configmgr: faster / simpler compare for keys.

A surprising amount of time is/was spent comparing keys in the
std::map red/black tree traversing nodes. Since we don't need
the data truly sorted, instead sort in length buckets. Kills
90k rtl_ustring_compare_withLength calls on startup, around
0.9% of headless start.

Change-Id: Ib23aff151ad50d56bbf2ba3e28882cc81898d9ec

configmgr/source/access.hxx

@@ -25,6 +25,7 @@
 #include <map>
 #include <set>
 #include <vector>
+#include "config_map.hxx"
 
 #include <boost/noncopyable.hpp>
 #include <boost/shared_ptr.hpp>
@@ -486,7 +487,7 @@ private:
             bool theDirectlyModified);
     };
 
-    typedef std::map< OUString, ModifiedChild > ModifiedChildren;
+    typedef config_map< ModifiedChild > ModifiedChildren;
 
     rtl::Reference< ChildAccess > getModifiedChild(
         ModifiedChildren::iterator const & childIterator);
@@ -515,7 +516,7 @@ private:
 
     rtl::Reference< Access > getNotificationRoot();
 
-    typedef std::map< OUString, ChildAccess * > WeakChildMap;
+    typedef config_map< ChildAccess * > WeakChildMap;
 
     typedef
         std::multiset<
@@ -535,7 +536,7 @@ private:
                 com::sun::star::beans::XPropertyChangeListener > >
         PropertyChangeListenersElement;
 
-    typedef std::map< OUString, PropertyChangeListenersElement >
+    typedef config_map< PropertyChangeListenersElement >
         PropertyChangeListeners;
 
     typedef
@@ -544,7 +545,7 @@ private:
                 com::sun::star::beans::XVetoableChangeListener > >
         VetoableChangeListenersElement;
 
-    typedef std::map< OUString, VetoableChangeListenersElement >
+    typedef config_map< VetoableChangeListenersElement >
         VetoableChangeListeners;
 
     typedef

configmgr/source/components.hxx

@@ -148,8 +148,7 @@ private:
     typedef std::set< RootAccess * > WeakRootSet;
 
     typedef
-        std::map<
-            OUString,
+        config_map<
             com::sun::star::uno::Reference<
                 com::sun::star::beans::XPropertySet > >
         ExternalServices;

configmgr/source/config_map.hxx

+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+#ifndef CONFIG_MAP_HXX
+#define CONFIG_MAP_HXX
+
+#include <map>
+#include <rtl/ustring.hxx>
+
+// The realisation here is that while a map is a reasonably compact
+// representation, there is often no need to have it completely
+// sorted, so we can use a fast in-line length comparison as the
+// initial compare, rather than sorting of sub string contents.
+
+struct LengthContentsCompare
+{
+    inline bool operator()( const OUString &a, const OUString &b ) const
+    {
+        if (a.getLength() == b.getLength())
+            return a < b;
+        else
+            return a.getLength() < b.getLength();
+    }
+};
+
+template< class T > struct config_map : public std::map< OUString, T, LengthContentsCompare > { };
+
+#endif // CONFIG_MAP_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

configmgr/source/data.hxx

@@ -23,7 +23,7 @@
 #include <sal/config.h>
 
 #include <climits>
-#include <map>
+#include "config_map.hxx"
 #include <vector>
 
 #include <boost/noncopyable.hpp>
@@ -86,7 +86,7 @@ struct Data: private boost::noncopyable {
         OUString const & url);
 
 private:
-    typedef std::map< OUString, rtl::Reference< ExtensionXcu > >
+    typedef config_map< rtl::Reference< ExtensionXcu > >
         ExtensionXcuAdditions;
 
     rtl::Reference< Node > root_;

configmgr/source/nodemap.hxx

@@ -21,13 +21,13 @@
 #define INCLUDED_CONFIGMGR_SOURCE_NODEMAP_HXX
 
 #include <sal/config.h>
-#include <map>
+#include "config_map.hxx"
 #include <rtl/ref.hxx>
 #include <node.hxx>
 
 namespace configmgr {
 
-typedef std::map< OUString, rtl::Reference< Node > > NodeMapImpl;
+typedef config_map< rtl::Reference< Node > > NodeMapImpl;
 class NodeMap
 {
     NodeMapImpl maImpl;