view hgext/convert/cvs.py @ 51577:b5d494f7d28a

push: rework the computation of fallbackheads to be correct

The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.

The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)

In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::

  e
  |
  d f
  |/
  c
  |
  b
  |
  a

The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.

I added a couple of performance related common for further investigation later
on.

# cvs.py: CVS conversion code inspired by hg-cvs-import and git-cvsimport
#
#  Copyright 2005-2009 Olivia Mackall <[e-mail]> 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 (
    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(
                br'(?:(.*?)(?::(.*?))?@)?([^:/]*)(?::(\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:[e-mail]:2401/cvsroot/foo
                            # Ah<Z
                            if part1 == b'/1':
                                part1, part2 = part2.split(b' ', 1)
                                format = format1
                            # :pserver:[e-mail]:/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('rwb')

        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])