tntdb::IBlob

IBlob Class Reference

Implementation base of Blob values. More...

#include <tntdb/iface/iblob.h>

Inheritance diagram for IBlob:


Public Member Functions
virtual	~IBlob ()
	Destructor.
virtual void	assign (const char *data, std::size_t len)=0
	Assign data of a given length.
virtual char *	reserve (std::size_t len, bool shrink)=0
	Makes sure, the buffer has at least len bytes.
virtual IBlob *	create () const=0
	Create a value implementation.
virtual void	destroy ()=0
	Destroy a value implementation.
std::size_t	size () const
	Returns the size of the blob-data.
const char *	data () const
	Returns a pointer to the blob-data or 0 if the blob is empty.
bool	operator== (const IBlob &other) const
	Returns true if the two instances contain the same data.
Protected Attributes
char *	_data
std::size_t	_size

Detailed Description

This class serves as the base for the shared implementation classes used in Blob objects. The non-virtual interface consists of a pointer to the blob-data and its size. The implementor has to override three virtual methods, IBlob::assign, IBlob::create and IBlob::destroy. The main purpose of these methods is to customize memory allocation of blob-data, aswell as the shared implementation class derived from IBlob. A default implementation, called BlobImpl, is provided, that uses new/delete and the implementation class.

Member Function Documentation

virtual void assign	(	const char *	data,
		std::size_t	len
	)			`[pure virtual]`

The len bytes of the data pointed to by data are copied to this blob.

Implemented in BlobImpl.

virtual IBlob* create ( ) const [pure virtual]

Returns a pointer to a implementation class derived from IBlob. IBlob::destroy must be implemented accordingly to destroy this instance.

Implemented in BlobImpl.

virtual void destroy ( ) [pure virtual]

Destroys an instance previously created by the IBlob::create.

Implemented in BlobImpl.

IBlob Class Reference

Public Member Functions

Protected Attributes

Detailed Description

Member Function Documentation