text: /*
  **  ClanLib SDK
  **  Copyright (c) 1997-2016 The ClanLib Team
  **
  **  This software is provided 'as-is', without any express or implied
  **  warranty.  In no event will the authors be held liable for any damages
  **  arising from the use of this software.
  **
  **  Permission is granted to anyone to use this software for any purpose,
  **  including commercial applications, and to alter it and redistribute it
  **  freely, subject to the following restrictions:
  **
  **  1. The origin of this software must not be misrepresented; you must not
  **     claim that you wrote the original software. If you use this software
  **     in a product, an acknowledgment in the product documentation would be
  **     appreciated but is not required.
  **  2. Altered source versions must be plainly marked as such, and must not be
  **     misrepresented as being the original software.
  **  3. This notice may not be removed or altered from any source distribution.
  **
  **  Note: Some of the libraries ClanLib may link to may have additional
  **  requirements or restrictions.
  **
  **  File Author(s):
  **
  **    Magnus Norddahl
  */
  
  #pragma once
  
  #include "iodevice.h"
  
  namespace clan
  {
  	/// \addtogroup clanCore_I_O_Data clanCore I/O Data
  	/// \{
  
  	/// \brief I/O device provider interface.
  	class IODeviceProvider
  	{
  	public:
  		virtual ~IODeviceProvider() { return; }
  
  		/// \brief Returns the size of data stream.
  		/** <p>Returns -1 if the size is unknown.</p>*/
  		virtual int get_size() const { return -1; }
  
  		/// \brief Returns the position in the data stream.
  		/** <p>Returns -1 if the position is unknown.</p>*/
  		virtual int get_position() const { return -1; }
  
  		/// \brief Send data to device.
  		virtual int send(const void *data, int len, bool send_all = true) = 0;
  
  		/// \brief Receive data from device.
  		virtual int receive(void *data, int len, bool receive_all = true) = 0;
  
  		/// \brief Peek data from device.
  		virtual int peek(void *data, int len) = 0;
  
  		/// \brief Returns a new provider to the same resource.
  		virtual IODeviceProvider *duplicate() = 0;
  
  		/// \brief Seek in data stream.
  		virtual bool seek(int /*position*/, IODevice::SeekMode /*mode*/) { return false; }
  	};
  
  	/// \}
  }
  