similar: take the first match instead of the last

It seems more natural. This makes the next patch slightly cleaner.

mercurial/similar.py

@@ -1,121 +1,121 b''
 # similar.py - mechanisms for finding similar files
 #
 # Copyright 2005-2007 Matt Mackall <[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.
 
 from __future__ import absolute_import
 
 import hashlib
 
 from .i18n import _
 from . import (
     bdiff,
     mdiff,
 )
 
 def _findexactmatches(repo, added, removed):
     '''find renamed files that have no changes
 
     Takes a list of new filectxs and a list of removed filectxs, and yields
     (before, after) tuples of exact matches.
     '''
     numfiles = len(added) + len(removed)
 
     # Get hashes of removed files.
     hashes = {}
-    for i, fctx in enumerate(removed):
+    for i, fctx in enumerate(reversed(removed)):
         repo.ui.progress(_('searching for exact renames'), i, total=numfiles,
                          unit=_('files'))
         h = hashlib.sha1(fctx.data()).digest()
         hashes[h] = fctx
 
     # For each added file, see if it corresponds to a removed file.
     for i, fctx in enumerate(added):
         repo.ui.progress(_('searching for exact renames'), i + len(removed),
                 total=numfiles, unit=_('files'))
         adata = fctx.data()
         h = hashlib.sha1(adata).digest()
         if h in hashes:
             rfctx = hashes[h]
             # compare between actual file contents for exact identity
             if adata == rfctx.data():
                 yield (rfctx, fctx)
 
     # Done
     repo.ui.progress(_('searching for exact renames'), None)
 
 def _ctxdata(fctx):
     # lazily load text
     orig = fctx.data()
     return orig, mdiff.splitnewlines(orig)
 
 def _score(fctx, otherdata):
     orig, lines = otherdata
     text = fctx.data()
     # bdiff.blocks() returns blocks of matching lines
     # count the number of bytes in each
     equal = 0
     matches = bdiff.blocks(text, orig)
     for x1, x2, y1, y2 in matches:
         for line in lines[y1:y2]:
             equal += len(line)
 
     lengths = len(text) + len(orig)
     return equal * 2.0 / lengths
 
 def score(fctx1, fctx2):
     return _score(fctx1, _ctxdata(fctx2))
 
 def _findsimilarmatches(repo, added, removed, threshold):
     '''find potentially renamed files based on similar file content
 
     Takes a list of new filectxs and a list of removed filectxs, and yields
     (before, after, score) tuples of partial matches.
     '''
     copies = {}
     for i, r in enumerate(removed):
         repo.ui.progress(_('searching for similar files'), i,
                          total=len(removed), unit=_('files'))
 
         data = None
         for a in added:
             bestscore = copies.get(a, (None, threshold))[1]
             if data is None:
                 data = _ctxdata(r)
             myscore = _score(a, data)
-            if myscore >= bestscore:
+            if myscore > bestscore:
                 copies[a] = (r, myscore)
     repo.ui.progress(_('searching'), None)
 
     for dest, v in copies.iteritems():
         source, bscore = v
         yield source, dest, bscore
 
 def _dropempty(fctxs):
     return [x for x in fctxs if x.size() > 0]
 
 def findrenames(repo, added, removed, threshold):
     '''find renamed files -- yields (before, after, score) tuples'''
     wctx = repo[None]
     pctx = wctx.p1()
 
     # Zero length files will be frequently unrelated to each other, and
     # tracking the deletion/addition of such a file will probably cause more
     # harm than good. We strip them out here to avoid matching them later on.
     addedfiles = _dropempty(wctx[fp] for fp in sorted(added))
     removedfiles = _dropempty(pctx[fp] for fp in sorted(removed) if fp in pctx)
 
     # Find exact matches.
     matchedfiles = set()
     for (a, b) in _findexactmatches(repo, addedfiles, removedfiles):
         matchedfiles.add(b)
         yield (a.path(), b.path(), 1.0)
 
     # If the user requested similar files to be matched, search for them also.
     if threshold < 1.0:
         addedfiles = [x for x in addedfiles if x not in matchedfiles]
         for (a, b, score) in _findsimilarmatches(repo, addedfiles,
                                                  removedfiles, threshold):
             yield (a.path(), b.path(), score)

tests/test-addremove-similar.t

@@ -1,174 +1,174 b''
   $ hg init rep; cd rep
 
   $ touch empty-file
   $ $PYTHON -c 'for x in range(10000): print(x)' > large-file
 
   $ hg addremove
   adding empty-file
   adding large-file
 
   $ hg commit -m A
 
   $ rm large-file empty-file
   $ $PYTHON -c 'for x in range(10,10000): print(x)' > another-file
 
   $ hg addremove -s50
   adding another-file
   removing empty-file
   removing large-file
   recording removal of large-file as rename to another-file (99% similar)
 
   $ hg commit -m B
 
 comparing two empty files caused ZeroDivisionError in the past
 
   $ hg update -C 0
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ rm empty-file
   $ touch another-empty-file
   $ hg addremove -s50
   adding another-empty-file
   removing empty-file
 
   $ cd ..
 
   $ hg init rep2; cd rep2
 
   $ $PYTHON -c 'for x in range(10000): print(x)' > large-file
   $ $PYTHON -c 'for x in range(50): print(x)' > tiny-file
 
   $ hg addremove
   adding large-file
   adding tiny-file
 
   $ hg commit -m A
 
   $ $PYTHON -c 'for x in range(70): print(x)' > small-file
   $ rm tiny-file
   $ rm large-file
 
   $ hg addremove -s50
   removing large-file
   adding small-file
   removing tiny-file
   recording removal of tiny-file as rename to small-file (82% similar)
 
   $ hg commit -m B
 
 should be sorted by path for stable result
 
   $ for i in `python $TESTDIR/seq.py 0 9`; do
   >     cp small-file $i
   > done
   $ rm small-file
   $ hg addremove
   adding 0
   adding 1
   adding 2
   adding 3
   adding 4
   adding 5
   adding 6
   adding 7
   adding 8
   adding 9
   removing small-file
   recording removal of small-file as rename to 0 (100% similar)
   recording removal of small-file as rename to 1 (100% similar)
   recording removal of small-file as rename to 2 (100% similar)
   recording removal of small-file as rename to 3 (100% similar)
   recording removal of small-file as rename to 4 (100% similar)
   recording removal of small-file as rename to 5 (100% similar)
   recording removal of small-file as rename to 6 (100% similar)
   recording removal of small-file as rename to 7 (100% similar)
   recording removal of small-file as rename to 8 (100% similar)
   recording removal of small-file as rename to 9 (100% similar)
   $ hg commit -m '10 same files'
 
 pick one from many identical files
 
   $ cp 0 a
   $ rm `python $TESTDIR/seq.py 0 9`
   $ hg addremove
   removing 0
   removing 1
   removing 2
   removing 3
   removing 4
   removing 5
   removing 6
   removing 7
   removing 8
   removing 9
   adding a
-  recording removal of 9 as rename to a (100% similar)
+  recording removal of 0 as rename to a (100% similar)
   $ hg revert -aq
 
 pick one from many similar files
 
   $ cp 0 a
   $ for i in `python $TESTDIR/seq.py 0 9`; do
   >     echo $i >> $i
   > done
   $ hg commit -m 'make them slightly different'
   $ rm `python $TESTDIR/seq.py 0 9`
   $ hg addremove -s50
   removing 0
   removing 1
   removing 2
   removing 3
   removing 4
   removing 5
   removing 6
   removing 7
   removing 8
   removing 9
   adding a
-  recording removal of 9 as rename to a (99% similar)
+  recording removal of 0 as rename to a (99% similar)
   $ hg commit -m 'always the same file should be selected'
 
 should all fail
 
   $ hg addremove -s foo
   abort: similarity must be a number
   [255]
   $ hg addremove -s -1
   abort: similarity must be between 0 and 100
   [255]
   $ hg addremove -s 1e6
   abort: similarity must be between 0 and 100
   [255]
 
   $ cd ..
 
 Issue1527: repeated addremove causes Abort
 
   $ hg init rep3; cd rep3
   $ mkdir d
   $ echo a > d/a
   $ hg add d/a
   $ hg commit -m 1
 
   $ mv d/a d/b
   $ hg addremove -s80
   removing d/a
   adding d/b
   recording removal of d/a as rename to d/b (100% similar) (glob)
   $ hg debugstate
   r   0          0 1970-01-01 00:00:00 d/a
   a   0         -1 unset               d/b
   copy: d/a -> d/b
   $ mv d/b c
 
 no copies found here (since the target isn't in d
 
   $ hg addremove -s80 d
   removing d/b (glob)
 
 copies here
 
   $ hg addremove -s80
   adding c
   recording removal of d/a as rename to c (100% similar) (glob)
 
   $ cd ..