JLigierObjectIterator.hh

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#ifndef __JNET__JLIGIEROBJECTITERATOR__
#define __JNET__JLIGIEROBJECTITERATOR__

#include <vector>
#include <exception>

#include "JLang/JAbstractObjectIterator.hh"
#include "JNet/JPrefix.hh"
#include "JNet/JServerSocket.hh"
#include "JNet/JSocketChannel.hh"
#include "JNet/JSelectReader.hh"


/**
 * \author mdejong
 */

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

namespace JNET {

  using JLANG::JAbstractObjectIterator;

  typedef JSocketInputChannel<JPrefix>   JSocketInputChannel_t;
  
  
  /**
   * Get total size of internet packet.
   *
   * \param  prefix           prefix
   * \return                  number of bytes
   */
  inline int getSizeOfPacket(const JPrefix& prefix)
  {
    return prefix.getSize() + sizeof(JPrefix);
  }


  
  /**
   * Object iteration through ControlHost server.
   * This class implements the JLANG::JObjectIterator interface.
   */
  template<class T>
  class JLigierObjectIterator :
    public JServerSocket,
    public JAbstractObjectIterator<T>,
    public std::vector<JSocketInputChannel_t>
  {
  public:

    /**
     * Constructor.
     *
     * \param  port           server port
     * \param  backlog        server backlog
     * \param  buffer_size    socket buffer size
     * \param  timeout_us     timeout [us]
     */
    JLigierObjectIterator(const int port,
                          const int backlog,
                          const int buffer_size = 262144,
                          const int timeout_us  = 10) :
      JServerSocket(port,backlog),
      buffer_size  (buffer_size),
      timeout_us   (timeout_us)
    {}


    /**
     * Set object.
     *
     * \param  object     reference to object to be set
     * \return            true if set; else false
     */
    virtual bool setObject(T& object) override 
    {
      using namespace std;

      for ( ; ; ) {

        select.reset();
        select.setReaderMask(this->getFileDescriptor());
 
        for (const_iterator channel = this->begin(); channel != this->end(); ++channel) {
          if (!channel->isReady()) {
            select.setReaderMask(channel->getFileDescriptor());
          }
        }

        if (select(timeout_us) > 0) {

          for (iterator channel = this->begin(); channel != this->end(); ) {

            if (select.hasReaderMask(*channel)) {

              try {

                channel->read();

                if (channel->isReady()) {

                  if (channel->prefix.getTag() == getTag<T>()) {

                    channel->seekg(sizeof(JPrefix));

                    *channel >> object;     // read object
                  
                    channel->reset();

                    return true;

                  } else {
                    
                    channel->reset();       // skip data
                  }
                }
              }
              catch(const exception& error) {
                
                channel->shutdown();
                
                channel = this->erase(channel);

                continue;
              }
            }

            ++channel;
          }

          if (select.hasReaderMask(*this)) {

            JTCPSocket socket(this->getFileDescriptor());
            
            //socket.setSendBufferSize   (buffer_size);
            socket.setReceiveBufferSize(buffer_size);
            
            socket.setKeepAlive  (true);
            socket.setNonBlocking(true);

            this->push_back(JSocketInputChannel_t(socket));
          }
        }
      }

      return false;
    }

  private:
    JSelectReader select;
    int           buffer_size;
    int           timeout_us;
  };
}

#endif