From 1b96bb8b1517d60e08b69f9f122f1ac4851645f6 Mon Sep 17 00:00:00 2001
From: John Haddon <thehaddonyoof@gmail.com>
Date: Tue, 14 Oct 2014 13:03:35 +0100
Subject: [PATCH] Removed unnecessary InternedString construction from
 Expression node.

This knocks 6% off the runtime when traversing a cached scene generated by 100 CustomAttributes nodes each with expressions.
---
 include/Gaffer/Expression.h |  6 +++++
 src/Gaffer/Expression.cpp   | 47 +++++++++++++++++++++++++++----------
 2 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/include/Gaffer/Expression.h b/include/Gaffer/Expression.h
index 1e9b32dab66..15538cc65c5 100644
--- a/include/Gaffer/Expression.h
+++ b/include/Gaffer/Expression.h
@@ -106,6 +106,12 @@ class Expression : public ComputeNode
 
 	private :
 
+		CompoundPlug *inPlug();
+		const CompoundPlug *inPlug() const;
+
+		ValuePlug *outPlug();
+		const ValuePlug *outPlug() const;
+
 		void plugSet( Plug *plug );
 		void parentChanged( GraphComponent *child, GraphComponent *oldParent );
 
diff --git a/src/Gaffer/Expression.cpp b/src/Gaffer/Expression.cpp
index 235409665ef..25823786a8e 100644
--- a/src/Gaffer/Expression.cpp
+++ b/src/Gaffer/Expression.cpp
@@ -48,6 +48,9 @@
 
 using namespace Gaffer;
 
+static IECore::InternedString g_inPlugName( "in" );
+static IECore::InternedString g_outPlugName( "out" );
+
 //////////////////////////////////////////////////////////////////////////
 // Expression implementation
 //////////////////////////////////////////////////////////////////////////
@@ -106,8 +109,8 @@ void Expression::affects( const Plug *input, AffectedPlugsContainer &outputs ) c
 {
 	ComputeNode::affects( input, outputs );
 
-	const CompoundPlug *in = getChild<CompoundPlug>( "in" );
-	const ValuePlug *out = getChild<ValuePlug>( "out" );
+	const CompoundPlug *in = inPlug();
+	const ValuePlug *out = outPlug();
 	if( in && out )
 	{
 		if( input->parent<CompoundPlug>() == in )
@@ -127,11 +130,11 @@ void Expression::affects( const Plug *input, AffectedPlugsContainer &outputs ) c
 void Expression::hash( const ValuePlug *output, const Context *context, IECore::MurmurHash &h ) const
 {
 	ComputeNode::hash( output, context, h );
-	if( output == getChild<ValuePlug>( "out" ) )
+	if( output == outPlug() )
 	{
 		enginePlug()->hash( h );
 		expressionPlug()->hash( h );
-		const CompoundPlug *in = getChild<CompoundPlug>( "in" );
+		const CompoundPlug *in = inPlug();
 		if( in )
 		{
 			in->hash( h );
@@ -156,11 +159,11 @@ void Expression::hash( const ValuePlug *output, const Context *context, IECore::
 
 void Expression::compute( ValuePlug *output, const Context *context ) const
 {
-	if( output == getChild<ValuePlug>( "out" ) )
+	if( output == outPlug() )
 	{
 		if( m_engine )
 		{
-			const CompoundPlug *in = getChild<CompoundPlug>( "in" );
+			const CompoundPlug *in = inPlug();
 			std::vector<const ValuePlug *> inputs;
 			for( ChildContainer::const_iterator it = in->children().begin(); it!=in->children().end(); it++ )
 			{
@@ -179,6 +182,26 @@ void Expression::compute( ValuePlug *output, const Context *context ) const
 	ComputeNode::compute( output, context );
 }
 
+CompoundPlug *Expression::inPlug()
+{
+	return getChild<CompoundPlug>( g_inPlugName );
+}
+
+const CompoundPlug *Expression::inPlug() const
+{
+	return getChild<CompoundPlug>( g_inPlugName );
+}
+
+ValuePlug *Expression::outPlug()
+{
+	return getChild<ValuePlug>( g_outPlugName );
+}
+
+const ValuePlug *Expression::outPlug() const
+{
+	return getChild<ValuePlug>( g_outPlugName );
+}
+
 void Expression::plugSet( Plug *plug )
 {
 	if( !parent<Node>() )
@@ -246,12 +269,12 @@ void Expression::updatePlugs( const std::string &dstPlugPath, std::vector<std::s
 	// if the expression was invalid, remove our plugs
 	if( !dstPlugPath.size() )
 	{
-		Plug *in = getChild<Plug>( "in" );
+		Plug *in = inPlug();
 		if( in )
 		{
 			removeChild( in );
 		}
-		Plug *out = getChild<Plug>( "out" );
+		Plug *out = outPlug();
 		if( out )
 		{
 			removeChild( out );
@@ -267,8 +290,8 @@ void Expression::updatePlugs( const std::string &dstPlugPath, std::vector<std::s
 		throw IECore::Exception( boost::str( boost::format( "Destination plug \"%s\" does not exist" ) % dstPlugPath ) );
 	}
 
-	CompoundPlugPtr inPlugs = new CompoundPlug( "in", Plug::In, Plug::Default | Plug::Dynamic );
-	setChild( "in", inPlugs );
+	CompoundPlugPtr inPlugs = new CompoundPlug( g_inPlugName, Plug::In, Plug::Default | Plug::Dynamic );
+	setChild( g_inPlugName, inPlugs );
 	for( std::vector<std::string>::const_iterator it = srcPlugPaths.begin(); it!=srcPlugPaths.end(); it++ )
 	{
 		ValuePlug *srcPlug = p->descendant<ValuePlug>( *it );
@@ -281,8 +304,8 @@ void Expression::updatePlugs( const std::string &dstPlugPath, std::vector<std::s
 		inPlug->setInput( srcPlug );
 	}
 
-	PlugPtr outPlug = dstPlug->createCounterpart( "out", Plug::Out );
-	setChild( "out", outPlug );
+	PlugPtr outPlug = dstPlug->createCounterpart( g_outPlugName, Plug::Out );
+	setChild( g_outPlugName, outPlug );
 	dstPlug->setInput( outPlug );
 }