hgext/convert/common.py

convert: add support for deterministic progress bar on scanning phase

This makes it possible to estimate how long the "scanning source"
phase will take, if the specified source repo type supports a quick
"how many changes" check.

# common.py - common code for the convert extension
#
#  Copyright 2005-2009 Matt 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 base64, errno, subprocess, os, datetime, re
import cPickle as pickle
from mercurial import util
from mercurial.i18n import _

propertycache = util.propertycache

def encodeargs(args):
    def encodearg(s):
        lines = base64.encodestring(s)
        lines = [l.splitlines()[0] for l in lines]
        return ''.join(lines)

    s = pickle.dumps(args)
    return encodearg(s)

def decodeargs(s):
    s = base64.decodestring(s)
    return pickle.loads(s)

class MissingTool(Exception):
    pass

def checktool(exe, name=None, abort=True):
    name = name or exe
    if not util.findexe(exe):
        exc = abort and util.Abort or MissingTool
        raise exc(_('cannot find required "%s" tool') % name)

class NoRepo(Exception):
    pass

SKIPREV = 'SKIP'

class commit(object):
    def __init__(self, author, date, desc, parents, branch=None, rev=None,
                 extra={}, sortkey=None):
        self.author = author or 'unknown'
        self.date = date or '0 0'
        self.desc = desc
        self.parents = parents
        self.branch = branch
        self.rev = rev
        self.extra = extra
        self.sortkey = sortkey

class converter_source(object):
    """Conversion source interface"""

    def __init__(self, ui, path=None, rev=None):
        """Initialize conversion source (or raise NoRepo("message")
        exception if path is not a valid repository)"""
        self.ui = ui
        self.path = path
        self.rev = rev

        self.encoding = 'utf-8'

    def checkhexformat(self, revstr, mapname='splicemap'):
        """ fails if revstr is not a 40 byte hex. mercurial and git both uses
            such format for their revision numbering
        """
        if not re.match(r'[0-9a-fA-F]{40,40}$', revstr):
            raise util.Abort(_('%s entry %s is not a valid revision'
                               ' identifier') % (mapname, revstr))

    def before(self):
        pass

    def after(self):
        pass

    def setrevmap(self, revmap):
        """set the map of already-converted revisions"""
        pass

    def getheads(self):
        """Return a list of this repository's heads"""
        raise NotImplementedError

    def getfile(self, name, rev):
        """Return a pair (data, mode) where data is the file content
        as a string and mode one of '', 'x' or 'l'. rev is the
        identifier returned by a previous call to getchanges().
        Data is None if file is missing/deleted in rev.
        """
        raise NotImplementedError

    def getchanges(self, version, full):
        """Returns a tuple of (files, copies).

        files is a sorted list of (filename, id) tuples for all files
        changed between version and its first parent returned by
        getcommit(). If full, all files in that revision is returned.
        id is the source revision id of the file.

        copies is a dictionary of dest: source
        """
        raise NotImplementedError

    def getcommit(self, version):
        """Return the commit object for version"""
        raise NotImplementedError

    def numcommits(self):
        """Return the number of commits in this source.

        If unknown, return None.
        """
        return None

    def gettags(self):
        """Return the tags as a dictionary of name: revision

        Tag names must be UTF-8 strings.
        """
        raise NotImplementedError

    def recode(self, s, encoding=None):
        if not encoding:
            encoding = self.encoding or 'utf-8'

        if isinstance(s, unicode):
            return s.encode("utf-8")
        try:
            return s.decode(encoding).encode("utf-8")
        except UnicodeError:
            try:
                return s.decode("latin-1").encode("utf-8")
            except UnicodeError:
                return s.decode(encoding, "replace").encode("utf-8")

    def getchangedfiles(self, rev, i):
        """Return the files changed by rev compared to parent[i].

        i is an index selecting one of the parents of rev.  The return
        value should be the list of files that are different in rev and
        this parent.

        If rev has no parents, i is None.

        This function is only needed to support --filemap
        """
        raise NotImplementedError

    def converted(self, rev, sinkrev):
        '''Notify the source that a revision has been converted.'''
        pass

    def hasnativeorder(self):
        """Return true if this source has a meaningful, native revision
        order. For instance, Mercurial revisions are store sequentially
        while there is no such global ordering with Darcs.
        """
        return False

    def hasnativeclose(self):
        """Return true if this source has ability to close branch.
        """
        return False

    def lookuprev(self, rev):
        """If rev is a meaningful revision reference in source, return
        the referenced identifier in the same format used by getcommit().
        return None otherwise.
        """
        return None

    def getbookmarks(self):
        """Return the bookmarks as a dictionary of name: revision

        Bookmark names are to be UTF-8 strings.
        """
        return {}

    def checkrevformat(self, revstr, mapname='splicemap'):
        """revstr is a string that describes a revision in the given
           source control system.  Return true if revstr has correct
           format.
        """
        return True

class converter_sink(object):
    """Conversion sink (target) interface"""

    def __init__(self, ui, path):
        """Initialize conversion sink (or raise NoRepo("message")
        exception if path is not a valid repository)

        created is a list of paths to remove if a fatal error occurs
        later"""
        self.ui = ui
        self.path = path
        self.created = []

    def revmapfile(self):
        """Path to a file that will contain lines
        source_rev_id sink_rev_id
        mapping equivalent revision identifiers for each system."""
        raise NotImplementedError

    def authorfile(self):
        """Path to a file that will contain lines
        srcauthor=dstauthor
        mapping equivalent authors identifiers for each system."""
        return None

    def putcommit(self, files, copies, parents, commit, source, revmap, full):
        """Create a revision with all changed files listed in 'files'
        and having listed parents. 'commit' is a commit object
        containing at a minimum the author, date, and message for this
        changeset.  'files' is a list of (path, version) tuples,
        'copies' is a dictionary mapping destinations to sources,
        'source' is the source repository, and 'revmap' is a mapfile
        of source revisions to converted revisions. Only getfile() and
        lookuprev() should be called on 'source'. 'full' means that 'files'
        is complete and all other files should be removed.

        Note that the sink repository is not told to update itself to
        a particular revision (or even what that revision would be)
        before it receives the file data.
        """
        raise NotImplementedError

    def puttags(self, tags):
        """Put tags into sink.

        tags: {tagname: sink_rev_id, ...} where tagname is an UTF-8 string.
        Return a pair (tag_revision, tag_parent_revision), or (None, None)
        if nothing was changed.
        """
        raise NotImplementedError

    def setbranch(self, branch, pbranches):
        """Set the current branch name. Called before the first putcommit
        on the branch.
        branch: branch name for subsequent commits
        pbranches: (converted parent revision, parent branch) tuples"""
        pass

    def setfilemapmode(self, active):
        """Tell the destination that we're using a filemap

        Some converter_sources (svn in particular) can claim that a file
        was changed in a revision, even if there was no change.  This method
        tells the destination that we're using a filemap and that it should
        filter empty revisions.
        """
        pass

    def before(self):
        pass

    def after(self):
        pass

    def putbookmarks(self, bookmarks):
        """Put bookmarks into sink.

        bookmarks: {bookmarkname: sink_rev_id, ...}
        where bookmarkname is an UTF-8 string.
        """
        pass

    def hascommitfrommap(self, rev):
        """Return False if a rev mentioned in a filemap is known to not be
        present."""
        raise NotImplementedError

    def hascommitforsplicemap(self, rev):
        """This method is for the special needs for splicemap handling and not
        for general use. Returns True if the sink contains rev, aborts on some
        special cases."""
        raise NotImplementedError

class commandline(object):
    def __init__(self, ui, command):
        self.ui = ui
        self.command = command

    def prerun(self):
        pass

    def postrun(self):
        pass

    def _cmdline(self, cmd, *args, **kwargs):
        cmdline = [self.command, cmd] + list(args)
        for k, v in kwargs.iteritems():
            if len(k) == 1:
                cmdline.append('-' + k)
            else:
                cmdline.append('--' + k.replace('_', '-'))
            try:
                if len(k) == 1:
                    cmdline.append('' + v)
                else:
                    cmdline[-1] += '=' + v
            except TypeError:
                pass
        cmdline = [util.shellquote(arg) for arg in cmdline]
        if not self.ui.debugflag:
            cmdline += ['2>', os.devnull]
        cmdline = ' '.join(cmdline)
        return cmdline

    def _run(self, cmd, *args, **kwargs):
        def popen(cmdline):
            p = subprocess.Popen(cmdline, shell=True, bufsize=-1,
                    close_fds=util.closefds,
                    stdout=subprocess.PIPE)
            return p
        return self._dorun(popen, cmd, *args, **kwargs)

    def _run2(self, cmd, *args, **kwargs):
        return self._dorun(util.popen2, cmd, *args, **kwargs)

    def _dorun(self, openfunc, cmd,  *args, **kwargs):
        cmdline = self._cmdline(cmd, *args, **kwargs)
        self.ui.debug('running: %s\n' % (cmdline,))
        self.prerun()
        try:
            return openfunc(cmdline)
        finally:
            self.postrun()

    def run(self, cmd, *args, **kwargs):
        p = self._run(cmd, *args, **kwargs)
        output = p.communicate()[0]
        self.ui.debug(output)
        return output, p.returncode

    def runlines(self, cmd, *args, **kwargs):
        p = self._run(cmd, *args, **kwargs)
        output = p.stdout.readlines()
        p.wait()
        self.ui.debug(''.join(output))
        return output, p.returncode

    def checkexit(self, status, output=''):
        if status:
            if output:
                self.ui.warn(_('%s error:\n') % self.command)
                self.ui.warn(output)
            msg = util.explainexit(status)[0]
            raise util.Abort('%s %s' % (self.command, msg))

    def run0(self, cmd, *args, **kwargs):
        output, status = self.run(cmd, *args, **kwargs)
        self.checkexit(status, output)
        return output

    def runlines0(self, cmd, *args, **kwargs):
        output, status = self.runlines(cmd, *args, **kwargs)
        self.checkexit(status, ''.join(output))
        return output

    @propertycache
    def argmax(self):
        # POSIX requires at least 4096 bytes for ARG_MAX
        argmax = 4096
        try:
            argmax = os.sysconf("SC_ARG_MAX")
        except (AttributeError, ValueError):
            pass

        # Windows shells impose their own limits on command line length,
        # down to 2047 bytes for cmd.exe under Windows NT/2k and 2500 bytes
        # for older 4nt.exe. See http://support.microsoft.com/kb/830473 for
        # details about cmd.exe limitations.

        # Since ARG_MAX is for command line _and_ environment, lower our limit
        # (and make happy Windows shells while doing this).
        return argmax // 2 - 1

    def _limit_arglist(self, arglist, cmd, *args, **kwargs):
        cmdlen = len(self._cmdline(cmd, *args, **kwargs))
        limit = self.argmax - cmdlen
        bytes = 0
        fl = []
        for fn in arglist:
            b = len(fn) + 3
            if bytes + b < limit or len(fl) == 0:
                fl.append(fn)
                bytes += b
            else:
                yield fl
                fl = [fn]
                bytes = b
        if fl:
            yield fl

    def xargs(self, arglist, cmd, *args, **kwargs):
        for l in self._limit_arglist(arglist, cmd, *args, **kwargs):
            self.run0(cmd, *(list(args) + l), **kwargs)

class mapfile(dict):
    def __init__(self, ui, path):
        super(mapfile, self).__init__()
        self.ui = ui
        self.path = path
        self.fp = None
        self.order = []
        self._read()

    def _read(self):
        if not self.path:
            return
        try:
            fp = open(self.path, 'r')
        except IOError, err:
            if err.errno != errno.ENOENT:
                raise
            return
        for i, line in enumerate(fp):
            line = line.splitlines()[0].rstrip()
            if not line:
                # Ignore blank lines
                continue
            try:
                key, value = line.rsplit(' ', 1)
            except ValueError:
                raise util.Abort(
                    _('syntax error in %s(%d): key/value pair expected')
                    % (self.path, i + 1))
            if key not in self:
                self.order.append(key)
            super(mapfile, self).__setitem__(key, value)
        fp.close()

    def __setitem__(self, key, value):
        if self.fp is None:
            try:
                self.fp = open(self.path, 'a')
            except IOError, err:
                raise util.Abort(_('could not open map file %r: %s') %
                                 (self.path, err.strerror))
        self.fp.write('%s %s\n' % (key, value))
        self.fp.flush()
        super(mapfile, self).__setitem__(key, value)

    def close(self):
        if self.fp:
            self.fp.close()
            self.fp = None

def makedatetimestamp(t):
    """Like util.makedate() but for time t instead of current time"""
    delta = (datetime.datetime.utcfromtimestamp(t) -
             datetime.datetime.fromtimestamp(t))
    tz = delta.days * 86400 + delta.seconds
    return t, tz