view hgext/convert/monotone.py @ 40811:e13ab4acf555

rust: peek_mut optim for lazy ancestors

This is one of the two optimizations that are also
present in the Python code: replacing pairs of pop/push
on the BinaryHeap by single updates, hence having it
under the hood maintain its consistency (sift) only once.

On Mozilla central, the measured gain (see details below)
is around 7%.

Creating the PeekMut object by calling peek_mut() right away
instead of peek() first is less efficient (gain is only 4%, stats
not included).
Our interpretation is that its creation has a cost which is vasted
in the cases where it ends by droping the value (Peekmut::pop()
just does self.heap.pop() anyway). On the other hand, the immutable
peek() is very fast: it's just taking a reference in the
underlying vector.

The Python version still has another optimization:
if parent(current) == current-1, then the heap doesn't need
to maintain its consistency, since we already know that
it's bigger than all the others in the heap.
Rust's BinaryHeap doesn't allow us to mutate its biggest
element with no housekeeping, but we tried it anyway, with a
copy of the BinaryHeap implementation with a dedicaded added
method: it's not worth the technical debt in our opinion
(we measured only a further 1.6% improvement).
One possible explanation would be that the sift is really fast
anyway in that case, whereas it's not in the case of Python,
because it's at least partly done in slow Python code.
Still it's possible that replacing BinaryHeap by something more
dedicated to discrete ordered types could be faster.

Measurements on mozilla-central:

Three runs of 'hg perfancestors' on the parent changeset:

Moyenne des médianes: 0.100587
! wall 0.100062 comb 0.100000 user 0.100000 sys 0.000000 (best of 98)
! wall 0.135804 comb 0.130000 user 0.130000 sys 0.000000 (max of 98)
! wall 0.102864 comb 0.102755 user 0.099286 sys 0.003469 (avg of 98)
! wall 0.101486 comb 0.110000 user 0.110000 sys 0.000000 (median of 98)

! wall 0.096804 comb 0.090000 user 0.090000 sys 0.000000 (best of 100)
! wall 0.132235 comb 0.130000 user 0.120000 sys 0.010000 (max of 100)
! wall 0.100258 comb 0.100300 user 0.096000 sys 0.004300 (avg of 100)
! wall 0.098384 comb 0.100000 user 0.100000 sys 0.000000 (median of 100)

! wall 0.099925 comb 0.100000 user 0.100000 sys 0.000000 (best of 98)
! wall 0.133518 comb 0.140000 user 0.130000 sys 0.010000 (max of 98)
! wall 0.102381 comb 0.102449 user 0.098265 sys 0.004184 (avg of 98)
! wall 0.101891 comb 0.090000 user 0.090000 sys 0.000000 (median of 98)

Mean of the medians: 0.100587

On the present changeset:

! wall 0.091344 comb 0.090000 user 0.090000 sys 0.000000 (best of 100)
! wall 0.122728 comb 0.120000 user 0.110000 sys 0.010000 (max of 100)
! wall 0.093268 comb 0.093300 user 0.089300 sys 0.004000 (avg of 100)
! wall 0.092567 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)

! wall 0.093294 comb 0.080000 user 0.080000 sys 0.000000 (best of 100)
! wall 0.144887 comb 0.150000 user 0.140000 sys 0.010000 (max of 100)
! wall 0.097708 comb 0.097700 user 0.093400 sys 0.004300 (avg of 100)
! wall 0.094980 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)

! wall 0.091262 comb 0.090000 user 0.080000 sys 0.010000 (best of 100)
! wall 0.123772 comb 0.130000 user 0.120000 sys 0.010000 (max of 100)
! wall 0.093188 comb 0.093200 user 0.089300 sys 0.003900 (avg of 100)
! wall 0.092364 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)

Mean of the medians is 0.0933

Differential Revision: https://phab.mercurial-scm.org/D5358

# monotone.py - monotone support for the convert extension
#
#  Copyright 2008, 2009 Mikkel Fahnoe Jorgensen <[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.
from __future__ import absolute_import

import os
import re

from mercurial.i18n import _
from mercurial import (
    error,
    pycompat,
)
from mercurial.utils import dateutil

from . import common

class monotone_source(common.converter_source, common.commandline):
    def __init__(self, ui, repotype, path=None, revs=None):
        common.converter_source.__init__(self, ui, repotype, path, revs)
        if revs and len(revs) > 1:
            raise error.Abort(_('monotone source does not support specifying '
                               'multiple revs'))
        common.commandline.__init__(self, ui, 'mtn')

        self.ui = ui
        self.path = path
        self.automatestdio = False
        self.revs = revs

        norepo = common.NoRepo(_("%s does not look like a monotone repository")
                             % path)
        if not os.path.exists(os.path.join(path, '_MTN')):
            # Could be a monotone repository (SQLite db file)
            try:
                f = open(path, 'rb')
                header = f.read(16)
                f.close()
            except IOError:
                header = ''
            if header != 'SQLite format 3\x00':
                raise norepo

        # regular expressions for parsing monotone output
        space    = br'\s*'
        name     = br'\s+"((?:\\"|[^"])*)"\s*'
        value    = name
        revision = br'\s+\[(\w+)\]\s*'
        lines    = br'(?:.|\n)+'

        self.dir_re      = re.compile(space + "dir" + name)
        self.file_re     = re.compile(space + "file" + name +
                                      "content" + revision)
        self.add_file_re = re.compile(space + "add_file" + name +
                                      "content" + revision)
        self.patch_re    = re.compile(space + "patch" + name +
                                      "from" + revision + "to" + revision)
        self.rename_re   = re.compile(space + "rename" + name + "to" + name)
        self.delete_re   = re.compile(space + "delete" + name)
        self.tag_re      = re.compile(space + "tag" + name + "revision" +
                                      revision)
        self.cert_re     = re.compile(lines + space + "name" + name +
                                      "value" + value)

        attr = space + "file" + lines + space + "attr" + space
        self.attr_execute_re = re.compile(attr  + '"mtn:execute"' +
                                          space + '"true"')

        # cached data
        self.manifest_rev = None
        self.manifest = None
        self.files = None
        self.dirs  = None

        common.checktool('mtn', abort=False)

    def mtnrun(self, *args, **kwargs):
        if self.automatestdio:
            return self.mtnrunstdio(*args, **kwargs)
        else:
            return self.mtnrunsingle(*args, **kwargs)

    def mtnrunsingle(self, *args, **kwargs):
        kwargs[r'd'] = self.path
        return self.run0('automate', *args, **kwargs)

    def mtnrunstdio(self, *args, **kwargs):
        # Prepare the command in automate stdio format
        kwargs = pycompat.byteskwargs(kwargs)
        command = []
        for k, v in kwargs.iteritems():
            command.append("%s:%s" % (len(k), k))
            if v:
                command.append("%s:%s" % (len(v), v))
        if command:
            command.insert(0, 'o')
            command.append('e')

        command.append('l')
        for arg in args:
            command += "%d:%s" % (len(arg), arg)
        command.append('e')
        command = ''.join(command)

        self.ui.debug("mtn: sending '%s'\n" % command)
        self.mtnwritefp.write(command)
        self.mtnwritefp.flush()

        return self.mtnstdioreadcommandoutput(command)

    def mtnstdioreadpacket(self):
        read = None
        commandnbr = ''
        while read != ':':
            read = self.mtnreadfp.read(1)
            if not read:
                raise error.Abort(_('bad mtn packet - no end of commandnbr'))
            commandnbr += read
        commandnbr = commandnbr[:-1]

        stream = self.mtnreadfp.read(1)
        if stream not in 'mewptl':
            raise error.Abort(_('bad mtn packet - bad stream type %s') % stream)

        read = self.mtnreadfp.read(1)
        if read != ':':
            raise error.Abort(_('bad mtn packet - no divider before size'))

        read = None
        lengthstr = ''
        while read != ':':
            read = self.mtnreadfp.read(1)
            if not read:
                raise error.Abort(_('bad mtn packet - no end of packet size'))
            lengthstr += read
        try:
            length = long(lengthstr[:-1])
        except TypeError:
            raise error.Abort(_('bad mtn packet - bad packet size %s')
                % lengthstr)

        read = self.mtnreadfp.read(length)
        if len(read) != length:
            raise error.Abort(_("bad mtn packet - unable to read full packet "
                "read %s of %s") % (len(read), length))

        return (commandnbr, stream, length, read)

    def mtnstdioreadcommandoutput(self, command):
        retval = []
        while True:
            commandnbr, stream, length, output = self.mtnstdioreadpacket()
            self.ui.debug('mtn: read packet %s:%s:%s\n' %
                (commandnbr, stream, length))

            if stream == 'l':
                # End of command
                if output != '0':
                    raise error.Abort(_("mtn command '%s' returned %s") %
                        (command, output))
                break
            elif stream in 'ew':
                # Error, warning output
                self.ui.warn(_('%s error:\n') % self.command)
                self.ui.warn(output)
            elif stream == 'p':
                # Progress messages
                self.ui.debug('mtn: ' + output)
            elif stream == 'm':
                # Main stream - command output
                retval.append(output)

        return ''.join(retval)

    def mtnloadmanifest(self, rev):
        if self.manifest_rev == rev:
            return
        self.manifest = self.mtnrun("get_manifest_of", rev).split("\n\n")
        self.manifest_rev = rev
        self.files = {}
        self.dirs = {}

        for e in self.manifest:
            m = self.file_re.match(e)
            if m:
                attr = ""
                name = m.group(1)
                node = m.group(2)
                if self.attr_execute_re.match(e):
                    attr += "x"
                self.files[name] = (node, attr)
            m = self.dir_re.match(e)
            if m:
                self.dirs[m.group(1)] = True

    def mtnisfile(self, name, rev):
        # a non-file could be a directory or a deleted or renamed file
        self.mtnloadmanifest(rev)
        return name in self.files

    def mtnisdir(self, name, rev):
        self.mtnloadmanifest(rev)
        return name in self.dirs

    def mtngetcerts(self, rev):
        certs = {"author":"<missing>", "date":"<missing>",
            "changelog":"<missing>", "branch":"<missing>"}
        certlist = self.mtnrun("certs", rev)
        # mtn < 0.45:
        #   key "[e-mail]"
        # mtn >= 0.45:
        #   key [ff58a7ffb771907c4ff68995eada1c4da068d328]
        certlist = re.split('\n\n      key ["\[]', certlist)
        for e in certlist:
            m = self.cert_re.match(e)
            if m:
                name, value = m.groups()
                value = value.replace(r'\"', '"')
                value = value.replace(r'\\', '\\')
                certs[name] = value
        # Monotone may have subsecond dates: 2005-02-05T09:39:12.364306
        # and all times are stored in UTC
        certs["date"] = certs["date"].split('.')[0] + " UTC"
        return certs

    # implement the converter_source interface:

    def getheads(self):
        if not self.revs:
            return self.mtnrun("leaves").splitlines()
        else:
            return self.revs

    def getchanges(self, rev, full):
        if full:
            raise error.Abort(_("convert from monotone does not support "
                              "--full"))
        revision = self.mtnrun("get_revision", rev).split("\n\n")
        files = {}
        ignoremove = {}
        renameddirs = []
        copies = {}
        for e in revision:
            m = self.add_file_re.match(e)
            if m:
                files[m.group(1)] = rev
                ignoremove[m.group(1)] = rev
            m = self.patch_re.match(e)
            if m:
                files[m.group(1)] = rev
            # Delete/rename is handled later when the convert engine
            # discovers an IOError exception from getfile,
            # but only if we add the "from" file to the list of changes.
            m = self.delete_re.match(e)
            if m:
                files[m.group(1)] = rev
            m = self.rename_re.match(e)
            if m:
                toname = m.group(2)
                fromname = m.group(1)
                if self.mtnisfile(toname, rev):
                    ignoremove[toname] = 1
                    copies[toname] = fromname
                    files[toname] = rev
                    files[fromname] = rev
                elif self.mtnisdir(toname, rev):
                    renameddirs.append((fromname, toname))

        # Directory renames can be handled only once we have recorded
        # all new files
        for fromdir, todir in renameddirs:
            renamed = {}
            for tofile in self.files:
                if tofile in ignoremove:
                    continue
                if tofile.startswith(todir + '/'):
                    renamed[tofile] = fromdir + tofile[len(todir):]
                    # Avoid chained moves like:
                    # d1(/a) => d3/d1(/a)
                    # d2 => d3
                    ignoremove[tofile] = 1
            for tofile, fromfile in renamed.items():
                self.ui.debug (_("copying file in renamed directory "
                                 "from '%s' to '%s'")
                               % (fromfile, tofile), '\n')
                files[tofile] = rev
                copies[tofile] = fromfile
            for fromfile in renamed.values():
                files[fromfile] = rev

        return (files.items(), copies, set())

    def getfile(self, name, rev):
        if not self.mtnisfile(name, rev):
            return None, None
        try:
            data = self.mtnrun("get_file_of", name, r=rev)
        except Exception:
            return None, None
        self.mtnloadmanifest(rev)
        node, attr = self.files.get(name, (None, ""))
        return data, attr

    def getcommit(self, rev):
        extra = {}
        certs = self.mtngetcerts(rev)
        if certs.get('suspend') == certs["branch"]:
            extra['close'] = 1
        dateformat = "%Y-%m-%dT%H:%M:%S"
        return common.commit(
            author=certs["author"],
            date=dateutil.datestr(dateutil.strdate(certs["date"], dateformat)),
            desc=certs["changelog"],
            rev=rev,
            parents=self.mtnrun("parents", rev).splitlines(),
            branch=certs["branch"],
            extra=extra)

    def gettags(self):
        tags = {}
        for e in self.mtnrun("tags").split("\n\n"):
            m = self.tag_re.match(e)
            if m:
                tags[m.group(1)] = m.group(2)
        return tags

    def getchangedfiles(self, rev, i):
        # This function is only needed to support --filemap
        # ... and we don't support that
        raise NotImplementedError

    def before(self):
        # Check if we have a new enough version to use automate stdio
        version = 0.0
        try:
            versionstr = self.mtnrunsingle("interface_version")
            version = float(versionstr)
        except Exception:
            raise error.Abort(_("unable to determine mtn automate interface "
                "version"))

        if version >= 12.0:
            self.automatestdio = True
            self.ui.debug("mtn automate version %f - using automate stdio\n" %
                version)

            # launch the long-running automate stdio process
            self.mtnwritefp, self.mtnreadfp = self._run2('automate', 'stdio',
                '-d', self.path)
            # read the headers
            read = self.mtnreadfp.readline()
            if read != 'format-version: 2\n':
                raise error.Abort(_('mtn automate stdio header unexpected: %s')
                    % read)
            while read != '\n':
                read = self.mtnreadfp.readline()
                if not read:
                    raise error.Abort(_("failed to reach end of mtn automate "
                        "stdio headers"))
        else:
            self.ui.debug("mtn automate version %s - not using automate stdio "
                "(automate >= 12.0 - mtn >= 0.46 is needed)\n" % version)

    def after(self):
        if self.automatestdio:
            self.mtnwritefp.close()
            self.mtnwritefp = None
            self.mtnreadfp.close()
            self.mtnreadfp = None