contrib/casesmash.py

perf: benchmark command for revlog indexes

We didn't have explicit microbenchmark coverage for loading revlog
indexes. That seems like a useful thing to have, so let's add it.

We currently measure the low-level nodemap APIs. There is room to
hook in at the actual revlog layer. This could be done as a follow-up.

The hackiest thing about this patch is specifying revlog paths.
Other commands have arguments that allow resolution of changelog,
manifest, and filelog. I needed to hook in at a lower level of
the revlog API than what the existing helper functions to resolve
revlogs allowed. I was too lazy to write some new APIs. This could
be done as a follow-up easily enough.

Example output for `hg perfrevlogindex 00changelog.i` on my
Firefox repo (404418 revisions):

! revlog constructor
! wall 0.003106 comb 0.000000 user 0.000000 sys 0.000000 (best of 912)
! read
! wall 0.003077 comb 0.000000 user 0.000000 sys 0.000000 (best of 924)
! create index object
! wall 0.000000 comb 0.000000 user 0.000000 sys 0.000000 (best of 1803994)
! retrieve index entry for rev 0
! wall 0.000193 comb 0.000000 user 0.000000 sys 0.000000 (best of 14037)
! look up missing node
! wall 0.003313 comb 0.000000 user 0.000000 sys 0.000000 (best of 865)
! look up node at rev 0
! wall 0.003295 comb 0.010000 user 0.010000 sys 0.000000 (best of 858)
! look up node at 1/4 len
! wall 0.002598 comb 0.010000 user 0.010000 sys 0.000000 (best of 1103)
! look up node at 1/2 len
! wall 0.001909 comb 0.000000 user 0.000000 sys 0.000000 (best of 1507)
! look up node at 3/4 len
! wall 0.001213 comb 0.000000 user 0.000000 sys 0.000000 (best of 2275)
! look up node at tip
! wall 0.000453 comb 0.000000 user 0.000000 sys 0.000000 (best of 5697)
! look up all nodes (forward)
! wall 0.094615 comb 0.100000 user 0.100000 sys 0.000000 (best of 100)
! look up all nodes (reverse)
! wall 0.045889 comb 0.050000 user 0.050000 sys 0.000000 (best of 100)
! retrieve all index entries (forward)
! wall 0.078398 comb 0.080000 user 0.060000 sys 0.020000 (best of 100)
! retrieve all index entries (reverse)
! wall 0.079376 comb 0.080000 user 0.070000 sys 0.010000 (best of 100)

from __future__ import absolute_import
import __builtin__
import os
from mercurial import (
    util,
)

def lowerwrap(scope, funcname):
    f = getattr(scope, funcname)
    def wrap(fname, *args, **kwargs):
        d, base = os.path.split(fname)
        try:
            files = os.listdir(d or '.')
        except OSError:
            files = []
        if base in files:
            return f(fname, *args, **kwargs)
        for fn in files:
            if fn.lower() == base.lower():
                return f(os.path.join(d, fn), *args, **kwargs)
        return f(fname, *args, **kwargs)
    scope.__dict__[funcname] = wrap

def normcase(path):
    return path.lower()

os.path.normcase = normcase

for f in 'file open'.split():
    lowerwrap(__builtin__, f)

for f in "chmod chown open lstat stat remove unlink".split():
    lowerwrap(os, f)

for f in "exists lexists".split():
    lowerwrap(os.path, f)

lowerwrap(util, 'posixfile')