##// END OF EJS Templates
revlog: change generaldelta delta parent heuristic...
revlog: change generaldelta delta parent heuristic The old generaldelta heuristic was "if p1 (or p2) was closer than the last full text, use it, otherwise use prev". This was problematic when a repo contained multiple branches that were very different. If commits to branch A were pushed, and the last full text was branch B, it would generate a fulltext. Then if branch B was pushed, it would generate another fulltext. The problem is that the last fulltext (and delta'ing against `prev` in general) has no correlation with the contents of the incoming revision, and therefore will always have degenerate cases. According to the blame, that algorithm was chosen to minimize the chain length. Since there is already code that protects against that (the delta-vs-fulltext code), and since it has been improved since the original generaldelta algorithm went in (2011), I believe the chain length criteria will still be preserved. The new algorithm always diffs against p1 (or p2 if it's closer), unless the resulting delta will fail the delta-vs-fulltext check, in which case we delta against prev. Some before and after stats on manifest.d size. internal large repo old heuristic - 2.0 GB new heuristic - 1.2 GB mozilla-central old heuristic - 242 MB new heuristic - 261 MB The regression in mozilla central is due to the new heuristic choosing p2r as the delta when it's closer to the tip. Switching the algorithm to always prefer p1r brings the size back down (242 MB). This is result of the way in which mozilla does merges and pushes, and the result could easily swing the other direction in other repos (depending on if they merge X into Y or Y into X), but will never be as degenerate as before. I future patch will address the regression by introducing an optional, even more aggressive delta heuristic which will knock the mozilla manifest size down dramatically.

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fancyopts.py
127 lines | 3.5 KiB | text/x-python | PythonLexer
# fancyopts.py - better command line parsing
#
# Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import getopt
from .i18n import _
from . import util
def gnugetopt(args, options, longoptions):
"""Parse options mostly like getopt.gnu_getopt.
This is different from getopt.gnu_getopt in that an argument of - will
become an argument of - instead of vanishing completely.
"""
extraargs = []
if '--' in args:
stopindex = args.index('--')
extraargs = args[stopindex + 1:]
args = args[:stopindex]
opts, parseargs = getopt.getopt(args, options, longoptions)
args = []
while parseargs:
arg = parseargs.pop(0)
if arg and arg[0] == '-' and len(arg) > 1:
parseargs.insert(0, arg)
topts, newparseargs = getopt.getopt(parseargs, options, longoptions)
opts = opts + topts
parseargs = newparseargs
else:
args.append(arg)
args.extend(extraargs)
return opts, args
def fancyopts(args, options, state, gnu=False):
"""
read args, parse options, and store options in state
each option is a tuple of:
short option or ''
long option
default value
description
option value label(optional)
option types include:
boolean or none - option sets variable in state to true
string - parameter string is stored in state
list - parameter string is added to a list
integer - parameter strings is stored as int
function - call function with parameter
non-option args are returned
"""
namelist = []
shortlist = ''
argmap = {}
defmap = {}
for option in options:
if len(option) == 5:
short, name, default, comment, dummy = option
else:
short, name, default, comment = option
# convert opts to getopt format
oname = name
name = name.replace('-', '_')
argmap['-' + short] = argmap['--' + oname] = name
defmap[name] = default
# copy defaults to state
if isinstance(default, list):
state[name] = default[:]
elif callable(default):
state[name] = None
else:
state[name] = default
# does it take a parameter?
if not (default is None or default is True or default is False):
if short:
short += ':'
if oname:
oname += '='
if short:
shortlist += short
if name:
namelist.append(oname)
# parse arguments
if gnu:
parse = gnugetopt
else:
parse = getopt.getopt
opts, args = parse(args, shortlist, namelist)
# transfer result to state
for opt, val in opts:
name = argmap[opt]
obj = defmap[name]
t = type(obj)
if callable(obj):
state[name] = defmap[name](val)
elif t is type(1):
try:
state[name] = int(val)
except ValueError:
raise util.Abort(_('invalid value %r for option %s, '
'expected int') % (val, opt))
elif t is type(''):
state[name] = val
elif t is type([]):
state[name].append(val)
elif t is type(None) or t is type(False):
state[name] = True
# return unparsed args
return args