From 18ba1ff5285ec24eef4301875032035cbef93a36 Mon Sep 17 00:00:00 2001
From: stevenknight <stevenknight@fdb21ef1-2011-0410-befe-b5e4ea1792b1>
Date: Fri, 1 Mar 2002 14:20:18 +0000
Subject: [PATCH] Performance:  Use a dictionary, not a list, for a Node's
 parents.  (Stephen Kennedy)

git-svn-id: http://scons.tigris.org/svn/scons/trunk@280 fdb21ef1-2011-0410-befe-b5e4ea1792b1
---
 src/CHANGES.txt                    |  4 ++++
 src/engine/SCons/Node/NodeTests.py |  9 ---------
 src/engine/SCons/Node/__init__.py  | 11 +++--------
 3 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/src/CHANGES.txt b/src/CHANGES.txt
index ddbbdfcb..cc3db983 100644
--- a/src/CHANGES.txt
+++ b/src/CHANGES.txt
@@ -10,6 +10,10 @@
 
 RELEASE 0.06 - 
 
+  From Stephen Kennedy:
+
+  - Performance:  Use a dictionary, not a list, for a Node's parents.
+
   From Steven Knight:
 
   - Add .zip files to the packages we build.
diff --git a/src/engine/SCons/Node/NodeTests.py b/src/engine/SCons/Node/NodeTests.py
index 54f06e68..574e9cd1 100644
--- a/src/engine/SCons/Node/NodeTests.py
+++ b/src/engine/SCons/Node/NodeTests.py
@@ -468,15 +468,6 @@ class NodeTestCase(unittest.TestCase):
         assert five in kids
         assert six in kids
 
-    def test_add_parent(self):
-        """Test adding parents to a Node."""
-        node = SCons.Node.Node()
-        parent = SCons.Node.Node()
-        node._add_parent(parent)
-        assert node.get_parents() == [parent]
-        node._add_parent(parent)
-        assert node.get_parents() == [parent]
-
     def test_state(self):
 	"""Test setting and getting the state of a node
 	"""
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index 918543dd..4c54c533 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -60,7 +60,7 @@ class Node:
         self.depends = []       # explicit dependencies (from Depends)
         self.implicit = {}	# implicit (scanned) dependencies
         self.ignore = []	# dependencies to ignore
-        self.parents = []
+        self.parents = {}
         self.wkids = None       # Kids yet to walk, when it's an array
 	self.builder = None
         self.scanners = []
@@ -215,12 +215,7 @@ class Node:
 	    collection.extend(child)
 
         for c in child:
-            c._add_parent(self)
-
-    def _add_parent(self, parent):
-        """Adds 'parent' to the list of parents of this node"""
-
-        if parent not in self.parents: self.parents.append(parent)
+            c.parents[self] = 1
 
     def add_wkid(self, wkid):
         """Add a node to the list of kids waiting to be evaluated"""
@@ -240,7 +235,7 @@ class Node:
                + reduce(lambda x, y: x + y, self.implicit.values(), [])
 
     def get_parents(self):
-        return self.parents
+        return self.parents.keys()
 
     def set_state(self, state):
         self.state = state
-- 
2.26.2