tags-cache: skip the filternode step if we are not going to use it
When warming the hgtagsfnodescache, we don't need the actual result, so we can
simply skip the part that "filter" fnode we read from the cache. So provide a
quite visible speed up to the top level `hg debugupdatecache` function.
### 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: 19.947581
after: 18.916804 (-5.17%, -1.03)
#!/usr/bin/env python3
__doc__ = """Same as `echo a >> b`, but ensures a changed mtime of b.
Without this svn will not detect workspace changes."""
import os
import stat
import sys
if sys.version_info[0] >= 3:
text = os.fsencode(sys.argv[1])
fname = os.fsencode(sys.argv[2])
else:
text = sys.argv[1]
fname = sys.argv[2]
f = open(fname, "ab")
try:
before = os.fstat(f.fileno())[stat.ST_MTIME]
f.write(text)
f.write(b"\n")
finally:
f.close()
inc = 1
now = os.stat(fname)[stat.ST_MTIME]
while now == before:
t = now + inc
inc += 1
os.utime(fname, (t, t))
now = os.stat(fname)[stat.ST_MTIME]