[ESPEasy console] reduce load when USB HWCDC is not connected

lib/ESPEasySerial/Port_ESPEasySerial_USB_HWCDC.cpp

@@ -48,6 +48,20 @@ static void hwcdcEventCallback(void *arg, esp_event_base_t event_base, int32_t e
   }
 }
 
+bool Port_ESPEasySerial_USB_HWCDC_t::isConnected() const
+{
+  static bool connected_cache{};
+  static uint32_t lastChecked{};
+  if (!connected_cache) {
+    const int32_t timePassedSince = (int32_t) (millis() - lastChecked);
+    if (timePassedSince < 1000) return false;
+    lastChecked = millis();
+  }
+  connected_cache = _hwcdc_serial != nullptr && _hwcdc_serial->isConnected();
+  return connected_cache;  
+}
+
+
 Port_ESPEasySerial_USB_HWCDC_t::Port_ESPEasySerial_USB_HWCDC_t(const ESPEasySerialConfig& config)
   
 # if ARDUINO_USB_CDC_ON_BOOT // Serial used for USB CDC
@@ -71,7 +85,7 @@ Port_ESPEasySerial_USB_HWCDC_t::Port_ESPEasySerial_USB_HWCDC_t(const ESPEasySeri
 
     //    _hwcdc_serial->begin();
 
-    //    _hwcdc_serial->onEvent(hwcdcEventCallback);
+    // _hwcdc_serial->onEvent(hwcdcEventCallback);
   }
 }
 
@@ -106,7 +120,7 @@ void Port_ESPEasySerial_USB_HWCDC_t::end() {
 
 int Port_ESPEasySerial_USB_HWCDC_t::available(void)
 {
-  if (_hwcdc_serial != nullptr && _hwcdc_serial->isConnected()) {
+  if (isConnected()) {
       return _hwcdc_serial->available();
   }
   return 0;
@@ -114,7 +128,7 @@ int Port_ESPEasySerial_USB_HWCDC_t::available(void)
 
 int Port_ESPEasySerial_USB_HWCDC_t::availableForWrite(void)
 {
-  if (_hwcdc_serial != nullptr && _hwcdc_serial->isConnected()) {
+  if (isConnected()) {
       return _hwcdc_serial->availableForWrite();
   }
   return 0;
@@ -122,7 +136,7 @@ int Port_ESPEasySerial_USB_HWCDC_t::availableForWrite(void)
 
 int Port_ESPEasySerial_USB_HWCDC_t::peek(void)
 {
-  if (_hwcdc_serial != nullptr && _hwcdc_serial->isConnected()) {
+  if (isConnected()) {
     return _hwcdc_serial->peek();
   }
   return 0;
@@ -130,7 +144,7 @@ int Port_ESPEasySerial_USB_HWCDC_t::peek(void)
 
 int Port_ESPEasySerial_USB_HWCDC_t::read(void)
 {
-  if (_hwcdc_serial != nullptr && _hwcdc_serial->isConnected()) {
+  if (isConnected()) {
     return _hwcdc_serial->read();
   }
   return 0;
@@ -139,7 +153,7 @@ int Port_ESPEasySerial_USB_HWCDC_t::read(void)
 size_t Port_ESPEasySerial_USB_HWCDC_t::read(uint8_t *buffer,
                                             size_t   size)
 {
-  if (_hwcdc_serial != nullptr && _hwcdc_serial->isConnected()) {
+  if (isConnected()) {
     return _hwcdc_serial->read(buffer, size);
   }
   return 0;
@@ -147,7 +161,7 @@ size_t Port_ESPEasySerial_USB_HWCDC_t::read(uint8_t *buffer,
 
 void Port_ESPEasySerial_USB_HWCDC_t::flush(void)
 {
-  if (_hwcdc_serial != nullptr && _hwcdc_serial->isConnected()) {
+  if (isConnected()) {
     return _hwcdc_serial->flush();
   }
 }
@@ -176,7 +190,7 @@ size_t Port_ESPEasySerial_USB_HWCDC_t::write(const uint8_t *buffer,
 
 Port_ESPEasySerial_USB_HWCDC_t::operator bool() const
 {
-  if (_hwcdc_serial != nullptr && _hwcdc_serial->isConnected()) {
+  if (isConnected()) {
     // return usbActive;
     return true;
   }
@@ -212,4 +226,5 @@ bool Port_ESPEasySerial_USB_HWCDC_t::setRS485Mode(int8_t rtsPin, bool enableColl
   return false;
 }
 
+
 #endif // if USES_HWCDC

lib/ESPEasySerial/Port_ESPEasySerial_USB_HWCDC.h

@@ -43,6 +43,9 @@ public:
   bool setRS485Mode(int8_t rtsPin, bool enableCollisionDetection = false);
 
 private:
+
+  bool isConnected() const;
+
 #if !ARDUINO_USB_CDC_ON_BOOT
   HWCDC myUsbSerial;
 #endif

src/src/ESPEasyCore/ESPEasy_Console_Port.cpp

@@ -217,6 +217,7 @@ ESPEasySerialPort EspEasy_Console_Port::getPortType() const
 
 bool EspEasy_Console_Port::process_serialWriteBuffer()
 {
+  if (_serialWriteBuffer.getNrMessages() == 0) { return false; }
   if (_serial == nullptr) { return false; }
 #ifdef ESP32
 
@@ -234,35 +235,44 @@ bool EspEasy_Console_Port::process_serialWriteBuffer()
   PrintToString str;
   str.reserve(CONSOLE_MAX_WRITE_CHUNKSIZE);
 
+  size_t totalWritten = 0;
+
   do
   {
-    if (availableForWrite == 0) { return false; }
+    if (availableForWrite == 0) { return totalWritten > 0; }
 
     if (availableForWrite == 1) {
       // For only a single byte, just write it directly
-      return _serialWriteBuffer.process(_serial, availableForWrite);
+      if (_serialWriteBuffer.process(_serial, availableForWrite)) {
+        ++totalWritten;
+      }
+
+      return totalWritten > 0;
     }
 
-    size_t chunkSize = availableForWrite;
+    const size_t chunkSize = availableForWrite > CONSOLE_MAX_WRITE_CHUNKSIZE
+      ? CONSOLE_MAX_WRITE_CHUNKSIZE
+      : availableForWrite;
 
-    if (chunkSize > CONSOLE_MAX_WRITE_CHUNKSIZE) {
-      chunkSize = CONSOLE_MAX_WRITE_CHUNKSIZE;
-    }
     availableForWrite -= chunkSize;
 
     if (!_serialWriteBuffer.process(&str, chunkSize)) {
       // Nothing left to write
-      return false;
+      return totalWritten > 0;
     }
 
-    if (_serial->write(str.get().c_str(), str.length()) < chunkSize) {
+    const size_t lastWritten = _serial->write(str.get().c_str(), str.length());
+
+    totalWritten += lastWritten;
+
+    if (lastWritten < chunkSize) {
       // Try to end on a full log line to lower the chance of SDK debug logs
       // interfering with console output.
       ++nrLinesWritten;
     }
     str.clear();
   } while (availableForWrite > 0 && nrLinesWritten < 3);
-  return true;
+  return totalWritten > 0;
 }
 
 bool EspEasy_Console_Port::process_consoleInput(uint8_t SerialInByte)

src/src/ESPEasyCore/ESPEasy_Console_serial0_only.cpp

@@ -74,21 +74,19 @@ void EspEasy_Console_t::loop()
 }
 
 bool EspEasy_Console_t::process_serialWriteBuffer() {
-
+#  if FEATURE_TIMING_STATS
-# if FEATURE_TIMING_STATS
   START_TIMER;
-  bool res = false;
 
   if (_mainSerial.process_serialWriteBuffer()) {
-    res = true;
+    STOP_TIMER(CONSOLE_WRITE_SERIAL);
+    return true;
   }
 
-  if (res) { STOP_TIMER(CONSOLE_WRITE_SERIAL); }
+  return false;
-  return res;
 
-# else // if FEATURE_TIMING_STATS
+#  else // if FEATURE_TIMING_STATS
   return _mainSerial.process_serialWriteBuffer();
-# endif // if FEATURE_TIMING_STATS
+#  endif // if FEATURE_TIMING_STATS
 }
 
 void EspEasy_Console_t::setDebugOutput(bool enable)

src/src/ESPEasyCore/ESPEasy_Console_single_serial.cpp

@@ -101,14 +101,13 @@ void EspEasy_Console_t::loop()
 bool EspEasy_Console_t::process_serialWriteBuffer() {
 #  if FEATURE_TIMING_STATS
   START_TIMER;
-  bool res = false;
 
   if (_mainSerial.process_serialWriteBuffer()) {
-    res = true;
+    STOP_TIMER(CONSOLE_WRITE_SERIAL);
+    return true;
   }
 
-  if (res) { STOP_TIMER(CONSOLE_WRITE_SERIAL); }
+  return false;
-  return res;
 
 #  else // if FEATURE_TIMING_STATS
   return _mainSerial.process_serialWriteBuffer();