data_buffer.h

//*****************************************************************************
//
// Author		: Konstantin Chizhov
// Date			: 2016
// All rights reserved.

// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
// Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.

// Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation and/or
// other materials provided with the distribution.

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
// IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
// INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
// EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//*****************************************************************************

#pragma once
#include <stdint.h>
#include <stddef.h>
#include <array.h>
#include <binary_stream.h>
#include <net/net_addr.h>

namespace Mcucpp
{

	class DataChunk
	{
		uint8_t *_data;
		DataChunk * _next;
		uint16_t _size;
		uint16_t _storage;
		friend class DataBufferBase;
		friend class DataBufferIterator;
		DataChunk(const DataChunk&)=delete;
        DataChunk & operator=(const DataChunk &) = delete;

	public:

        DataChunk& operator=(DataChunk&& ) = default;


		~DataChunk()
		{
			Release(this);
		}

		DataChunk(DataChunk&&)=default;

		DataChunk(uint8_t *data, size_t size)
			:_data(data), _next(0), _size(size), _storage(0)
		{

		}

		DataChunk(uint8_t *data, size_t size, size_t storageSize)
			:_data(data), _next(0), _size(size), _storage(storageSize)
		{

		}

		uint8_t &operator[](size_t index)
		{
			return _data[index];
		}

		uint8_t operator[](size_t index)const
		{
			return _data[index];
		}

		bool Resize(size_t s)
		{
			if(s > _storage)
				return false;
			_size = s;
			return true;
		}

		uint8_t* Data() const {return _data; }
		size_t Size() const {return _size; }

		size_t Capacity() const {return _storage ? _storage : _size; }
		DataChunk* Next() const {return _next; }
		DataChunk* Prev(DataChunk* first) const ;

		static DataChunk* GetNew(size_t size);
		static DataChunk* GetNew(const void *data, size_t size);

		static void Release(DataChunk * data);
		static void ReleaseRecursive(DataChunk * data);
		static DataChunk *FindLast(DataChunk *first);
	};


	class DataBufferBase
	{
		DataChunk *_first;
		DataChunk *_current;
		size_t _pos;
		static uint8_t _dummy;
		friend class DataBufferIterator;
	public:
		DataBufferBase();
		~DataBufferBase();


		DataBufferBase(const DataBufferBase &) = delete;
		DataBufferBase & operator=(const DataBufferBase &) = delete;

		DataBufferBase& operator=(DataBufferBase&& ) noexcept;
        DataBufferBase(DataBufferBase &&) noexcept;

		DataBufferBase(DataChunk* chain)
		:_first(chain), _current(nullptr), _pos(0)
		{

		}

		DataChunk* MoveToBufferList()
		{
			DataChunk* result = _first;
			_first = 0;
			_current = 0;
			_pos = 0;
			return result;
		}

		DataChunk* BufferList(){ return _first;}

		uint8_t operator*() const
		{
			if(!_current)
				return 0;
			return (*_current)[_pos];
		}

		uint8_t& operator*()
		{
			if(!_current)
				return _dummy;
			return (*_current)[_pos];
		}

		DataBufferBase& operator++()
		{
			if(_current)
			{
				if(++_pos >= _current->Size())
				{
					_pos = 0;
					_current = _current->Next();
				}
			}
			return *this;
		}

		DataBufferBase& operator--()
		{
			if(_current)
			{
				if(_pos == 0)
				{
				    _current = _current->Prev(_first);
				    if(_current)
                    {
                        _pos = _current->Size();
                    }
				}else
				{
				    _pos--;
				}
			}
			return *this;
		}

		uint8_t Read()
		{
			if(!_current)
				return 0;
			uint8_t value = (*_current)[_pos++];
			if(_pos >= _current->Size())
			{
				_pos = 0;
				_current = _current->Next();
			}
			return value;
		}

		void Write(uint8_t byte)
		{
			if(!_current)
				return;

			(*_current)[_pos++] = byte;
			if(_pos >= _current->Size())
			{
				_pos = 0;
				_current = _current->Next();
			}
		}

		void WriteMac(const Net::MacAddr &addr)
		{
			for(size_t i = 0; i < addr.Length(); i++)
			{
				Write(addr[i]);
			}
		}

		void WriteIp(const Net::IpAddr &addr)
		{
			for(size_t i = 0; i < addr.Length(); i++)
			{
				Write(addr[i]);
			}
		}

		Net::MacAddr ReadMac()
		{
			Net::MacAddr addr;
			for(size_t i = 0; i < addr.Length(); i++)
			{
				addr[i] = Read();
			}
			return addr;
		}

		Net::IpAddr ReadIp()
		{
			uint8_t a = Read();
			uint8_t b = Read();
			uint8_t c = Read();
			uint8_t d = Read();
			return Net::IpAddr(a, b, c, d);
		}

		void Clear();
		bool InsertFront(size_t size);
		bool InsertBack(size_t size);
		bool Insert(size_t pos, size_t size);
		void AttachBack(DataChunk* buffer);
		void AttachFront(DataChunk* buffer);
		DataChunk* DetachFront();
		DataChunk* CurrentChunck(){ return _current; }

		bool Seek(size_t pos);
		size_t Tell();
		size_t Size();
		unsigned Parts();
	};

	typedef Mcucpp::BinaryStream<DataBufferBase> DataBuffer;

	class DataBufferIterator
	{
		DataChunk *_current;
		size_t _pos;
	public:
		DataBufferIterator(DataChunk *first)
		:_current(first),
		_pos(0)
		{}

		uint8_t operator*() const
		{
			if(!_current)
				return 0;
			return (*_current)[_pos];
		}

		uint8_t& operator*()
		{
			if(!_current)
				return DataBufferBase::_dummy;
			return (*_current)[_pos];
		}

		DataBufferIterator& operator++()
		{
			if(_current)
			{
				if(++_pos >= _current->Size())
				{
					_pos = 0;
					_current = _current->Next();
				}
			}
			return *this;
		}

		bool operator== (const DataBufferIterator & other)
		{
			return _current == other._current && _pos == other._pos;
		}

		bool operator!= (const DataBufferIterator & other)
		{
			return _current != other._current;
		}
	};

	static inline DataBufferIterator begin(DataBuffer &buffer)
	{
		return DataBufferIterator(buffer.BufferList());
	}

	static inline DataBufferIterator end(DataBuffer &buffer)
	{
	    (void)buffer;
		return DataBufferIterator(nullptr);
	}

}