##// END OF EJS Templates
bdiff: replace hash algorithm...
bdiff: replace hash algorithm This patch replaces lyhash with the hash algorithm used by diffutils. The algorithm has its origins in Git commit 2e9d1410, which is all the way back from 1992. The license header in the code at that revision in GPL v2. I have not performed an extensive analysis of the distribution (and therefore buckets) of hash output. However, `hg perfbdiff` gives some clear wins. I'd like to think that if it is good enough for diffutils it is good enough for us? From the mozilla-unified repository: $ perfbdiff -m 3041e4d59df2 ! wall 0.053271 comb 0.060000 user 0.060000 sys 0.000000 (best of 100) ! wall 0.035827 comb 0.040000 user 0.040000 sys 0.000000 (best of 100) $ perfbdiff 0e9928989e9c --alldata --count 100 ! wall 6.204277 comb 6.200000 user 6.200000 sys 0.000000 (best of 3) ! wall 4.309710 comb 4.300000 user 4.300000 sys 0.000000 (best of 3) From the hg repo: $ perfbdiff 35000 --alldata --count 1000 ! wall 0.660358 comb 0.660000 user 0.660000 sys 0.000000 (best of 15) ! wall 0.534092 comb 0.530000 user 0.530000 sys 0.000000 (best of 19) Looking at the generated assembly and statistical profiler output from the kernel level, I believe there is room to make this function even faster. Namely, we're still consuming data character by character instead of at the word level. This translates to more loop iterations and more instructions. At this juncture though, the real performance killer is that we're hashing every line. We should get a significant speedup if we change the algorithm to find the longest prefix, longest suffix, treat those as single "lines" and then only do the line splitting and hashing on the parts that are different. That will require a lot of C code, however. I'm optimistic this approach could result in a ~2x speedup.

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hgk.py
348 lines | 11.2 KiB | text/x-python | PythonLexer
# Minimal support for git commands on an hg repository
#
# Copyright 2005, 2006 Chris Mason <mason@suse.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''browse the repository in a graphical way
The hgk extension allows browsing the history of a repository in a
graphical way. It requires Tcl/Tk version 8.4 or later. (Tcl/Tk is not
distributed with Mercurial.)
hgk consists of two parts: a Tcl script that does the displaying and
querying of information, and an extension to Mercurial named hgk.py,
which provides hooks for hgk to get information. hgk can be found in
the contrib directory, and the extension is shipped in the hgext
repository, and needs to be enabled.
The :hg:`view` command will launch the hgk Tcl script. For this command
to work, hgk must be in your search path. Alternately, you can specify
the path to hgk in your configuration file::
[hgk]
path = /location/of/hgk
hgk can make use of the extdiff extension to visualize revisions.
Assuming you had already configured extdiff vdiff command, just add::
[hgk]
vdiff=vdiff
Revisions context menu will now display additional entries to fire
vdiff on hovered and selected revisions.
'''
from __future__ import absolute_import
import os
from mercurial.i18n import _
from mercurial.node import (
nullid,
nullrev,
short,
)
from mercurial import (
cmdutil,
commands,
obsolete,
patch,
scmutil,
)
cmdtable = {}
command = cmdutil.command(cmdtable)
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'ships-with-hg-core'
@command('debug-diff-tree',
[('p', 'patch', None, _('generate patch')),
('r', 'recursive', None, _('recursive')),
('P', 'pretty', None, _('pretty')),
('s', 'stdin', None, _('stdin')),
('C', 'copy', None, _('detect copies')),
('S', 'search', "", _('search'))],
('[OPTION]... NODE1 NODE2 [FILE]...'),
inferrepo=True)
def difftree(ui, repo, node1=None, node2=None, *files, **opts):
"""diff trees from two commits"""
def __difftree(repo, node1, node2, files=[]):
assert node2 is not None
mmap = repo[node1].manifest()
mmap2 = repo[node2].manifest()
m = scmutil.match(repo[node1], files)
modified, added, removed = repo.status(node1, node2, m)[:3]
empty = short(nullid)
for f in modified:
# TODO get file permissions
ui.write((":100664 100664 %s %s M\t%s\t%s\n") %
(short(mmap[f]), short(mmap2[f]), f, f))
for f in added:
ui.write((":000000 100664 %s %s N\t%s\t%s\n") %
(empty, short(mmap2[f]), f, f))
for f in removed:
ui.write((":100664 000000 %s %s D\t%s\t%s\n") %
(short(mmap[f]), empty, f, f))
##
while True:
if opts['stdin']:
try:
line = raw_input().split(' ')
node1 = line[0]
if len(line) > 1:
node2 = line[1]
else:
node2 = None
except EOFError:
break
node1 = repo.lookup(node1)
if node2:
node2 = repo.lookup(node2)
else:
node2 = node1
node1 = repo.changelog.parents(node1)[0]
if opts['patch']:
if opts['pretty']:
catcommit(ui, repo, node2, "")
m = scmutil.match(repo[node1], files)
diffopts = patch.difffeatureopts(ui)
diffopts.git = True
chunks = patch.diff(repo, node1, node2, match=m,
opts=diffopts)
for chunk in chunks:
ui.write(chunk)
else:
__difftree(repo, node1, node2, files=files)
if not opts['stdin']:
break
def catcommit(ui, repo, n, prefix, ctx=None):
nlprefix = '\n' + prefix
if ctx is None:
ctx = repo[n]
# use ctx.node() instead ??
ui.write(("tree %s\n" % short(ctx.changeset()[0])))
for p in ctx.parents():
ui.write(("parent %s\n" % p))
date = ctx.date()
description = ctx.description().replace("\0", "")
ui.write(("author %s %s %s\n" % (ctx.user(), int(date[0]), date[1])))
if 'committer' in ctx.extra():
ui.write(("committer %s\n" % ctx.extra()['committer']))
ui.write(("revision %d\n" % ctx.rev()))
ui.write(("branch %s\n" % ctx.branch()))
if obsolete.isenabled(repo, obsolete.createmarkersopt):
if ctx.obsolete():
ui.write(("obsolete\n"))
ui.write(("phase %s\n\n" % ctx.phasestr()))
if prefix != "":
ui.write("%s%s\n" % (prefix,
description.replace('\n', nlprefix).strip()))
else:
ui.write(description + "\n")
if prefix:
ui.write('\0')
@command('debug-merge-base', [], _('REV REV'))
def base(ui, repo, node1, node2):
"""output common ancestor information"""
node1 = repo.lookup(node1)
node2 = repo.lookup(node2)
n = repo.changelog.ancestor(node1, node2)
ui.write(short(n) + "\n")
@command('debug-cat-file',
[('s', 'stdin', None, _('stdin'))],
_('[OPTION]... TYPE FILE'),
inferrepo=True)
def catfile(ui, repo, type=None, r=None, **opts):
"""cat a specific revision"""
# in stdin mode, every line except the commit is prefixed with two
# spaces. This way the our caller can find the commit without magic
# strings
#
prefix = ""
if opts['stdin']:
try:
(type, r) = raw_input().split(' ')
prefix = " "
except EOFError:
return
else:
if not type or not r:
ui.warn(_("cat-file: type or revision not supplied\n"))
commands.help_(ui, 'cat-file')
while r:
if type != "commit":
ui.warn(_("aborting hg cat-file only understands commits\n"))
return 1
n = repo.lookup(r)
catcommit(ui, repo, n, prefix)
if opts['stdin']:
try:
(type, r) = raw_input().split(' ')
except EOFError:
break
else:
break
# git rev-tree is a confusing thing. You can supply a number of
# commit sha1s on the command line, and it walks the commit history
# telling you which commits are reachable from the supplied ones via
# a bitmask based on arg position.
# you can specify a commit to stop at by starting the sha1 with ^
def revtree(ui, args, repo, full="tree", maxnr=0, parents=False):
def chlogwalk():
count = len(repo)
i = count
l = [0] * 100
chunk = 100
while True:
if chunk > i:
chunk = i
i = 0
else:
i -= chunk
for x in xrange(chunk):
if i + x >= count:
l[chunk - x:] = [0] * (chunk - x)
break
if full is not None:
if (i + x) in repo:
l[x] = repo[i + x]
l[x].changeset() # force reading
else:
if (i + x) in repo:
l[x] = 1
for x in xrange(chunk - 1, -1, -1):
if l[x] != 0:
yield (i + x, full is not None and l[x] or None)
if i == 0:
break
# calculate and return the reachability bitmask for sha
def is_reachable(ar, reachable, sha):
if len(ar) == 0:
return 1
mask = 0
for i in xrange(len(ar)):
if sha in reachable[i]:
mask |= 1 << i
return mask
reachable = []
stop_sha1 = []
want_sha1 = []
count = 0
# figure out which commits they are asking for and which ones they
# want us to stop on
for i, arg in enumerate(args):
if arg.startswith('^'):
s = repo.lookup(arg[1:])
stop_sha1.append(s)
want_sha1.append(s)
elif arg != 'HEAD':
want_sha1.append(repo.lookup(arg))
# calculate the graph for the supplied commits
for i, n in enumerate(want_sha1):
reachable.append(set())
visit = [n]
reachable[i].add(n)
while visit:
n = visit.pop(0)
if n in stop_sha1:
continue
for p in repo.changelog.parents(n):
if p not in reachable[i]:
reachable[i].add(p)
visit.append(p)
if p in stop_sha1:
continue
# walk the repository looking for commits that are in our
# reachability graph
for i, ctx in chlogwalk():
if i not in repo:
continue
n = repo.changelog.node(i)
mask = is_reachable(want_sha1, reachable, n)
if mask:
parentstr = ""
if parents:
pp = repo.changelog.parents(n)
if pp[0] != nullid:
parentstr += " " + short(pp[0])
if pp[1] != nullid:
parentstr += " " + short(pp[1])
if not full:
ui.write("%s%s\n" % (short(n), parentstr))
elif full == "commit":
ui.write("%s%s\n" % (short(n), parentstr))
catcommit(ui, repo, n, ' ', ctx)
else:
(p1, p2) = repo.changelog.parents(n)
(h, h1, h2) = map(short, (n, p1, p2))
(i1, i2) = map(repo.changelog.rev, (p1, p2))
date = ctx.date()[0]
ui.write("%s %s:%s" % (date, h, mask))
mask = is_reachable(want_sha1, reachable, p1)
if i1 != nullrev and mask > 0:
ui.write("%s:%s " % (h1, mask)),
mask = is_reachable(want_sha1, reachable, p2)
if i2 != nullrev and mask > 0:
ui.write("%s:%s " % (h2, mask))
ui.write("\n")
if maxnr and count >= maxnr:
break
count += 1
# git rev-list tries to order things by date, and has the ability to stop
# at a given commit without walking the whole repo. TODO add the stop
# parameter
@command('debug-rev-list',
[('H', 'header', None, _('header')),
('t', 'topo-order', None, _('topo-order')),
('p', 'parents', None, _('parents')),
('n', 'max-count', 0, _('max-count'))],
('[OPTION]... REV...'))
def revlist(ui, repo, *revs, **opts):
"""print revisions"""
if opts['header']:
full = "commit"
else:
full = None
copy = [x for x in revs]
revtree(ui, copy, repo, full, opts['max_count'], opts['parents'])
@command('view',
[('l', 'limit', '',
_('limit number of changes displayed'), _('NUM'))],
_('[-l LIMIT] [REVRANGE]'))
def view(ui, repo, *etc, **opts):
"start interactive history viewer"
os.chdir(repo.root)
optstr = ' '.join(['--%s %s' % (k, v) for k, v in opts.iteritems() if v])
if repo.filtername is None:
optstr += '--hidden'
cmd = ui.config("hgk", "path", "hgk") + " %s %s" % (optstr, " ".join(etc))
ui.debug("running %s\n" % cmd)
ui.system(cmd)