bisect: avoid copying ancestor list for non-merge commits
During a bisection, hg needs to compute a list of all ancestors for every
candidate commit. This is accomplished via a bottom-up traversal of the set of
candidates, during which each revision's ancestor list is populated using the
ancestor list of its parent(s). Previously, this involved copying the entire
list, which could be very long in if the bisection range was large.
To help improve this, we can observe that each candidate commit is visited
exactly once, at which point its ancestor list is copied into its children's
lists and then dropped. In the case of non-merge commits, a commit's ancestor
list consists exactly of its parent's list plus itself. This means that we can
trivially reuse the parent's existing list for one of its non-merge children,
which avoids copying entirely if that commit is the parent's only child. This
makes bisections over linear ranges of commits much faster.
During some informal testing in the large publicly-available `mozilla-central`
repository, this noticeably sped up bisections over large ranges of history:
Setup:
$ cd mozilla-central
$ hg bisect --reset
$ hg bisect --good 0
$ hg log -r tip -T '{rev}\n'
628417
Test:
$ time hg bisect --bad tip --noupdate
Before:
real 3m35.927s
user 3m35.553s
sys 0m0.319s
After:
real 1m41.142s
user 1m40.810s
sys 0m0.285s
# cvs.py: CVS conversion code inspired by hg-cvs-import and git-cvsimport
#
# Copyright 2005-2009 Olivia Mackall <olivia@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.
import errno
import os
import re
import socket
from mercurial.i18n import _
from mercurial.pycompat import (
getattr,
open,
)
from mercurial import (
encoding,
error,
util,
)
from mercurial.utils import (
dateutil,
procutil,
)
from . import (
common,
cvsps,
)
stringio = util.stringio
checktool = common.checktool
commit = common.commit
converter_source = common.converter_source
makedatetimestamp = common.makedatetimestamp
NoRepo = common.NoRepo
class convert_cvs(converter_source):
def __init__(self, ui, repotype, path, revs=None):
super(convert_cvs, self).__init__(ui, repotype, path, revs=revs)
cvs = os.path.join(path, b"CVS")
if not os.path.exists(cvs):
raise NoRepo(_(b"%s does not look like a CVS checkout") % path)
checktool(b'cvs')
self.changeset = None
self.files = {}
self.tags = {}
self.lastbranch = {}
self.socket = None
self.cvsroot = open(os.path.join(cvs, b"Root"), b'rb').read()[:-1]
self.cvsrepo = open(os.path.join(cvs, b"Repository"), b'rb').read()[:-1]
self.encoding = encoding.encoding
self._connect()
def _parse(self):
if self.changeset is not None:
return
self.changeset = {}
maxrev = 0
if self.revs:
if len(self.revs) > 1:
raise error.Abort(
_(
b'cvs source does not support specifying '
b'multiple revs'
)
)
# TODO: handle tags
try:
# patchset number?
maxrev = int(self.revs[0])
except ValueError:
raise error.Abort(
_(b'revision %s is not a patchset number') % self.revs[0]
)
d = encoding.getcwd()
try:
os.chdir(self.path)
cache = b'update'
if not self.ui.configbool(b'convert', b'cvsps.cache'):
cache = None
db = cvsps.createlog(self.ui, cache=cache)
db = cvsps.createchangeset(
self.ui,
db,
fuzz=int(self.ui.config(b'convert', b'cvsps.fuzz')),
mergeto=self.ui.config(b'convert', b'cvsps.mergeto'),
mergefrom=self.ui.config(b'convert', b'cvsps.mergefrom'),
)
for cs in db:
if maxrev and cs.id > maxrev:
break
id = b"%d" % cs.id
cs.author = self.recode(cs.author)
self.lastbranch[cs.branch] = id
cs.comment = self.recode(cs.comment)
if self.ui.configbool(b'convert', b'localtimezone'):
cs.date = makedatetimestamp(cs.date[0])
date = dateutil.datestr(cs.date, b'%Y-%m-%d %H:%M:%S %1%2')
self.tags.update(dict.fromkeys(cs.tags, id))
files = {}
for f in cs.entries:
files[f.file] = b"%s%s" % (
b'.'.join([(b"%d" % x) for x in f.revision]),
[b'', b'(DEAD)'][f.dead],
)
# add current commit to set
c = commit(
author=cs.author,
date=date,
parents=[(b"%d" % p.id) for p in cs.parents],
desc=cs.comment,
branch=cs.branch or b'',
)
self.changeset[id] = c
self.files[id] = files
self.heads = self.lastbranch.values()
finally:
os.chdir(d)
def _connect(self):
root = self.cvsroot
conntype = None
user, host = None, None
cmd = [b'cvs', b'server']
self.ui.status(_(b"connecting to %s\n") % root)
if root.startswith(b":pserver:"):
root = root[9:]
m = re.match(r'(?:(.*?)(?::(.*?))?@)?([^:/]*)(?::(\d*))?(.*)', root)
if m:
conntype = b"pserver"
user, passw, serv, port, root = m.groups()
if not user:
user = b"anonymous"
if not port:
port = 2401
else:
port = int(port)
format0 = b":pserver:%s@%s:%s" % (user, serv, root)
format1 = b":pserver:%s@%s:%d%s" % (user, serv, port, root)
if not passw:
passw = b"A"
cvspass = os.path.expanduser(b"~/.cvspass")
try:
pf = open(cvspass, b'rb')
for line in pf.read().splitlines():
part1, part2 = line.split(b' ', 1)
# /1 :pserver:user@example.com:2401/cvsroot/foo
# Ah<Z
if part1 == b'/1':
part1, part2 = part2.split(b' ', 1)
format = format1
# :pserver:user@example.com:/cvsroot/foo Ah<Z
else:
format = format0
if part1 == format:
passw = part2
break
pf.close()
except IOError as inst:
if inst.errno != errno.ENOENT:
if not getattr(inst, 'filename', None):
inst.filename = cvspass
raise
sck = socket.socket()
sck.connect((serv, port))
sck.send(
b"\n".join(
[
b"BEGIN AUTH REQUEST",
root,
user,
passw,
b"END AUTH REQUEST",
b"",
]
)
)
if sck.recv(128) != b"I LOVE YOU\n":
raise error.Abort(_(b"CVS pserver authentication failed"))
self.writep = self.readp = sck.makefile(b'r+')
if not conntype and root.startswith(b":local:"):
conntype = b"local"
root = root[7:]
if not conntype:
# :ext:user@host/home/user/path/to/cvsroot
if root.startswith(b":ext:"):
root = root[5:]
m = re.match(br'(?:([^@:/]+)@)?([^:/]+):?(.*)', root)
# Do not take Windows path "c:\foo\bar" for a connection strings
if os.path.isdir(root) or not m:
conntype = b"local"
else:
conntype = b"rsh"
user, host, root = m.group(1), m.group(2), m.group(3)
if conntype != b"pserver":
if conntype == b"rsh":
rsh = encoding.environ.get(b"CVS_RSH") or b"ssh"
if user:
cmd = [rsh, b'-l', user, host] + cmd
else:
cmd = [rsh, host] + cmd
# popen2 does not support argument lists under Windows
cmd = b' '.join(procutil.shellquote(arg) for arg in cmd)
self.writep, self.readp = procutil.popen2(cmd)
self.realroot = root
self.writep.write(b"Root %s\n" % root)
self.writep.write(
b"Valid-responses ok error Valid-requests Mode"
b" M Mbinary E Checked-in Created Updated"
b" Merged Removed\n"
)
self.writep.write(b"valid-requests\n")
self.writep.flush()
r = self.readp.readline()
if not r.startswith(b"Valid-requests"):
raise error.Abort(
_(
b'unexpected response from CVS server '
b'(expected "Valid-requests", but got %r)'
)
% r
)
if b"UseUnchanged" in r:
self.writep.write(b"UseUnchanged\n")
self.writep.flush()
self.readp.readline()
def getheads(self):
self._parse()
return self.heads
def getfile(self, name, rev):
def chunkedread(fp, count):
# file-objects returned by socket.makefile() do not handle
# large read() requests very well.
chunksize = 65536
output = stringio()
while count > 0:
data = fp.read(min(count, chunksize))
if not data:
raise error.Abort(
_(b"%d bytes missing from remote file") % count
)
count -= len(data)
output.write(data)
return output.getvalue()
self._parse()
if rev.endswith(b"(DEAD)"):
return None, None
args = (b"-N -P -kk -r %s --" % rev).split()
args.append(self.cvsrepo + b'/' + name)
for x in args:
self.writep.write(b"Argument %s\n" % x)
self.writep.write(b"Directory .\n%s\nco\n" % self.realroot)
self.writep.flush()
data = b""
mode = None
while True:
line = self.readp.readline()
if line.startswith(b"Created ") or line.startswith(b"Updated "):
self.readp.readline() # path
self.readp.readline() # entries
mode = self.readp.readline()[:-1]
count = int(self.readp.readline()[:-1])
data = chunkedread(self.readp, count)
elif line.startswith(b" "):
data += line[1:]
elif line.startswith(b"M "):
pass
elif line.startswith(b"Mbinary "):
count = int(self.readp.readline()[:-1])
data = chunkedread(self.readp, count)
else:
if line == b"ok\n":
if mode is None:
raise error.Abort(_(b'malformed response from CVS'))
return (data, b"x" in mode and b"x" or b"")
elif line.startswith(b"E "):
self.ui.warn(_(b"cvs server: %s\n") % line[2:])
elif line.startswith(b"Remove"):
self.readp.readline()
else:
raise error.Abort(_(b"unknown CVS response: %s") % line)
def getchanges(self, rev, full):
if full:
raise error.Abort(_(b"convert from cvs does not support --full"))
self._parse()
return sorted(self.files[rev].items()), {}, set()
def getcommit(self, rev):
self._parse()
return self.changeset[rev]
def gettags(self):
self._parse()
return self.tags
def getchangedfiles(self, rev, i):
self._parse()
return sorted(self.files[rev])