phases: add a function to compute heads from root

mercurial/phases.py

@@ -1,142 +1,169 b''
 # Mercurial phases support code
 #
 # Copyright 2011 Pierre-Yves David <[e-mail]>
 #                Logilab SA        <[e-mail]>
 #                Augie Fackler     <[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.
 
 import errno
 from node import nullid, bin, hex, short
 from i18n import _
 
 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, inst:
         if inst.errno != errno.ENOENT:
             raise
     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)))
         repo._dirtyphases = False
     finally:
         f.close()
 
 def filterunknown(repo, phaseroots=None):
     """remove unknown nodes from the phase boundary
 
     no data is lost as unknown node only old data for their descentants
     """
     if phaseroots is None:
         phaseroots = repo._phaseroots
     for phase, nodes in enumerate(phaseroots):
         missing = [node for node in nodes if node not in repo]
         if missing:
             for mnode in missing:
                 msg = _('Removing unknown node %(n)s from %(p)i-phase boundary')
                 repo.ui.debug(msg, {'n': short(mnode), 'p': phase})
             nodes.symmetric_difference_update(missing)
             repo._dirtyphases = True
 
 def advanceboundary(repo, targetphase, nodes):
     """Add nodes to a phase changing other nodes phases if necessary.
 
     This function move boundary *forward* this means that all nodes are set
     in the target phase or kept in a *lower* phase.
 
     Simplify boundary to contains phase roots only."""
     for phase in xrange(targetphase + 1, len(allphases)):
         # filter nodes that are not in a compatible phase already
         # XXX rev phase cache might have been invalidated by a previous loop
         # XXX we need to be smarter here
         nodes = [n for n in nodes if repo[n].phase() >= phase]
         if not nodes:
             break # no roots to move anymore
         roots = repo._phaseroots[phase]
         olds = roots.copy()
         ctxs = list(repo.set('roots((%ln::) - (%ln::%ln))', olds, olds, nodes))
         roots.clear()
         roots.update(ctx.node() for ctx in ctxs)
         if olds != roots:
             # invalidate cache (we probably could be smarter here
             if '_phaserev' in vars(repo):
                 del repo._phaserev
             repo._dirtyphases = True
 
 def retractboundary(repo, targetphase, nodes):
     """Set nodes back to a phase changing other nodes phases if necessary.
 
     This function move boundary *backward* this means that all nodes are set
     in the target phase or kept in a *higher* phase.
 
     Simplify boundary to contains phase roots only."""
     currentroots = repo._phaseroots[targetphase]
     newroots = [n for n in nodes if repo[n].phase() < targetphase]
     if newroots:
         currentroots.update(newroots)
         ctxs = repo.set('roots(%ln::)', currentroots)
         currentroots.intersection_update(ctx.node() for ctx in ctxs)
         if '_phaserev' in vars(repo):
             del repo._phaserev
         repo._dirtyphases = True
 
 
 def listphases(repo):
     """List phases root for serialisation over pushkey"""
     keys = {}
     for phase in trackedphases:
         for root in repo._phaseroots[phase]:
             keys[hex(root)] = '%i' % phase
     if repo.ui.configbool('phases', 'publish', True):
         # Add an extra data to let remote know we are a publishing repo.
         # Publishing repo can't just pretend they are old repo. When pushing to
         # a publishing repo, the client still need to push phase boundary
         #
         # Push do not only push changeset. It also push phase data. New
         # phase data may apply to common changeset which won't be push (as they
         # are common).  Here is a very simple example:
         #
         # 1) repo A push changeset X as draft to repo B
         # 2) repo B make changeset X public
         # 3) repo B push to repo A. X is not pushed but the data that X as now
         #    public should
         #
         # The server can't handle it on it's own as it has no idea of client
         # phase data.
         keys['publishing'] = 'True'
     return keys
 
 def pushphase(repo, nhex, oldphasestr, newphasestr):
     """List phases root for serialisation over pushkey"""
     lock = repo.lock()
     try:
         currentphase = repo[nhex].phase()
         newphase = abs(int(newphasestr)) # let's avoid negative index surprise
         oldphase = abs(int(oldphasestr)) # let's avoid negative index surprise
         if currentphase == oldphase and newphase < oldphase:
             advanceboundary(repo, newphase, [bin(nhex)])
             return 1
         else:
             return 0
     finally:
         lock.release()
+
+def analyzeremotephases(repo, subset, roots):
+    """Compute phases heads and root in a subset of node from root dict
+
+    * subset is heads of the subset
+    * roots is {<nodeid> => phase} mapping. key and value are string.
+
+    Accept unknown element input
+    """
+    # build list from dictionary
+    phaseroots = [[] for p in allphases]
+    for nhex, phase in roots.iteritems():
+        if nhex == 'publishing': # ignore data related to publish option
+            continue
+        node = bin(nhex)
+        phase = int(phase)
+        if node in repo:
+            phaseroots[phase].append(node)
+    # compute heads
+    phaseheads = [[] for p in allphases]
+    for phase in allphases[:-1]:
+        toproof = phaseroots[phase + 1]
+        revset = repo.set('heads((%ln + parents(%ln)) - (%ln::%ln))',
+                          subset, toproof, toproof, subset)
+        phaseheads[phase].extend(c.node() for c in revset)
+    return phaseheads, phaseroots
+