more stuff for header hover

src/rntuple.cpp

@@ -718,6 +718,21 @@ struct Sec_Hover_Fn {
   Sec_Hover_Info &info;
   u64 &cur_field_off;
 
+  template <typename F>
+  b8 titled_section(const char *title, F &&fn) const
+  {
+    String8_Node *prev_desc = info.desc;
+    info.desc = push_str8_node_child(arena, prev_desc, title);
+
+    b8 ok = fn();
+
+    if (!ok) {
+      pop_str8_node_child(prev_desc, info.desc);
+      info.desc = prev_desc;
+    }
+    return ok;
+  }
+
   template <typename T>
   b8 field(const char *desc_fmt, Display_Fn<T> display_val) const
   {
@@ -752,6 +767,9 @@ struct Sec_Hover_Fn {
     // String size can be stored as different types, like u8 (by ROOT I/O) or u32 (by RNTuple).
     TStrSize str_size;
     memcpy(&str_size, data + start + cur_field_off, sizeof(TStrSize));
+    // TEMP DEBUG
+    if (str_size > 1000)
+      return false;
     if (roff < cur_field_off + sizeof(TStrSize) + str_size) {
       info.rng = { start + cur_field_off, sizeof(TStrSize) + (u64)str_size };
       u8 *buf = arena_push_array_nozero<u8>(arena, str_size + 1);
@@ -879,26 +897,61 @@ struct Sec_Hover_Fn {
     });
   }
 
-  b8 schema_description() const
+  b8 field_desc() const
   {
-    return titled_section("Schema Description", [this] {
+    static const char *const field_struct_names[] = {
-      return list_frame_preamble();
+      "Leaf", "Collection", "Record", "Variant", "Unsplit"
+    };
+    return titled_section("Field", [this] {
+      u64 flags_off = start + cur_field_off + 22;
+      u16 flags;
+      memcpy(&flags, data + flags_off, sizeof(flags));
+      b8 ok = field_le<i64>("Size: %" PRIi64)  
+          || field_le<u32>("Field version: %u")
+          || field_le<u32>("Type version: %u")
+          || field_le<u32>("On-disk parent id: %u")
+          || field<u16>("Field structure: %s", [] (Arena *arena, String8_Node *prev, const char *fmt, u16 type) {
+            const char *name = (type >= countof(field_struct_names)) ? "Unknown" : field_struct_names[type];
+            return push_str8_node_child(arena, prev, fmt, name);
+          })
+          || field_le<u16>("Flags: %u")
+          ;
+      if (ok)
+        return ok;
+
+      using ROOT::Experimental::Internal::RNTupleSerializer;
+
+      if ((flags & RNTupleSerializer::kFlagRepetitiveField) && field_le<u64>("N Repetitions: %" PRIu64))
+        return true;
+      if ((flags & RNTupleSerializer::kFlagProjectedField) && field_le<u32>("On disk proj.src id: %u"))
+        return true;
+      if ((flags & RNTupleSerializer::kFlagHasTypeChecksum) && field_le<u32>("Checksum: %u"))
+        return true;
+
+      return field_str8<u32>("Name: %s")
+          || field_str8<u32>("Type Name: %s")
+          || field_str8<u32>("Type Alias: %s")
+          || field_str8<u32>("Description: %s")
+          ;
     });
   }
 
-  template <typename F>
+  b8 schema_description() const
-  b8 titled_section(const char *title, F &&fn) const
   {
-    String8_Node *prev_desc = info.desc;
+    return titled_section("Schema Description", [this] {
-    info.desc = push_str8_node_child(arena, prev_desc, title);
+      if (list_frame_preamble())
-
+        return true;
-    b8 ok = fn();
+      // we need to read back the number of fields to know how long is the next section.
-
+      u64 n_fields_off = cur_field_off - sizeof(u32);
-    if (!ok) {
+      u32 n_fields;
-      pop_str8_node_child(prev_desc, info.desc);
+      memcpy(&n_fields, data + start + n_fields_off, sizeof(n_fields));
-      info.desc = prev_desc;
+      for (u32 i = 0; i < n_fields; ++i)
-    }
+        if (field_desc())
-    return ok;
+          return true;
+      if (field<i64>("Size: %" PRIi64, hover_display_val_le_abs<i64>))
+        return true;
+      return false; // TODO
+    });
   }
 };
 
@@ -1059,6 +1112,7 @@ Sec_Hover_Info get_section_hover_info(Arena *arena, Section section, u64 off, co
           || hover.field_str8<u32>("Description: %s")
           || hover.field_str8<u32>("ROOT version: %s")
           || hover.schema_description()
+          || hover.range("Payload", section.range.len - hover.cur_field_off) // TODO
           || hover.field_le<u64>("Checksum: 0x%" PRIX64)
           ;
         }