Re: Why doesn't Info `T' cache node tree for current file?

[Stefan Monnier]

>> Anyway, no _need_ to do anything. My thought was that if someone uses
>> `T', s?he is likely to do so again, and likely with the same
>> file. Since we have gone to the trouble of building the node tree
>> (graph), why not save it for possible reuse? That's all.

> It is not very quick, since the code has to reread all Info subfiles
> (its slowest part).  When the delay after typing `T' is more than 1 sec,
> this is unbearable for many users.

I haven't heard any complaint about it, so it looks like those delays
rarely if ever occur.  And I believe machines are getting faster more
quickly than manuals are getting larger, so I don't expect reports to
become much more frequent in the future.

OTOH, such caching might be necessary for Drew's breadcrumbs (a small
delay is fine for `T' but is problematic if it occurs at every page).

> So we could cache the TOC buffer per Info file, if this costs us
> nothing.  I see one problem: how to refresh the cached TOC buffer when
> the Info file changes - the usual key `g' for buffer refreshing is
> already allocated to `Info-goto-node'.

The refresh should be 100% automatic by recording the timestamps of
the files.


        Stefan