ref: 3a41ce3bf314caad67c2c52a06142f7ac60611c7
dir: /sys/src/cmd/hg/mercurial/copies.py/
# copies.py - copy detection for Mercurial
#
# Copyright 2008 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.
from i18n import _
import util
import heapq
def _nonoverlap(d1, d2, d3):
"Return list of elements in d1 not in d2 or d3"
return sorted([d for d in d1 if d not in d3 and d not in d2])
def _dirname(f):
s = f.rfind("/")
if s == -1:
return ""
return f[:s]
def _dirs(files):
d = set()
for f in files:
f = _dirname(f)
while f not in d:
d.add(f)
f = _dirname(f)
return d
def _findoldnames(fctx, limit):
"find files that path was copied from, back to linkrev limit"
old = {}
seen = set()
orig = fctx.path()
visit = [(fctx, 0)]
while visit:
fc, depth = visit.pop()
s = str(fc)
if s in seen:
continue
seen.add(s)
if fc.path() != orig and fc.path() not in old:
old[fc.path()] = (depth, fc.path()) # remember depth
if fc.rev() is not None and fc.rev() < limit:
continue
visit += [(p, depth - 1) for p in fc.parents()]
# return old names sorted by depth
return [o[1] for o in sorted(old.values())]
def _findlimit(repo, a, b):
"find the earliest revision that's an ancestor of a or b but not both"
# basic idea:
# - mark a and b with different sides
# - if a parent's children are all on the same side, the parent is
# on that side, otherwise it is on no side
# - walk the graph in topological order with the help of a heap;
# - add unseen parents to side map
# - clear side of any parent that has children on different sides
# - track number of interesting revs that might still be on a side
# - track the lowest interesting rev seen
# - quit when interesting revs is zero
cl = repo.changelog
working = len(cl) # pseudo rev for the working directory
if a is None:
a = working
if b is None:
b = working
side = {a: -1, b: 1}
visit = [-a, -b]
heapq.heapify(visit)
interesting = len(visit)
limit = working
while interesting:
r = -heapq.heappop(visit)
if r == working:
parents = [cl.rev(p) for p in repo.dirstate.parents()]
else:
parents = cl.parentrevs(r)
for p in parents:
if p not in side:
# first time we see p; add it to visit
side[p] = side[r]
if side[p]:
interesting += 1
heapq.heappush(visit, -p)
elif side[p] and side[p] != side[r]:
# p was interesting but now we know better
side[p] = 0
interesting -= 1
if side[r]:
limit = r # lowest rev visited
interesting -= 1
return limit
def copies(repo, c1, c2, ca, checkdirs=False):
"""
Find moves and copies between context c1 and c2
"""
# avoid silly behavior for update from empty dir
if not c1 or not c2 or c1 == c2:
return {}, {}
# avoid silly behavior for parent -> working dir
if c2.node() is None and c1.node() == repo.dirstate.parents()[0]:
return repo.dirstate.copies(), {}
limit = _findlimit(repo, c1.rev(), c2.rev())
m1 = c1.manifest()
m2 = c2.manifest()
ma = ca.manifest()
def makectx(f, n):
if len(n) != 20: # in a working context?
if c1.rev() is None:
return c1.filectx(f)
return c2.filectx(f)
return repo.filectx(f, fileid=n)
ctx = util.lrucachefunc(makectx)
copy = {}
fullcopy = {}
diverge = {}
def checkcopies(f, m1, m2):
'''check possible copies of f from m1 to m2'''
c1 = ctx(f, m1[f])
for of in _findoldnames(c1, limit):
fullcopy[f] = of # remember for dir rename detection
if of in m2: # original file not in other manifest?
# if the original file is unchanged on the other branch,
# no merge needed
if m2[of] != ma.get(of):
c2 = ctx(of, m2[of])
ca = c1.ancestor(c2)
# related and named changed on only one side?
if ca and (ca.path() == f or ca.path() == c2.path()):
if c1 != ca or c2 != ca: # merge needed?
copy[f] = of
elif of in ma:
diverge.setdefault(of, []).append(f)
repo.ui.debug(_(" searching for copies back to rev %d\n") % limit)
u1 = _nonoverlap(m1, m2, ma)
u2 = _nonoverlap(m2, m1, ma)
if u1:
repo.ui.debug(_(" unmatched files in local:\n %s\n")
% "\n ".join(u1))
if u2:
repo.ui.debug(_(" unmatched files in other:\n %s\n")
% "\n ".join(u2))
for f in u1:
checkcopies(f, m1, m2)
for f in u2:
checkcopies(f, m2, m1)
diverge2 = set()
for of, fl in diverge.items():
if len(fl) == 1:
del diverge[of] # not actually divergent
else:
diverge2.update(fl) # reverse map for below
if fullcopy:
repo.ui.debug(_(" all copies found (* = to merge, ! = divergent):\n"))
for f in fullcopy:
note = ""
if f in copy: note += "*"
if f in diverge2: note += "!"
repo.ui.debug(" %s -> %s %s\n" % (f, fullcopy[f], note))
del diverge2
if not fullcopy or not checkdirs:
return copy, diverge
repo.ui.debug(_(" checking for directory renames\n"))
# generate a directory move map
d1, d2 = _dirs(m1), _dirs(m2)
invalid = set()
dirmove = {}
# examine each file copy for a potential directory move, which is
# when all the files in a directory are moved to a new directory
for dst, src in fullcopy.iteritems():
dsrc, ddst = _dirname(src), _dirname(dst)
if dsrc in invalid:
# already seen to be uninteresting
continue
elif dsrc in d1 and ddst in d1:
# directory wasn't entirely moved locally
invalid.add(dsrc)
elif dsrc in d2 and ddst in d2:
# directory wasn't entirely moved remotely
invalid.add(dsrc)
elif dsrc in dirmove and dirmove[dsrc] != ddst:
# files from the same directory moved to two different places
invalid.add(dsrc)
else:
# looks good so far
dirmove[dsrc + "/"] = ddst + "/"
for i in invalid:
if i in dirmove:
del dirmove[i]
del d1, d2, invalid
if not dirmove:
return copy, diverge
for d in dirmove:
repo.ui.debug(_(" dir %s -> %s\n") % (d, dirmove[d]))
# check unaccounted nonoverlapping files against directory moves
for f in u1 + u2:
if f not in fullcopy:
for d in dirmove:
if f.startswith(d):
# new file added in a directory that was moved, move it
df = dirmove[d] + f[len(d):]
if df not in copy:
copy[f] = df
repo.ui.debug(_(" file %s -> %s\n") % (f, copy[f]))
break
return copy, diverge