setdiscovery: randomly pick between heads and sample when taking full sample
Before this changeset, the discovery protocol was too heads-centric. Heads of the
undiscovered set were always sent for discovery and any room remaining in the
sample were filled with exponential samples (and random ones if any room
remained).
This behaved extremely poorly when the number of heads exceeded the sample size,
because we keep just asking about the existence of heads, then their direct parent
and so on. As a result, the 'O(log(len(repo)))' discovery turns into a
'O(len(repo))' one. As a solution we take a random sample of the heads plus
exponential samples. This way we ensure some exponential sampling is achieved,
bringing back some logarithmic convergence of the discovery again.
This patch only applies this principle in one place. More places will be updated
in future patches.
One test is impacted because the random sample happen to be different. By
chance, it helps a bit in this case.
import os
import osutil
import util
import _winreg
def systemrcpath():
'''return default os-specific hgrc search path'''
rcpath = []
filename = util.executablepath()
# Use mercurial.ini found in directory with hg.exe
progrc = os.path.join(os.path.dirname(filename), 'mercurial.ini')
if os.path.isfile(progrc):
rcpath.append(progrc)
return rcpath
# Use hgrc.d found in directory with hg.exe
progrcd = os.path.join(os.path.dirname(filename), 'hgrc.d')
if os.path.isdir(progrcd):
for f, kind in osutil.listdir(progrcd):
if f.endswith('.rc'):
rcpath.append(os.path.join(progrcd, f))
return rcpath
# else look for a system rcpath in the registry
value = util.lookupreg('SOFTWARE\\Mercurial', None,
_winreg.HKEY_LOCAL_MACHINE)
if not isinstance(value, str) or not value:
return rcpath
value = util.localpath(value)
for p in value.split(os.pathsep):
if p.lower().endswith('mercurial.ini'):
rcpath.append(p)
elif os.path.isdir(p):
for f, kind in osutil.listdir(p):
if f.endswith('.rc'):
rcpath.append(os.path.join(p, f))
return rcpath
def userrcpath():
'''return os-specific hgrc search path to the user dir'''
home = os.path.expanduser('~')
path = [os.path.join(home, 'mercurial.ini'),
os.path.join(home, '.hgrc')]
userprofile = os.environ.get('USERPROFILE')
if userprofile and userprofile != home:
path.append(os.path.join(userprofile, 'mercurial.ini'))
path.append(os.path.join(userprofile, '.hgrc'))
return path