[Rust] Allow reflection verifier to start with custom root

Author: Muon

rust/reflection/src/lib.rs

@@ -22,6 +22,7 @@ pub use vector_of_any::VectorOfAny;
 mod r#struct;
 pub use crate::r#struct::Struct;
 pub use crate::reflection_generated::reflection;
+pub use crate::reflection_verifier::verify_with_options;
 pub use crate::safe_buffer::SafeBuffer;
 
 use flatbuffers::{

rust/reflection/src/reflection_verifier.rs

@@ -28,10 +28,17 @@ pub fn verify_with_options(
     schema: &Schema,
     opts: &VerifierOptions,
     buf_loc_to_obj_idx: &mut HashMap<usize, i32>,
+    root_table_name: Option<&str>,
 ) -> FlatbufferResult<()> {
     let mut verifier = Verifier::new(opts, buffer);
-    if let Some(table_object) = schema.root_table() {
-        if let core::result::Result::Ok(table_pos) = verifier.get_uoffset(0) {
+    let root_table = match root_table_name {
+        Some(name) => schema
+            .objects()
+            .lookup_by_key(name, |o, k| o.key_compare_with_value(k)),
+        None => schema.root_table(),
+    };
+    if let Some(table_object) = root_table {
+        if let Ok(table_pos) = verifier.get_uoffset(0) {
             // Inserts -1 as object index for root table
             buf_loc_to_obj_idx.insert(table_pos.try_into()?, -1);
             let mut verified = vec![false; buffer.len()];

rust/reflection/src/safe_buffer.rs

@@ -49,7 +49,7 @@ impl<'a> SafeBuffer<'a> {
         opts: &VerifierOptions,
     ) -> FlatbufferResult<Self> {
         let mut buf_loc_to_obj_idx = HashMap::new();
-        verify_with_options(&buf, schema, opts, &mut buf_loc_to_obj_idx)?;
+        verify_with_options(&buf, schema, opts, &mut buf_loc_to_obj_idx, None)?;
         Ok(SafeBuffer {
             buf,
             schema,
@@ -141,7 +141,9 @@ impl<'a> SafeTable<'a> {
     pub fn get_field_string(&self, field_name: &str) -> FlatbufferResult<Option<&str>> {
         if let Some(field) = self.safe_buf.find_field_by_name(self.loc, field_name)? {
             // SAFETY: the buffer was verified during construction.
-            Ok(Some(unsafe { get_field_string(&Table::new(&self.safe_buf.buf, self.loc), &field) }))
+            Ok(Some(unsafe {
+                get_field_string(&Table::new(&self.safe_buf.buf, self.loc), &field)
+            }))
         } else {
             Err(FlatbufferError::FieldNotFound)
         }