[Performance] Test valid path only if file info has to be retrieved

[Glandos]

Filesystem::isValidPath seems to be useless here, since we already have our file info anyway.

After applying #34910 it still gives me the following improvement, when running preview generator on a folder with 1473 images, all already generated.

• Before:

 Performance counter stats for './occ preview:generate-all -vv --path=/users/files/photos/2008 - 09 - Viet Nam/' (5 runs):

         13 124,93 msec task-clock                       #    0,653 CPUs utilized            ( +-  1,17% )
             5 826      context-switches                 #  451,999 /sec                     ( +-  1,01% )
               719      cpu-migrations                   #   55,782 /sec                     ( +-  6,37% )
            20 846      page-faults                      #    1,617 K/sec                    ( +-  0,01% )
    24 144 069 088      cycles                           #    1,873 GHz                      ( +-  1,17% )  (50,38%)
     5 539 208 540      instructions                     #    0,23  insn per cycle           ( +-  0,17% )  (74,88%)
     1 124 152 538      branches                         #   87,215 M/sec                    ( +-  0,16% )  (74,30%)
       164 879 701      branch-misses                    #   14,65% of all branches          ( +-  0,31% )  (75,34%)

            20,084 +- 0,267 seconds time elapsed  ( +-  1,33% )

• After:

 Performance counter stats for './occ preview:generate-all -vv --path=/users/files/photos/2008 - 09 - Viet Nam/' (5 runs):

         10 918,60 msec task-clock                       #    0,615 CPUs utilized            ( +-  1,20% )
             5 702      context-switches                 #  531,419 /sec                     ( +-  1,06% )
               802      cpu-migrations                   #   74,745 /sec                     ( +-  8,95% )
            20 827      page-faults                      #    1,941 K/sec                    ( +-  0,01% )
    20 074 183 445      cycles                           #    1,871 GHz                      ( +-  1,19% )  (49,12%)
     4 660 549 008      instructions                     #    0,24  insn per cycle           ( +-  0,17% )  (74,39%)
       928 891 708      branches                         #   86,571 M/sec                    ( +-  0,13% )  (75,05%)
       137 892 289      branch-misses                    #   14,85% of all branches          ( +-  0,40% )  (75,87%)

            17,768 +- 0,242 seconds time elapsed  ( +-  1,36% )

It's a small use case, but 10% improvement seems valuable to me :)

[Glandos]

Is there anything I can do for the failing tests? As far as I understand:

• Performance testing / performance-8.0 (pull_request) => can't find remote ref
• S3 primary storage / php8.0-objectstore_multibucket-minio (pull_request) => Failed to connect to localhost port 9000
• S3 primary storage / s3-primary-summary (pull_request) => if true; then exit 1; fi, so designed to fail
• continuous-integration/drone/pr => failed on acceptance-app-files-sharing but this seems to fail at random

[icewind1991]

I've restarted the failing S3 test, you can ignore the other 2 failures

[welcome]

Thanks for your first pull request and welcome to the community! Feel free to keep them coming! If you are looking for issues to tackle then have a look at this selection: https://github.com/nextcloud/server/issues?q=is%3Aopen+is%3Aissue+label%3A%22good+first+issue%22