Reduce the amount of stat traffic generated by a walk.

When we switched to the new walk code for commands, we no longer passed a
list of specific files to the repo or dirstate walk or changes methods.
This meant that we always walked and attempted to match everything,
which was not efficient.

Now, if we are given any patterns to match, or nothing at all, we still
walk everything.  But if we are given only file names that contain no
glob characters, we only walk those.

mercurial/commands.py

@@ -47,7 +47,8 b" def walk(repo, pats, opts, head = ''):"
     cwd = repo.getcwd()
     c = 0
     if cwd: c = len(cwd) + 1
-    for src, fn in repo.walk(match = matchpats(cwd, pats, opts, head)):
+    files, matchfn = matchpats(cwd, pats, opts, head)
+    for src, fn in repo.walk(files = files, match = matchfn):
         yield src, fn, fn[c:]
 
 revrangesep = ':'
@@ -1007,7 +1008,8 b' def status(ui, repo, *pats, **opts):'
     R = removed
     ? = not tracked'''
 
-    (c, a, d, u) = repo.changes(match = matchpats(repo.getcwd(), pats, opts))
+    files, matchfn = matchpats(repo.getcwd(), pats, opts)
+    (c, a, d, u) = repo.changes(files = files, match = matchfn)
     (c, a, d, u) = map(lambda x: relfilter(repo, x), (c, a, d, u))
 
     for f in c:

mercurial/util.py

@@ -66,7 +66,15 b" def globre(pat, head = '^', tail = '$'):"
             res += re.escape(c)
     return head + res + tail
 
-def matcher(cwd, pats, inc, exc, head = ''):
+_globchars = {'[': 1, '{': 1, '*': 1, '?': 1}
+
+def matcher(cwd, names, inc, exc, head = ''):
+    def patlike(name):
+        for prefix in 're:', 'glob:', 'path:':
+            if name.startswith(prefix): return True
+        for c in name:
+            if c in _globchars: return True
+
     def regex(name, tail):
         '''convert a pattern into a regular expression'''
         if name.startswith('re:'):
@@ -77,6 +85,8 b' def matcher(cwd, pats, inc, exc, head = '
             return head + globre(name[5:], '', tail)
         return head + globre(name, '', tail)
 
+    cwdsep = cwd + os.sep
+
     def under(fn):
         """check if fn is under our cwd"""
         return not cwd or fn.startswith(cwdsep)
@@ -86,16 +96,25 b' def matcher(cwd, pats, inc, exc, head = '
         if pats:
             pat = '(?:%s)' % '|'.join([regex(p, tail) for p in pats])
             if cwd:
-                pat = re.escape(cwd + os.sep) + pat
+                pat = re.escape(cwdsep) + pat
             return re.compile(pat).match
 
-    cwdsep = cwd + os.sep
-    patmatch = matchfn(pats, '$') or (lambda fn: True)
+    pats = filter(patlike, names)
+    files = [n for n in names if not patlike(n)]
+    if pats: plain = []
+    elif cwd: plain = [cwdsep + f for f in files]
+    else: plain = files
+        
+    patmatch = matchfn(pats, '$')
+    filematch = matchfn(files, '(?:/|$)')
     incmatch = matchfn(inc, '(?:/|$)') or under
     excmatch = matchfn(exc, '(?:/|$)') or (lambda fn: False)
 
-    return lambda fn: (incmatch(fn) and not excmatch(fn) and
-                       (fn.endswith('/') or patmatch(fn)))
+    return plain, lambda fn: (incmatch(fn) and not excmatch(fn) and
+                              (fn.endswith('/') or
+                               (not pats and not files) or
+                               (pats and patmatch(fn)) or
+                               (files and filematch(fn))))
 
 def system(cmd, errprefix=None):
     """execute a shell command that must succeed"""