vlShmWriter.h

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/*********************************************************************
 ** Copyright (c) 1992-2010 VT MAK
 ** All rights reserved.
 *********************************************************************/
#pragma once

#include "vlShmQueue.h"

#ifdef DtUSE_UTILITIES_NAMESPACE
namespace DtUSE_UTILITIES_NAMESPACE
{
#endif

#define DEBUG 0

   class DT_DLL_VLUTIL DtClientServerWriter
   {
   public:
      DtClientServerWriter() {};
      virtual ~DtClientServerWriter() {};

      virtual int Write (char *buf, size_t size) = 0;
      virtual int Writev (char **buflist, size_t *sizelist, int n) = 0;

   };

   class DT_DLL_VLUTIL DtShmMsgQueueWriter : public DtClientServerWriter
   {
   public:

      DtShmMsgQueueWriter(DtShmMsgQueue *q, int size, int sem, int firstSem,
                          bool wait, bool pleaseInit, bool dropOldest = true);

      virtual ~DtShmMsgQueueWriter() {}

      virtual int Write (char *buf, size_t size);
      virtual int Writev (char **buflist, size_t *sizelist, int n);

      void setInternal(int mode) {qManager.setInternal(mode); }
      void setGoAway(int mode) {qManager.setGoAway(mode); }
      int newDropped() { return newLost; }
      int oldDropped() { return oldLost; }
      int msgsSent()   { return notLost; }

      DtShmMsgQueueManager qManager;
      bool resourceWait;
      int queueBack;

   private:

      int enqueuev (char **buflist, size_t *sizelist, int n, int totalSize);
      void copyv(char **buflist, size_t *sizelist, int n, int endSize);
      int findSpace(int start, int request, int *available);
      void moveFront(void);

      int newLost;
      int oldLost;
      int notLost;

      int verifyQueue(void); 
#if DEBUG
#endif


   };

#ifdef DtUSE_UTILITIES_NAMESPACE
} 
#endif