schema: short circuit subsystem selector

Problem: Fluxion profiling revealed hotspots related to string finding
and string comparisons in `subsystem_selector_t`.

Add metadata to the `subsystem_selector_t` to store the number of
subsystems. Resource graphs most commonly have only one subsystem, so
we can short-circuit expensive string finding and comparisons if
m_subsystem_size == 1.

Author: milroy

resource/modules/resource_match.cpp

@@ -1421,9 +1421,12 @@ static std::shared_ptr<f_resource_graph_t> create_filtered_graph (
         edg_infra_map_t emap = get (&resource_relation_t::idata, g);
 
         // Set vertex and edge filters based on subsystems to use
+        int subsys_size = ctx->db->metadata.roots.size ();
         const multi_subsystemsS &filter = ctx->matcher->subsystemsS ();
-        subsystem_selector_t<vtx_t, f_vtx_infra_map_t> vtxsel (vmap, filter);
-        subsystem_selector_t<edg_t, f_edg_infra_map_t> edgsel (emap, filter);
+        subsystem_selector_t<vtx_t, f_vtx_infra_map_t> vtxsel (vmap, filter,
+                                                               subsys_size);
+        subsystem_selector_t<edg_t, f_edg_infra_map_t> edgsel (emap, filter,
+                                                               subsys_size);
         fg = std::make_shared<f_resource_graph_t> (g, edgsel, vtxsel);
     } catch (std::bad_alloc &e) {
         errno = ENOMEM;

resource/reapi/bindings/c++/reapi_cli_impl.hpp

@@ -310,12 +310,15 @@ std::shared_ptr<f_resource_graph_t> resource_query_t::create_filtered_graph ()
     std::shared_ptr<f_resource_graph_t> fg = nullptr;
 
     resource_graph_t &g = db->resource_graph;
+    int subsys_size = db->metadata.roots.size ();
     vtx_infra_map_t vmap = get (&resource_pool_t::idata, g);
     edg_infra_map_t emap = get (&resource_relation_t::idata, g);
     const multi_subsystemsS &filter = 
                         matcher->subsystemsS ();
-    subsystem_selector_t<vtx_t, f_vtx_infra_map_t> vtxsel (vmap, filter);
-    subsystem_selector_t<edg_t, f_edg_infra_map_t> edgsel (emap, filter);
+    subsystem_selector_t<vtx_t, f_vtx_infra_map_t> vtxsel (vmap, filter,
+                                                           subsys_size);
+    subsystem_selector_t<edg_t, f_edg_infra_map_t> edgsel (emap, filter,
+                                                           subsys_size);
 
     try {
         fg = std::make_shared<f_resource_graph_t> (g, edgsel, vtxsel);

resource/schema/resource_graph.hpp

@@ -45,13 +45,19 @@ class subsystem_selector_t {
 public:
     subsystem_selector_t () {}
     ~subsystem_selector_t () {}
-    subsystem_selector_t (inframap &im, const multi_subsystemsS &sel)
+    subsystem_selector_t (inframap &im, const multi_subsystemsS &sel,
+                          int subsys_size)
     {
         // must be lightweight -- e.g., bundled property map.
         m_imap = im;
         m_selector = sel;
+        m_single_subsystem = (subsys_size == 1) ? true : false;
     }
     bool operator () (const graph_entity &ent) const {
+        // Short circuit for single subsystem. This will be a common case.
+        // TODO: make systems ints or enums for faster comparison and search.
+        if (m_single_subsystem)
+           return true;
         typedef typename boost::property_traits<inframap>::value_type infra_type;
         const infra_type &inf = get (m_imap, ent);
         const multi_subsystems_t &subsystems = inf.member_of;
@@ -72,6 +78,7 @@ class subsystem_selector_t {
 private:
     multi_subsystemsS m_selector;
     inframap m_imap;
+    bool m_single_subsystem;
 };
 
 using vtx_infra_map_t = boost::property_map<resource_graph_t, pinfra_t>::type;

resource/utilities/resource-query.cpp

@@ -525,11 +525,14 @@ static std::shared_ptr<f_resource_graph_t> create_filtered_graph (
     std::shared_ptr<f_resource_graph_t> fg = nullptr;
 
     resource_graph_t &g = ctx->db->resource_graph;
+    int subsys_size = ctx->db->metadata.roots.size ();
     vtx_infra_map_t vmap = get (&resource_pool_t::idata, g);
     edg_infra_map_t emap = get (&resource_relation_t::idata, g);
     const multi_subsystemsS &filter = ctx->matcher->subsystemsS ();
-    subsystem_selector_t<vtx_t, f_vtx_infra_map_t> vtxsel (vmap, filter);
-    subsystem_selector_t<edg_t, f_edg_infra_map_t> edgsel (emap, filter);
+    subsystem_selector_t<vtx_t, f_vtx_infra_map_t> vtxsel (vmap, filter,
+                                                           subsys_size);
+    subsystem_selector_t<edg_t, f_edg_infra_map_t> edgsel (emap, filter,
+                                                           subsys_size);
 
     try {
         fg = std::make_shared<f_resource_graph_t> (g, edgsel, vtxsel);