[PATCH 3 of 4] dirstate: skip step 3 in walk if nothing new will match

[Simon Heimberg]

# HG changeset patch
# User Simon Heimberg <simohe at besonet.ch>
# Date 1242323666 -7200
# Node ID 19a134f738f5ac0720bc08fbe6507f4eb4769fd9
# Parent  4095d02302b74f9ce2c90fe283d84ad31ce2da83
dirstate: skip step 3 in walk if nothing new will match

nothing will ever match on match.never
nothing new will match on match.exact (all found in step 1)
nothing new will match on match.match when
  there is no pattern and
  there is no direcory in pats

diff -r 4095d02302b7 -r 19a134f738f5 mercurial/dirstate.py
--- a/mercurial/dirstate.py	Don Mai 14 10:50:45 2009 +0200
+++ b/mercurial/dirstate.py	Don Mai 14 19:54:26 2009 +0200
@@ -460,6 +460,11 @@
         join = self._join
         work = []
         wadd = work.append
+        dostep3 = match.anypats() or match.__class__.__name__ == 'always'
+        nomatches = not dostep3 and match.__class__.__name__ in 'never exact'.split()
+        if nomatches:
+            #skip step 2
+            dirignore = util.always
 
         files = set(match.files())
         if not files or '.' in files:
@@ -476,6 +481,7 @@
                 st = lstat(join(nf))
                 kind = getkind(st.st_mode)
                 if kind == dirkind:
+                    dostep3 = True
                     if nf in dmap:
                         #file deleted on disc but still in dirstate
                         results[nf] = None
@@ -497,6 +503,7 @@
                         keep = True
                         break
                     elif fn.startswith(prefix):
+                        dostep3 = True
                         keep = True
                         break
                 if not keep:
@@ -541,11 +548,12 @@
                         results[nf] = None
 
         # step 3: report unseen items in the dmap hash
-        visit = sorted([f for f in dmap if f not in results and matchfn(f)])
-        for nf, st in zip(visit, util.statfiles([join(i) for i in visit])):
-            if not st is None and not getkind(st.st_mode) in (regkind, lnkkind):
-                st = None
-            results[nf] = st
+        if dostep3 and not nomatches:
+            visit = sorted([f for f in dmap if f not in results and matchfn(f)])
+            for nf, st in zip(visit, util.statfiles([join(i) for i in visit])):
+                if not st is None and not getkind(st.st_mode) in (regkind, lnkkind):
+                    st = None
+                results[nf] = st
 
         del results['.hg']
         return results