\input gets slower after each \input

[Phelype Oleinik]

On 27/04/2021 12:34, barbara beeton wrote:
> 
> This has come up before, although with situations involving different
> input file names, not the same name as in the present test.  When a
> file access is completed (definitively closed), ur-TeX would attempt
> to remove the name from the string pool.  But if anything else had
> been added to the string pool, the name was not removed, since the
> complications of garbage collection outweighed the space saving.  I
> don't think that approach has changed

It doesn't seem to have been changed, because as Ulrike noted, the
example eventually explodes with a string pool overflow, and all it
does is to input the same file over and over again.

However the access time for string memory is constant, since it is just
a pointer to a large array.  In fact, the sample takes roughly the same
time to run regardless if the file is |abcdefghijklmnopqrstuvwxyz.tex|
or just |a.tex|, which indicates that it is not _how much_ string memory
is used, but how many strings are added to the pool.

My questioning is if the space saved by reusing some chunks of the
string pool is worth the time taken to search through it...
Speaking of which: if a string is reused when found in the pool, why
does the example runs out of string space?  Shouldn't it reuse always
the same string?

Phelype