Add --message-rate option to mosquitto_sub

When active, this prints the count of messages received each second.

ChangeLog.txt

@@ -190,6 +190,8 @@ Clients:
 - Add `--tls-keylog` option which can be used to generate a file that can be
   used by wireshark to decrypt TLS traffic for debugging purposes.
 - mosquitto_sub payload hex output can now be split by fixed field length.
+- Add `--message-rate` option to mosquitto_sub, for printing the count of
+  messages received each second.
 
 DB Dump:
 - Add `--json` output mode.

client/client_shared.c

@@ -869,6 +869,11 @@ int client_config_line_proc(struct mosq_config *cfg, int pub_or_sub, int argc, c
 				cfg->max_inflight = (unsigned int )tmpi;
 			}
 			i++;
+		}else if(!strcmp(argv[i], "--message-rate")){
+			if(pub_or_sub != CLIENT_SUB){
+				goto unknown_option;
+			}
+			cfg->message_rate = true;
 		}else if(!strcmp(argv[i], "--nodelay")){
 			cfg->tcp_nodelay = true;
 		}else if(!strcmp(argv[i], "--no-tls")){

client/client_shared.h

@@ -142,6 +142,7 @@ struct mosq_config {
 	bool have_topic_alias; /* pub */
 	bool tcp_nodelay;
 	bool no_tls;
+	bool message_rate; /* sub */
 };
 
 extern const char hexseplist[32];

client/sub_client.c

@@ -37,8 +37,10 @@ Contributors:
 #include "sub_client_output.h"
 
 struct mosq_config cfg;
+static bool run = true;
 bool process_messages = true;
 int msg_count = 0;
+int message_rate_msg_count = 0;
 struct mosquitto *g_mosq = NULL;
 int last_mid = 0;
 static bool timed_out = false;
@@ -76,6 +78,7 @@ static void my_signal_handler(int signum)
 		}else{
 			exit(-1);
 		}
+		run = false;
 	}
 	if(signum == SIGALRM){
 		timed_out = true;
@@ -92,6 +95,8 @@ static void my_message_callback(struct mosquitto *mosq, void *obj, const struct
 	UNUSED(obj);
 	UNUSED(properties);
 
+	message_rate_msg_count++;
+
 	if(process_messages == false) return;
 
 	if(cfg.retained_only && !message->retain && process_messages){
@@ -393,6 +398,10 @@ int main(int argc, char *argv[])
 	if(cfg.debug){
 		mosquitto_log_callback_set(g_mosq, my_log_callback);
 	}
+	if(cfg.message_rate){
+		process_messages = false;
+		cfg.watch = false;
+	}
 	mosquitto_subscribe_callback_set(g_mosq, my_subscribe_callback);
 	mosquitto_connect_v5_callback_set(g_mosq, my_connect_callback);
 	mosquitto_message_v5_callback_set(g_mosq, my_message_callback);
@@ -436,7 +445,21 @@ int main(int argc, char *argv[])
 	}
 #endif
 
-	rc = mosquitto_loop_forever(g_mosq, -1, 1);
+	if(cfg.message_rate){
+		rc = mosquitto_loop_start(g_mosq);
+		if(rc){
+			return rc;
+		}
+		while(run){
+			struct timespec ts = {1,0};
+			nanosleep(&ts, NULL);
+			int message_count = message_rate_msg_count;
+			message_rate_msg_count = 0;
+			printf("%d msgs/s\n", message_count);
+		}
+	}else{
+		rc = mosquitto_loop_forever(g_mosq, -1, 1);
+	}
 
 	mosquitto_destroy(g_mosq);
 	mosquitto_lib_cleanup();

man/mosquitto_sub.1.xml

@@ -43,6 +43,7 @@
 			<arg><option>-i</option> <replaceable>client-id</replaceable></arg>
 			<arg><option>-I</option> <replaceable>client-id-prefix</replaceable></arg>
 			<arg><option>-k</option> <replaceable>keepalive-time</replaceable></arg>
+			<arg><option>--message-rate</option></arg>
 			<arg><option>-N</option></arg>
 			<arg><option>--nodelay</option></arg>
 			<arg><option>--pretty</option></arg>
@@ -431,6 +432,17 @@
 					</para>
 				</listitem>
 			</varlistentry>
+			<varlistentry>
+				<term><option>--message-rate</option></term>
+				<listitem>
+                    <para>
+                        Instead of printing the messages received, print a count
+                        of the messages received at one second intervals. Other
+                        options related to output formatting are not valid when
+                        this option is active.
+					</para>
+				</listitem>
+			</varlistentry>
 			<varlistentry>
 				<term><option>-N</option></term>
 				<listitem>