add: debug logging and status cache

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required (VERSION 3.7)
 project(core
-        VERSION 0.2.4
+        VERSION 0.2.5
         LANGUAGES C)
 
 add_executable(core src/main.c)

src/handlers/http.c

@@ -90,6 +90,7 @@ handle_http_request(struct mg_connection *nc, struct http_message *hm)
         /* Normalize path - resolve "." and ".." (in-place). */
         if (!mg_normalize_uri_path(&hm->uri, &hm->uri)) {
             mg_http_send_error(nc, 400, global_config.http_server_opts.extra_headers);
+            LOGGER_DEBUG("failed to normalize uri %.*s\n", hm->uri.len, hm->uri.p);
             return;
         }
         char *request_file_org = malloc(sizeof(char) * hm->uri.len);
@@ -112,10 +113,12 @@ handle_http_request(struct mg_connection *nc, struct http_message *hm)
         {
             response.status_code = 0;
             mg_serve_http(nc, hm, global_config.http_server_opts);
+            LOGGER_DEBUG("serving %.*s\n", hm->uri.len, hm->uri.p);
             return;
         }
         else
         {
+            LOGGER_DEBUG("serving 'not found'\n");
             endpoint = router_get_not_found_endpoint();
         }
     }
@@ -142,10 +145,13 @@ handle_http_request(struct mg_connection *nc, struct http_message *hm)
     }
     else
     {
+        LOGGER_DEBUG("calling endpoint function %p\n", endpoint->func);
         endpoint->func(nc, hm, endpoint->args, &response);
+        LOGGER_DEBUG("sending response to %p\n", nc);
         send_response(nc, &response);
     }
 
+    LOGGER_DEBUG("freeing endpoint args\n");
     for(int i = 0; i < endpoint->args_count; ++i)
     {
         if(endpoint->args[i].type == ENDPOINT_ARG_TYPE_STR)
@@ -169,6 +175,7 @@ handler_http(struct mg_connection *nc, int ev, void *p)
     }
     if(ev == MG_EV_HTTP_REQUEST)
     {
+        LOGGER_DEBUG("new http request (%p)\n", nc);
         struct http_message *hm = (struct http_message*)p;
         handle_http_request(nc, hm);
     }

src/status.c

@@ -2,16 +2,21 @@
 #include <logger.h>
 
 relay_t **global_relay_status_list;
+char *relay_status_list_json_str;
+size_t relay_status_list_json_str_len;
 
 void
 status_init()
 {
     global_relay_status_list = relay_get_all();
+    relay_status_list_json_str = NULL;
+    relay_status_list_json_str_len = 0;
 }
 
 void
 status_reload_entry(int relay_id)
 {
+    LOGGER_DEBUG("reloading relay status\n");
     relay_t **relays = global_relay_status_list;
     for(int i = 0; relays[i] != NULL; ++i)
     {
@@ -25,12 +30,15 @@ status_reload_entry(int relay_id)
         relay_free(relays[i]);
         relays[i] = updated_relay;
         relays[i]->is_on = is_on_backup;
+        relay_status_list_json_str = NULL;
+        relay_status_list_json_str_len = 0;
     }
 }
 
 void
 status_update_entry(int relay_id, int is_on)
 {
+    LOGGER_DEBUG("updating relay status ([%d] = %d)\n", relay_id, is_on);
     relay_t **relays = global_relay_status_list;
     for(int i = 0; relays[i] != NULL; ++i)
     {
@@ -39,32 +47,62 @@ status_update_entry(int relay_id, int is_on)
             continue;
         }
         relays[i]->is_on = is_on;
+        relay_status_list_json_str = NULL;
+        relay_status_list_json_str_len = 0;
     }
 }
 
-static int is_websocket(const struct mg_connection *nc)
+static int
+is_websocket(const struct mg_connection *nc)
 {
     return nc->flags & MG_F_IS_WEBSOCKET;
 }
 
+static void
+validate_json_str_cache()
+{
+    if(!relay_status_list_json_str)
+    {
+        relay_t **relays = global_relay_status_list;
+
+        cJSON *json = relay_list_to_json(relays);
+
+        char *json_str = cJSON_Print(json);
+        size_t json_str_len = strlen(json_str);
+
+        LOGGER_DEBUG("writing new json string to cache\n");
+        relay_status_list_json_str = json_str;
+        relay_status_list_json_str_len = json_str_len;
+
+        cJSON_Delete(json);
+    }
+
+}
+
+
 void
 status_broadcast(struct mg_mgr *mgr)
 {
     struct mg_connection *c;
-    relay_t **relays = global_relay_status_list;
+    validate_json_str_cache();
+    
+    char *json_str = relay_status_list_json_str;
+    size_t json_str_len = relay_status_list_json_str_len;
 
-    cJSON *json = relay_list_to_json(relays);
+    int c_count = 0;
-    char *json_str = cJSON_Print(json);
-    size_t json_str_len = strlen(json_str);
 
     for (c = mg_next(mgr, NULL); c != NULL; c = mg_next(mgr, c)) {
         if(is_websocket(c))
         {
             mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT, json_str, json_str_len);
+            ++c_count;
         }
     }
-    free(json_str);
+
-    cJSON_Delete(json);
+    if(c_count)
+    {
+        LOGGER_DEBUG("finished status broadcast to %d client(s)\n", c_count);
+    }
 }
 
 void
@@ -75,20 +113,19 @@ status_send(struct mg_connection *c)
         return;
     }
 
-    relay_t **relays = global_relay_status_list;
+    validate_json_str_cache();
-
+    
-    cJSON *json = relay_list_to_json(relays);
+    char *json_str = relay_status_list_json_str;
-    char *json_str = cJSON_Print(json);
+    size_t json_str_len = relay_status_list_json_str_len;
-    size_t json_str_len = strlen(json_str);
 
     mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT, json_str, json_str_len);
 
-    free(json_str);
+    LOGGER_DEBUG("finished status send\n");
-    cJSON_Delete(json);
 }
 
 void
 status_free()
 {
     relay_free_list(global_relay_status_list);
+    free(relay_status_list_json_str);
 }