SocketSelector.h++

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/* ---------------------------------------------------------------------------
   commonc++ - A C++ Common Class Library
   Copyright (C) 2005-2014  Mark A Lindner

   This file is part of commonc++.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free
   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   ---------------------------------------------------------------------------
*/

#ifndef __ccxx_SocketSelector_hxx
#define __ccxx_SocketSelector_hxx

#include <commonc++/Common.h++>
#include <commonc++/AtomicCounter.h++>
#include <commonc++/CircularBuffer.h++>
#include <commonc++/CriticalSection.h++>
#include <commonc++/Iterator.h++>
#include <commonc++/StaticObjectPool.h++>
#include <commonc++/ServerSocket.h++>
#include <commonc++/StreamSocket.h++>
#include <commonc++/Thread.h++>
#include <commonc++/Mutex.h++>

#ifdef CCXX_OS_POSIX
#include <sys/select.h>
#endif

namespace ccxx {

class SocketSelector;

class COMMONCPP_API Connection
{
  friend class SocketSelector;

 public:

  static const size_t DEFAULT_BUFFER_SIZE;

  virtual ~Connection();

  bool writeData(ByteBuffer& buffer);

  bool writeData(const byte_t* buf, size_t count);

  bool writeLine(const String& text);

  void beginWrite();

  void endWrite();

  void cancelWrite();

  size_t readData(ByteBuffer& buffer, bool fully = true);

  size_t readData(byte_t* buf, size_t count, bool fully = true);

  size_t readLine(String& text, size_t maxLen);

  uint32_t readUInt32();

  uint64_t readUInt64();

  inline StreamSocket* getSocket()
  { return(_socket); }

  void setReadLowWaterMark(size_t count);

  void setReadHighWaterMark(size_t count);

  inline size_t getReadLowWaterMark() const
  { return(_readLoMark); }

  bool isReadLow() const;

  bool isReadHigh() const;

  void setWriteLowWaterMark(size_t count);

  void setWriteHighWaterMark(size_t count);

  inline size_t getWriteLowWaterMark() const
  { return(_writeLoMark); }

  inline size_t getWriteHighWaterMark() const
  { return(_writeHiMark); }

  bool isWriteLow() const;

  bool isWriteHigh() const;

  size_t getBytesAvailableToRead() const;

  size_t getBytesAvailableToWrite() const;

  void close(bool immediate = false);

  inline byte_t getOOBData()
  { _oobFlag = false; return(_oobData); }

  inline bool getOOBFlag() const
  { return(_oobFlag); }

  inline time_ms_t getTimestamp() const
  { return(_lastRecv); }

  bool isClosePending() const;

 protected:

  Connection(size_t bufferSize = DEFAULT_BUFFER_SIZE);

 private:

  void read();
  void readOOB();
  void write();

  void attach(SocketSelector* selector, StreamSocket* socket);

  inline void setOOBFlag(bool flag)
  {  _oobFlag = flag; }

  inline void setTimestamp(time_ms_t stamp)
  { _lastRecv = stamp; }

  StreamSocket* _socket;

 protected:

  CircularByteBuffer readBuffer;
  CircularByteBuffer writeBuffer;

 private:

  SocketSelector* _selector;
  size_t _readLoMark;
  size_t _readHiMark;
  size_t _writeLoMark;
  size_t _writeHiMark;
  bool _oobFlag;
  bool _closePending;
  byte_t _oobData;
  time_ms_t _lastRecv;
  mutable CriticalSection _readLock;
  mutable CriticalSection _writeLock;
  static const bool _isSameEndianness;

  CCXX_COPY_DECLS(Connection);
};

class COMMONCPP_API SocketSelector : public Thread
{
 public:

  SocketSelector(uint_t maxConnections = 64,
                 timespan_ms_t defaultIdleLimit = 0);

  virtual ~SocketSelector();

  void run();
  void cleanup();

  void wakeup();

  size_t getConnectionCount() const;

  virtual bool init(ServerSocket* socket);

  uint_t writeAll(const byte_t* buf, size_t count);

 protected:

  virtual Connection* connectionReady(const SocketAddress& address) = 0;

  virtual void dataReceived(Connection* connection) = 0;

  virtual void dataSent(Connection* connection);

  virtual void dataReceivedOOB(Connection* connection);

  virtual void connectionClosed(Connection* connection) = 0;

  virtual void connectionTimedOut(Connection* connection) = 0;

  virtual void exceptionOccurred(Connection* connection,
                                 const IOException& ex);

  class ConnectionList; // fwd decl

  ConnectionList* _connections;

 private:

  void _connectionTimedOut(Connection* connection);
  void _connectionClosed(Connection* connection);

  Mutex _mutex;
  StaticObjectPool<StreamSocket> _pool;
  timespan_ms_t _idleLimit;
  ServerSocket* _ssock;
#ifndef CCXX_OS_WINDOWS
  int _wakePipe[2];
  AtomicCounter _wakeFlag;
#endif

  CCXX_COPY_DECLS(SocketSelector);
};

} // namespace ccxx

#endif // __ccxx_SocketSelector_hxx