add websocket support

code/components/jomjol_helper/websocket.cpp

@@ -0,0 +1,129 @@
+#include "esp_log.h"
+#include <esp_http_server.h>
+
+#include "../../include/defines.h"
+
+#include "ClassLogFile.h"
+#include "freertos/ringbuf.h"
+#include "psram.h"
+
+#include "websocket.h"
+
+
+#define MAX_MESSAGE_LENGTH  100
+
+static const char *TAG = "WEBSOCKET";
+
+static httpd_handle_t server = NULL;
+static httpd_handle_t websocket_handle = NULL;
+
+/*
+ * Structure holding server handle and message
+ * in order to use out of request send */
+struct async_resp_arg {
+    httpd_handle_t hd;
+    char message[MAX_MESSAGE_LENGTH];
+};
+
+
+/*
+ * async send function, which we put into the httpd work queue
+ */
+static void websocket_send_pending_message(void *arg) {
+    esp_err_t ret;
+    struct async_resp_arg *resp_arg = (struct async_resp_arg *)arg;
+
+    LogFile.WriteToFile(ESP_LOG_DEBUG, TAG, "Sending Websocket message: '" + std::string(resp_arg->message) + "'");
+    
+    httpd_ws_frame_t ws_pkt;
+    memset(&ws_pkt, 0, sizeof(httpd_ws_frame_t));
+    ws_pkt.payload = (uint8_t *)resp_arg->message;
+    ws_pkt.len = strlen(resp_arg->message);
+    ws_pkt.type = HTTPD_WS_TYPE_TEXT;
+
+    static size_t max_clients = CONFIG_LWIP_MAX_LISTENING_TCP;
+    size_t fds = max_clients;
+    int client_fds[max_clients];
+
+    ret = httpd_get_client_list(server, &fds, client_fds);
+    if (ret != ESP_OK) {
+        LogFile.WriteToFile(ESP_LOG_ERROR, TAG, "Failed to get Websocket client ist: " + std::to_string(ret) + "!");
+        free_psram_heap("websocket msg", resp_arg);
+        return;
+    }
+
+    /* Send it to all websocket clients */
+    for (int i = 0; i < fds; i++) {
+        int client_info = httpd_ws_get_fd_info(server, client_fds[i]);
+        if (client_info == HTTPD_WS_CLIENT_WEBSOCKET) {
+            httpd_ws_send_frame_async(websocket_handle, client_fds[i], &ws_pkt);
+        }
+    }
+
+    free_psram_heap("websocket msg", resp_arg);
+}
+
+
+esp_err_t schedule_websocket_message(std::string message) {
+   // return 0;
+    esp_err_t ret;
+
+    if (websocket_handle == NULL) { // No websocket connecten open
+        return ESP_OK;
+    }
+
+    LogFile.WriteToFile(ESP_LOG_DEBUG, TAG, "Scheduled websocket message: '" + message + "'");
+
+    struct async_resp_arg *resp_arg = (struct async_resp_arg *)malloc_psram_heap("websocket msg", 
+            sizeof(struct async_resp_arg), MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
+    if (resp_arg == NULL) {
+        LogFile.WriteToFile(ESP_LOG_ERROR, TAG, "Failed to malloc memory for scheduled websocket message!");
+        return ESP_ERR_NO_MEM;
+    }
+   
+    strncpy(resp_arg->message, message.c_str(), MAX_MESSAGE_LENGTH);
+
+    ret = httpd_queue_work(websocket_handle, websocket_send_pending_message, resp_arg);
+    if (ret != ESP_OK) {
+        LogFile.WriteToFile(ESP_LOG_ERROR, TAG, "Websocket Scheduling failed: " + std::to_string(ret) + "!");
+        free_psram_heap("websocket msg", resp_arg);
+    }
+
+    return ret;
+}
+
+
+static esp_err_t ws_handler(httpd_req_t *req) {
+    if (req->method == HTTP_GET) {
+        LogFile.WriteToFile(ESP_LOG_DEBUG, TAG, "Handshake done, the new websocket connection was opened");
+        websocket_handle = req->handle;
+    }
+
+    return ESP_OK;
+}
+
+
+static const httpd_uri_t ws_uri = {
+    .uri        = "/ws",
+    .method     = HTTP_GET,
+    .handler    = ws_handler,
+    .user_ctx   = NULL,
+    .is_websocket = true
+};
+
+
+esp_err_t start_websocket_server(httpd_handle_t _server) {
+    esp_err_t ret;
+
+    LogFile.WriteToFile(ESP_LOG_DEBUG, TAG, "Init Websocket Server");
+
+    server = _server;
+
+    // Registering the ws handler
+    LogFile.WriteToFile(ESP_LOG_DEBUG, TAG, "Registering URI handler");
+    ret = httpd_register_uri_handler(server, &ws_uri);
+    if (ret != ESP_OK) {
+        LogFile.WriteToFile(ESP_LOG_ERROR, TAG, "Registering Websocket URI handler failed: " + std::to_string(ret));
+    }
+    return ret;
+}