view hgext/convert/monotone.py @ 48390:322525db4c98

status: use filesystem time boundary to invalidate racy mtime

We record the filesystem time at the start of the status walk and use that as a
boundary to detect files that might be modified during (or right after) the
status run without the mtime allowing that edition to be detected.  We
currently do this at a second precision. In a later patch, we will use
nanosecond precision when available.

To cope with "broken" time on the file system where file could be in the
future, we also keep mtime for file over one day in the future. See inline
comment for details.

Large file tests get a bit more confused as we reduce the odds for race
condition.

As a "side effect", the win32text extension is happy again.

Differential Revision: https://phab.mercurial-scm.org/D11794

# 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.pycompat import open
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(
                _(
                    b'monotone source does not support specifying '
                    b'multiple revs'
                )
            )
        common.commandline.__init__(self, ui, b'mtn')

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

        norepo = common.NoRepo(
            _(b"%s does not look like a monotone repository") % path
        )
        if not os.path.exists(os.path.join(path, b'_MTN')):
            # Could be a monotone repository (SQLite db file)
            try:
                f = open(path, b'rb')
                header = f.read(16)
                f.close()
            except IOError:
                header = b''
            if header != b'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 + b"dir" + name)
        self.file_re = re.compile(
            space + b"file" + name + b"content" + revision
        )
        self.add_file_re = re.compile(
            space + b"add_file" + name + b"content" + revision
        )
        self.patch_re = re.compile(
            space + b"patch" + name + b"from" + revision + b"to" + revision
        )
        self.rename_re = re.compile(space + b"rename" + name + b"to" + name)
        self.delete_re = re.compile(space + b"delete" + name)
        self.tag_re = re.compile(space + b"tag" + name + b"revision" + revision)
        self.cert_re = re.compile(
            lines + space + b"name" + name + b"value" + value
        )

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

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

        common.checktool(b'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['d'] = self.path
        return self.run0(b'automate', *args, **kwargs)

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

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

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

        return self.mtnstdioreadcommandoutput(command)

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

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

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

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

        read = self.mtnreadfp.read(length)
        if len(read) != length:
            raise error.Abort(
                _(
                    b"bad mtn packet - unable to read full packet "
                    b"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(
                b'mtn: read packet %s:%s:%d\n' % (commandnbr, stream, length)
            )

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

        return b''.join(retval)

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

        for e in self.manifest:
            m = self.file_re.match(e)
            if m:
                attr = b""
                name = m.group(1)
                node = m.group(2)
                if self.attr_execute_re.match(e):
                    attr += b"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 = {
            b"author": b"<missing>",
            b"date": b"<missing>",
            b"changelog": b"<missing>",
            b"branch": b"<missing>",
        }
        certlist = self.mtnrun(b"certs", rev)
        # mtn < 0.45:
        #   key "[e-mail]"
        # mtn >= 0.45:
        #   key [ff58a7ffb771907c4ff68995eada1c4da068d328]
        certlist = re.split(br'\n\n {6}key ["\[]', certlist)
        for e in certlist:
            m = self.cert_re.match(e)
            if m:
                name, value = m.groups()
                value = value.replace(br'\"', b'"')
                value = value.replace(br'\\', b'\\')
                certs[name] = value
        # Monotone may have subsecond dates: 2005-02-05T09:39:12.364306
        # and all times are stored in UTC
        certs[b"date"] = certs[b"date"].split(b'.')[0] + b" UTC"
        return certs

    # implement the converter_source interface:

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

    def getchanges(self, rev, full):
        if full:
            raise error.Abort(
                _(b"convert from monotone does not support --full")
            )
        revision = self.mtnrun(b"get_revision", rev).split(b"\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 + b'/'):
                    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(
                    b"copying file in renamed directory from '%s' to '%s'"
                    % (fromfile, tofile),
                    b'\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(b"get_file_of", name, r=rev)
        except Exception:
            return None, None
        self.mtnloadmanifest(rev)
        node, attr = self.files.get(name, (None, b""))
        return data, attr

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

    def gettags(self):
        tags = {}
        for e in self.mtnrun(b"tags").split(b"\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
        try:
            versionstr = self.mtnrunsingle(b"interface_version")
            version = float(versionstr)
        except Exception:
            raise error.Abort(
                _(b"unable to determine mtn automate interface version")
            )

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

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