# Mercurial phases support code
#
# Copyright 2011 Pierre-Yves David <pierre-yves.david@ens-lyon.org>
#                Logilab SA        <contact@logilab.fr>
#                Augie Fackler     <durin42@gmail.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 nullid, bin, hex

allphases = range(2)
trackedphases = allphases[1:]

def readroots(repo):
    """Read phase roots from disk"""
    roots = [set() for i in allphases]
    roots[0].add(nullid)
    try:
        f = repo.sopener('phaseroots')
        try:
            for line in f:
                phase, nh = line.strip().split()
                roots[int(phase)].add(bin(nh))
        finally:
            f.close()
    except IOError:
        pass # default value are enough
    return roots

def writeroots(repo):
    """Write phase roots from disk"""
    f = repo.sopener('phaseroots', 'w', atomictemp=True)
    try:
        for phase, roots in enumerate(repo._phaseroots):
            for h in roots:
                f.write('%i %s\n' % (phase, hex(h)))
    finally:
        f.close()