comparison mercurial/utils/repoviewutil.py @ 51487:1a9bdd0e1c44

branchcache: write branchmap in subset inheritance order

This way, we can guarantee a valid subset has been written before touching the
branchmap of another filter.

This is especially useful as we are bout to start deleting outdated branchmap
file.

51486:0ddc34330d41

#                Logilab SA        <[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.


### Nearest subset relation
# Nearest subset of filter X is a filter Y so that:
# * Y is included in X,
# * X - Y is as small as possible.

    b'visible': b'served',
    b'served.hidden': b'served',
    b'served': b'immutable',
    b'immutable': b'base',
}

51487:1a9bdd0e1c44

#                Logilab SA        <[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.

from .. import error

### Nearest subset relation
# Nearest subset of filter X is a filter Y so that:
# * Y is included in X,
# * X - Y is as small as possible.

    b'visible': b'served',
    b'served.hidden': b'served',
    b'served': b'immutable',
    b'immutable': b'base',
}


def get_ordered_subset():
    """return a list of subset name from dependencies to dependents"""
    _unfinalized = set(subsettable.values())
    ordered = []

    # the subset table is expected to be small so we do the stupid N² version
    # of the algorithm
    while _unfinalized:
        this_level = []
        for candidate in _unfinalized:
            dependency = subsettable.get(candidate)
            if dependency not in _unfinalized:
                this_level.append(candidate)

        if not this_level:
            msg = "cyclic dependencies in repoview subset %r"
            msg %= subsettable
            raise error.ProgrammingError(msg)

        this_level.sort(key=lambda x: x if x is not None else '')

        ordered.extend(this_level)
        _unfinalized.difference_update(this_level)

    return ordered