show number of entries

src/render.cpp

@@ -361,6 +361,7 @@ void update_and_render(Arena *arena, App_State &app, f32 delta_time_ms)
       ImGui::Text("TFile compression: %u", app.tfile_data.compression);
       ImGui::Text("Num pages: %lu", app.rndata.n_pages);
       ImGui::Text("Num elements: %lu", app.rndata.n_elems);
+      ImGui::Text("Num entries: %lu", app.rndata.n_entries);
       if (app.rndata.tot_page_uncomp_size) {
         ImGui::Text("Pages uncompressed size: %s (comp.ratio = %.3f)",
                     to_pretty_size(scratch.arena, app.rndata.tot_page_uncomp_size).c(),

src/rntuple.cpp

@@ -88,7 +88,8 @@ void gather_ntuple_metadata(Arena *arena, RMicroFileReader &reader, const RNTupl
   
   u64 n_pages = 0;
   u64 n_duplicate_page_ranges = 0;
-  u64 n_elems = 0;
+  u64 n_elems = 0; // total number of page elements
+  u64 n_entries = 0;
   u64 tot_page_comp_size = 0;
   Page_Info_Node *pinfo_head = nullptr, *pinfo_tail = nullptr;
   Page_Info_Node *last_inserted_pinfo = nullptr;
@@ -106,6 +107,7 @@ void gather_ntuple_metadata(Arena *arena, RMicroFileReader &reader, const RNTupl
   // gather clusters and pages metadata
   for (const RClusterDescriptor &cluster_desc : descriptor.GetClusterIterable()) {
     ++n_clusters;
+    n_entries += cluster_desc.GetNEntries();
 
     for (const RClusterDescriptor::RColumnRange &col_range : cluster_desc.GetColumnRangeIterable()) {
       const auto &col_descriptor = descriptor.GetColumnDescriptor(col_range.fPhysicalColumnId);
@@ -304,6 +306,7 @@ void gather_ntuple_metadata(Arena *arena, RMicroFileReader &reader, const RNTupl
   rndata.tot_page_list_size = tot_page_list_size;
   rndata.clusters = clusters;
   rndata.n_clusters = n_clusters;
+  rndata.n_entries = n_entries;
 }
 
 internal

src/rntuple.h

@@ -90,6 +90,8 @@ struct RNTuple_Data {
 
   Cluster_Info *clusters;
   u64 n_clusters;
+  // total number of entries of all clusters
+  u64 n_entries;
 
   Page_Info_Group *page_groups;
   u64 n_page_groups;