lib/message_generator.dart - dart-protoc-plugin - Git at Google

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 part of protoc;

 class MessageGenerator extends ProtobufContainer {
   /// Returns the mixin for this message, or null if none.
   ///
   /// First searches [declaredMixins], then internal mixins declared by
   /// [findMixin].
   static PbMixin _getMixin(DescriptorProto desc, FileDescriptorProto file,
       Map<String, PbMixin> declaredMixins, PbMixin defaultMixin) {
     if (!desc.hasOptions() || !desc.options.hasExtension(Dart_options.mixin)) {
       return defaultMixin;
     }

     String name = desc.options.getExtension(Dart_options.mixin);
     if (name.isEmpty) return null; // don't use any mixins (override default)
     var mixin = declaredMixins[name] ?? findMixin(name);
     if (mixin == null) {
       throw '${desc.name} in ${file.name}: mixin "$name" not found';
     }
     return mixin;
   }

   /// The name of the Dart class to generate.
   final String classname;

   /// The fully-qualified name of the message (without any leading '.').
   final String fullName;

   /// The part of the fully qualified name that comes after the package prefix.
   ///
   /// For nested messages this will include the names of the parents.
   ///
   /// For example:
   /// ```
   /// package foo;
   ///
   /// message Container {
   ///   message Nested {
   ///     int32 int32_value = 1;
   ///   }
   /// }
   /// ```
   /// The nested message will have a `fullName` of 'foo.Container.Nested', and a
   /// `messageName` of 'Container.Nested'.
   String get messageName =>
       fullName.substring(package.length == 0 ? 0 : package.length + 1);

   final PbMixin mixin;

   final ProtobufContainer _parent;
   final DescriptorProto _descriptor;
   final List<EnumGenerator> _enumGenerators = <EnumGenerator>[];
   final List<MessageGenerator> _messageGenerators = <MessageGenerator>[];
   final List<ExtensionGenerator> _extensionGenerators = <ExtensionGenerator>[];

   // populated by resolve()
   List<ProtobufField> _fieldList;

   MessageGenerator(DescriptorProto descriptor, ProtobufContainer parent,
       Map<String, PbMixin> declaredMixins, PbMixin defaultMixin)
       : _descriptor = descriptor,
         _parent = parent,
         classname = messageOrEnumClassName(descriptor.name,
             parent: parent?.classname ?? ''),
         assert(parent != null),
         fullName = parent.fullName == ''
             ? descriptor.name
             : '${parent.fullName}.${descriptor.name}',
         mixin = _getMixin(descriptor, parent.fileGen.descriptor, declaredMixins,
             defaultMixin) {
     for (EnumDescriptorProto e in _descriptor.enumType) {
       _enumGenerators.add(new EnumGenerator(e, this));
     }

     for (DescriptorProto n in _descriptor.nestedType) {
       _messageGenerators
           .add(new MessageGenerator(n, this, declaredMixins, defaultMixin));
     }

     for (FieldDescriptorProto x in _descriptor.extension) {
       _extensionGenerators.add(new ExtensionGenerator(x, this));
     }
   }

   String get package => _parent.package;

   /// The generator of the .pb.dart file that will declare this type.
   FileGenerator get fileGen => _parent.fileGen;

   /// Throws an exception if [resolve] hasn't been called yet.
   void checkResolved() {
     if (_fieldList == null) {
       throw new StateError("message not resolved: ${fullName}");
     }
   }

   /// Returns a const expression that evaluates to the JSON for this message.
   /// [usage] represents the .pb.dart file where the expression will be used.
   String getJsonConstant(FileGenerator usage) {
     var name = "$classname\$json";
     if (usage.protoFileUri == fileGen.protoFileUri) {
       return name;
     }
     return "$fileImportPrefix.$name";
   }

   /// Adds all mixins used in this message and any submessages.
   void addMixinsTo(Set<PbMixin> output) {
     if (mixin != null) {
       output.addAll(mixin.findMixinsToApply());
     }
     for (var m in _messageGenerators) {
       m.addMixinsTo(output);
     }
   }

   // Registers message and enum types that can be used elsewhere.
   void register(GenerationContext ctx) {
     ctx.registerFieldType(this);
     for (var m in _messageGenerators) {
       m.register(ctx);
     }
     for (var e in _enumGenerators) {
       e.register(ctx);
     }
   }

   // Creates fields and resolves extension targets.
   void resolve(GenerationContext ctx) {
     if (_fieldList != null) throw new StateError("message already resolved");

     var reserved = mixin?.findReservedNames() ?? const <String>[];
     var fields = messageFieldNames(_descriptor, reserved: reserved);

     _fieldList = <ProtobufField>[];
     for (MemberNames names in fields.values) {
       _fieldList.add(new ProtobufField.message(names, this, ctx));
     }

     for (var m in _messageGenerators) {
       m.resolve(ctx);
     }
     for (var x in _extensionGenerators) {
       x.resolve(ctx);
     }
   }

   bool get needsFixnumImport {
     if (_fieldList == null) throw new StateError("message not resolved");
     for (var field in _fieldList) {
       if (field.needsFixnumImport) return true;
     }
     for (var m in _messageGenerators) {
       if (m.needsFixnumImport) return true;
     }
     for (var x in _extensionGenerators) {
       if (x.needsFixnumImport) return true;
     }
     return false;
   }

   /// Adds dependencies of [generate] to [imports].
   ///
   /// For each .pb.dart file that the generated code needs to import,
   /// add its generator.
   void addImportsTo(
       Set<FileGenerator> imports, Set<FileGenerator> enumImports) {
     if (_fieldList == null) throw new StateError("message not resolved");
     for (var field in _fieldList) {
       var typeGen = field.baseType.generator;
       if (typeGen is EnumGenerator) {
         enumImports.add(typeGen.fileGen);
       } else if (typeGen != null) {
         imports.add(typeGen.fileGen);
       }
     }
     for (var m in _messageGenerators) {
       m.addImportsTo(imports, enumImports);
     }
     for (var x in _extensionGenerators) {
       x.addImportsTo(imports, enumImports);
     }
   }

   // Returns the number of enums in this message and all nested messages.
   int get enumCount {
     var count = _enumGenerators.length;
     for (var m in _messageGenerators) {
       count += m.enumCount;
     }
     return count;
   }

   /// Adds dependencies of [generateConstants] to [imports].
   ///
   /// For each .pbjson.dart file that the generated code needs to import,
   /// add its generator.
   void addConstantImportsTo(Set<FileGenerator> imports) {
     if (_fieldList == null) throw new StateError("message not resolved");
     for (var m in _messageGenerators) {
       m.addConstantImportsTo(imports);
     }
     for (var x in _extensionGenerators) {
       x.addConstantImportsTo(imports);
     }
   }

   void generate(IndentingWriter out) {
     checkResolved();

     for (MessageGenerator m in _messageGenerators) {
       m.generate(out);
     }

     var mixinClause = '';
     if (mixin != null) {
       var mixinNames = mixin.findMixinsToApply().map((m) => m.name);
       mixinClause = ' with ${mixinNames.join(", ")}';
     }

     String packageClause = package == ''
         ? ''
         : ', package: const $_protobufImportPrefix.PackageName(\'$package\')';
     out.addBlock(
         'class ${classname} extends $_protobufImportPrefix.GeneratedMessage${mixinClause} {',
         '}', () {
       out.addBlock(
           'static final $_protobufImportPrefix.BuilderInfo _i = '
           'new $_protobufImportPrefix.BuilderInfo(\'${messageName}\'$packageClause)',
           ';', () {
         for (ProtobufField field in _fieldList) {
           var dartFieldName = field.memberNames.fieldName;
           out.println(field.generateBuilderInfoCall(fileGen, dartFieldName));
         }

         if (_descriptor.extensionRange.length > 0) {
           out.println('..hasExtensions = true');
         }
         if (!_hasRequiredFields(this, new Set())) {
           out.println('..hasRequiredFields = false');
         }
       });

       for (ExtensionGenerator x in _extensionGenerators) {
         x.generate(out);
       }

       out.println();

       out.println('${classname}() : super();');
       out.println('${classname}.fromBuffer(List<int> i,'
           ' [$_protobufImportPrefix.ExtensionRegistry r = $_protobufImportPrefix.ExtensionRegistry.EMPTY])'
           ' : super.fromBuffer(i, r);');
       out.println('${classname}.fromJson(String i,'
           ' [$_protobufImportPrefix.ExtensionRegistry r = $_protobufImportPrefix.ExtensionRegistry.EMPTY])'
           ' : super.fromJson(i, r);');
       out.println('${classname} clone() =>'
           ' new ${classname}()..mergeFromMessage(this);');
       out.println('$classname copyWith(void Function($classname) updates) =>'
           ' super.copyWith((message) => updates(message as $classname));');

       out.println('$_protobufImportPrefix.BuilderInfo get info_ => _i;');

       // Factory functions which can be used as default value closures.
       out.println('static ${classname} create() =>'
           ' new ${classname}();');
       out.println(
           'static $_protobufImportPrefix.PbList<${classname}> createRepeated() =>'
           ' new $_protobufImportPrefix.PbList<${classname}>();');
       out.println(
           'static ${classname} getDefault() => _defaultInstance ??= create()..freeze();');
       out.println('static ${classname} _defaultInstance;');
       out.addBlock('static void $checkItem($classname v) {', '}', () {
         out.println('if (v is! $classname)'
             " $_protobufImportPrefix.checkItemFailed(v, _i.messageName);");
       });
       generateFieldsAccessorsMutators(out);
       if (fullName == 'google.protobuf.Any') {
         generateAnyMethods(out);
       }
     });
     out.println();
   }

   // Returns true if the message type has any required fields.  If it doesn't,
   // we can optimize out calls to its isInitialized()/_findInvalidFields()
   // methods.
   //
   // already_seen is used to avoid checking the same type multiple times
   // (and also to protect against unbounded recursion).
   bool _hasRequiredFields(MessageGenerator type, Set alreadySeen) {
     if (type._fieldList == null) throw new StateError("message not resolved");

     if (alreadySeen.contains(type.fullName)) {
       // The type is already in cache.  This means that either:
       // a. The type has no required fields.
       // b. We are in the midst of checking if the type has required fields,
       //    somewhere up the stack.  In this case, we know that if the type
       //    has any required fields, they'll be found when we return to it,
       //    and the whole call to HasRequiredFields() will return true.
       //    Therefore, we don't have to check if this type has required fields
       //    here.
       return false;
     }
     alreadySeen.add(type.fullName);
     // If the type has extensions, an extension with message type could contain
     // required fields, so we have to be conservative and assume such an
     // extension exists.
     if (type._descriptor.extensionRange.length > 0) {
       return true;
     }

     for (ProtobufField field in type._fieldList) {
       if (field.isRequired) {
         return true;
       }
       if (field.baseType.isMessage) {
         MessageGenerator child = field.baseType.generator;
         if (_hasRequiredFields(child, alreadySeen)) {
           return true;
         }
       }
     }
     return false;
   }

   /// Generates methods for the Any message class for packing and unpacking
   /// values.
   void generateAnyMethods(IndentingWriter out) {
     out.println('''
   /// Unpacks the message in [value] into [instance].
   ///
   /// Throws a [InvalidProtocolBufferException] if [typeUrl] does not correspond
   /// to the type of [instance].
   ///
   /// A typical usage would be `any.unpackInto(new Message())`.
   ///
   /// Returns [instance].
   T unpackInto<T extends $_protobufImportPrefix.GeneratedMessage>(T instance,
       {$_protobufImportPrefix.ExtensionRegistry extensionRegistry = $_protobufImportPrefix.ExtensionRegistry.EMPTY}) {
     $_protobufImportPrefix.unpackIntoHelper(value, instance, typeUrl,
         extensionRegistry: extensionRegistry);
     return instance;
   }

   /// Returns `true` if the encoded message matches the type of [instance].
   ///
   /// Can be used with a default instance:
   /// `any.canUnpackInto(Message.getDefault())`
   bool canUnpackInto($_protobufImportPrefix.GeneratedMessage instance) {
     return $_protobufImportPrefix.canUnpackIntoHelper(instance, typeUrl);
   }

   /// Creates a new [Any] encoding [message].
   ///
   /// The [typeUrl] will be [typeUrlPrefix]/`fullName` where `fullName` is
   /// the fully qualified name of the type of [message].
   static Any pack($_protobufImportPrefix.GeneratedMessage message,
       {String typeUrlPrefix = 'type.googleapis.com'}) {
     return new Any()
       ..value = message.writeToBuffer()
       ..typeUrl = '\${typeUrlPrefix}/\${message.info_.messageName}';
   }''');
   }

   void generateFieldsAccessorsMutators(IndentingWriter out) {
     for (ProtobufField field in _fieldList) {
       out.println();
       generateFieldAccessorsMutators(field, out);
     }
   }

   void generateFieldAccessorsMutators(
       ProtobufField field, IndentingWriter out) {
     var fieldTypeString = field.getDartType(fileGen);
     var defaultExpr = field.getDefaultExpr();
     var names = field.memberNames;

     _emitOverrideIf(field.overridesGetter, out);
     var getterExpr = _getterExpression(
         fieldTypeString, field.index, defaultExpr, field.isRepeated);
     out.println('${fieldTypeString} get ${names.fieldName} => ${getterExpr};');

     if (field.isRepeated) {
       if (field.overridesSetter) {
         throw 'Field ${field.fullName} cannot override a setter for '
             '${names.fieldName} because it is repeated.';
       }
       if (field.overridesHasMethod) {
         throw 'Field ${field.fullName} cannot override '
             '${names.hasMethodName}() because it is repeated.';
       }
       if (field.overridesClearMethod) {
         throw 'Field ${field.fullName} cannot override '
             '${names.clearMethodName}() because it is repeated.';
       }
     } else {
       var fastSetter = field.baseType.setter;
       _emitOverrideIf(field.overridesSetter, out);
       if (fastSetter != null) {
         out.println('set ${names.fieldName}'
             '($fieldTypeString v) { '
             '$fastSetter(${field.index}, v);'
             ' }');
       } else {
         out.println('set ${names.fieldName}'
             '($fieldTypeString v) { '
             'setField(${field.number}, v);'
             ' }');
       }
       _emitOverrideIf(field.overridesHasMethod, out);
       out.println('bool ${names.hasMethodName}() =>'
           ' \$_has(${field.index});');
       _emitOverrideIf(field.overridesClearMethod, out);
       out.println('void ${names.clearMethodName}() =>'
           ' clearField(${field.number});');
     }
   }

   String _getterExpression(
       String fieldType, int index, String defaultExpr, bool isRepeated) {
     if (fieldType == 'String') {
       return '\$_getS($index, $defaultExpr)';
     }
     if (fieldType == 'Int64' && defaultExpr == 'null') {
       return '\$_getI64($index)';
     }
     if (defaultExpr == 'null') {
       return isRepeated ? '\$_getList($index)' : '\$_getN($index)';
     }
     return '\$_get($index, $defaultExpr)';
   }

   void _emitOverrideIf(bool condition, IndentingWriter out) {
     if (condition) {
       out.println('@override');
     }
   }

   void generateEnums(IndentingWriter out) {
     for (EnumGenerator e in _enumGenerators) {
       e.generate(out);
     }

     for (MessageGenerator m in _messageGenerators) {
       m.generateEnums(out);
     }
   }

   /// Writes a Dart constant containing the JSON for the ProtoDescriptor.
   /// Also writes a separate constant for each nested message,
   /// to avoid duplication.
   void generateConstants(IndentingWriter out) {
     const nestedTypeTag = 3;
     const enumTypeTag = 4;
     assert(_descriptor.info_.fieldInfo[nestedTypeTag].name == "nestedType");
     assert(_descriptor.info_.fieldInfo[enumTypeTag].name == "enumType");

     var name = getJsonConstant(fileGen);
     var json = _descriptor.writeToJsonMap();
     var nestedTypeNames =
         _messageGenerators.map((m) => m.getJsonConstant(fileGen)).toList();
     var nestedEnumNames =
         _enumGenerators.map((e) => e.getJsonConstant(fileGen)).toList();

     out.addBlock("const $name = const {", "};", () {
       for (var key in json.keys) {
         out.print("'$key': ");
         if (key == "$nestedTypeTag") {
           // refer to message constants by name instead of repeating each value
           out.println("const [${nestedTypeNames.join(", ")}],");
           continue;
         } else if (key == "$enumTypeTag") {
           // refer to enum constants by name
           out.println("const [${nestedEnumNames.join(", ")}],");
           continue;
         }
         writeJsonConst(out, json[key]);
         out.println(",");
       }
     });
     out.println();

     for (var m in _messageGenerators) {
       m.generateConstants(out);
     }

     for (var e in _enumGenerators) {
       e.generateConstants(out);
     }
   }
 }
	// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	part of protoc;

	class MessageGenerator extends ProtobufContainer {
	/// Returns the mixin for this message, or null if none.
	///
	/// First searches [declaredMixins], then internal mixins declared by
	/// [findMixin].
	static PbMixin _getMixin(DescriptorProto desc, FileDescriptorProto file,
	Map<String, PbMixin> declaredMixins, PbMixin defaultMixin) {
	if (!desc.hasOptions() \|\| !desc.options.hasExtension(Dart_options.mixin)) {
	return defaultMixin;
	}

	String name = desc.options.getExtension(Dart_options.mixin);
	if (name.isEmpty) return null; // don't use any mixins (override default)
	var mixin = declaredMixins[name] ?? findMixin(name);
	if (mixin == null) {
	throw '${desc.name} in ${file.name}: mixin "$name" not found';
	}
	return mixin;
	}

	/// The name of the Dart class to generate.
	final String classname;

	/// The fully-qualified name of the message (without any leading '.').
	final String fullName;

	/// The part of the fully qualified name that comes after the package prefix.
	///
	/// For nested messages this will include the names of the parents.
	///
	/// For example:
	/// ```
	/// package foo;
	///
	/// message Container {
	/// message Nested {
	/// int32 int32_value = 1;
	/// }
	/// }
	/// ```
	/// The nested message will have a `fullName` of 'foo.Container.Nested', and a
	/// `messageName` of 'Container.Nested'.
	String get messageName =>
	fullName.substring(package.length == 0 ? 0 : package.length + 1);

	final PbMixin mixin;

	final ProtobufContainer _parent;
	final DescriptorProto _descriptor;
	final List<EnumGenerator> _enumGenerators = <EnumGenerator>[];
	final List<MessageGenerator> _messageGenerators = <MessageGenerator>[];
	final List<ExtensionGenerator> _extensionGenerators = <ExtensionGenerator>[];

	// populated by resolve()
	List<ProtobufField> _fieldList;

	MessageGenerator(DescriptorProto descriptor, ProtobufContainer parent,
	Map<String, PbMixin> declaredMixins, PbMixin defaultMixin)
	: _descriptor = descriptor,
	_parent = parent,
	classname = messageOrEnumClassName(descriptor.name,
	parent: parent?.classname ?? ''),
	assert(parent != null),
	fullName = parent.fullName == ''
	? descriptor.name
	: '${parent.fullName}.${descriptor.name}',
	mixin = _getMixin(descriptor, parent.fileGen.descriptor, declaredMixins,
	defaultMixin) {
	for (EnumDescriptorProto e in _descriptor.enumType) {
	_enumGenerators.add(new EnumGenerator(e, this));
	}

	for (DescriptorProto n in _descriptor.nestedType) {
	_messageGenerators
	.add(new MessageGenerator(n, this, declaredMixins, defaultMixin));
	}

	for (FieldDescriptorProto x in _descriptor.extension) {
	_extensionGenerators.add(new ExtensionGenerator(x, this));
	}
	}

	String get package => _parent.package;

	/// The generator of the .pb.dart file that will declare this type.
	FileGenerator get fileGen => _parent.fileGen;

	/// Throws an exception if [resolve] hasn't been called yet.
	void checkResolved() {
	if (_fieldList == null) {
	throw new StateError("message not resolved: ${fullName}");
	}
	}

	/// Returns a const expression that evaluates to the JSON for this message.
	/// [usage] represents the .pb.dart file where the expression will be used.
	String getJsonConstant(FileGenerator usage) {
	var name = "$classname\$json";
	if (usage.protoFileUri == fileGen.protoFileUri) {
	return name;
	}
	return "$fileImportPrefix.$name";
	}

	/// Adds all mixins used in this message and any submessages.
	void addMixinsTo(Set<PbMixin> output) {
	if (mixin != null) {
	output.addAll(mixin.findMixinsToApply());
	}
	for (var m in _messageGenerators) {
	m.addMixinsTo(output);
	}
	}

	// Registers message and enum types that can be used elsewhere.
	void register(GenerationContext ctx) {
	ctx.registerFieldType(this);
	for (var m in _messageGenerators) {
	m.register(ctx);
	}
	for (var e in _enumGenerators) {
	e.register(ctx);
	}
	}

	// Creates fields and resolves extension targets.
	void resolve(GenerationContext ctx) {
	if (_fieldList != null) throw new StateError("message already resolved");

	var reserved = mixin?.findReservedNames() ?? const <String>[];
	var fields = messageFieldNames(_descriptor, reserved: reserved);

	_fieldList = <ProtobufField>[];
	for (MemberNames names in fields.values) {
	_fieldList.add(new ProtobufField.message(names, this, ctx));
	}

	for (var m in _messageGenerators) {
	m.resolve(ctx);
	}
	for (var x in _extensionGenerators) {
	x.resolve(ctx);
	}
	}

	bool get needsFixnumImport {
	if (_fieldList == null) throw new StateError("message not resolved");
	for (var field in _fieldList) {
	if (field.needsFixnumImport) return true;
	}
	for (var m in _messageGenerators) {
	if (m.needsFixnumImport) return true;
	}
	for (var x in _extensionGenerators) {
	if (x.needsFixnumImport) return true;
	}
	return false;
	}

	/// Adds dependencies of [generate] to [imports].
	///
	/// For each .pb.dart file that the generated code needs to import,
	/// add its generator.
	void addImportsTo(
	Set<FileGenerator> imports, Set<FileGenerator> enumImports) {
	if (_fieldList == null) throw new StateError("message not resolved");
	for (var field in _fieldList) {
	var typeGen = field.baseType.generator;
	if (typeGen is EnumGenerator) {
	enumImports.add(typeGen.fileGen);
	} else if (typeGen != null) {
	imports.add(typeGen.fileGen);
	}
	}
	for (var m in _messageGenerators) {
	m.addImportsTo(imports, enumImports);
	}
	for (var x in _extensionGenerators) {
	x.addImportsTo(imports, enumImports);
	}
	}

	// Returns the number of enums in this message and all nested messages.
	int get enumCount {
	var count = _enumGenerators.length;
	for (var m in _messageGenerators) {
	count += m.enumCount;
	}
	return count;
	}

	/// Adds dependencies of [generateConstants] to [imports].
	///
	/// For each .pbjson.dart file that the generated code needs to import,
	/// add its generator.
	void addConstantImportsTo(Set<FileGenerator> imports) {
	if (_fieldList == null) throw new StateError("message not resolved");
	for (var m in _messageGenerators) {
	m.addConstantImportsTo(imports);
	}
	for (var x in _extensionGenerators) {
	x.addConstantImportsTo(imports);
	}
	}

	void generate(IndentingWriter out) {
	checkResolved();

	for (MessageGenerator m in _messageGenerators) {
	m.generate(out);
	}

	var mixinClause = '';
	if (mixin != null) {
	var mixinNames = mixin.findMixinsToApply().map((m) => m.name);
	mixinClause = ' with ${mixinNames.join(", ")}';
	}

	String packageClause = package == ''
	? ''
	: ', package: const $_protobufImportPrefix.PackageName(\'$package\')';
	out.addBlock(
	'class ${classname} extends $_protobufImportPrefix.GeneratedMessage${mixinClause} {',
	'}', () {
	out.addBlock(
	'static final $_protobufImportPrefix.BuilderInfo _i = '
	'new $_protobufImportPrefix.BuilderInfo(\'${messageName}\'$packageClause)',
	';', () {
	for (ProtobufField field in _fieldList) {
	var dartFieldName = field.memberNames.fieldName;
	out.println(field.generateBuilderInfoCall(fileGen, dartFieldName));
	}

	if (_descriptor.extensionRange.length > 0) {
	out.println('..hasExtensions = true');
	}
	if (!_hasRequiredFields(this, new Set())) {
	out.println('..hasRequiredFields = false');
	}
	});

	for (ExtensionGenerator x in _extensionGenerators) {
	x.generate(out);
	}

	out.println();

	out.println('${classname}() : super();');
	out.println('${classname}.fromBuffer(List<int> i,'
	' [$_protobufImportPrefix.ExtensionRegistry r = $_protobufImportPrefix.ExtensionRegistry.EMPTY])'
	' : super.fromBuffer(i, r);');
	out.println('${classname}.fromJson(String i,'
	' [$_protobufImportPrefix.ExtensionRegistry r = $_protobufImportPrefix.ExtensionRegistry.EMPTY])'
	' : super.fromJson(i, r);');
	out.println('${classname} clone() =>'
	' new ${classname}()..mergeFromMessage(this);');
	out.println('$classname copyWith(void Function($classname) updates) =>'
	' super.copyWith((message) => updates(message as $classname));');

	out.println('$_protobufImportPrefix.BuilderInfo get info_ => _i;');

	// Factory functions which can be used as default value closures.
	out.println('static ${classname} create() =>'
	' new ${classname}();');
	out.println(
	'static $_protobufImportPrefix.PbList<${classname}> createRepeated() =>'
	' new $_protobufImportPrefix.PbList<${classname}>();');
	out.println(
	'static ${classname} getDefault() => _defaultInstance ??= create()..freeze();');
	out.println('static ${classname} _defaultInstance;');
	out.addBlock('static void $checkItem($classname v) {', '}', () {
	out.println('if (v is! $classname)'
	" $_protobufImportPrefix.checkItemFailed(v, _i.messageName);");
	});
	generateFieldsAccessorsMutators(out);
	if (fullName == 'google.protobuf.Any') {
	generateAnyMethods(out);
	}
	});
	out.println();
	}

	// Returns true if the message type has any required fields. If it doesn't,
	// we can optimize out calls to its isInitialized()/_findInvalidFields()
	// methods.
	//
	// already_seen is used to avoid checking the same type multiple times
	// (and also to protect against unbounded recursion).
	bool _hasRequiredFields(MessageGenerator type, Set alreadySeen) {
	if (type._fieldList == null) throw new StateError("message not resolved");

	if (alreadySeen.contains(type.fullName)) {
	// The type is already in cache. This means that either:
	// a. The type has no required fields.
	// b. We are in the midst of checking if the type has required fields,
	// somewhere up the stack. In this case, we know that if the type
	// has any required fields, they'll be found when we return to it,
	// and the whole call to HasRequiredFields() will return true.
	// Therefore, we don't have to check if this type has required fields
	// here.
	return false;
	}
	alreadySeen.add(type.fullName);
	// If the type has extensions, an extension with message type could contain
	// required fields, so we have to be conservative and assume such an
	// extension exists.
	if (type._descriptor.extensionRange.length > 0) {
	return true;
	}

	for (ProtobufField field in type._fieldList) {
	if (field.isRequired) {
	return true;
	}
	if (field.baseType.isMessage) {
	MessageGenerator child = field.baseType.generator;
	if (_hasRequiredFields(child, alreadySeen)) {
	return true;
	}
	}
	}
	return false;
	}

	/// Generates methods for the Any message class for packing and unpacking
	/// values.
	void generateAnyMethods(IndentingWriter out) {
	out.println('''
	/// Unpacks the message in [value] into [instance].
	///
	/// Throws a [InvalidProtocolBufferException] if [typeUrl] does not correspond
	/// to the type of [instance].
	///
	/// A typical usage would be `any.unpackInto(new Message())`.
	///
	/// Returns [instance].
	T unpackInto<T extends $_protobufImportPrefix.GeneratedMessage>(T instance,
	{$_protobufImportPrefix.ExtensionRegistry extensionRegistry = $_protobufImportPrefix.ExtensionRegistry.EMPTY}) {
	$_protobufImportPrefix.unpackIntoHelper(value, instance, typeUrl,
	extensionRegistry: extensionRegistry);
	return instance;
	}

	/// Returns `true` if the encoded message matches the type of [instance].
	///
	/// Can be used with a default instance:
	/// `any.canUnpackInto(Message.getDefault())`
	bool canUnpackInto($_protobufImportPrefix.GeneratedMessage instance) {
	return $_protobufImportPrefix.canUnpackIntoHelper(instance, typeUrl);
	}

	/// Creates a new [Any] encoding [message].
	///
	/// The [typeUrl] will be [typeUrlPrefix]/`fullName` where `fullName` is
	/// the fully qualified name of the type of [message].
	static Any pack($_protobufImportPrefix.GeneratedMessage message,
	{String typeUrlPrefix = 'type.googleapis.com'}) {
	return new Any()
	..value = message.writeToBuffer()
	..typeUrl = '\${typeUrlPrefix}/\${message.info_.messageName}';
	}''');
	}

	void generateFieldsAccessorsMutators(IndentingWriter out) {
	for (ProtobufField field in _fieldList) {
	out.println();
	generateFieldAccessorsMutators(field, out);
	}
	}

	void generateFieldAccessorsMutators(
	ProtobufField field, IndentingWriter out) {
	var fieldTypeString = field.getDartType(fileGen);
	var defaultExpr = field.getDefaultExpr();
	var names = field.memberNames;

	_emitOverrideIf(field.overridesGetter, out);
	var getterExpr = _getterExpression(
	fieldTypeString, field.index, defaultExpr, field.isRepeated);
	out.println('${fieldTypeString} get ${names.fieldName} => ${getterExpr};');

	if (field.isRepeated) {
	if (field.overridesSetter) {
	throw 'Field ${field.fullName} cannot override a setter for '
	'${names.fieldName} because it is repeated.';
	}
	if (field.overridesHasMethod) {
	throw 'Field ${field.fullName} cannot override '
	'${names.hasMethodName}() because it is repeated.';
	}
	if (field.overridesClearMethod) {
	throw 'Field ${field.fullName} cannot override '
	'${names.clearMethodName}() because it is repeated.';
	}
	} else {
	var fastSetter = field.baseType.setter;
	_emitOverrideIf(field.overridesSetter, out);
	if (fastSetter != null) {
	out.println('set ${names.fieldName}'
	'($fieldTypeString v) { '
	'$fastSetter(${field.index}, v);'
	' }');
	} else {
	out.println('set ${names.fieldName}'
	'($fieldTypeString v) { '
	'setField(${field.number}, v);'
	' }');
	}
	_emitOverrideIf(field.overridesHasMethod, out);
	out.println('bool ${names.hasMethodName}() =>'
	' \$_has(${field.index});');
	_emitOverrideIf(field.overridesClearMethod, out);
	out.println('void ${names.clearMethodName}() =>'
	' clearField(${field.number});');
	}
	}

	String _getterExpression(
	String fieldType, int index, String defaultExpr, bool isRepeated) {
	if (fieldType == 'String') {
	return '\$_getS($index, $defaultExpr)';
	}
	if (fieldType == 'Int64' && defaultExpr == 'null') {
	return '\$_getI64($index)';
	}
	if (defaultExpr == 'null') {
	return isRepeated ? '\$_getList($index)' : '\$_getN($index)';
	}
	return '\$_get($index, $defaultExpr)';
	}

	void _emitOverrideIf(bool condition, IndentingWriter out) {
	if (condition) {
	out.println('@override');
	}
	}

	void generateEnums(IndentingWriter out) {
	for (EnumGenerator e in _enumGenerators) {
	e.generate(out);
	}

	for (MessageGenerator m in _messageGenerators) {
	m.generateEnums(out);
	}
	}

	/// Writes a Dart constant containing the JSON for the ProtoDescriptor.
	/// Also writes a separate constant for each nested message,
	/// to avoid duplication.
	void generateConstants(IndentingWriter out) {
	const nestedTypeTag = 3;
	const enumTypeTag = 4;
	assert(_descriptor.info_.fieldInfo[nestedTypeTag].name == "nestedType");
	assert(_descriptor.info_.fieldInfo[enumTypeTag].name == "enumType");

	var name = getJsonConstant(fileGen);
	var json = _descriptor.writeToJsonMap();
	var nestedTypeNames =
	_messageGenerators.map((m) => m.getJsonConstant(fileGen)).toList();
	var nestedEnumNames =
	_enumGenerators.map((e) => e.getJsonConstant(fileGen)).toList();

	out.addBlock("const $name = const {", "};", () {
	for (var key in json.keys) {
	out.print("'$key': ");
	if (key == "$nestedTypeTag") {
	// refer to message constants by name instead of repeating each value
	out.println("const [${nestedTypeNames.join(", ")}],");
	continue;
	} else if (key == "$enumTypeTag") {
	// refer to enum constants by name
	out.println("const [${nestedEnumNames.join(", ")}],");
	continue;
	}
	writeJsonConst(out, json[key]);
	out.println(",");
	}
	});
	out.println();

	for (var m in _messageGenerators) {
	m.generateConstants(out);
	}

	for (var e in _enumGenerators) {
	e.generateConstants(out);
	}
	}
	}