[gdal-dev] GDAL block cache question

[Antonio Valentino]

Il giorno Wed, 8 Oct 2008 14:02:23 -0400
"Luke Roth" <roth.luke at gmail.com> ha scritto:

> Hi everybody,
> 
> I've been working on writing an image viewer using GDAL, and I'd like

Hi Luke,
unfortunately I don't have an answer for you but I would like to ask
you some more about the application you are working on.
It seems to me it is written in C++, is it?
Which is the target platform?
Which GUI toolkit are you going to use?
Will it be open source?
Do you have in mind a particular target about data (optical/SAR images,
raster/vector data)? 
What about meta-data and geographic info?

> to take advantage of the block cache to avoid keeping multiple copies
> of things in memory where I can.  I'm currently using the
> GetLockedBlockRef() function, which works well, but can sometimes lead
> to large delays when scrolling around and reading in new data.  Is
> there any easy way to check to see if a particular block is present in
> the cache before trying to read it?  I've found the
> TryGetLockedBlockRef() function, which I could use to read the data
> from the cache, note which blocks are not valid, and go back and read
> those blocks in idle time or in a separate thread, but it's protected
> and I don't really want to mess with the GDAL class hierarchy if I
> don't have to.  Is there a straightforward way to do this?

I hope I'm not too boring.

thanks

-- 
Antonio Valentino