[Info-vax] Empty blocks in FILES-11 directory files.

[Volker Halle]

osuv... at gmail.com schrieb am Sonntag, 25. September 2022 um 19:59:55 UTC+2:
> On Sunday, September 25, 2022 at 10:27:19 AM UTC-4, Volker Halle wrote: 
> > Please read the second half of that sentence: I strongly believe you can't do a window turn (which involves the XQP), if you are already in the XQP executing a directory operation. So directory files must be contiguous. 
> >
> There is a middle ground, such as what happens with the pager. The page file doesn't have to be contiguous, 
> but the file can't have extension headers (i.e. all retrieval pointers must fit in the primary header). If the header 
> for the directory file is cached in memory, a window turn won't require I/O.

Even if a directory would only be allowed to have a primary file header, you would still have to do a window turn, if there are more than ACP_WINDOW (default: 7) retrieval pointers. When handling directory expansion/compression the XQP is already operating in XQP 'secondary context' and I bet, that the XQP cannot invoke a window turn in that context.

Volker.