Implement content signature caching and --max-drift (Anthony Roach)

3 files changed, 41 insertions, 8 deletions

diff --git a/src/engine/SCons/Node/FS.py b/src/engine/SCons/Node/FS.py
index 0f8425f..c49361d 100644
--- a/src/engine/SCons/Node/FS.py
+++ b/src/engine/SCons/Node/FS.py
@@ -520,10 +520,19 @@ class File(Entry):
         else:
             return 0
 
-    def store_sigs(self):
-        """Update a file's .sconsign entry with its current info."""
-        self.dir.sconsign().set(self.name, self.get_timestamp(),
-                                self.get_bsig(), self.get_csig())
+    def store_csig(self):
+        old = self.get_prevsiginfo()
+        self.dir.sconsign().set(self.name,
+                                self.get_timestamp(),
+                                old[1],
+                                self.get_csig())
+
+    def store_bsig(self):
+        old = self.get_prevsiginfo()
+        self.dir.sconsign().set(self.name,
+                                self.get_timestamp(),
+                                self.get_bsig(),
+                                old[2])
 
     def get_prevsiginfo(self):
         """Fetch the previous signature information from the
diff --git a/src/engine/SCons/Node/NodeTests.py b/src/engine/SCons/Node/NodeTests.py
index 4caebb5..447ef93 100644
--- a/src/engine/SCons/Node/NodeTests.py
+++ b/src/engine/SCons/Node/NodeTests.py
@@ -266,11 +266,17 @@ class NodeTestCase(unittest.TestCase):
         node.set_csig('zzz')
         assert node.get_csig() == 'zzz'
 
+    def test_store_bsig(self):
+        """Test calling the method to store a build signature
+        """
+        node = SCons.Node.Node()
+        node.store_bsig()
+
     def test_store_sigs(self):
-        """Test calling the method to store signatures
+        """Test calling the method to store a content signature
         """
         node = SCons.Node.Node()
-        node.store_sigs()
+        node.store_csig()
 
     def test_set_precious(self):
         """Test setting a Node's precious value
diff --git a/src/engine/SCons/Node/__init__.py b/src/engine/SCons/Node/__init__.py
index 9c39d25..a9ca790 100644
--- a/src/engine/SCons/Node/__init__.py
+++ b/src/engine/SCons/Node/__init__.py
@@ -120,9 +120,14 @@ class Node:
             def get_parents(node, parent): return node.get_parents()
             def clear_cache(node, parent): 
                 node.implicit = None
+                node.bsig = None
             w = Walker(self, get_parents, ignore_cycle, clear_cache)
             while w.next(): pass
 
+        # clear out the content signature, since the contents of this
+        # node were presumably just changed:
+        self.csig = None
+
     def depends_on(self, nodes):
         """Does this node depend on any of 'nodes'?"""
         for node in nodes:
@@ -194,6 +199,11 @@ class Node:
         of its dependency files and build information)."""
         self.bsig = bsig
 
+    def store_bsig(self):
+        """Make the build signature permanent (that is, store it in the
+        .sconsign file or equivalent)."""
+        pass
+
     def get_csig(self):
         """Get the signature of the node's content."""
         return self.csig
@@ -202,11 +212,19 @@ class Node:
         """Set the signature of the node's content."""
         self.csig = csig
 
-    def store_sigs(self):
-        """Make the signatures permanent (that is, store them in the
+    def store_csig(self):
+        """Make the content signature permanent (that is, store it in the
         .sconsign file or equivalent)."""
         pass
 
+    def get_prevsiginfo(self):
+        """Fetch the previous signature information from the
+        .sconsign entry."""
+        return None
+
+    def get_timestamp(self):
+        return 0
+
     def set_precious(self, precious = 1):
         """Set the Node's precious value."""
         self.precious = precious