view mercurial/filemerge.py @ 6144:08e0825b8106

revlog.revision: avoid opening the datafile without need.

If there's no inline data, revlog.revision opens the data file every
time it's called.  This is useful if we're going to call chunk many
times, but, if we're going to call it only once, it's better to let
chunk open the file - if we're lucky, all the data we're going to need
is already cached and we won't need to even look at the file.

# filemerge.py - file-level merge handling for Mercurial
#
# Copyright 2006, 2007, 2008 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

from node import *
from i18n import _
import util, os, tempfile, context, simplemerge, re, filecmp

def _toolstr(ui, tool, part, default=""):
    return ui.config("merge-tools", tool + "." + part, default)

def _toolbool(ui, tool, part, default=False):
    return ui.configbool("merge-tools", tool + "." + part, default)

def _findtool(ui, tool):
    k = _toolstr(ui, tool, "regkey")
    if k:
        p = util.lookup_reg(k, _toolstr(ui, tool, "regname"))
        if p:
            p = util.find_exe(p + _toolstr(ui, tool, "regappend"))
            if p:
                return p
    return util.find_exe(_toolstr(ui, tool, "executable", tool))

def _picktool(repo, ui, path, binary, symlink):
    def check(tool, pat, symlink, binary):
        tmsg = tool
        if pat:
            tmsg += " specified for " + pat
        if pat and not _findtool(ui, tool): # skip search if not matching
            ui.warn(_("couldn't find merge tool %s\n") % tmsg)
        elif symlink and not _toolbool(ui, tool, "symlink"):
            ui.warn(_("tool %s can't handle symlinks\n") % tmsg)
        elif binary and not _toolbool(ui, tool, "binary"):
            ui.warn(_("tool %s can't handle binary\n") % tmsg)
        elif not util.gui() and _toolbool(ui, tool, "gui"):
            ui.warn(_("tool %s requires a GUI\n") % tmsg)
        else:
            return True
        return False

    # HGMERGE takes precedence
    hgmerge = os.environ.get("HGMERGE")
    if hgmerge:
        return (hgmerge, hgmerge)

    # then patterns
    for pat, tool in ui.configitems("merge-patterns"):
        mf = util.matcher(repo.root, "", [pat], [], [])[1]
        if mf(path) and check(tool, pat, symlink, False):
                toolpath = _findtool(ui, tool)
                return (tool, '"' + toolpath + '"')

    # then merge tools
    tools = {}
    for k,v in ui.configitems("merge-tools"):
        t = k.split('.')[0]
        if t not in tools:
            tools[t] = int(_toolstr(ui, t, "priority", "0"))
    names = tools.keys()
    tools = [(-p,t) for t,p in tools.items()]
    tools.sort()
    uimerge = ui.config("ui", "merge")
    if uimerge:
        if uimerge not in names:
            return (uimerge, uimerge)
        tools.insert(0, (None, uimerge)) # highest priority
    tools.append((None, "hgmerge")) # the old default, if found
    for p,t in tools:
        toolpath = _findtool(ui, t)
        if toolpath and check(t, None, symlink, binary):
            return (t, '"' + toolpath + '"')
    # internal merge as last resort
    return (not (symlink or binary) and "internal:merge" or None, None)

def _eoltype(data):
    "Guess the EOL type of a file"
    if '\0' in data: # binary
        return None
    if '\r\n' in data: # Windows
        return '\r\n'
    if '\r' in data: # Old Mac
        return '\r'
    if '\n' in data: # UNIX
        return '\n'
    return None # unknown

def _matcheol(file, origfile):
    "Convert EOL markers in a file to match origfile"
    tostyle = _eoltype(open(origfile, "rb").read())
    if tostyle:
        data = open(file, "rb").read()
        style = _eoltype(data)
        if style:
            newdata = data.replace(style, tostyle)
            if newdata != data:
                open(file, "wb").write(newdata)

def filemerge(repo, fw, fd, fo, wctx, mctx):
    """perform a 3-way merge in the working directory

    fw = original filename in the working directory
    fd = destination filename in the working directory
    fo = filename in other parent
    wctx, mctx = working and merge changecontexts
    """

    def temp(prefix, ctx):
        pre = "%s~%s." % (os.path.basename(ctx.path()), prefix)
        (fd, name) = tempfile.mkstemp(prefix=pre)
        data = repo.wwritedata(ctx.path(), ctx.data())
        f = os.fdopen(fd, "wb")
        f.write(data)
        f.close()
        return name

    def isbin(ctx):
        try:
            return util.binary(ctx.data())
        except IOError:
            return False

    fco = mctx.filectx(fo)
    if not fco.cmp(wctx.filectx(fd).data()): # files identical?
        return None

    ui = repo.ui
    fcm = wctx.filectx(fw)
    fca = fcm.ancestor(fco) or repo.filectx(fw, fileid=nullrev)
    binary = isbin(fcm) or isbin(fco) or isbin(fca)
    symlink = fcm.islink() or fco.islink()
    tool, toolpath = _picktool(repo, ui, fw, binary, symlink)
    ui.debug(_("picked tool '%s' for %s (binary %s symlink %s)\n") %
               (tool, fw, binary, symlink))

    if not tool:
        tool = "internal:local"
        if ui.prompt(_(" no tool found to merge %s\n"
                       "keep (l)ocal or take (o)ther?") % fw,
                     _("[lo]"), _("l")) != _("l"):
            tool = "internal:other"
    if tool == "internal:local":
        return 0
    if tool == "internal:other":
        repo.wwrite(fd, fco.data(), fco.fileflags())
        return 0
    if tool == "internal:fail":
        return 1

    # do the actual merge
    a = repo.wjoin(fd)
    b = temp("base", fca)
    c = temp("other", fco)
    out = ""
    back = a + ".orig"
    util.copyfile(a, back)

    if fw != fo:
        repo.ui.status(_("merging %s and %s\n") % (fw, fo))
    else:
        repo.ui.status(_("merging %s\n") % fw)
    repo.ui.debug(_("my %s other %s ancestor %s\n") % (fcm, fco, fca))

    # do we attempt to simplemerge first?
    if _toolbool(ui, tool, "premerge", not (binary or symlink)):
        r = simplemerge.simplemerge(a, b, c, quiet=True)
        if not r:
            ui.debug(_(" premerge successful\n"))
            os.unlink(back)
            os.unlink(b)
            os.unlink(c)
            return 0
        util.copyfile(back, a) # restore from backup and try again

    env = dict(HG_FILE=fd,
               HG_MY_NODE=str(wctx.parents()[0]),
               HG_OTHER_NODE=str(mctx),
               HG_MY_ISLINK=fcm.islink(),
               HG_OTHER_ISLINK=fco.islink(),
               HG_BASE_ISLINK=fca.islink())

    if tool == "internal:merge":
        r = simplemerge.simplemerge(a, b, c, label=['local', 'other'])
    else:
        args = _toolstr(ui, tool, "args", '$local $base $other')
        if "$output" in args:
            out, a = a, back # read input from backup, write to original
        replace = dict(local=a, base=b, other=c, output=out)
        args = re.sub("\$(local|base|other|output)",
                      lambda x: '"%s"' % replace[x.group()[1:]], args)
        r = util.system(toolpath + ' ' + args, cwd=repo.root, environ=env)

    if not r and _toolbool(ui, tool, "checkconflicts"):
        if re.match("^(<<<<<<< .*|=======|>>>>>>> .*)$", fcm.data()):
            r = 1

    if not r and _toolbool(ui, tool, "checkchanged"):
        if filecmp.cmp(repo.wjoin(fd), back):
            if ui.prompt(_(" output file %s appears unchanged\n"
                "was merge successful (yn)?") % fd,
                _("[yn]"), _("n")) != _("y"):
                r = 1

    if _toolbool(ui, tool, "fixeol"):
        _matcheol(repo.wjoin(fd), back)

    if r:
        repo.ui.warn(_("merging %s failed!\n") % fd)
    else:
        os.unlink(back)

    os.unlink(b)
    os.unlink(c)
    return r