http_server: Simplified httpd_get_client_list() to return clients in int array

components/esp_http_server/include/esp_http_server.h

@@ -415,14 +415,6 @@ typedef struct httpd_uri {
 #endif
 } httpd_uri_t;
 
-/**
- * @brief Structure for holding list of clients
- */
-typedef struct httpd_client_list {
-    size_t active_clients;      /*!< number of active clients in this struct */
-    int    client_fds[];        /*!< array of file descriptors of all active clients */
-} httpd_client_list_t;
-
 /**
  * @brief   Registers a URI handler
  *
@@ -1484,14 +1476,15 @@ esp_err_t httpd_sess_update_lru_counter(httpd_handle_t handle, int sockfd);
  * @brief   Returns list of current socket descriptors of active sessions
  *
  * @param[in] handle    Handle to server returned by httpd_start
- * @param[in] max_fds   Maximum number of socket fds the supplied list could hold
- * @param[out] fd_list  Structure holding socket descriptors
+ * @param[in,out] fds   In: Number of fds allocated in the supplied structure client_fds
+ *                      Out: Number of valid client fds returned in client_fds,
+ * @param[out] client_fds  Array of client fds
  *
  * @return
  *  - ESP_OK              : Successfully retrieved session list
- *  - ESP_ERR_INVALID_ARG : Wrong arguments or list is longer than maximum
+ *  - ESP_ERR_INVALID_ARG : Wrong arguments or list is longer than allocated
  */
-esp_err_t httpd_get_client_list(httpd_handle_t handle, size_t max_fds, httpd_client_list_t *fd_list);
+esp_err_t httpd_get_client_list(httpd_handle_t handle, size_t *fds, int *client_fds);
 
 /** End of Session
  * @}

components/esp_http_server/src/httpd_main.c

@@ -104,17 +104,18 @@ esp_err_t httpd_queue_work(httpd_handle_t handle, httpd_work_fn_t work, void *ar
     return ESP_OK;
 }
 
-esp_err_t httpd_get_client_list(httpd_handle_t handle, size_t max_fds, httpd_client_list_t *fd_list)
+esp_err_t httpd_get_client_list(httpd_handle_t handle, size_t *fds, int *client_fds)
 {
     struct httpd_data *hd = (struct httpd_data *) handle;
-    if (hd == NULL || max_fds == 0 || fd_list == NULL || max_fds < hd->config.max_open_sockets) {
+    if (hd == NULL || fds == NULL || *fds == 0 || client_fds == NULL || *fds < hd->config.max_open_sockets) {
         return ESP_ERR_INVALID_ARG;
     }
-    fd_list->active_clients = 0;
+    size_t max_fds = *fds;
+    *fds = 0;
     for (int i = 0; i < hd->config.max_open_sockets; ++i) {
         if (hd->hd_sd[i].fd != -1) {
-            if (fd_list->active_clients < max_fds) {
-                fd_list->client_fds[fd_list->active_clients++] = hd->hd_sd[i].fd;
+            if (*fds < max_fds) {
+                client_fds[(*fds)++] = hd->hd_sd[i].fd;
             } else {
                 return ESP_ERR_INVALID_ARG;
             }

examples/protocols/https_server/wss_server/main/wss_server_example.c

@@ -210,14 +210,9 @@ static void connect_handler(void* arg, esp_event_base_t event_base,
     }
 }
 
+// Get all clients and send async message
 static void wss_server_send_messages(httpd_handle_t* server)
 {
-    // Get all clients and send async message
-    struct {
-        size_t active_clients;
-        int    client_fds[max_clients];
-    } client_list;
-
     bool send_messages = true;
 
     // Send async message to all connected clients that use websocket protocol every 10 seconds
@@ -227,10 +222,11 @@ static void wss_server_send_messages(httpd_handle_t* server)
         if (!*server) { // httpd might not have been created by now
             continue;
         }
-
-        if (httpd_get_client_list(*server, max_clients, (httpd_client_list_t*)&client_list) == ESP_OK) {
-            for (size_t i=0; i < client_list.active_clients; ++i) {
-                int sock = client_list.client_fds[i];
+        size_t clients = max_clients;
+        int    client_fds[max_clients];
+        if (httpd_get_client_list(*server, &clients, client_fds) == ESP_OK) {
+            for (size_t i=0; i < clients; ++i) {
+                int sock = client_fds[i];
                 if (httpd_ws_get_fd_info(*server, sock) == HTTPD_WS_CLIENT_WEBSOCKET) {
                     ESP_LOGI(TAG, "Active client (fd=%d) -> sending async message", sock);
                     struct async_resp_arg *resp_arg = malloc(sizeof(struct async_resp_arg));