feat: Server Side Events (SSE)

Author: miqmago

libraries/WebServer/src/WebServer.cpp

@@ -314,6 +314,11 @@ void WebServer::handleClient() {
           _contentLength = CONTENT_LENGTH_NOT_SET;
           _handleRequest();
 
+          if (_currentClient.isSSE()) {
+            _currentStatus = HC_WAIT_CLOSE;
+            _statusChange = millis();
+            keepCurrentClient = true;
+          }
 // Fix for issue with Chrome based browsers: https://github.com/espressif/arduino-esp32/issues/3652
 //           if (_currentClient.connected()) {
 //             _currentStatus = HC_WAIT_CLOSE;
@@ -329,6 +334,10 @@ void WebServer::handleClient() {
       }
       break;
     case HC_WAIT_CLOSE:
+      if (_currentClient.isSSE()) {
+        // Never close connection
+        _statusChange = millis();
+      }
       // Wait for client to close the connection
       if (millis() - _statusChange <= HTTP_MAX_CLOSE_WAIT) {
         keepCurrentClient = true;

libraries/WiFi/src/WiFiClient.cpp

@@ -174,7 +174,7 @@ class WiFiClientSocketHandle {
     }
 };
 
-WiFiClient::WiFiClient():_connected(false),next(NULL)
+WiFiClient::WiFiClient():_connected(false),_sse(false),next(NULL)
 {
 }
 
@@ -321,7 +321,7 @@ int WiFiClient::setOption(int option, int *value)
 
 int WiFiClient::getOption(int option, int *value)
 {
-	socklen_t size = sizeof(int);
+    socklen_t size = sizeof(int);
     int res = getsockopt(fd(), IPPROTO_TCP, option, (char *)value, &size);
     if(res < 0) {
         log_e("fail on fd %d, errno: %d, \"%s\"", fd(), errno, strerror(errno));
@@ -608,3 +608,13 @@ int WiFiClient::fd() const
     }
 }
 
+void WiFiClient::setSSE(bool sse)
+{
+    _sse = sse;
+}
+
+bool WiFiClient::isSSE()
+{
+    return _sse;
+}
+

libraries/WiFi/src/WiFiClient.h

@@ -42,6 +42,7 @@ class WiFiClient : public ESPLwIPClient
     std::shared_ptr<WiFiClientSocketHandle> clientSocketHandle;
     std::shared_ptr<WiFiClientRxBuffer> _rxBuffer;
     bool _connected;
+    bool _sse;
 
 public:
     WiFiClient *next;
@@ -63,6 +64,8 @@ class WiFiClient : public ESPLwIPClient
     void flush();
     void stop();
     uint8_t connected();
+    void setSSE(bool sse);
+    bool isSSE();
 
     operator bool()
     {