/mercurial/cmdutil.py

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# cmdutil.py - help for command processing in mercurial
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from node import hex, nullid, nullrev, short
from i18n import _
import os, sys, errno, re, tempfile
import util, scmutil, templater, patch, error, templatekw, revlog, copies
import match as matchmod
import context, repair, graphmod, revset, phases, obsolete, pathutil
import changelog
import bookmarks
import lock as lockmod

def parsealiases(cmd):
    return cmd.lstrip("^").split("|")

def findpossible(cmd, table, strict=False):
    """
    Return cmd -> (aliases, command table entry)
    for each matching command.
    Return debug commands (or their aliases) only if no normal command matches.
    """
    choice = {}
    debugchoice = {}

    if cmd in table:
        # short-circuit exact matches, "log" alias beats "^log|history"
        keys = [cmd]
    else:
        keys = table.keys()

    for e in keys:
        aliases = parsealiases(e)
        found = None
        if cmd in aliases:
            found = cmd
        elif not strict:
            for a in aliases:
                if a.startswith(cmd):
                    found = a
                    break
        if found is not None:
            if aliases[0].startswith("debug") or found.startswith("debug"):
                debugchoice[found] = (aliases, table[e])
            else:
                choice[found] = (aliases, table[e])

    if not choice and debugchoice:
        choice = debugchoice

    return choice

def findcmd(cmd, table, strict=True):
    """Return (aliases, command table entry) for command string."""
    choice = findpossible(cmd, table, strict)

    if cmd in choice:
        return choice[cmd]

    if len(choice) > 1:
        clist = choice.keys()
        clist.sort()
        raise error.AmbiguousCommand(cmd, clist)

    if choice:
        return choice.values()[0]

    raise error.UnknownCommand(cmd)

def findrepo(p):
    while not os.path.isdir(os.path.join(p, ".hg")):
        oldp, p = p, os.path.dirname(p)
        if p == oldp:
            return None

    return p

def bailifchanged(repo):
    if repo.dirstate.p2() != nullid:
        raise util.Abort(_('outstanding uncommitted merge'))
    modified, added, removed, deleted = repo.status()[:4]
    if modified or added or removed or deleted:
        raise util.Abort(_('uncommitted changes'))
    ctx = repo[None]
    for s in sorted(ctx.substate):
        if ctx.sub(s).dirty():
            raise util.Abort(_("uncommitted changes in subrepo %s") % s)

def logmessage(ui, opts):
    """ get the log message according to -m and -l option """
    message = opts.get('message')
    logfile = opts.get('logfile')

    if message and logfile:
        raise util.Abort(_('options --message and --logfile are mutually '
                           'exclusive'))
    if not message and logfile:
        try:
            if logfile == '-':
                message = ui.fin.read()
            else:
                message = '\n'.join(util.readfile(logfile).splitlines())
        except IOError, inst:
            raise util.Abort(_("can't read commit message '%s': %s") %
                             (logfile, inst.strerror))
    return message

def getcommiteditor(edit=False, finishdesc=None, extramsg=None, **opts):
    """get appropriate commit message editor according to '--edit' option

    'finishdesc' is a function to be called with edited commit message
    (= 'description' of the new changeset) just after editing, but
    before checking empty-ness. It should return actual text to be
    stored into history. This allows to change description before
    storing.

    'extramsg' is a extra message to be shown in the editor instead of
    'Leave message empty to abort commit' line. 'HG: ' prefix and EOL
    is automatically added.

    'getcommiteditor' returns 'commitforceeditor' regardless of
    'edit', if one of 'finishdesc' or 'extramsg' is specified, because
    they are specific for usage in MQ.
    """
    if edit or finishdesc or extramsg:
        return lambda r, c, s: commitforceeditor(r, c, s,
                                                 finishdesc=finishdesc,
                                                 extramsg=extramsg)
    else:
        return commiteditor

def loglimit(opts):
    """get the log limit according to option -l/--limit"""
    limit = opts.get('limit')
    if limit:
        try:
            limit = int(limit)
        except ValueError:
            raise util.Abort(_('limit must be a positive integer'))
        if limit <= 0:
            raise util.Abort(_('limit must be positive'))
    else:
        limit = None
    return limit

def makefilename(repo, pat, node, desc=None,
                  total=None, seqno=None, revwidth=None, pathname=None):
    node_expander = {
        'H': lambda: hex(node),
        'R': lambda: str(repo.changelog.rev(node)),
        'h': lambda: short(node),
        'm': lambda: re.sub('[^\w]', '_', str(desc))
        }
    expander = {
        '%': lambda: '%',
        'b': lambda: os.path.basename(repo.root),
        }

    try:
        if node:
            expander.update(node_expander)
        if node:
            expander['r'] = (lambda:
                    str(repo.changelog.rev(node)).zfill(revwidth or 0))
        if total is not None:
            expander['N'] = lambda: str(total)
        if seqno is not None:
            expander['n'] = lambda: str(seqno)
        if total is not None and seqno is not None:
            expander['n'] = lambda: str(seqno).zfill(len(str(total)))
        if pathname is not None:
            expander['s'] = lambda: os.path.basename(pathname)
            expander['d'] = lambda: os.path.dirname(pathname) or '.'
            expander['p'] = lambda: pathname

        newname = []
        patlen = len(pat)
        i = 0
        while i < patlen:
            c = pat[i]
            if c == '%':
                i += 1
                c = pat[i]
                c = expander[c]()
            newname.append(c)
            i += 1
        return ''.join(newname)
    except KeyError, inst:
        raise util.Abort(_("invalid format spec '%%%s' in output filename") %
                         inst.args[0])

def makefileobj(repo, pat, node=None, desc=None, total=None,
                seqno=None, revwidth=None, mode='wb', modemap=None,
                pathname=None):

    writable = mode not in ('r', 'rb')

    if not pat or pat == '-':
        fp = writable and repo.ui.fout or repo.ui.fin
        if util.safehasattr(fp, 'fileno'):
            return os.fdopen(os.dup(fp.fileno()), mode)
        else:
            # if this fp can't be duped properly, return
            # a dummy object that can be closed
            class wrappedfileobj(object):
                noop = lambda x: None
                def __init__(self, f):
                    self.f = f
                def __getattr__(self, attr):
                    if attr == 'close':
                        return self.noop
                    else:
                        return getattr(self.f, attr)

            return wrappedfileobj(fp)
    if util.safehasattr(pat, 'write') and writable:
        return pat
    if util.safehasattr(pat, 'read') and 'r' in mode:
        return pat
    fn = makefilename(repo, pat, node, desc, total, seqno, revwidth, pathname)
    if modemap is not None:
        mode = modemap.get(fn, mode)
        if mode == 'wb':
            modemap[fn] = 'ab'
    return open(fn, mode)

def openrevlog(repo, cmd, file_, opts):
    """opens the changelog, manifest, a filelog or a given revlog"""
    cl = opts['changelog']
    mf = opts['manifest']
    msg = None
    if cl and mf:
        msg = _('cannot specify --changelog and --manifest at the same time')
    elif cl or mf:
        if file_:
            msg = _('cannot specify filename with --changelog or --manifest')
        elif not repo:
            msg = _('cannot specify --changelog or --manifest '
                    'without a repository')
    if msg:
        raise util.Abort(msg)

    r = None
    if repo:
        if cl:
            r = repo.unfiltered().changelog
        elif mf:
            r = repo.manifest
        elif file_:
            filelog = repo.file(file_)
            if len(filelog):
                r = filelog
    if not r:
        if not file_:
            raise error.CommandError(cmd, _('invalid arguments'))
        if not os.path.isfile(file_):
            raise util.Abort(_("revlog '%s' not found") % file_)
        r = revlog.revlog(scmutil.opener(os.getcwd(), audit=False),
                          file_[:-2] + ".i")
    return r

def copy(ui, repo, pats, opts, rename=False):
    # called with the repo lock held
    #
    # hgsep => pathname that uses "/" to separate directories
    # ossep => pathname that uses os.sep to separate directories
    cwd = repo.getcwd()
    targets = {}
    after = opts.get("after")
    dryrun = opts.get("dry_run")
    wctx = repo[None]

    def walkpat(pat):
        srcs = []
        badstates = after and '?' or '?r'
        m = scmutil.match(repo[None], [pat], opts, globbed=True)
        for abs in repo.walk(m):
            state = repo.dirstate[abs]
            rel = m.rel(abs)
            exact = m.exact(abs)
            if state in badstates:
                if exact and state == '?':
                    ui.warn(_('%s: not copying - file is not managed\n') % rel)
                if exact and state == 'r':
                    ui.warn(_('%s: not copying - file has been marked for'
                              ' remove\n') % rel)
                continue
            # abs: hgsep
            # rel: ossep
            srcs.append((abs, rel, exact))
        return srcs

    # abssrc: hgsep
    # relsrc: ossep
    # otarget: ossep
    def copyfile(abssrc, relsrc, otarget, exact):
        abstarget = pathutil.canonpath(repo.root, cwd, otarget)
        if '/' in abstarget:
            # We cannot normalize abstarget itself, this would prevent
            # case only renames, like a => A.
            abspath, absname = abstarget.rsplit('/', 1)
            abstarget = repo.dirstate.normalize(abspath) + '/' + absname
        reltarget = repo.pathto(abstarget, cwd)
        target = repo.wjoin(abstarget)
        src = repo.wjoin(abssrc)
        state = repo.dirstate[abstarget]

        scmutil.checkportable(ui, abstarget)

        # check for collisions
        prevsrc = targets.get(abstarget)
        if prevsrc is not None:
            ui.warn(_('%s: not overwriting - %s collides with %s\n') %
                    (reltarget, repo.pathto(abssrc, cwd),
                     repo.pathto(prevsrc, cwd)))
            return

        # check for overwrites
        exists = os.path.lexists(target)
        samefile = False
        if exists and abssrc != abstarget:
            if (repo.dirstate.normalize(abssrc) ==
                repo.dirstate.normalize(abstarget)):
                if not rename:
                    ui.warn(_("%s: can't copy - same file\n") % reltarget)
                    return
                exists = False
                samefile = True

        if not after and exists or after and state in 'mn':
            if not opts['force']:
                ui.warn(_('%s: not overwriting - file exists\n') %
                        reltarget)
                return

        if after:
            if not exists:
                if rename:
                    ui.warn(_('%s: not recording move - %s does not exist\n') %
                            (relsrc, reltarget))
                else:
                    ui.warn(_('%s: not recording copy - %s does not exist\n') %
                            (relsrc, reltarget))
                return
        elif not dryrun:
            try:
                if exists:
                    os.unlink(target)
                targetdir = os.path.dirname(target) or '.'
                if not os.path.isdir(targetdir):
                    os.makedirs(targetdir)
                if samefile:
                    tmp = target + "~hgrename"
                    os.rename(src, tmp)
                    os.rename(tmp, target)
                else:
                    util.copyfile(src, target)
                srcexists = True
            except IOError, inst:
                if inst.errno == errno.ENOENT:
                    ui.warn(_('%s: deleted in working copy\n') % relsrc)
                    srcexists = False
                else:
                    ui.warn(_('%s: cannot copy - %s\n') %
                            (relsrc, inst.strerror))
                    return True # report a failure

        if ui.verbose or not exact:
            if rename:
                ui.status(_('moving %s to %s\n') % (relsrc, reltarget))
            else:
                ui.status(_('copying %s to %s\n') % (relsrc, reltarget))

        targets[abstarget] = abssrc

        # fix up dirstate
        scmutil.dirstatecopy(ui, repo, wctx, abssrc, abstarget,
                             dryrun=dryrun, cwd=cwd)
        if rename and not dryrun:
            if not after and srcexists and not samefile:
                util.unlinkpath(repo.wjoin(abssrc))
            wctx.forget([abssrc])

    # pat: ossep
    # dest ossep
    # srcs: list of (hgsep, hgsep, ossep, bool)
    # return: function that takes hgsep and returns ossep
    def targetpathfn(pat, dest, srcs):
        if os.path.isdir(pat):
            abspfx = pathutil.canonpath(repo.root, cwd, pat)
            abspfx = util.localpath(abspfx)
            if destdirexists:
                striplen = len(os.path.split(abspfx)[0])
            else:
                striplen = len(abspfx)
            if striplen:
                striplen += len(os.sep)
            res = lambda p: os.path.join(dest, util.localpath(p)[striplen:])
        elif destdirexists:
            res = lambda p: os.path.join(dest,
                                         os.path.basename(util.localpath(p)))
        else:
            res = lambda p: dest
        return res

    # pat: ossep
    # dest ossep
    # srcs: list of (hgsep, hgsep, ossep, bool)
    # return: function that takes hgsep and returns ossep
    def targetpathafterfn(pat, dest, srcs):
        if matchmod.patkind(pat):
            # a mercurial pattern
            res = lambda p: os.path.join(dest,
                                         os.path.basename(util.localpath(p)))
        else:
            abspfx = pathutil.canonpath(repo.root, cwd, pat)
            if len(abspfx) < len(srcs[0][0]):
                # A directory. Either the target path contains the last
                # component of the source path or it does not.
                def evalpath(striplen):
                    score = 0
                    for s in srcs:
                        t = os.path.join(dest, util.localpath(s[0])[striplen:])
                        if os.path.lexists(t):
                            score += 1
                    return score

                abspfx = util.localpath(abspfx)
                striplen = len(abspfx)
                if striplen:
                    striplen += len(os.sep)
                if os.path.isdir(os.path.join(dest, os.path.split(abspfx)[1])):
                    score = evalpath(striplen)
                    striplen1 = len(os.path.split(abspfx)[0])
                    if striplen1:
                        striplen1 += len(os.sep)
                    if evalpath(striplen1) > score:
                        striplen = striplen1
                res = lambda p: os.path.join(dest,
                                             util.localpath(p)[striplen:])
            else:
                # a file
                if destdirexists:
                    res = lambda p: os.path.join(dest,
                                        os.path.basename(util.localpath(p)))
                else:
                    res = lambda p: dest
        return res


    pats = scmutil.expandpats(pats)
    if not pats:
        raise util.Abort(_('no source or destination specified'))
    if len(pats) == 1:
        raise util.Abort(_('no destination specified'))
    dest = pats.pop()
    destdirexists = os.path.isdir(dest) and not os.path.islink(dest)
    if not destdirexists:
        if len(pats) > 1 or matchmod.patkind(pats[0]):
            raise util.Abort(_('with multiple sources, destination must be an '
                               'existing directory'))
        if util.endswithsep(dest):
            raise util.Abort(_('destination %s is not a directory') % dest)

    tfn = targetpathfn
    if after:
        tfn = targetpathafterfn
    copylist = []
    for pat in pats:
        srcs = walkpat(pat)
        if not srcs:
            continue
        copylist.append((tfn(pat, dest, srcs), srcs))
    if not copylist:
        raise util.Abort(_('no files to copy'))

    errors = 0
    for targetpath, srcs in copylist:
        for abssrc, relsrc, exact in srcs:
            if copyfile(abssrc, relsrc, targetpath(abssrc), exact):
                errors += 1

    if errors:
        ui.warn(_('(consider using --after)\n'))

    return errors != 0

def service(opts, parentfn=None, initfn=None, runfn=None, logfile=None,
    runargs=None, appendpid=False):
    '''Run a command as a service.'''

    def writepid(pid):
        if opts['pid_file']:
            mode = appendpid and 'a' or 'w'
            fp = open(opts['pid_file'], mode)
            fp.write(str(pid) + '\n')
            fp.close()

    if opts['daemon'] and not opts['daemon_pipefds']:
        # Signal child process startup with file removal
        lockfd, lockpath = tempfile.mkstemp(prefix='hg-service-')
        os.close(lockfd)
        try:
            if not runargs:
                runargs = util.hgcmd() + sys.argv[1:]
            runargs.append('--daemon-pipefds=%s' % lockpath)
            # Don't pass --cwd to the child process, because we've already
            # changed directory.
            for i in xrange(1, len(runargs)):
                if runargs[i].startswith('--cwd='):
                    del runargs[i]
                    break
                elif runargs[i].startswith('--cwd'):
                    del runargs[i:i + 2]
                    break
            def condfn():
                return not os.path.exists(lockpath)
            pid = util.rundetached(runargs, condfn)
            if pid < 0:
                raise util.Abort(_('child process failed to start'))
            writepid(pid)
        finally:
            try:
                os.unlink(lockpath)
            except OSError, e:
                if e.errno != errno.ENOENT:
                    raise
        if parentfn:
            return parentfn(pid)
        else:
            return

    if initfn:
        initfn()

    if not opts['daemon']:
        writepid(os.getpid())

    if opts['daemon_pipefds']:
        lockpath = opts['daemon_pipefds']
        try:
            os.setsid()
        except AttributeError:
            pass
        os.unlink(lockpath)
        util.hidewindow()
        sys.stdout.flush()
        sys.stderr.flush()

        nullfd = os.open(os.devnull, os.O_RDWR)
        logfilefd = nullfd
        if logfile:
            logfilefd = os.open(logfile, os.O_RDWR | os.O_CREAT | os.O_APPEND)
        os.dup2(nullfd, 0)
        os.dup2(logfilefd, 1)
        os.dup2(logfilefd, 2)
        if nullfd not in (0, 1, 2):
            os.close(nullfd)
        if logfile and logfilefd not in (0, 1, 2):
            os.close(logfilefd)

    if runfn:
        return runfn()

def tryimportone(ui, repo, hunk, parents, opts, msgs, updatefunc):
    """Utility function used by commands.import to import a single patch

    This function is explicitly defined here to help the evolve extension to
    wrap this part of the import logic.

    The API is currently a bit ugly because it a simple code translation from
    the import command. Feel free to make it better.

    :hunk: a patch (as a binary string)
    :parents: nodes that will be parent of the created commit
    :opts: the full dict of option passed to the import command
    :msgs: list to save commit message to.
           (used in case we need to save it when failing)
    :updatefunc: a function that update a repo to a given node
                 updatefunc(<repo>, <node>)
    """
    tmpname, message, user, date, branch, nodeid, p1, p2 = \
        patch.extract(ui, hunk)

    editor = getcommiteditor(**opts)
    update = not opts.get('bypass')
    strip = opts["strip"]
    sim = float(opts.get('similarity') or 0)
    if not tmpname:
        return (None, None, False)
    msg = _('applied to working directory')

    rejects = False

    try:
        cmdline_message = logmessage(ui, opts)
        if cmdline_message:
            # pickup the cmdline msg
            message = cmdline_message
        elif message:
            # pickup the patch msg
            message = message.strip()
        else:
            # launch the editor
            message = None
        ui.debug('message:\n%s\n' % message)

        if len(parents) == 1:
            parents.append(repo[nullid])
        if opts.get('exact'):
            if not nodeid or not p1:
                raise util.Abort(_('not a Mercurial patch'))
            p1 = repo[p1]
            p2 = repo[p2 or nullid]
        elif p2:
            try:
                p1 = repo[p1]
                p2 = repo[p2]
                # Without any options, consider p2 only if the
                # patch is being applied on top of the recorded
                # first parent.
                if p1 != parents[0]:
                    p1 = parents[0]
                    p2 = repo[nullid]
            except error.RepoError:
                p1, p2 = parents
        else:
            p1, p2 = parents

        n = None
        if update:
            if p1 != parents[0]:
                updatefunc(repo, p1.node())
            if p2 != parents[1]:
                repo.setparents(p1.node(), p2.node())

            if opts.get('exact') or opts.get('import_branch'):
                repo.dirstate.setbranch(branch or 'default')

            partial = opts.get('partial', False)
            files = set()
            try:
                patch.patch(ui, repo, tmpname, strip=strip, files=files,
                            eolmode=None, similarity=sim / 100.0)
            except patch.PatchError, e:
                if not partial:
                    raise util.Abort(str(e))
                if partial:
                    rejects = True

            files = list(files)
            if opts.get('no_commit'):
                if message:
                    msgs.append(message)
            else:
                if opts.get('exact') or p2:
                    # If you got here, you either use --force and know what
                    # you are doing or used --exact or a merge patch while
                    # being updated to its first parent.
                    m = None
                else:
                    m = scmutil.matchfiles(repo, files or [])
                n = repo.commit(message, opts.get('user') or user,
                                opts.get('date') or date, match=m,
                                editor=editor, force=partial)
        else:
            if opts.get('exact') or opts.get('import_branch'):
                branch = branch or 'default'
            else:
                branch = p1.branch()
            store = patch.filestore()
            try:
                files = set()
                try:
                    patch.patchrepo(ui, repo, p1, store, tmpname, strip,
                                    files, eolmode=None)
                except patch.PatchError, e:
                    raise util.Abort(str(e))
                memctx = context.makememctx(repo, (p1.node(), p2.node()),
                                            message,
                                            opts.get('user') or user,
                                            opts.get('date') or date,
                                            branch, files, store,
                                            editor=getcommiteditor())
                n = memctx.commit()
            finally:
                store.close()
        if opts.get('exact') and hex(n) != nodeid:
            raise util.Abort(_('patch is damaged or loses information'))
        if n:
            # i18n: refers to a short changeset id
            msg = _('created %s') % short(n)
        return (msg, n, rejects)
    finally:
        os.unlink(tmpname)

def export(repo, revs, template='hg-%h.patch', fp=None, switch_parent=False,
           opts=None):
    '''export changesets as hg patches.'''

    total = len(revs)
    revwidth = max([len(str(rev)) for rev in revs])
    filemode = {}

    def single(rev, seqno, fp):
        ctx = repo[rev]
        node = ctx.node()
        parents = [p.node() for p in ctx.parents() if p]
        branch = ctx.branch()
        if switch_parent:
            parents.reverse()
        prev = (parents and parents[0]) or nullid

        shouldclose = False
        if not fp and len(template) > 0:
            desc_lines = ctx.description().rstrip().split('\n')
            desc = desc_lines[0]    #Commit always has a first line.
            fp = makefileobj(repo, template, node, desc=desc, total=total,
                             seqno=seqno, revwidth=revwidth, mode='wb',
                             modemap=filemode)
            if fp != template:
                shouldclose = True
        if fp and fp != sys.stdout and util.safehasattr(fp, 'name'):
            repo.ui.note("%s\n" % fp.name)

        if not fp:
            write = repo.ui.write
        else:
            def write(s, **kw):
                fp.write(s)


        write("# HG changeset patch\n")
        write("# User %s\n" % ctx.user())
        write("# Date %d %d\n" % ctx.date())
        write("#      %s\n" % util.datestr(ctx.date()))
        if branch and branch != 'default':
            write("# Branch %s\n" % branch)
        write("# Node ID %s\n" % hex(node))
        write("# Parent  %s\n" % hex(prev))
        if len(parents) > 1:
            write("# Parent  %s\n" % hex(parents[1]))
        write(ctx.description().rstrip())
        write("\n\n")

        for chunk, label in patch.diffui(repo, prev, node, opts=opts):
            write(chunk, label=label)

        if shouldclose:
            fp.close()

    for seqno, rev in enumerate(revs):
        single(rev, seqno + 1, fp)

def diffordiffstat(ui, repo, diffopts, node1, node2, match,
                   changes=None, stat=False, fp=None, prefix='',
                   listsubrepos=False):
    '''show diff or diffstat.'''
    if fp is None:
        write = ui.write
    else:
        def write(s, **kw):
            fp.write(s)

    if stat:
        diffopts = diffopts.copy(context=0)
        width = 80
        if not ui.plain():
            width = ui.termwidth()
        chunks = patch.diff(repo, node1, node2, match, changes, diffopts,
                            prefix=prefix)
        for chunk, label in patch.diffstatui(util.iterlines(chunks),
                                             width=width,
                                             git=diffopts.git):
            write(chunk, label=label)
    else:
        for chunk, label in patch.diffui(repo, node1, node2, match,
                                         changes, diffopts, prefix=prefix):
            write(chunk, label=label)

    if listsubrepos:
        ctx1 = repo[node1]
        ctx2 = repo[node2]
        for subpath, sub in scmutil.itersubrepos(ctx1, ctx2):
            tempnode2 = node2
            try:
                if node2 is not None:
                    tempnode2 = ctx2.substate[subpath][1]
            except KeyError:
                # A subrepo that existed in node1 was deleted between node1 and
                # node2 (inclusive). Thus, ctx2's substate won't contain that
                # subpath. The best we can do is to ignore it.
                tempnode2 = None
            submatch = matchmod.narrowmatcher(subpath, match)
            sub.diff(ui, diffopts, tempnode2, submatch, changes=changes,
                     stat=stat, fp=fp, prefix=prefix)

class changeset_printer(object):
    '''show changeset information when templating not requested.'''

    def __init__(self, ui, repo, patch, diffopts, buffered):
        self.ui = ui
        self.repo = repo
        self.buffered = buffered
        self.patch = patch
        self.diffopts = diffopts
        self.header = {}
        self.hunk = {}
        self.lastheader = None
        self.footer = None

    def flush(self, rev):
        if rev in self.header:
            h = self.header[rev]
            if h != self.lastheader:
                self.lastheader = h
                self.ui.write(h)
            del self.header[rev]
        if rev in self.hunk:
            self.ui.write(self.hunk[rev])
            del self.hunk[rev]
            return 1
        return 0

    def close(self):
        if self.footer:
            self.ui.write(self.footer)

    def show(self, ctx, copies=None, matchfn=None, **props):
        if self.buffered:
            self.ui.pushbuffer()
            self._show(ctx, copies, matchfn, props)
            self.hunk[ctx.rev()] = self.ui.popbuffer(labeled=True)
        else:
            self._show(ctx, copies, matchfn, props)

    def _show(self, ctx, copies, matchfn, props):
        '''show a single changeset or file revision'''
        changenode = ctx.node()
        rev = ctx.rev()

        if self.ui.quiet:
            self.ui.write("%d:%s\n" % (rev, short(changenode)),
                          label='log.node')
            return

        log = self.repo.changelog
        date = util.datestr(ctx.date())

        hexfunc = self.ui.debugflag and hex or short

        parents = [(p, hexfunc(log.node(p)))
                   for p in self._meaningful_parentrevs(log, rev)]

        # i18n: column positioning for "hg log"
        self.ui.write(_("changeset:   %d:%s\n") % (rev, hexfunc(changenode)),
                      label='log.changeset changeset.%s' % ctx.phasestr())

        branch = ctx.branch()
        # don't show the default branch name
        if branch != 'default':
            # i18n: column positioning for "hg log"
            self.ui.write(_("branch:      %s\n") % branch,
                          label='log.branch')
        for bookmark in self.repo.nodebookmarks(changenode):
            # i18n: column positioning for "hg log"
            self.ui.write(_("bookmark:    %s\n") % bookmark,
                    label='log.bookmark')
        for tag in self.repo.nodetags(changenode):
            # i18n: column positioning for "hg log"
            self.ui.write(_("tag:         %s\n") % tag,
                          label='log.tag')
        if self.ui.debugflag and ctx.phase():
            # i18n: column positioning for "hg log"
            self.ui.write(_("phase:       %s\n") % _(ctx.phasestr()),
                          label='log.phase')
        for parent in parents:
            # i18n: column positioning for "hg log"
            self.ui.write(_("parent:      %d:%s\n") % parent,
                          label='log.parent changeset.%s' % ctx.phasestr())

        if self.ui.debugflag:
            mnode = ctx.manifestnode()
            # i18n: column positioning for "hg log"
            self.ui.write(_("manifest:    %d:%s\n") %
                          (self.repo.manifest.rev(mnode), hex(mnode)),
                          label='ui.debug log.manifest')
        # i18n: column positioning for "hg log"
        self.ui.write(_("user:        %s\n") % ctx.user(),
                      label='log.user')
        # i18n: column positioning for "hg log"
        self.ui.write(_("date:        %s\n") % date,
                      label='log.date')

        if self.ui.debugflag:
            files = self.repo.status(log.parents(changenode)[0], changenode)[:3]
            for key, value in zip([# i18n: column positioning for "hg log"
                                   _("files:"),
                                   # i18n: column positioning for "hg log"
                                   _("files+:"),
                                   # i18n: column positioning for "hg log"
                                   _("files-:")], files):
                if value:
                    self.ui.write("%-12s %s\n" % (key, " ".join(value)),
                                  label='ui.debug log.files')
        elif ctx.files() and self.ui.verbose:
            # i18n: column positioning for "hg log"
            self.ui.write(_("files:       %s\n") % " ".join(ctx.files()),
                          label='ui.note log.files')
        if copies and self.ui.verbose:
            copies = ['%s (%s)' % c for c in copies]
            # i18n: column positioning for "hg log"
            self.ui.write(_("copies:      %s\n") % ' '.join(copies),
                          label='ui.note log.copies')

        extra = ctx.extra()
        if extra and self.ui.debugflag:
            for key, value in sorted(extra.items()):
                # i18n: column positioning for "hg log"
                self.ui.write(_("extra:       %s=%s\n")
                              % (key, value.encode('string_escape')),
                              label='ui.debug log.extra')

        description = ctx.description().strip()
        if description:
            if self.ui.verbose:
                self.ui.write(_("description:\n"),
                              label='ui.note log.description')
                self.ui.write(description,
                              label='ui.note log.description')
                self.ui.write("\n\n")
            else:
                # i18n: column positioning for "hg log"
                self.ui.write(_("summary:     %s\n") %
                              description.splitlines()[0],
                              label='log.summary')
        self.ui.write("\n")

        self.showpatch(changenode, matchfn)

    def showpatch(self, node, matchfn):
        if not matchfn:
            matchfn = self.patch
        if matchfn:
            stat = self.diffopts.get('stat')
            diff = self.diffopts.get('patch')
            diffopts = patch.diffopts(self.ui, self.diffopts)
            prev = self.repo.changelog.parents(node)[0]
            if stat:
                diffordiffstat(self.ui, self.repo, diffopts, prev, node,
                               match=matchfn, stat=True)
            if diff:
                if stat:
                    self.ui.write("\n")
                diffordiffstat(self.ui, self.repo, diffopts, prev, node,
                               match=matchfn, stat=False)
            self.ui.write("\n")

    def _meaningful_parentrevs(self, log, rev):
        """Return list of meaningful (or all if debug) parentrevs for rev.

        For merges (two non-nullrev revisions) both parents are meaningful.
        Otherwise the first parent revision is considered meaningful if it
        is not the preceding revision.
        """
        parents = log.parentrevs(rev)
        if not self.ui.debugflag and parents[1] == nullrev:
            if parents[0] >= rev - 1:
                parents = []
            else:
                parents = [parents[0]]
        return parents


class changeset_templater(changeset_printer):
    '''format changeset information.'''

    def __init__(self, ui, repo, patch, diffopts, tmpl, mapfile, buffered):
        changeset_printer.__init__(self, ui, repo, patch, diffopts, buffered)
        formatnode = ui.debugflag and (lambda x: x) or (lambda x: x[:12])
        defaulttempl = {
            'parent': '{rev}:{node|formatnode} ',
            'manifest': '{rev}:{node|formatnode}',
            'file_copy': '{name} ({source})',
            'extra': '{key}={value|stringescape}'
            }
        # filecopy is preserved for compatibility reasons
        defaulttempl['filecopy'] = defaulttempl['file_copy']
        self.t = templater.templater(mapfile, {'formatnode': formatnode},
                                     cache=defaulttempl)
        if tmpl:
            self.t.cache['changeset'] = tmpl

        self.cache = {}

    def _meaningful_parentrevs(self, ctx):
        """Return list of meaningful (or all if debug) parentrevs for rev.
        """
        parents = ctx.parents()
        if len(parents) > 1:
            return parents
        if self.ui.debugflag:
            return [parents[0], self.repo['null']]
        if parents[0].rev() >= ctx.rev() - 1:
            return []
        return parents

    def _show(self, ctx, copies, matchfn, props):
        '''show a single changeset or file revision'''

        showlist = templatekw.showlist

        # showparents() behaviour depends on ui trace level which
        # causes unexpected behaviours at templating level and makes
        # it harder to extract it in a standalone function. Its
        # behaviour cannot be changed so leave it here for now.
        def showparents(**args):
            ctx = args['ctx']
            parents = [[('rev', p.rev()), ('node', p.hex())]
                       for p in self._meaningful_parentrevs(ctx)]
            return showlist('parent', parents, **args)

        props = props.copy()
        props.update(templatekw.keywords)
        props['parents'] = showparents
        props['templ'] = self.t
        props['ctx'] = ctx
        props['repo'] = self.repo
        props['revcache'] = {'copies': copies}
        props['cache'] = self.cache

        # find correct templates for current mode

        tmplmodes = [
            (True, None),
            (self.ui.verbose, 'verbose'),
            (self.ui.quiet, 'quiet'),
            (self.ui.debugflag, 'debug'),
        ]

        types = {'header': '', 'footer':'', 'changeset': 'changeset'}
        for mode, postfix  in tmplmodes:
            for type in types:
                cur = postfix and ('%s_%s' % (type, postfix)) or type
                if mode and cur in self.t:
                    types[type] = cur

        try:

            # write header
            if types['header']:
                h = templater.stringify(self.t(types['header'], **props))
                if self.buffered:
                    self.header[ctx.rev()] = h
                else:
                    if self.lastheader != h:
                        self.lastheader = h
                        self.ui.write(h)

            # write changeset metadata, then patch if requested
            key = types['changeset']
            self.ui.write(templater.stringify(self.t(key, **props)))
            self.showpatch(ctx.node(), matchfn)

            if types['footer']:
                if not self.footer:
                    self.footer = templater.stringify(self.t(types['footer'],
                                                      **props))

        except KeyError, inst:
            msg = _("%s: no key named '%s'")
            raise util.Abort(msg % (self.t.mapfile, inst.args[0]))
        except SyntaxError, inst:
            raise util.Abort('%s: %s' % (self.t.mapfile, inst.args[0]))

def gettemplate(ui, tmpl, style):
    """
    Find the template matching the given template spec or style.
    """

    # ui settings
    if not tmpl and not style:
        tmpl = ui.config('ui', 'logtemplate')
        if tmpl:
            try:
                tmpl = templater.parsestring(tmpl)
            except SyntaxError:
                tmpl = templater.parsestring(tmpl, quoted=False)
            return tmpl, None
        else:
            style = util.expandpath(ui.config('ui', 'style', ''))

    if style:
        mapfile = style
        if not os.path.split(mapfile)[0]:
            mapname = (templater.templatepath('map-cmdline.' + mapfile)
                       or templater.templatepath(mapfile))
            if mapname:
                mapfile = mapname
        return None, mapfile

    if not tmpl:
        return None, None

    # looks like a literal template?
    if '{' in tmpl:
        return tmpl, None

    # perhaps a stock style?
    if not os.path.split(tmpl)[0]:
        mapname = (templater.templatepath('map-cmdline.' + tmpl)
                   or templater.templatepath(tmpl))
        if mapname and os.path.isfile(mapname):
            return None, mapname

    # perhaps it's a reference to [templates]
    t = ui.config('templates', tmpl)
    if t:
        try:
            tmpl = templater.parsestring(t)
        except SyntaxError:
            tmpl = templater.parsestring(t, quoted=False)
        return tmpl, None

    # perhaps it's a path to a map or a template
    if ('/' in tmpl or '\\' in tmpl) and os.path.isfile(tmpl):
        # is it a mapfile for a style?
        if os.path.basename(tmpl).startswith("map-"):
            return None, os.path.realpath(tmpl)
        tmpl = open(tmpl).read()
        return tmpl, None

    # constant string?
    return tmpl, None

def show_changeset(ui, repo, opts, buffered=False):
    """show one changeset using template or regular display.

    Display format will be the first non-empty hit of:
    1. option 'template'
    2. option 'style'
    3. [ui] setting 'logtemplate'
    4. [ui] setting 'style'
    If all of these values are either the unset or the empty string,
    regular display via changeset_printer() is done.
    """
    # options
    patch = None
    if opts.get('patch') or opts.get('stat'):
        patch = scmutil.matchall(repo)

    tmpl, mapfile = gettemplate(ui, opts.get('template'), opts.get('style'))

    if not tmpl and not mapfile:
        return changeset_printer(ui, repo, patch, opts, buffered)

    try:
        t = changeset_templater(ui, repo, patch, opts, tmpl, mapfile, buffered)
    except SyntaxError, inst:
        raise util.Abort(inst.args[0])
    return t

def showmarker(ui, marker):
    """utility function to display obsolescence marker in a readable way

    To be used by debug function."""
    ui.write(hex(marker.precnode()))
    for repl in marker.succnodes():
        ui.write(' ')
        ui.write(hex(repl))
    ui.write(' %X ' % marker._data[2])
    ui.write('{%s}' % (', '.join('%r: %r' % t for t in
                                 sorted(marker.metadata().items()))))
    ui.write('\n')

def finddate(ui, repo, date):
    """Find the tipmost changeset that matches the given date spec"""

    df = util.matchdate(date)
    m = scmutil.matchall(repo)
    results = {}

    def prep(ctx, fns):
        d = ctx.date()
        if df(d[0]):
            results[ctx.rev()] = d

    for ctx in walkchangerevs(repo, m, {'rev': None}, prep):
        rev = ctx.rev()
        if rev in results:
            ui.status(_("found revision %s from %s\n") %
                      (rev, util.datestr(results[rev])))
            return str(rev)

    raise util.Abort(_("revision matching date not found"))

def increasingwindows(windowsize=8, sizelimit=512):
    while True:
        yield windowsize
        if windowsize < sizelimit:
            windowsize *= 2

class FileWalkError(Exception):
    pass

def walkfilerevs(repo, match, follow, revs, fncache):
    '''Walks the file history for the matched files.

    Returns the changeset revs that are involved in the file history.

    Throws FileWalkError if the file history can't be walked using
    filelogs alone.
    '''
    wanted = set()
    copies = []
    minrev, maxrev = min(revs), max(revs)
    def filerevgen(filelog, last):
        """
        Only files, no patterns.  Check the history of each file.

        Examines filelog entries within minrev, maxrev linkrev range
        Returns an iterator yielding (linkrev, parentlinkrevs, copied)
        tuples in backwards order
        """
        cl_count = len(repo)
        revs = []
        for j in xrange(0, last + 1):
            linkrev = filelog.linkrev(j)
            if linkrev < minrev:
                continue
            # only yield rev for which we have the changelog, it can
            # happen while doing "hg log" during a pull or commit
            if linkrev >= cl_count:
                break

            parentlinkrevs = []
            for p in filelog.parentrevs(j):
                if p != nullrev:
                    parentlinkrevs.append(filelog.linkrev(p))
            n = filelog.node(j)
            revs.append((linkrev, parentlinkrevs,
                         follow and filelog.renamed(n)))

        return reversed(revs)
    def iterfiles():
        pctx = repo['.']
        for filename in match.files():
            if follow:
                if filename not in pctx:
                    raise util.Abort(_('cannot follow file not in parent '
                                       'revision: "%s"') % filename)
                yield filename, pctx[filename].filenode()
            else:
                yield filename, None
        for filename_node in copies:
            yield filename_node

    for file_, node in iterfiles():
        filelog = repo.file(file_)
        if not len(filelog):
            if node is None:
                # A zero count may be a directory or deleted file, so
                # try to find matching entries on the slow path.
                if follow:
                    raise util.Abort(
                        _('cannot follow nonexistent file: "%s"') % file_)
                raise FileWalkError("Cannot walk via filelog")
            else:
                continue

        if node is None:
            last = len(filelog) - 1
        else:
            last = filelog.rev(node)


        # keep track of all ancestors of the file
        ancestors = set([filelog.linkrev(last)])

        # iterate from latest to oldest revision
        for rev, flparentlinkrevs, copied in filerevgen(filelog, last):
            if not follow:
                if rev > maxrev:
                    continue
            else:
                # Note that last might not be the first interesting
                # rev to us:
                # if the file has been changed after maxrev, we'll
                # have linkrev(last) > maxrev, and we still need
                # to explore the file graph
                if rev not in ancestors:
                    continue
                # XXX insert 1327 fix here
                if flparentlinkrevs:
                    ancestors.update(flparentlinkrevs)

            fncache.setdefault(rev, []).append(file_)
            wanted.add(rev)
            if copied:
                copies.append(copied)

    return wanted

def walkchangerevs(repo, match, opts, prepare):
    '''Iterate over files and the revs in which they changed.

    Callers most commonly need to iterate backwards over the history
    in which they are interested. Doing so has awful (quadratic-looking)
    performance, so we use iterators in a "windowed" way.

    We walk a window of revisions in the desired order.  Within the
    window, we first walk forwards to gather data, then in the desired
    order (usually backwards) to display it.

    This function returns an iterator yielding contexts. Before
    yielding each context, the iterator will first call the prepare
    function on each context in the window in forward order.'''

    follow = opts.get('follow') or opts.get('follow_first')

    if opts.get('rev'):
        revs = scmutil.revrange(repo, opts.get('rev'))
    elif follow:
        revs = repo.revs('reverse(:.)')
    else:
        revs = revset.spanset(repo)
        revs.reverse()
    if not revs:
        return []
    wanted = set()
    slowpath = match.anypats() or (match.files() and opts.get('removed'))
    fncache = {}
    change = repo.changectx

    # First step is to fill wanted, the set of revisions that we want to yield.
    # When it does not induce extra cost, we also fill fncache for revisions in
    # wanted: a cache of filenames that were changed (ctx.files()) and that
    # match the file filtering conditions.

    if not slowpath and not match.files():
        # No files, no patterns.  Display all revs.
        wanted = revs

    if not slowpath and match.files():
        # We only have to read through the filelog to find wanted revisions

        try:
            wanted = walkfilerevs(repo, match, follow, revs, fncache)
        except FileWalkError:
            slowpath = True

            # We decided to fall back to the slowpath because at least one
            # of the paths was not a file. Check to see if at least one of them
            # existed in history, otherwise simply return
            for path in match.files():
                if path == '.' or path in repo.store:
                    break
            else:
                return []

    if slowpath:
        # We have to read the changelog to match filenames against
        # changed files

        if follow:
            raise util.Abort(_('can only follow copies/renames for explicit '
                               'filenames'))

        # The slow path checks files modified in every changeset.
        # This is really slow on large repos, so compute the set lazily.
        class lazywantedset(object):
            def __init__(self):
                self.set = set()
                self.revs = set(revs)

            # No need to worry about locality here because it will be accessed
            # in the same order as the increasing window below.
            def __contains__(self, value):
                if value in self.set:
                    return True
                elif not value in self.revs:
                    return False
                else:
                    self.revs.discard(value)
                    ctx = change(value)
                    matches = filter(match, ctx.files())
                    if matches:
                        fncache[value] = matches
                        self.set.add(value)
                        return True…