# 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 or any later version.
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 _findlimit(repo, a, b):
"""Find the earliest revision that's an ancestor of a or b but not both,
None if no such revision exists.
"""
# 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)
hascommonancestor = False
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 < 0:
continue
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
hascommonancestor = True
if side[r]:
limit = r # lowest rev visited
interesting -= 1
if not hascommonancestor:
return None
return limit
def _chain(src, dst, a, b):
'''chain two sets of copies a->b'''
t = a.copy()
for k, v in b.iteritems():
if v in t:
# found a chain
if t[v] != k:
# file wasn't renamed back to itself
t[k] = t[v]
if v not in dst:
# chain was a rename, not a copy
del t[v]
if v in src:
# file is a copy of an existing file
t[k] = v
# remove criss-crossed copies
for k, v in t.items():
if k in src and v in dst:
del t[k]
return t
def _tracefile(fctx, actx):
'''return file context that is the ancestor of fctx present in actx'''
stop = actx.rev()
am = actx.manifest()
for f in fctx.ancestors():
if am.get(f.path(), None) == f.filenode():
return f
if f.rev() < stop:
return None
def _dirstatecopies(d):
ds = d._repo.dirstate
c = ds.copies().copy()
for k in c.keys():
if ds[k] not in 'anm':
del c[k]
return c
def _forwardcopies(a, b):
'''find {dst@b: src@a} copy mapping where a is an ancestor of b'''
# check for working copy
w = None
if b.rev() is None:
w = b
b = w.p1()
if a == b:
# short-circuit to avoid issues with merge states
return _dirstatecopies(w)
# find where new files came from
# we currently don't try to find where old files went, too expensive
# this means we can miss a case like 'hg rm b; hg cp a b'
cm = {}
for f in b:
if f not in a:
ofctx = _tracefile(b[f], a)
if ofctx:
cm[f] = ofctx.path()
# combine copies from dirstate if necessary
if w is not None:
cm = _chain(a, w, cm, _dirstatecopies(w))
return cm
def _backwardcopies(a, b):
# because the forward mapping is 1:n, we can lose renames here
# in particular, we find renames better than copies
f = _forwardcopies(b, a)
r = {}
for k, v in f.iteritems():
r[v] = k
return r
def pathcopies(x, y):
'''find {dst@y: src@x} copy mapping for directed compare'''
if x == y or not x or not y:
return {}
a = y.ancestor(x)
if a == x:
return _forwardcopies(x, y)
if a == y:
return _backwardcopies(x, y)
return _chain(x, y, _backwardcopies(x, a), _forwardcopies(a, y))
def mergecopies(repo, c1, c2, ca):
"""
Find moves and copies between context c1 and c2 that are relevant
for merging.
Returns two dicts, "copy" and "diverge".
"copy" is a mapping from destination name -> source name,
where source is in c1 and destination is in c2 or vice-versa.
"diverge" is a mapping of source name -> list of destination names
for divergent renames.
"renamedelete" is a mapping of source name -> list of destination
names for files deleted in c1 that were renamed in c2 or vice-versa.
"""
# 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.p1():
return repo.dirstate.copies(), {}, {}
limit = _findlimit(repo, c1.rev(), c2.rev())
if limit is None:
# no common ancestor, no copies
return {}, {}, {}
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 related(f1, f2, limit):
# Walk back to common ancestor to see if the two files originate
# from the same file. Since workingfilectx's rev() is None it messes
# up the integer comparison logic, hence the pre-step check for
# None (f1 and f2 can only be workingfilectx's initially).
if f1 == f2:
return f1 # a match
g1, g2 = f1.ancestors(), f2.ancestors()
try:
f1r, f2r = f1.rev(), f2.rev()
if f1r is None:
f1 = g1.next()
if f2r is None:
f2 = g2.next()
while True:
f1r, f2r = f1.rev(), f2.rev()
if f1r > f2r:
f1 = g1.next()
elif f2r > f1r:
f2 = g2.next()
elif f1 == f2:
return f1 # a match
elif f1r == f2r or f1r < limit or f2r < limit:
return False # copy no longer relevant
except StopIteration:
return False
def checkcopies(f, m1, m2):
'''check possible copies of f from m1 to m2'''
of = None
seen = set([f])
for oc in ctx(f, m1[f]).ancestors():
ocr = oc.rev()
of = oc.path()
if of in seen:
# check limit late - grab last rename before
if ocr < limit:
break
continue
seen.add(of)
fullcopy[f] = of # remember for dir rename detection
if of not in m2:
continue # no match, keep looking
if m2[of] == ma.get(of):
break # no merge needed, quit early
c2 = ctx(of, m2[of])
cr = related(oc, c2, ca.rev())
if cr and (of == f or of == c2.path()): # non-divergent
copy[f] = of
of = None
break
if 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)
renamedelete = {}
renamedelete2 = set()
diverge2 = set()
for of, fl in diverge.items():
if len(fl) == 1 or of in c1 or of in c2:
del diverge[of] # not actually divergent, or not a rename
if of not in c1 and of not in c2:
# renamed on one side, deleted on the other side, but filter
# out files that have been renamed and then deleted
renamedelete[of] = [f for f in fl if f in c1 or f in c2]
renamedelete2.update(fl) # reverse map for below
else:
diverge2.update(fl) # reverse map for below
if fullcopy:
repo.ui.debug(" all copies found (* = to merge, ! = divergent, "
"% = renamed and deleted):\n")
for f in fullcopy:
note = ""
if f in copy:
note += "*"
if f in diverge2:
note += "!"
if f in renamedelete2:
note += "%"
repo.ui.debug(" %s -> %s %s\n" % (f, fullcopy[f], note))
del diverge2
if not fullcopy:
return copy, diverge, renamedelete
repo.ui.debug(" checking for directory renames\n")
# generate a directory move map
d1, d2 = c1.dirs(), c2.dirs()
d1.add('')
d2.add('')
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, renamedelete
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, renamedelete