/*
* Chunk.h
*
*  Created on: Sep 28, 2010
*      Author: daniele
*/

#ifndef CHUNK_H_
#define CHUNK_H_

#include <vector>
#include "BufferDescriptor.h"

class Chunk
{
public:
	/**
	* Constructs an empty buffer, with no data, offset and size set to 0.
	* It's possibile to specify a custom offset for consistency when returning an empty chunk.
	* @param offset an offset
	*/
	Chunk( std::size_t offset = 0 );

	/**
	* Construct a chunk of data.
	* @param data a buffer of bytes.
	* @param descriptor a descriptor containing the absolute offset and the size of the data.
	*/
	Chunk(char const * data, BufferDescriptor descriptor);

	/**
	* Construct a chunk of data.
	* @param data a buffer of bytes.
	* @param size the size of the data contained in the buffer.
	*/
	Chunk(char const * data, std::size_t size);

	virtual ~Chunk();

	/**
	* Gives a pointer to the data contained in the buffer.
	* @return a pointer to buffer.
	*/
	char* ptr() { return &_data[0]; }

	/**
	* Gives a reference to internal vector (used for storing data).
	* @return a reference to vector<char>
	*/
	const std::vector<char>& vector() const { return _data; }

	/**
	* Gives a pointer to const data.
	* @return a pointer to const.
	*/
	char const * const_ptr() { return &_data[0]; }

	/**
	* Tells the offset of the Chunk.
	* @return an absolute offset.
	*/
	std::size_t offset() { return _descriptor.offset(); }

	/**
	* Tells the size of the data contained in the Chunk.
	* @return a size in bytes.
	*/
	std::size_t size() { return _descriptor.size(); }

	bool equal(const Chunk& another) const
	{
		bool descriptor_equal = ( descriptor() == another.descriptor() );
		bool content_equal = ( vector() == another.vector() );
		return ( descriptor_equal && content_equal );
	}

	/**
	* Tells the descriptor of the Chunk.
	* @return a buffer descriptor.
	*/
	BufferDescriptor descriptor() const { return _descriptor; }

	bool operator==(Chunk const & another)
	{
		return equal(another);
	}

private:
	std::vector<char> _data;
	BufferDescriptor _descriptor;
};

#if 0
template <typename T>
class CastedChunk : public Chunk {
	T& casted_data() { return static_cast<T>( this->ptr() ); }
};
#endif

#endif /* CHUNK_H_ */