[tahoe-dev] Random access to files

[Shawn Willden]

On Tuesday 27 January 2009 06:12:19 am zooko wrote:
> Sounds great!  I guess for step 2 we add get_range(offset=0,
> length=None) and we remove the call to self._download_all_segments in
> CiphertextDownloader.start():

I need to make sure I understand how this code works. Everything is a 
callback!  It looks to me like the set of segments selected for download is 
defined in the loop in _download_all_segments:

        for segnum in range(self._vup.num_segments):
            d.addCallback(self._download_segment, segnum)
            # this pause, at the end of write, prevents pre-fetch from
            # happening until the consumer is ready for more data.
            d.addCallback(self._check_for_pause)
        return d

Is it really as simple as restricting the range of this for loop?

> I can't think of anything that would make this hard, and I would be
> happy to see that feature added, but I am focussing on the imminent
> Tahoe-1.3.0 release so I won't be working on it in the short term.

I may.  It's not an issue for me at the moment, but it will become one.

Thanks,

	Shawn.