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

[David Jones]

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.