# HG changeset patch
# User Matt Mackall <mpm@selenic.com>
# Date 1308434029 18000
# Node ID 5ef7b87530f69ad35aac3600848ac53a573acde9
# Parent  2a758ffc821eea5074e88ef3d795d2ba7fd69f2e
fileset: prescan parse tree to optimize status usage

We only call status if needed to avoid walking the working directory
or comparing manifests.

Similarly, we scan for whether unknown or ignored files are mentioned
so we can include them.

diff -r 2a758ffc821e -r 5ef7b87530f6 mercurial/fileset.py
--- a/mercurial/fileset.py	Sat Jun 18 16:53:49 2011 -0500
+++ b/mercurial/fileset.py	Sat Jun 18 16:53:49 2011 -0500
@@ -204,21 +204,7 @@
         self.ctx = ctx
         self.subset = subset
         self._status = status
-        if status is None:
-            # desperately wants optimizing
-            r = self.ctx._repo
-            self._status = r.status(self.ctx.p1(), self.ctx,
-                                    unknown=True, ignored=True, clean=True)
-        if subset is None:
-            self.subset = []
-            for c in self._status:
-                self.subset.extend(c)
     def status(self):
-        if not self._status:
-            r = self.ctx._repo
-            # also wants optimizing
-            self._status = r.status(self.ctx.p1(), self.ctx,
-                                    unknown=True, ignored=True, clean=True)
         return self._status
     def matcher(self, patterns):
         return self.ctx.match(patterns)
@@ -227,8 +213,35 @@
     def narrow(self, files):
         return matchctx(self.ctx, self.filter(files), self._status)
 
+def _intree(funcs, tree):
+    if isinstance(tree, tuple):
+        if tree[0] == 'func' and tree[1][0] == 'symbol':
+            if tree[1][1] in funcs:
+                return True
+        for s in tree[1:]:
+            if _intree(funcs, s):
+                return True
+    return False
+
 def getfileset(ctx, expr):
     tree, pos = parse(expr)
     if (pos != len(expr)):
         raise error.ParseError("invalid token", pos)
-    return getset(matchctx(ctx), tree)
+
+    # do we need status info?
+    if _intree(['modified', 'added', 'removed', 'deleted',
+                'unknown', 'ignored', 'clean'], tree):
+        unknown = _intree(['unknown'], tree)
+        ignored = _intree(['ignored'], tree)
+
+        r = ctx._repo
+        status = r.status(ctx.p1(), ctx,
+                          unknown=unknown, ignored=ignored, clean=True)
+        subset = []
+        for c in status:
+            subset.extend(c)
+    else:
+        status = None
+        subset = ctx.walk(ctx.match([]))
+
+    return getset(matchctx(ctx, subset, status), tree)