JSocketNonblocking.hh

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#ifndef __JNET__JSOCKETNONBLOCKINGIO__
#define __JNET__JSOCKETNONBLOCKINGIO__

#include "JNet/JSocket.hh"
#include "JNet/JSocketStatus.hh"


/**
 * \author mdejong
 */

namespace JNET {}
namespace JPP { using namespace JNET; }

namespace JNET {


  /**
   * Auxiliary class for non-blocking socket I/O.
   */
  template<class JElement_t>
  class JSocketBuffer :
    public JSocketStatus
  {
  protected:
    /**
     * Default constructor.
     */
    JSocketBuffer() :
      JSocketStatus(),
      __data(NULL),
      __size(0)
    {}
    

  public:
    /**
     * Constructor.
     *
     * \param  buffer          I/O data
     * \param  length          number of bytes
     */
     JSocketBuffer(JElement_t* buffer, const int length) :
      JSocketStatus(),
      __data(buffer),
      __size(length)
    {}


    /**
     * Get size of pending data.
     * 
     * \return                 number of bytes
     */
    int getSize() const
    {
      return __size;
    }


    /**
     * Initialise buffer.
     *
     * \param  buffer          buffer
     */
    void set(const JSocketBuffer<JElement_t>& buffer)
    {
      set(buffer.__data, buffer.__size);
    }


    /**
     * Initialise buffer.
     *
     * \param  buffer          I/O data
     * \param  length          number of bytes
     */
    void set(JElement_t* buffer, const int length)
    {
      if (status == IO_BUSY) {
        THROW(JSocketException, "Set socket buffer I/O while busy.");
      }

      status  = (length != 0 ? IO_BUSY : IO_READY);
      counter = 0;
      __data  = buffer;
      __size  = length;
    }
    

    /**
     * Reset 
     */
    void reset()
    {
      JSocketStatus::reset();

      __data  = NULL;
      __size  = 0;
    }

    
  protected:
    JElement_t* __data;
    int         __size;
  };


  typedef  JSocketBuffer<char>        JSocketInputBuffer;
  typedef  JSocketBuffer<const char>  JSocketOutputBuffer;
  

  /**
   * Non-blocking socket reader.
   * This class can be used in case of non-blocking I/O
   * (see method JSocket::setNonBlocking()).
   */ 
  class JSocketNonblockingReader :
    public JSocket,
    public JSocketInputBuffer
  {
  public:
    /**
     * Constructor.
     *
     * \param  socket          socket
     */
    JSocketNonblockingReader(const JSocket& socket) :
      JSocket(socket),
      JSocketInputBuffer()
    {}


    /**
     * Continuation of non-blocking read method.
     *
     * \return                 status
     */
    JStatus_t read()
    {
      if (status == IO_BUSY) {

        ++counter;
        
        const int pos = JSocket::read(__data, __size);
        
        __data += pos;
        __size -= pos;

      } else {

        THROW(JSocketException, "Calling socket non-blocking read() while not busy.");
      }

      if (__size == 0) {
        status = IO_READY;
      }

      return status;
    }
  };


  /**
   * Non-blocking socket writer.
   * This class can be used in case of non-blocking I/O
   * (see method JSocket::setNonBlocking()).
   */ 
  class JSocketNonblockingWriter :
    public JSocket,
    public JSocketOutputBuffer
  {
  public:
    /**
     * Constructor.
     *
     * \param  socket          socket
     */
    JSocketNonblockingWriter(const JSocket& socket) :
      JSocket(socket),
      JSocketOutputBuffer()
    {}


    /**
     * Continuation of non-blocking write method.
     *
     * \return                 status
     */
    JStatus_t write()
    {
      if (status == IO_BUSY) {

        ++counter;
        
        const int pos = JSocket::write(__data, __size);
        
        __data += pos;
        __size -= pos;

      } else {

        THROW(JSocketException, "Calling socket non-blocking write() while not busy.");
      }

      if (__size == 0) {
        status = IO_READY;
      }

      return status;
    }
  };
}

#endif