revlog: optimize _chunkraw when startrev==endrev
In many cases, _chunkraw() is called with startrev==endrev. When
this is true, we can avoid an extra index lookup and some other
minor operations.
On the mozilla-unified repo, `hg perfrevlogchunks -c` says this
has the following impact:
! read w/ reused fd
! wall 0.371846 comb 0.370000 user 0.350000 sys 0.020000 (best of 27)
! wall 0.337930 comb 0.330000 user 0.300000 sys 0.030000 (best of 30)
! read batch w/ reused fd
! wall 0.014952 comb 0.020000 user 0.000000 sys 0.020000 (best of 197)
! wall 0.014866 comb 0.010000 user 0.000000 sys 0.010000 (best of 196)
So, we've gone from ~25x slower than batch to ~22.5x slower.
At this point, there's probably not much else we can do except
implement an optimized function in the index itself, including in C.
from __future__ import absolute_import
import os
import sys
from . import (
encoding,
osutil,
)
def _rcfiles(path):
rcs = [os.path.join(path, 'hgrc')]
rcdir = os.path.join(path, 'hgrc.d')
try:
rcs.extend([os.path.join(rcdir, f)
for f, kind in osutil.listdir(rcdir)
if f.endswith(".rc")])
except OSError:
pass
return rcs
def systemrcpath():
path = []
if sys.platform == 'plan9':
root = 'lib/mercurial'
else:
root = 'etc/mercurial'
# old mod_python does not set sys.argv
if len(getattr(sys, 'argv', [])) > 0:
p = os.path.dirname(os.path.dirname(sys.argv[0]))
if p != '/':
path.extend(_rcfiles(os.path.join(p, root)))
path.extend(_rcfiles('/' + root))
return path
def userrcpath():
if sys.platform == 'plan9':
return [encoding.environ['home'] + '/lib/hgrc']
else:
return [os.path.expanduser('~/.hgrc')]