[PATCH] similar: remove caching from the module level

[Sean Farley]

# HG changeset patch
# User Sean Farley <sean at farley.io>
# Date 1484336556 28800
#      Fri Jan 13 11:42:36 2017 -0800
# Node ID 7c54c9524a0954a3bd2f2fb4451028869f851f6d
# Parent  8540967cd9e0909a9a73dbff458c4cedd4db26aa
similar: remove caching from the module level

To prevent Bad Thingsâ„¢ from happening, let's rework the logic to not use
util.cachefunc.

diff --git a/mercurial/similar.py b/mercurial/similar.py
--- a/mercurial/similar.py
+++ b/mercurial/similar.py
@@ -11,11 +11,10 @@ import hashlib
 
 from .i18n import _
 from . import (
     bdiff,
     mdiff,
-    util,
 )
 
 def _findexactmatches(repo, added, removed):
     '''find renamed files that have no changes
 
@@ -41,20 +40,18 @@ def _findexactmatches(repo, added, remov
             yield (hashes[h], fctx)
 
     # Done
     repo.ui.progress(_('searching for exact renames'), None)
 
- at util.cachefunc
 def _ctxdata(fctx):
     # lazily load text
     orig = fctx.data()
     return orig, mdiff.splitnewlines(orig)
 
- at util.cachefunc
-def score(fctx1, fctx2):
-    text = fctx1.data()
-    orig, lines = _ctxdata(fctx2)
+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:
@@ -62,10 +59,13 @@ def score(fctx1, fctx2):
             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.
@@ -73,13 +73,16 @@ def _findsimilarmatches(repo, added, rem
     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]
-            myscore = score(a, r)
+            if data is None:
+                data = _ctxdata(r)
+            myscore = score(a, data)
             if myscore >= bestscore:
                 copies[a] = (r, myscore)
     repo.ui.progress(_('searching'), None)
 
     for dest, v in copies.iteritems():