added flush buffer function in uart com if

Reviewed-on: #13

linux/uart/UartComIF.cpp

@@ -79,6 +79,7 @@ int UartComIF::configureUartPort(UartCookie* uartCookie) {
     setStopBitOptions(&options, uartCookie);
     setDatasizeOptions(&options, uartCookie);
     setFixedOptions(&options);
+    setUartMode(&options, *uartCookie);
     if(uartCookie->getInputShouldBeFlushed()) {
         tcflush(fd, TCIFLUSH);
     }
@@ -403,13 +404,13 @@ ReturnValue_t UartComIF::handleNoncanonicalRead(UartCookie &uartCookie, UartDevi
         return RETURN_FAILED;
     }
     else if (bytesRead != static_cast<int>(requestLen)) {
-        sif::debug << "UartComIF::requestReceiveMessage: Only read " << bytesRead <<
+        if(uartCookie.isReplySizeFixed()) {
+            sif::warning << "UartComIF::requestReceiveMessage: Only read " << bytesRead <<
                     " of " << requestLen << " bytes" << std::endl;
             return RETURN_FAILED;
         }
-    else {
-        iter->second.replyLen = bytesRead;
     }
+    iter->second.replyLen = bytesRead;
     return HasReturnvaluesIF::RETURN_OK;
 }
 
@@ -442,6 +443,51 @@ ReturnValue_t UartComIF::readReceivedMessage(CookieIF *cookie,
     return RETURN_OK;
 }
 
+ReturnValue_t UartComIF::flushUartRxBuffer(CookieIF *cookie) {
+    std::string deviceFile;
+    UartDeviceMapIter uartDeviceMapIter;
+    UartCookie* uartCookie = dynamic_cast<UartCookie*>(cookie);
+    if(uartCookie == nullptr) {
+        sif::warning << "UartComIF::flushUartRxBuffer: Invalid uart cookie!" << std::endl;
+        return NULLPOINTER;
+    }
+    deviceFile = uartCookie->getDeviceFile();
+    uartDeviceMapIter = uartDeviceMap.find(deviceFile);
+    int fd = uartDeviceMapIter->second.fileDescriptor;
+    tcflush(fd, TCIFLUSH);
+    return RETURN_OK;
+}
+
+ReturnValue_t UartComIF::flushUartTxBuffer(CookieIF *cookie) {
+    std::string deviceFile;
+    UartDeviceMapIter uartDeviceMapIter;
+    UartCookie* uartCookie = dynamic_cast<UartCookie*>(cookie);
+    if(uartCookie == nullptr) {
+        sif::warning << "UartComIF::flushUartTxBuffer: Invalid uart cookie!" << std::endl;
+        return NULLPOINTER;
+    }
+    deviceFile = uartCookie->getDeviceFile();
+    uartDeviceMapIter = uartDeviceMap.find(deviceFile);
+    int fd = uartDeviceMapIter->second.fileDescriptor;
+    tcflush(fd, TCOFLUSH);
+    return RETURN_OK;
+}
+
+ReturnValue_t UartComIF::flushUartTxAndRxBuf(CookieIF *cookie) {
+    std::string deviceFile;
+    UartDeviceMapIter uartDeviceMapIter;
+    UartCookie* uartCookie = dynamic_cast<UartCookie*>(cookie);
+    if(uartCookie == nullptr) {
+        sif::warning << "UartComIF::flushUartTxAndRxBuf: Invalid uart cookie!" << std::endl;
+        return NULLPOINTER;
+    }
+    deviceFile = uartCookie->getDeviceFile();
+    uartDeviceMapIter = uartDeviceMap.find(deviceFile);
+    int fd = uartDeviceMapIter->second.fileDescriptor;
+    tcflush(fd, TCIOFLUSH);
+    return RETURN_OK;
+}
+
 void UartComIF::setUartMode(struct termios *options, UartCookie &uartCookie) {
     UartModes uartMode = uartCookie.getUartMode();
     if(uartMode == UartModes::NON_CANONICAL) {

linux/uart/UartComIF.h

@@ -41,6 +41,21 @@ public:
     ReturnValue_t readReceivedMessage(CookieIF *cookie, uint8_t **buffer,
             size_t *size) override;
 
+    /**
+     * @brief   This function discards all data received but not read in the UART buffer.
+     */
+    ReturnValue_t flushUartRxBuffer(CookieIF *cookie);
+
+    /**
+     * @brief   This function discards all data in the transmit buffer of the UART driver.
+     */
+    ReturnValue_t flushUartTxBuffer(CookieIF *cookie);
+
+    /**
+     * @brief   This function discards both data in the transmit and receive buffer of the UART.
+     */
+    ReturnValue_t flushUartTxAndRxBuf(CookieIF *cookie);
+
 private:
 
     using UartDeviceFile_t = std::string;

linux/uart/UartCookie.cpp

@@ -87,3 +87,11 @@ bool UartCookie::getInputShouldBeFlushed() {
 object_id_t UartCookie::getHandlerId() const {
     return this->handlerId;
 }
+
+void UartCookie::setNoFixedSizeReply() {
+    replySizeFixed = false;
+}
+
+bool UartCookie::isReplySizeFixed() {
+    return replySizeFixed;
+}

linux/uart/UartCookie.h

@@ -95,6 +95,14 @@ public:
     void setTwoStopBits();
     void setOneStopBit();
 
+    /**
+     * Calling this function prevents the UartComIF to return failed if not all requested bytes
+     * could be read. This is required by a device handler when the size of a reply is not known.
+     */
+    void setNoFixedSizeReply();
+
+    bool isReplySizeFixed();
+
 private:
 
     const object_id_t handlerId;
@@ -107,6 +115,7 @@ private:
     uint8_t bitsPerWord = 8;
     uint8_t readCycles = 1;
     StopBits stopBits = StopBits::ONE_STOP_BIT;
+    bool replySizeFixed = true;
 };
 
 #endif