Re: [xml] PATCH: implement xmlSaveToBuffer()

[Daniel Veillard <veillard redhat com>]

On Sun, Nov 06, 2005 at 07:33:19PM -0500, Rob Richards wrote:
> Geert Jansen wrote: 
> > See the attached patch. I took your original suggestion and used the 
> > original prototype for xmlSaveToBuffer(). I now create an 
> > xmlOutputBuffer from the xmlBuffer. This is done by a new function in 
> > xmlIO.c: xmlOutputBufferCreateBuffer(). It uses xmlAllocOutputBuffer() 
> > to create a new output buffer and then replaces either .buffer or 
> > .conv by the user supplied buffer. This requires me to free one buffer 
> > that was just allocated. This isn't ideal but I thought this would be 
> > better than either duplicating xmlAllocOutputBuffer() or changing it 
> > signature to accept a flag indicating that it should not allocate 
> > buffers.
> >
> > In order to ensure that xmlFreeSaveCtxt() does not free the user 
> > supplied buffer, I had to extend xmlSaveCtxt with two members: 
> > "user_buffer" and "user_conv" to indicate that buffer or conv 
> > respectively are allocated by the user and should not be freed. I 
> > didn't feel very confident about extending this structure but I could 
> > not come up with something else. Did you have something else in mind?
> Any reason why this couldn't or shouldn't be done the same way 
> xmlNewTextWriterMemory is done?
> Would only require the addition of write and close callbacks and not 
> require any of the other new stuff from the patch.

  Right, while Geert patch is correct, an approach where you reuse the
I/O callback to fill up a buffer looks cleaner to me.

Daniel

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veillard redhat com  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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