tcp.cpp

Go to the documentation of this file.

//
// Tcp.cpp
//
// TCP-Client.
//

#include "tcp.hpp"
#include "../tools/errorhandler.hpp"
#include "../tools/toolbox.hpp"
#include <stdio.h>      // for sprintf()

#include <sys/socket.h> // for socket(), bind(), and connect()
#include <arpa/inet.h>  // for sockaddr_in and inet_ntoa()
#include <string.h>     // for memset()
#include <netdb.h>      // for hostent


Tcp::Tcp()
{
        m_beVerbose = false;
        m_connectionSocket = -1;
        
        m_readThread.m_threadShouldRun = false;
        
        m_longStringWarningPrinted = false;
        m_disconnectFunction = NULL;
        m_disconnectFunctionObjPtr = NULL;
        m_readFunction = NULL;
        m_readFunctionObjPtr = NULL;

}

//
// Destruktor.
//
Tcp::~Tcp(void)
{
        close();
}


//
// Schreibe eine Anzahl Bytes auf die Schnittstelle.
//
// Dieser Aufruf wartet, bis alle Bytes geschrieben wurden.
//
bool Tcp::write(UINT8* buffer, UINT32 numberOfBytes)
{
        INT32 bytesSent;
        bool result;
        INT32* socketPtr = &m_connectionSocket;
        
        // Sende Daten an das Socket
        bytesSent = ::send(*socketPtr, buffer, numberOfBytes, 0);
        
        if (bytesSent != (INT32)numberOfBytes)
        {
                printWarning("Tcp::write: Failed to send data to socket.");
                result = false;
        }
        else
        {
                // Erfolg
                printInfoMessage("Tcp::write: Sent " + toString(numberOfBytes) + " bytes to client.", m_beVerbose);
                result = true;
        }

        return result;
}


//
// Setzt die Funktion, die bei einem Disconnect-Ereignis aufgerufen wird.
//
void Tcp::setDisconnectCallbackFunction(DisconnectFunction discFunction, void* obj)
{
        m_disconnectFunction = discFunction;
        m_disconnectFunctionObjPtr = obj;
}



bool Tcp::isOpen()
{
        if (m_connectionSocket >= 0)
        {
//              printInfoMessage("Tcp::isOpen: Reporting open connection.", m_beVerbose);
                return true;
        }

//      printInfoMessage("Tcp::isOpen: Reporting no connection.", m_beVerbose);
        return false;
}

//
// Definiere die Lese-Callback-Funktion.
//
void Tcp::setReadCallbackFunction(Tcp::ReadFunction readFunction, void* obj)
{
        m_readFunction = readFunction;
        m_readFunctionObjPtr = obj;
}

//
// Alternative open-Funktion.
//
bool Tcp::open(UINT32 ipAddress, UINT16 port,  bool enableVerboseDebugOutput)
{
        std::string ipAdrStr;
        
        ipAdrStr = ipAdrToString(ipAddress);
                                
        bool result = open(ipAdrStr, port, enableVerboseDebugOutput);
        
        return result;
}


//
// Oeffnet die Verbindung.
//
// -- Wir sind der Client, und wollen uns z.B. mit einem Scanner verbinden --
//
bool Tcp::open(std::string ipAddress, UINT16 port, bool enableVerboseDebugOutput)
{
        INT32 result;
        m_beVerbose = enableVerboseDebugOutput;

//      printInfoMessage("Tcp::open: Setting up input buffer with size=" + convertValueToString(requiredInputBufferSize) + " bytes.", m_beVerbose);
//      m_inBuffer.init(requiredInputBufferSize, m_beVerbose);
        
        printInfoMessage("Tcp::open: Opening connection.", m_beVerbose);
        
        // Socket erzeugen
        m_connectionSocket = -1;        // Keine Verbindung
        {
                ScopedLock lock(&m_socketMutex);                // Mutex setzen
                m_connectionSocket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
        }
        if (m_connectionSocket  < 0)
        {
        printError("Tcp::open: socket() failed, aborting.");
                return false;
        }

        // Socket ist da. Nun die Verbindung oeffnen.
        printInfoMessage("Tcp::open: Connecting. Target address is " + ipAddress + ":" + toString(port) + ".", m_beVerbose);
        
        struct sockaddr_in addr;
        struct hostent *server;
        server = gethostbyname(ipAddress.c_str());
        memset(&addr, 0, sizeof(addr));                 // Zero out structure
        addr.sin_family = AF_INET;
        bcopy((char *)server->h_addr, (char *)&addr.sin_addr.s_addr, server->h_length);
        addr.sin_port = htons(port);                            // Host-2-Network byte order
        result = connect(m_connectionSocket, (sockaddr*)(&addr), sizeof(addr));
        if (result < 0)
        {
                // Verbindungsversuch ist fehlgeschlagen
                std::string text = "Tcp::open: Failed to open TCP connection to " + ipAddress + ":" + toString(port) + ", aborting.";
                printError(text);
                return false;
        }

        printInfoMessage("Tcp::open: Connection established. Now starting read thread.", m_beVerbose);

        // Empfangsthread starten
        m_readThread.run(this);
        
        printInfoMessage("Tcp::open: Done, leaving now.", m_beVerbose);

        return true;
}


//
// Lese-Thread (Hauptfunktion).
//
void Tcp::readThreadFunction(bool& endThread, UINT16& waitTimeMs)
{
        INT32 result;

        // Lesen
        result = readInputData();

        // Ergebnis?
        if (result < 0)
        {
                // Verbindung wurde abgebrochen
                if (m_readThread.m_threadShouldRun == true)
                {
                        // Wir sollten eigentlich noch laufen!
                        printInfoMessage("Tcp::readThreadMain: Connection is lost! Read thread terminates now.", m_beVerbose);
                }
                waitTimeMs = 0;
        }
        else if (result == 0)
        {
                // Wir haben nichts empfangen. Schlafen und dann weiter...
                waitTimeMs = 1;
        }
        else
        {
                // Wir haben etwas empfangen, also nicht schlafen
                waitTimeMs = 0;
        }
}

//
// Read some data from the TCP connection.
//
INT32 Tcp::readInputData()
{
        // Prepare the input buffer
        const UINT16 max_length = 8192;
        UINT8 inBuffer[max_length];
        INT32 recvMsgSize = 0;
        
        // Ist die Verbindung offen?
        if (isOpen() == false)
        {
                printError("Tcp::readInputData: Connection is not open, aborting!");
                return -1;
        }
                
        // Read some data, if any
        recvMsgSize = recv(m_connectionSocket, inBuffer, max_length, 0);
        if (recvMsgSize < 0)
        {
                // Fehler
                printError("Tcp::readInputData: Failed to read data from socket, aborting!");
        }
        else if (recvMsgSize > 0)
        {
                // Erfolg
                printInfoMessage("Tcp::readInputData: Read " + toString(recvMsgSize) + " bytes from the connection.", m_beVerbose);
                
                // Falls eine Callback-Funktion definiert ist, rufe sie auf mit den
                // empfangenen Daten.
                if (m_readFunction != NULL)
                {
                        // Die Daten an die Callback-Funktion uebergeben
                        UINT32 length_uint32 = (UINT32)recvMsgSize;
                        m_readFunction(m_readFunctionObjPtr, inBuffer, length_uint32);
                }
                else
                {
                        // Es ist keine Callback-Funktion definiert, also die Daten im
                        // lokalen Puffer speichern.
                        for (INT32 i = 0; i < recvMsgSize; i++)
                        {
                                m_rxBuffer.push_back(inBuffer[i]);
                        }
                }
        }
        else if (recvMsgSize == 0)
        {
                // Verbindungsabbruch
                printInfoMessage("Tcp::readInputData: Read 0 bytes - connection is lost!", true);
                
                // Informieren?
                if (m_disconnectFunction != NULL)
                {
                        m_disconnectFunction(m_disconnectFunctionObjPtr);
                }
                
                // Mutex setzen
                ScopedLock lock(&m_socketMutex);

                m_connectionSocket = -1;        // Keine Verbindung mehr
        }
        
        return recvMsgSize;
}


//
// Close an open connection, if any.
//
void Tcp::close()
{
        printInfoMessage("Tcp::close: Closing Tcp connection.", m_beVerbose);

        if (isOpen() == true)
        {
                // Dem Lese-Thread ein Ende signalisieren
                m_readThread.m_threadShouldRun = false;

                // Verbindung schliessen
                ::close(m_connectionSocket);

                // Auf das Ende des Empfangsthreads warten
                printInfoMessage("Tcp::close: Waiting for the server thread to terminate...", m_beVerbose);

                // Thread stoppen
                stopReadThread();
        }
        else
        {
                printInfoMessage("Tcp::close: Nothing to do - no open connection? Aborting.", m_beVerbose);
        }

        printInfoMessage("Tcp::close: Done - Connection is now closed.", m_beVerbose);
}


void Tcp::stopReadThread()
{
        printInfoMessage("Tcp::stopReadThread: Stopping thread.", m_beVerbose);
        
//      m_readThread.m_threadShouldRun = false;
        m_readThread.join();

        printInfoMessage("Tcp::stopReadThread: Done - Read thread is now closed.", m_beVerbose);
}



UINT32 Tcp::getNumReadableBytes()
{
        return m_rxBuffer.size();
}


//
// Read function.
//
// 0..bufferLen bytes are returned.
// Return value is the number of returned bytes.
//
// DEPRECATED. Use the callback mechanism instead!
//
UINT32 Tcp::read(UINT8* buffer, UINT32 bufferLen)
{
        UINT32 bytesRead = 0;
        
        // Lesen
        while ((getNumReadableBytes() > 0) && (bufferLen > bytesRead))
        {
                buffer[bytesRead] = m_rxBuffer.front();
                m_rxBuffer.pop_front();
                bytesRead += 1; // m_inBuffer.read(buffer, bufferLen);
        }
        
        return bytesRead;
}


std::string Tcp::readString(UINT8 delimiter)
{
        UINT8 c = delimiter;
        std::string outString;
        const UINT16 maxStringLength = 8192;

        // String fuellen
        while (m_rxBuffer.size() > 0)
        {
                // Es sind noch Daten im Puffer
                c = m_rxBuffer.front();
                m_rxBuffer.pop_front();
                if (c == delimiter)
                {
                        // Trennzeichen gefunden - wir sind fertig!
                        outString = m_rxString;
                        m_rxString.clear();
                        break;
                }
                m_rxString += c;
        }

        // Ueberlauf der Ausgabe?
        if (m_rxString.length() > maxStringLength)
        {
                if (m_longStringWarningPrinted == false)
                {
                        // Die lange Version
                        printWarning("Receive-String has excessive length (" + toString(m_rxString.length()) +" bytes). Clearing string. On serial devices, incorrect bitrate settings may cause this behaviour.");
                        m_longStringWarningPrinted = true;
                }
                else
                {
                        // Die Kurzfassung
                        printWarning("Receive-String has excessive length (" + toString(m_rxString.length()) +" bytes). Clearing string.");
                }
                m_rxString.clear();
        }

        // Textmeldung
        if ((m_beVerbose == true) && (outString.length() > 0))
        {
                printInfoMessage("Tcp::readString: Returning string: " + outString, true);
        }

        return outString;
}