wxMemoryBuffer Class Reference
[Data Structures]

#include <wx/buffer.h>

List of all members.

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Detailed Description

A wxMemoryBuffer is a useful data structure for storing arbitrary sized blocks of memory. wxMemoryBuffer guarantees deletion of the memory block when the object is destroyed.

Library:  wxBase

Category:  Data Structures

Public Member Functions
	wxMemoryBuffer (const wxMemoryBuffer &src)
	wxMemoryBuffer (size_t size=DefBufSize)
void	AppendByte (char data)
void *	GetAppendBuf (size_t sizeNeeded)
size_t	GetBufSize () const
void *	GetData () const
size_t	GetDataLen () const
void *	GetWriteBuf (size_t sizeNeeded)
void	SetBufSize (size_t size)
void	SetDataLen (size_t size)
void	UngetAppendBuf (size_t sizeUsed)
void	UngetWriteBuf (size_t sizeUsed)

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Constructor & Destructor Documentation

wxMemoryBuffer::wxMemoryBuffer

(

const wxMemoryBuffer &

src

)

Copy constructor, refcounting is used for performance, but wxMemoryBuffer is not a copy-on-write structure so changes made to one buffer effect all copies made from it.

See also:

Reference Counting

wxMemoryBuffer::wxMemoryBuffer

(

size_t

size = DefBufSize

)

Create a new buffer.

Parameters:

size

size of the new buffer.

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Member Function Documentation

void wxMemoryBuffer::AppendByte

(

char

data

)

Append a single byte to the buffer.

Parameters:

data

New byte to append to the buffer.

void* wxMemoryBuffer::GetAppendBuf

(

size_t

sizeNeeded

)

Ensure that the buffer is big enough and return a pointer to the start of the empty space in the buffer. This pointer can be used to directly write data into the buffer, this new data will be appended to the existing data.

Parameters:

sizeNeeded

Amount of extra space required in the buffer for the append operation

size_t wxMemoryBuffer::GetBufSize

(

)

const

Returns the size of the buffer.

void* wxMemoryBuffer::GetData

(

)

const

Return a pointer to the data in the buffer.

size_t wxMemoryBuffer::GetDataLen

(

)

const

Returns the length of the valid data in the buffer.

void* wxMemoryBuffer::GetWriteBuf

(

size_t

sizeNeeded

)

Ensure the buffer is big enough and return a pointer to the buffer which can be used to directly write into the buffer up to sizeNeeded bytes.

void wxMemoryBuffer::SetBufSize

(

size_t

size

)

Ensures the buffer has at least size bytes available.

void wxMemoryBuffer::SetDataLen

(

size_t

size

)

Sets the length of the data stored in the buffer. Mainly useful for truncating existing data.

Parameters:

size

New length of the valid data in the buffer. This is distinct from the allocated size

void wxMemoryBuffer::UngetAppendBuf

(

size_t

sizeUsed

)

Update the length after completing a direct append, which you must have used GetAppendBuf() to initialise.

Parameters:

sizeUsed

This is the amount of new data that has been appended.

void wxMemoryBuffer::UngetWriteBuf

(

size_t

sizeUsed

)

Update the buffer after completing a direct write, which you must have used GetWriteBuf() to initialise.

Parameters:

sizeUsed

The amount of data written in to buffer by the direct write