discovery: add new set-based discovery
Adds a new discovery method based on repeatedly sampling the still
undecided subset of the local node graph to determine the set of nodes
common to both the client and the server.
For small differences between client and server, it uses about the same
or slightly fewer roundtrips than the old tree-based discovery. For
larger differences, it typically reduces the number of roundtrips
drastically (from 150 to 4, for instance).
The old discovery code now lives in treediscovery.py, the new code is
in setdiscovery.py.
Still missing is a hook for extensions to contribute nodes to the
initial sample. For instance, Augie's remotebranches could contribute
the last known state of the server's heads.
Credits for the actual sampler and computing common heads instead of
bases go to Benoit Boissinot.
#!/usr/bin/env python
from mercurial import demandimport
demandimport.enable()
import os, sys
from mercurial.i18n import _
from mercurial import simplemerge, fancyopts, util, ui
options = [('L', 'label', [], _('labels to use on conflict markers')),
('a', 'text', None, _('treat all files as text')),
('p', 'print', None,
_('print results instead of overwriting LOCAL')),
('', 'no-minimal', None,
_('do not try to minimize conflict regions')),
('h', 'help', None, _('display help and exit')),
('q', 'quiet', None, _('suppress output'))]
usage = _('''simplemerge [OPTS] LOCAL BASE OTHER
Simple three-way file merge utility with a minimal feature set.
Apply to LOCAL the changes necessary to go from BASE to OTHER.
By default, LOCAL is overwritten with the results of this operation.
''')
class ParseError(Exception):
"""Exception raised on errors in parsing the command line."""
def showhelp():
sys.stdout.write(usage)
sys.stdout.write('\noptions:\n')
out_opts = []
for shortopt, longopt, default, desc in options:
out_opts.append(('%2s%s' % (shortopt and '-%s' % shortopt,
longopt and ' --%s' % longopt),
'%s' % desc))
opts_len = max([len(opt[0]) for opt in out_opts])
for first, second in out_opts:
sys.stdout.write(' %-*s %s\n' % (opts_len, first, second))
try:
for fp in (sys.stdin, sys.stdout, sys.stderr):
util.set_binary(fp)
opts = {}
try:
args = fancyopts.fancyopts(sys.argv[1:], options, opts)
except fancyopts.getopt.GetoptError, e:
raise ParseError(e)
if opts['help']:
showhelp()
sys.exit(0)
if len(args) != 3:
raise ParseError(_('wrong number of arguments'))
sys.exit(simplemerge.simplemerge(ui.ui(), *args, **opts))
except ParseError, e:
sys.stdout.write("%s: %s\n" % (sys.argv[0], e))
showhelp()
sys.exit(1)
except util.Abort, e:
sys.stderr.write("abort: %s\n" % e)
sys.exit(255)
except KeyboardInterrupt:
sys.exit(255)