perf: add two more missing b prefixes for Python 3
# skip-blame just two more b prefixes
Differential Revision: https://phab.mercurial-scm.org/D5425
# ancestor.py - generic DAG ancestor algorithm for mercurial
#
# Copyright 2006 Matt Mackall <mpm@selenic.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 __future__ import absolute_import
import heapq
from .node import nullrev
from . import (
policy,
pycompat,
)
parsers = policy.importmod(r'parsers')
def commonancestorsheads(pfunc, *nodes):
"""Returns a set with the heads of all common ancestors of all nodes,
heads(::nodes[0] and ::nodes[1] and ...) .
pfunc must return a list of parent vertices for a given vertex.
"""
if not isinstance(nodes, set):
nodes = set(nodes)
if nullrev in nodes:
return set()
if len(nodes) <= 1:
return nodes
allseen = (1 << len(nodes)) - 1
seen = [0] * (max(nodes) + 1)
for i, n in enumerate(nodes):
seen[n] = 1 << i
poison = 1 << (i + 1)
gca = set()
interesting = len(nodes)
nv = len(seen) - 1
while nv >= 0 and interesting:
v = nv
nv -= 1
if not seen[v]:
continue
sv = seen[v]
if sv < poison:
interesting -= 1
if sv == allseen:
gca.add(v)
sv |= poison
if v in nodes:
# history is linear
return {v}
if sv < poison:
for p in pfunc(v):
sp = seen[p]
if p == nullrev:
continue
if sp == 0:
seen[p] = sv
interesting += 1
elif sp != sv:
seen[p] |= sv
else:
for p in pfunc(v):
if p == nullrev:
continue
sp = seen[p]
if sp and sp < poison:
interesting -= 1
seen[p] = sv
return gca
def ancestors(pfunc, *orignodes):
"""
Returns the common ancestors of a and b that are furthest from a
root (as measured by longest path).
pfunc must return a list of parent vertices for a given vertex.
"""
def deepest(nodes):
interesting = {}
count = max(nodes) + 1
depth = [0] * count
seen = [0] * count
mapping = []
for (i, n) in enumerate(sorted(nodes)):
depth[n] = 1
b = 1 << i
seen[n] = b
interesting[b] = 1
mapping.append((b, n))
nv = count - 1
while nv >= 0 and len(interesting) > 1:
v = nv
nv -= 1
dv = depth[v]
if dv == 0:
continue
sv = seen[v]
for p in pfunc(v):
if p == nullrev:
continue
dp = depth[p]
nsp = sp = seen[p]
if dp <= dv:
depth[p] = dv + 1
if sp != sv:
interesting[sv] += 1
nsp = seen[p] = sv
if sp:
interesting[sp] -= 1
if interesting[sp] == 0:
del interesting[sp]
elif dv == dp - 1:
nsp = sp | sv
if nsp == sp:
continue
seen[p] = nsp
interesting.setdefault(nsp, 0)
interesting[nsp] += 1
interesting[sp] -= 1
if interesting[sp] == 0:
del interesting[sp]
interesting[sv] -= 1
if interesting[sv] == 0:
del interesting[sv]
if len(interesting) != 1:
return []
k = 0
for i in interesting:
k |= i
return set(n for (i, n) in mapping if k & i)
gca = commonancestorsheads(pfunc, *orignodes)
if len(gca) <= 1:
return gca
return deepest(gca)
class incrementalmissingancestors(object):
'''persistent state used to calculate missing ancestors incrementally
Although similar in spirit to lazyancestors below, this is a separate class
because trying to support contains and missingancestors operations with the
same internal data structures adds needless complexity.'''
def __init__(self, pfunc, bases):
self.bases = set(bases)
if not self.bases:
self.bases.add(nullrev)
self.pfunc = pfunc
def hasbases(self):
'''whether the common set has any non-trivial bases'''
return self.bases and self.bases != {nullrev}
def addbases(self, newbases):
'''grow the ancestor set by adding new bases'''
self.bases.update(newbases)
def removeancestorsfrom(self, revs):
'''remove all ancestors of bases from the set revs (in place)'''
bases = self.bases
pfunc = self.pfunc
revs.difference_update(bases)
# nullrev is always an ancestor
revs.discard(nullrev)
if not revs:
return
# anything in revs > start is definitely not an ancestor of bases
# revs <= start needs to be investigated
start = max(bases)
keepcount = sum(1 for r in revs if r > start)
if len(revs) == keepcount:
# no revs to consider
return
for curr in pycompat.xrange(start, min(revs) - 1, -1):
if curr not in bases:
continue
revs.discard(curr)
bases.update(pfunc(curr))
if len(revs) == keepcount:
# no more potential revs to discard
break
def missingancestors(self, revs):
'''return all the ancestors of revs that are not ancestors of self.bases
This may include elements from revs.
Equivalent to the revset (::revs - ::self.bases). Revs are returned in
revision number order, which is a topological order.'''
revsvisit = set(revs)
basesvisit = self.bases
pfunc = self.pfunc
bothvisit = revsvisit.intersection(basesvisit)
revsvisit.difference_update(bothvisit)
if not revsvisit:
return []
start = max(max(revsvisit), max(basesvisit))
# At this point, we hold the invariants that:
# - revsvisit is the set of nodes we know are an ancestor of at least
# one of the nodes in revs
# - basesvisit is the same for bases
# - bothvisit is the set of nodes we know are ancestors of at least one
# of the nodes in revs and one of the nodes in bases. bothvisit and
# revsvisit are mutually exclusive, but bothvisit is a subset of
# basesvisit.
# Now we walk down in reverse topo order, adding parents of nodes
# already visited to the sets while maintaining the invariants. When a
# node is found in both revsvisit and basesvisit, it is removed from
# revsvisit and added to bothvisit. When revsvisit becomes empty, there
# are no more ancestors of revs that aren't also ancestors of bases, so
# exit.
missing = []
for curr in pycompat.xrange(start, nullrev, -1):
if not revsvisit:
break
if curr in bothvisit:
bothvisit.remove(curr)
# curr's parents might have made it into revsvisit through
# another path
for p in pfunc(curr):
revsvisit.discard(p)
basesvisit.add(p)
bothvisit.add(p)
continue
if curr in revsvisit:
missing.append(curr)
revsvisit.remove(curr)
thisvisit = revsvisit
othervisit = basesvisit
elif curr in basesvisit:
thisvisit = basesvisit
othervisit = revsvisit
else:
# not an ancestor of revs or bases: ignore
continue
for p in pfunc(curr):
if p == nullrev:
pass
elif p in othervisit or p in bothvisit:
# p is implicitly in thisvisit. This means p is or should be
# in bothvisit
revsvisit.discard(p)
basesvisit.add(p)
bothvisit.add(p)
else:
# visit later
thisvisit.add(p)
missing.reverse()
return missing
# Extracted from lazyancestors.__iter__ to avoid a reference cycle
def _lazyancestorsiter(parentrevs, initrevs, stoprev, inclusive):
seen = {nullrev}
heappush = heapq.heappush
heappop = heapq.heappop
heapreplace = heapq.heapreplace
see = seen.add
if inclusive:
visit = [-r for r in initrevs]
seen.update(initrevs)
heapq.heapify(visit)
else:
visit = []
heapq.heapify(visit)
for r in initrevs:
p1, p2 = parentrevs(r)
if p1 not in seen:
heappush(visit, -p1)
see(p1)
if p2 not in seen:
heappush(visit, -p2)
see(p2)
while visit:
current = -visit[0]
if current < stoprev:
break
yield current
# optimize out heapq operation if p1 is known to be the next highest
# revision, which is quite common in linear history.
p1, p2 = parentrevs(current)
if p1 not in seen:
if current - p1 == 1:
visit[0] = -p1
else:
heapreplace(visit, -p1)
see(p1)
else:
heappop(visit)
if p2 not in seen:
heappush(visit, -p2)
see(p2)
class lazyancestors(object):
def __init__(self, pfunc, revs, stoprev=0, inclusive=False):
"""Create a new object generating ancestors for the given revs. Does
not generate revs lower than stoprev.
This is computed lazily starting from revs. The object supports
iteration and membership.
cl should be a changelog and revs should be an iterable. inclusive is
a boolean that indicates whether revs should be included. Revs lower
than stoprev will not be generated.
Result does not include the null revision."""
self._parentrevs = pfunc
self._initrevs = revs = [r for r in revs if r >= stoprev]
self._stoprev = stoprev
self._inclusive = inclusive
self._containsseen = set()
self._containsiter = _lazyancestorsiter(self._parentrevs,
self._initrevs,
self._stoprev,
self._inclusive)
def __nonzero__(self):
"""False if the set is empty, True otherwise."""
try:
next(iter(self))
return True
except StopIteration:
return False
__bool__ = __nonzero__
def __iter__(self):
"""Generate the ancestors of _initrevs in reverse topological order.
If inclusive is False, yield a sequence of revision numbers starting
with the parents of each revision in revs, i.e., each revision is
*not* considered an ancestor of itself. Results are emitted in reverse
revision number order. That order is also topological: a child is
always emitted before its parent.
If inclusive is True, the source revisions are also yielded. The
reverse revision number order is still enforced."""
return _lazyancestorsiter(self._parentrevs, self._initrevs,
self._stoprev, self._inclusive)
def __contains__(self, target):
"""Test whether target is an ancestor of self._initrevs."""
seen = self._containsseen
if target in seen:
return True
iter = self._containsiter
if iter is None:
# Iterator exhausted
return False
# Only integer target is valid, but some callers expect 'None in self'
# to be False. So we explicitly allow it.
if target is None:
return False
see = seen.add
try:
while True:
rev = next(iter)
see(rev)
if rev == target:
return True
if rev < target:
return False
except StopIteration:
# Set to None to indicate fast-path can be used next time, and to
# free up memory.
self._containsiter = None
return False
class rustlazyancestors(object):
def __init__(self, index, revs, stoprev=0, inclusive=False):
self._index = index
self._stoprev = stoprev
self._inclusive = inclusive
# no need to prefilter out init revs that are smaller than stoprev,
# it's done by rustlazyancestors constructor.
# we need to convert to a list, because our ruslazyancestors
# constructor (from C code) doesn't understand anything else yet
self._initrevs = initrevs = list(revs)
self._containsiter = parsers.rustlazyancestors(
index, initrevs, stoprev, inclusive)
def __nonzero__(self):
"""False if the set is empty, True otherwise.
It's better to duplicate this essentially trivial method than
to subclass lazyancestors
"""
try:
next(iter(self))
return True
except StopIteration:
return False
def __iter__(self):
return parsers.rustlazyancestors(self._index,
self._initrevs,
self._stoprev,
self._inclusive)
def __contains__(self, target):
return target in self._containsiter