view hgext/parentrevspec.py @ 13287:d0e0d3d43e14 stable

subrepo: compare svn subrepo state to last committed revision

A subversion project revisions are a subset of the repository revisions, you
can ask subversion to update a working directory from one revision to another
without changing anything. Unfortunately, Mercurial will think the
subrepository has changed and will commit it again. To avoid useless commits,
we compare the subrepository state to its actual "parent" revision. To ensure
ascending compatibility with existing subrepositories which might reference
fake revisions, we also keep comparing with the subrepo working directory
revision.

NOTE: not sure if this should go in stable or not.

# Mercurial extension to make it easy to refer to the parent of a revision
#
# Copyright (C) 2007 Alexis S. L. Carvalho <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''interpret suffixes to refer to ancestor revisions

This extension allows you to use git-style suffixes to refer to the
ancestors of a specific revision.

For example, if you can refer to a revision as "foo", then::

  foo^N = Nth parent of foo
  foo^0 = foo
  foo^1 = first parent of foo
  foo^2 = second parent of foo
  foo^  = foo^1

  foo~N = Nth first grandparent of foo
  foo~0 = foo
  foo~1 = foo^1 = foo^ = first parent of foo
  foo~2 = foo^1^1 = foo^^ = first parent of first parent of foo
'''
from mercurial import error

def reposetup(ui, repo):
    if not repo.local():
        return

    class parentrevspecrepo(repo.__class__):
        def lookup(self, key):
            try:
                _super = super(parentrevspecrepo, self)
                return _super.lookup(key)
            except error.RepoError:
                pass

            circ = key.find('^')
            tilde = key.find('~')
            if circ < 0 and tilde < 0:
                raise
            elif circ >= 0 and tilde >= 0:
                end = min(circ, tilde)
            else:
                end = max(circ, tilde)

            cl = self.changelog
            base = key[:end]
            try:
                node = _super.lookup(base)
            except error.RepoError:
                # eek - reraise the first error
                return _super.lookup(key)

            rev = cl.rev(node)
            suffix = key[end:]
            i = 0
            while i < len(suffix):
                # foo^N => Nth parent of foo
                # foo^0 == foo
                # foo^1 == foo^ == 1st parent of foo
                # foo^2 == 2nd parent of foo
                if suffix[i] == '^':
                    j = i + 1
                    p = cl.parentrevs(rev)
                    if j < len(suffix) and suffix[j].isdigit():
                        j += 1
                        n = int(suffix[i + 1:j])
                        if n > 2 or n == 2 and p[1] == -1:
                            raise
                    else:
                        n = 1
                    if n:
                        rev = p[n - 1]
                    i = j
                # foo~N => Nth first grandparent of foo
                # foo~0 = foo
                # foo~1 = foo^1 == foo^ == 1st parent of foo
                # foo~2 = foo^1^1 == foo^^ == 1st parent of 1st parent of foo
                elif suffix[i] == '~':
                    j = i + 1
                    while j < len(suffix) and suffix[j].isdigit():
                        j += 1
                    if j == i + 1:
                        raise
                    n = int(suffix[i + 1:j])
                    for k in xrange(n):
                        rev = cl.parentrevs(rev)[0]
                    i = j
                else:
                    raise
            return cl.node(rev)

    repo.__class__ = parentrevspecrepo