improve performance by lazily resolving type args

schultek · Jan 30, 2024 · bb6aa17 · bb6aa17
1 parent db2ca09
commit bb6aa17
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Showing 8 changed files with 65 additions and 62 deletions.
diff --git a/packages/dart_mappable/lib/src/mapper_container.dart b/packages/dart_mappable/lib/src/mapper_container.dart
@@ -471,11 +471,17 @@ class _MapperContainerBase implements MapperContainer, TypeProvider {
     var mapper = _mapperFor(value);
     if (mapper != null) {
       try {
-        var typeArgs = value.runtimeType.args
+        return fn(
+            mapper,
+            value,
+            MappingContext(
+              container: this,
+              args: () {
+                return value.runtimeType.args
             .map((t) => t == UnresolvedType ? dynamic : t)
             .toList();
-        return fn(
-            mapper, value, MappingContext(container: this, args: typeArgs));
+              },
+            ));
       } catch (e, stacktrace) {
         Error.throwWithStackTrace(
           MapperException.chain(method, hint(), e),

diff --git a/packages/dart_mappable/lib/src/mapper_utils.dart b/packages/dart_mappable/lib/src/mapper_utils.dart
@@ -1,5 +1,3 @@
-import 'dart:collection';
-
 import 'package:type_plus/type_plus.dart';
 
 import 'annotations.dart';
@@ -81,25 +79,6 @@ extension TypeCheck<T> on T {
   }
 }
 
-class LazyList<T> with ListMixin<T> {
-  LazyList(this.create);
-
-  final Iterable<T> Function() create;
-
-  late final List<T> _list = create().toList();
-
-  @override
-  int get length => _list.length;
-  @override
-  set length(int newLength) => _list.length = newLength;
-
-  @override
-  T operator [](int index) => _list[index];
-
-  @override
-  void operator []=(int index, T value) => _list[index] = value;
-}
-
 extension MapperUtils<T extends Object> on MapperBase<T> {
   bool isValueEqual(T? value, Object? other, [MapperContainer? container]) {
     if (value == null) {
@@ -109,8 +88,9 @@ extension MapperUtils<T extends Object> on MapperBase<T> {
       if (!isFor(other)) return false;
       var context = MappingContext(
         container: container,
-        args: LazyList(() => value.runtimeType.args
-            .map((t) => t == UnresolvedType ? dynamic : t)),
+        args: () => value.runtimeType.args
+            .map((t) => t == UnresolvedType ? dynamic : t)
+            .toList(),
       );
       return equals(value, other as T, context);
     } catch (e, stacktrace) {
@@ -128,8 +108,9 @@ extension MapperUtils<T extends Object> on MapperBase<T> {
     try {
       var context = MappingContext(
         container: container,
-        args: LazyList(() => value.runtimeType.args
-            .map((t) => t == UnresolvedType ? dynamic : t)),
+        args: () => value.runtimeType.args
+            .map((t) => t == UnresolvedType ? dynamic : t)
+            .toList(),
       );
       return hash(value, context);
     } catch (e, stacktrace) {
@@ -147,8 +128,9 @@ extension MapperUtils<T extends Object> on MapperBase<T> {
     try {
       var context = MappingContext(
         container: container,
-        args: LazyList(() => value.runtimeType.args
-            .map((t) => t == UnresolvedType ? dynamic : t)),
+        args: () => value.runtimeType.args
+            .map((t) => t == UnresolvedType ? dynamic : t)
+            .toList(),
       );
       return stringify(value, context);
     } catch (e, stacktrace) {

diff --git a/packages/dart_mappable/lib/src/mappers/class_mapper.dart b/packages/dart_mappable/lib/src/mappers/class_mapper.dart
@@ -136,8 +136,9 @@ abstract class ClassMapperBase<T extends Object>
   /// The set of constructor parameters of this class.
   ///
   /// See [FieldMode] for more.
-  late final List<Field<T, dynamic>> _params =
-      fields.values.where((f) => f.mode != FieldMode.member).toList();
+  late final List<Field<T, dynamic>> _params = fields.values
+      .where((f) => f.mode != FieldMode.member && f.getter != null)
+      .toList();
 
   @override
   T decoder(Object? value, DecodingContext context) {

diff --git a/packages/dart_mappable/lib/src/mappers/interface_mapper.dart b/packages/dart_mappable/lib/src/mappers/interface_mapper.dart
@@ -177,9 +177,7 @@ abstract class InterfaceMapperBase<T extends Object> extends MapperBase<T> {
   }
 
   @protected
-  Object? encode(T value, EncodingContext context) {
-    return encodeFields(value, fields.values, ignoreNull, context);
-  }
+  Object? encode(T value, EncodingContext context);
 
   @protected
   @pragma('vm:prefer-inline')
@@ -189,12 +187,20 @@ abstract class InterfaceMapperBase<T extends Object> extends MapperBase<T> {
       bool ignoreNull,
       EncodingContext context) {
     bool shallow = context.options?.shallow ?? false;
+    if (shallow) {
     return {
       for (var f in fields)
-        if (f.getter != null && (!ignoreNull || f.get(value) != null))
-          f.key: shallow ? f.get(value) : f.encode(value, context),
+          if (!ignoreNull || f.get(value) != null) f.key: f.get(value),
     };
   }
+    if (ignoreNull) {
+      return {
+        for (var f in fields)
+          if (f.get(value) != null) f.key: f.get(value),
+      };
+    }
+    return {for (var f in fields) f.key: f.encode(value, context)};
+  }
 
   V decodeMap<V>(Map<String, dynamic> map) => decodeValue<V>(map);
 

diff --git a/packages/dart_mappable/lib/src/mappers/mapper_base.dart b/packages/dart_mappable/lib/src/mappers/mapper_base.dart
@@ -44,7 +44,7 @@ abstract class MapperBase<T extends Object> {
         value,
         DecodingContext(
           container: container,
-          args: type.args,
+          args: () => type.args,
           options: options,
         ),
       ) as V;
@@ -59,28 +59,29 @@ abstract class MapperBase<T extends Object> {
   Object? encodeValue<V>(V value,
       [EncodingOptions? options, MapperContainer? container]) {
     try {
-      Type type = V;
-
       var includeTypeId = options?.includeTypeId;
       includeTypeId ??= this.includeTypeId<V>(value);
 
-      if (includeTypeId) {
+      var result = this.encoder(
+        value as T,
+        EncodingContext(
+          container: container,
+          options: options?.inheritOptions ?? false ? options : null,
+          args: () {
+            Type type = V;
+            if (includeTypeId ?? false) {
         type = value.runtimeType;
       }
 
-      var typeArgs = type.args.map((t) => t == UnresolvedType ? dynamic : t);
+            var typeArgs =
+                type.args.map((t) => t == UnresolvedType ? dynamic : t);
 
       var fallback = this.type.base.args;
       if (typeArgs.length != fallback.length) {
         typeArgs = fallback;
       }
-
-      var result = this.encoder(
-        value as T,
-        EncodingContext(
-          container: container,
-          options: options?.inheritOptions ?? false ? options : null,
-          args: typeArgs.toList(),
+            return typeArgs.toList();
+          },
         ),
       );
 

diff --git a/packages/dart_mappable/lib/src/mappers/mapping_context.dart b/packages/dart_mappable/lib/src/mappers/mapping_context.dart
@@ -8,10 +8,13 @@ class MappingContext {
   final MapperContainer container;
 
   /// A list of type arguments to get the concrete type for a generic mapper.
-  final List<Type> args;
+  final List<Type> Function()? _args;
 
-  MappingContext({MapperContainer? container, this.args = const []})
-      : container = container ?? MapperContainer.globals;
+  late final List<Type> args = _args?.call() ?? [];
+
+  MappingContext({MapperContainer? container, List<Type> Function()? args})
+      : _args = args,
+        container = container ?? MapperContainer.globals;
 
   Type arg(int index, [List<int> argIndices = const []]) {
     var a = args[index];
@@ -35,16 +38,19 @@ class DecodingContext extends MappingContext {
   final bool inherited;
 
   DecodingContext change(
-      {MapperContainer? container, List<Type>? args, bool? inherited}) {
+      {MapperContainer? container,
+      List<Type> Function()? args,
+      bool? inherited}) {
     return DecodingContext(
       container: container ?? this.container,
-      args: args ?? this.args,
+      args: args ?? _args,
       options: options,
       inherited: inherited ?? this.inherited,
     );
   }
 
-  DecodingContext inherit({MapperContainer? container, List<Type>? args}) {
+  DecodingContext inherit(
+      {MapperContainer? container, List<Type> Function()? args}) {
     return change(container: container, args: args, inherited: true);
   }
 }
@@ -55,10 +61,11 @@ class EncodingContext extends MappingContext {
 
   final EncodingOptions? options;
 
-  EncodingContext change({MapperContainer? container, List<Type>? args}) {
+  EncodingContext change(
+      {MapperContainer? container, List<Type> Function()? args}) {
     return EncodingContext(
       container: container ?? this.container,
-      args: args ?? this.args,
+      args: args ?? _args,
       options: options,
     );
   }

diff --git a/packages/dart_mappable/lib/src/mappers/record_mapper.dart b/packages/dart_mappable/lib/src/mappers/record_mapper.dart
@@ -21,19 +21,19 @@ abstract class RecordMapperBase<T extends Record> extends InterfaceMapperBase<T>
 
   @override
   T decode(Object? value, DecodingContext context) {
-    return super.decode(value, context.change(args: apply(context)));
+    return super.decode(value, context.change(args: () => apply(context)));
   }
 
   @override
   Object? encode(T value, EncodingContext context) {
-    return super.encode(value, context.change(args: apply(context)));
+    return InterfaceMapperBase.encodeFields(value, fields.values, ignoreNull,
+        context.change(args: () => apply(context)));
   }
 
   @override
   bool isForType(Type type) {
     try {
-      var args = type.args;
-      var newArgs = apply(DecodingContext(args: args));
+      var newArgs = apply(DecodingContext(args: () => type.args));
       var instantiatedType = typeFactory
           .callWith(parameters: [<T>() => T], typeArguments: newArgs);
       return type == instantiatedType;

diff --git a/packages/dart_mappable_builder/lib/src/generators/mixins/decoding_mixin.dart b/packages/dart_mappable_builder/lib/src/generators/mixins/decoding_mixin.dart
@@ -74,7 +74,7 @@ mixin DecodingMixin on MapperGenerator<TargetClassMapperElement> {
     output.write('''
       @override
       DecodingContext inherit(DecodingContext context) {
-        return context.inherit(args: [${args.join(', ')}]);
+        return context.inherit(args: () => [${args.join(', ')}]);
       }
     ''');
   }