wxMemoryBuffer

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.

Derived from

None

Include files

<wx/buffer.h>



wxMemoryBuffer::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.



wxMemoryBuffer(size_t size)

Create a new buffer.

size
size of new buffer.



wxMemoryBuffer::GetData



void* GetData(void)

Return a pointer to the data in the buffer.



wxMemoryBuffer::GetBufSize



size_t GetBufSize(void)

Returns the size of the buffer.



wxMemoryBuffer::GetDataLen



size_t GetDataLen(void)

Returns the length of the valid data in the buffer.



wxMemoryBuffer::SetBufSize



void SetBufSize(size_t size)

Ensures the buffer has at least size bytes available.



wxMemoryBuffer::SetDataLen



void SetDataLen(size_t size)

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

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



wxMemoryBuffer::GetWriteBuf



void * 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.



wxMemoryBuffer::UngetWriteBuf



void UngetWriteBuf(size_t sizeUsed)

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

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



wxMemoryBuffer::GetAppendBuf



void * 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.

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



wxMemoryBuffer::UngetAppendBuf



void UngetAppendBuf(size_t sizeUsed)

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

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



wxMemoryBuffer::AppendByte



void AppendByte(char data)

Append a single byte to the buffer.

data
New byte to append to the buffer.



wxMemoryBuffer::AppendData



void AppendData(void* data, size_t len)

Single call to append a data block to the buffer.

data
Pointer to block to append to the buffer.
len
Length of data to append.
ymasuda 平成17年11月19日