view tests/test-issue4074.t @ 51599:b0aaffcb6fcf

tags-cache: directly perform a monimal walk for hgtagsfnodescache warming

We do something narrower than the path retrieving data. So lets use dedicated
code instead.

This provides further useful speedup:

### data-env-vars.name            = mozilla-try-2023-03-22-zstd-sparse-revlog
  # benchmark.name                = hg.debug.debug-update-cache
  # bin-env-vars.hg.flavor        = default
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.pre-state  = warm
before-this-series:  19.947581
skip-fnode-filter:   18.916804   (-5.17%, -1.03)
use-rev-num:         17.493725  (-12.30%, -2.45)
this-changesets:     15.919466  (-20.19%, -4.03)

#require no-pure

A script to generate nasty diff worst-case scenarios:

  $ cat > s.py <<EOF
  > import random
  > for x in range(100000):
  >     print
  >     if random.randint(0, 100) >= 50:
  >         x += 1
  >     print(hex(x))
  > EOF

  $ hg init a
  $ cd a

Check in a big file:

  $ "$PYTHON" ../s.py > a
  $ hg ci -qAm0

Modify it:

  $ "$PYTHON" ../s.py > a

Time a check-in, should never take more than 10 seconds user time:

  $ hg ci --time -m1 --config worker.enabled=no
  time: real .* secs .user [0-9][.].* sys .* (re)