 bool ctdb_getrecmaster_recv(struct ctdb_connection *ctdb,
 			   struct ctdb_request *req, uint32_t *recmaster)
@@ -200,3 +201,42 @@ void ctdb_free_publicips(struct ctdb_all_public_ips *ips)
 	}
 	free(ips);
 }
+
+bool ctdb_getdbseqnum_recv(struct ctdb_connection *ctdb,
+			   struct ctdb_request *req, uint64_t *seqnum)
+{
+	struct ctdb_reply_control *reply;
+
+	reply = unpack_reply_control(req, CTDB_CONTROL_GET_DB_SEQNUM);
+	if (!reply) {
+		return false;
+	}
+	if (reply->status == -1) {
+		DEBUG(ctdb, LOG_ERR, "ctdb_getdbseqnum_recv: status -1");
+		return false;
+	}
+
+	if (reply->datalen != sizeof(uint64_t)) {
+		DEBUG(ctdb, LOG_ERR, "ctdb_getdbseqnum wrong size of data was %d but expected %d bytes", reply->datalen, (int)sizeof(uint64_t));
+		return false;
+	}
+
+	*seqnum = *((uint64_t *)reply->data);
+
+	return true;
+}
+
+struct ctdb_request *ctdb_getdbseqnum_send(struct ctdb_connection *ctdb,
+					    uint32_t destnode,
+					    uint32_t dbid,
+					    ctdb_callback_t callback,
+					    void *private_data)
+{
+	uint64_t indata;
+
+	*((uint32_t *)&indata) = dbid;
+
+	return new_ctdb_control_request(ctdb, CTDB_CONTROL_GET_DB_SEQNUM,
+					destnode, &indata, sizeof(uint64_t),
+					callback, private_data);
+}

ctdb/libctdb/sync.c

@@ -244,3 +244,21 @@ struct ctdb_lock *ctdb_readrecordlock(struct ctdb_connection *ctdb,
 	}
 	return rrl.lock;
 }
+
+bool ctdb_getdbseqnum(struct ctdb_connection *ctdb,
+		      uint32_t destnode, uint32_t dbid,
+		      uint64_t *seqnum)
+{
+	struct ctdb_request *req;
+	bool done = false;
+	bool ret = false;
+
+	req = synchronous(ctdb,
+			  ctdb_getdbseqnum_send(ctdb, destnode, dbid, set, &done),
+			  &done);
+	if (req != NULL) {
+		ret = ctdb_getdbseqnum_recv(ctdb, req, seqnum);
+		ctdb_request_free(req);
+	}
+	return ret;
+}

ctdb/tools/ctdb.c

@@ -4131,6 +4131,32 @@ static int control_setdbreadonly(struct ctdb_context *ctdb, int argc, const char
 	return 0;
 }
 
+/*
+  get db seqnum
+ */
+static int control_getdbseqnum(struct ctdb_context *ctdb, int argc, const char **argv)
+{
+	bool ret;
+	uint32_t db_id;
+	uint64_t seqnum;
+
+	if (argc < 1) {
+		usage();
+	}
+
+	db_id = strtoul(argv[0], NULL, 0);
+
+	ret = ctdb_getdbseqnum(ctdb_connection, options.pnn, db_id, &seqnum);
+	if (!ret) {
+		DEBUG(DEBUG_ERR, ("Unable to get seqnum from node."));
+		return -1;
+	}
+
+	printf("Sequence number:%lld\n", (long long)seqnum);
+
+	return 0;
+}
+
 /*
   run an eventscript on a node
  */
@@ -5141,6 +5167,7 @@ static const struct {
 	{ "readkey", 	     control_readkey,      	true,	false,  "read the content off a database key", "<tdb-file> <key>" },
 	{ "writekey", 	     control_writekey,      	true,	false,  "write to a database key", "<tdb-file> <key> <value>" },
 	{ "checktcpport",    control_chktcpport,      	false,	true,  "check if a service is bound to a specific tcp port or not", "<port>" },
+	{ "getdbseqnum",     control_getdbseqnum,       false,	false, "get the sequence number off a database", "<dbid>" },
 };
 
 /*