Sync map accessors implementation from PR #700

protobuf/src/reflect/acc/v2/map.rs

@@ -1,3 +1,4 @@
+use std::collections::BTreeMap;
 use std::collections::HashMap;
 use std::fmt;
 use std::hash::Hash;
@@ -29,17 +30,15 @@ impl<'a> fmt::Debug for MapFieldAccessorHolder {
     }
 }
 
-struct MapFieldAccessorImpl<M, K, V>
+struct MapFieldAccessorImpl<M, T>
 where
     M: MessageFull,
-    K: ProtobufValue,
-    V: ProtobufValue,
 {
-    get_field: fn(&M) -> &HashMap<K, V>,
-    mut_field: fn(&mut M) -> &mut HashMap<K, V>,
+    get_field: fn(&M) -> &T,
+    mut_field: fn(&mut M) -> &mut T,
 }
 
-impl<M, K, V> MapFieldAccessor for MapFieldAccessorImpl<M, K, V>
+impl<M, K, V> MapFieldAccessor for MapFieldAccessorImpl<M, HashMap<K, V>>
 where
     M: MessageFull,
     K: ProtobufValue + Eq + Hash,
@@ -66,7 +65,35 @@ where
     }
 }
 
-/// Make accessor for map field
+impl<M, K, V> MapFieldAccessor for MapFieldAccessorImpl<M, BTreeMap<K, V>>
+where
+    M: MessageFull,
+    K: ProtobufValue + Ord,
+    K::RuntimeType: RuntimeTypeMapKey,
+    V: ProtobufValue,
+{
+    fn get_reflect<'a>(&self, m: &'a dyn MessageDyn) -> ReflectMapRef<'a> {
+        let m = m.downcast_ref().unwrap();
+        let map = (self.get_field)(m);
+        ReflectMapRef::new(map)
+    }
+
+    fn mut_reflect<'a>(&self, m: &'a mut dyn MessageDyn) -> ReflectMapMut<'a> {
+        let m = m.downcast_mut().unwrap();
+        let map = (self.mut_field)(m);
+        ReflectMapMut::new(map)
+    }
+
+    fn element_type(&self) -> (RuntimeType, RuntimeType) {
+        (
+            K::RuntimeType::runtime_type_box(),
+            V::RuntimeType::runtime_type_box(),
+        )
+    }
+}
+
+/// Make accessor for map field.
+/// This is code generated by rust-protobuf before 3.5.
 pub fn make_map_simpler_accessor<M, K, V>(
     name: &'static str,
     get_field: for<'a> fn(&'a M) -> &'a HashMap<K, V>,
@@ -77,11 +104,24 @@ where
     K: ProtobufValue + Hash + Eq,
     K::RuntimeType: RuntimeTypeMapKey,
     V: ProtobufValue,
+{
+    make_map_simpler_accessor_new(name, get_field, mut_field)
+}
+
+/// Make accessor for map field, new version
+pub fn make_map_simpler_accessor_new<M, T>(
+    name: &'static str,
+    get_field: for<'a> fn(&'a M) -> &'a T,
+    mut_field: for<'a> fn(&'a mut M) -> &'a mut T,
+) -> FieldAccessor
+where
+    M: MessageFull,
+    MapFieldAccessorImpl<M, T>: MapFieldAccessor,
 {
     FieldAccessor::new(
         name,
         AccessorV2::Map(MapFieldAccessorHolder {
-            accessor: Box::new(MapFieldAccessorImpl::<M, K, V> {
+            accessor: Box::new(MapFieldAccessorImpl::<M, T> {
                 get_field,
                 mut_field,
             }),

protobuf/src/reflect/rt/v2.rs

@@ -3,6 +3,7 @@
 #![doc(hidden)]
 
 pub use crate::reflect::acc::v2::map::make_map_simpler_accessor;
+pub use crate::reflect::acc::v2::map::make_map_simpler_accessor_new;
 pub use crate::reflect::acc::v2::repeated::make_vec_simpler_accessor;
 pub use crate::reflect::acc::v2::singular::make_message_field_accessor;
 pub use crate::reflect::acc::v2::singular::make_option_accessor;