added handling of "/cluster_heartbeat/id" to the HTTP server

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## [5.1.8] - 2024-04-??
 
+* added handling of _*/cluster_heartbeat/id*_ to the _*libmicrohttpd*_ HTTP server
 * server-side optimisations: removed the Unix pipe and the accompanying request/response POSIX threads from three WebSocket event loop functions: <_*ws_event_loop*_>, <_*video_event_loop*_> and <_*pv_event_loop*_>
 
 ## [5.1.7] - 2024-04-09

src/http.c

@@ -120,6 +120,7 @@ void *fetch_image(void *ptr);
 void *fetch_realtime_image_spectrum(void *ptr);
 void *fetch_pv_diagram(void *ptr);
 int submit_progress(char *root, char *datasetid, int len, int progress);
+extern void update_timestamp(void *ptr);
 
 PGconn *jvo_db_connect(char *db);
 char *get_jvo_path(PGconn *jvo_db, char *db, char *table, char *data_id);
@@ -1807,6 +1808,32 @@ static enum MHD_Result on_http_connection(void *cls,
             return http_bad_request(connection);
     }
 
+    if (strstr(url, "/cluster_heartbeat/") != NULL)
+    {
+        char *datasetId = strrchr(url, '/');
+
+        if (datasetId != NULL)
+        {
+            datasetId++; // skip the slash character
+
+#ifdef DEBUG
+            printf("[C] <cluster_heartbeat> request for '%s'\n", datasetId);
+#endif
+
+            void *item = get_dataset(datasetId);
+
+            if (item != NULL)
+            {
+                update_timestamp(item);
+                return http_ok(connection);
+            }
+            else
+                return http_not_found(connection);
+        }
+        else
+            return http_bad_request(connection);
+    }
+
     if (strstr(url, "/progress/") != NULL)
     {
         char *datasetId = strrchr(url, '/');

src/ws.c

@@ -3870,10 +3870,10 @@ void *send_cluster_heartbeat(void *arg)
 
     for (i = 0, iterator = cluster; iterator; iterator = iterator->next)
     {
-        // URL: http://cluster_ip:ws_port/heartbeat/id
+        // URL: http://cluster_ip:ws_port/cluster_heartbeat/id
         GString *url = g_string_new("http://");
         g_string_append_printf(url, "%s:", (char *)iterator->data);
-        g_string_append_printf(url, "%" PRIu16 "/heartbeat/%.*s", options.ws_port, (int)len, datasetid);
+        g_string_append_printf(url, "%" PRIu16 "/cluster_heartbeat/%.*s", options.http_port, (int)len, datasetid);
         // printf("[C] URL: '%s'\n", url->str);
 
         // set the individual URL