lok: encourage more sharing of config Node pages.

Profiles show lots of probe:do_wp_page events from things like
configmgr::Access::getUnmodifiedChild - as when we read we touch
lots of Node reference counts - un-necessarily.

So - reduce un-necessary reference counting thrash here in the
lok case through the environment variable. Quite possibly this
would also be safe and beneficial for the desktop app - needs
measurement.

measuring with coolmap and an empty hello-world.odt before & after:
before:
	unshared  3634 (14536kB)
	unshared  3631 (14524kB)
	unshared  3605 (14420kB)

after:
	unshared  3578 (14312kB)
	unshared  3613 (14452kB)
	unshared  3599 (14396kB)

Not hugely encouraging, perhaps there is another page touch
underneath we'll find when this is addressed.

Change-Id: I8ac74c5fcd17f8699139e914a7076a7848456e2a
Signed-off-by: Michael Meeks <michael.meeks@collabora.com>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/175197
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/182349
Tested-by: Jenkins

configmgr/source/components.cxx

@@ -492,6 +492,10 @@ Components::Components(
 {
     assert(context.is());
     lock_ = lock();
+
+    bool staticize = !!getenv("SAL_CONFIG_STATICIZE");
+    Node::setStaticizedFlag(staticize);
+
     OUString conf(expand(u"${CONFIGURATION_LAYERS}"_ustr));
     int layer = 0;
     for (sal_Int32 i = 0;;) {
@@ -629,6 +633,8 @@ Components::Components(
         }
         i = n;
     }
+
+    Node::setStaticizedFlag(false);
 }
 
 Components::~Components()

configmgr/source/node.cxx

@@ -65,7 +65,18 @@ rtl::Reference< Node > Node::getMember(OUString const & name) {
     return i == members.end() ? rtl::Reference< Node >() : i->second;
 }
 
-Node::Node(int layer): layer_(layer), finalized_(Data::NO_LAYER) {}
+bool Node::CreateStaticizedNodes = false;
+
+void Node::setStaticizedFlag(bool staticized)
+{
+    CreateStaticizedNodes = staticized;
+}
+
+Node::Node(int layer): layer_(layer), finalized_(Data::NO_LAYER)
+{
+    if (CreateStaticizedNodes)
+        staticize();
+}
 
 Node::Node(const Node & other):
     SimpleReferenceObject(), layer_(other.layer_), finalized_(other.finalized_)

configmgr/source/node.hxx

@@ -50,6 +50,9 @@ public:
     void setLayer(int layer);
     int getLayer() const { return layer_;}
 
+    /// when @staticized is set all new nodes will not ref-count
+    static void setStaticizedFlag(bool staticized);
+
     void setFinalized(int layer);
     int getFinalized() const { return finalized_;}
 
@@ -67,6 +70,7 @@ private:
     int layer_;
     int finalized_;
     OUString description_;
+    static bool CreateStaticizedNodes;
 };
 
 }