Protocol Buffer runtime library and 'protoc' plugin

lib/protobuf/plugin/MessageGenerator.dart

+// Copyright (c) 2011, 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.
+
+class MessageGenerator implements ProtobufContainer {
+
+  // Variables controlling output prettiness
+  static final String sp = " ";
+  static final bool _blankLines = true;
+  static final bool _fieldComments = true;
+
+  String _builderClassname;
+  String _classname;
+  GenerationContext _context;
+  final GoogleProtobuf_DescriptorProto _descriptor;
+  List<EnumGenerator> _enumGenerators;
+  List<ProtobufField> _fieldList;
+  String _fqname;
+  List<MessageGenerator> _messageGenerators;
+  List<ExtensionGenerator> _extensionGenerators;
+  GoogleProtobuf_FileOptions_OptimizeMode _optimizeFor;
+  ProtobufContainer _parent;
+
+  String get classname() => _classname;
+  String get fqname() => _fqname;
+  GoogleProtobuf_FileOptions_OptimizeMode get optimizeFor() => _optimizeFor;
+
+  MessageGenerator(GoogleProtobuf_DescriptorProto this._descriptor,
+      ProtobufContainer this._parent, GenerationContext this._context) {
+    String name = _descriptor.name;
+    _classname = (_parent === null || _parent.classname == "") ?
+        name :
+        "${_parent.classname}_${name}";
+
+    _builderClassname = "${_classname}_Builder";
+    _fqname = (_parent === null || _parent.fqname === null) ? _descriptor.name :
+        ( _parent.fqname == "." ?
+            ".${_descriptor.name}" :
+            "${_parent.fqname}.${_descriptor.name}" );
+    _optimizeFor = _parent != null ? _parent.optimizeFor : null;
+    _context.register(this);
+
+    _fieldList = [];
+
+    _enumGenerators = new List<EnumGenerator>();
+    for (GoogleProtobuf_EnumDescriptorProto e in _descriptor.enumType) {
+      _enumGenerators.add(new EnumGenerator(e, this, _context));
+    }
+
+    _messageGenerators = new List<MessageGenerator>();
+    for (GoogleProtobuf_DescriptorProto n in _descriptor.nestedType) {
+      _messageGenerators.add(new MessageGenerator(n, this, _context));
+    }
+
+    _extensionGenerators = new List<ExtensionGenerator>();
+    for (GoogleProtobuf_FieldDescriptorProto x in _descriptor.extension) {
+      _extensionGenerators.add(new ExtensionGenerator(x, this, _context));
+    }
+  }
+
+  void initializeFields() {
+    _fieldList = [];
+    ProtobufField._resetIndices();
+    for (GoogleProtobuf_FieldDescriptorProto field in _descriptor.field) {
+      _fieldList.add(new ProtobufField(field, _context));
+    }
+    for (MessageGenerator m in _messageGenerators) {
+      m.initializeFields();
+    }
+  }
+
+  void generate(IndentingWriter out,
+      [List<ExtensionGenerator> allExtensions = null]) {
+    for (EnumGenerator e in _enumGenerators) {
+      e.generate(out);
+    }
+
+    for (MessageGenerator m in _messageGenerators) {
+      m.generate(out, allExtensions);
+    }
+
+    out.addBlock("class ${_classname} extends GeneratedMessage${sp}{", "}", (){
+      for (ExtensionGenerator x in _extensionGenerators) {
+        if (allExtensions != null) {
+          allExtensions.add(x);
+        }
+        x.generate(out);
+      }
+
+      out.println("static ${_classname} _d;");
+      out.println("static ${_builderClassname} newBuilder()${sp}=>"
+          "${sp}new ${_builderClassname}();");
+      out.println("static ${_classname} get defaultInstance()${sp}=>"
+          "${sp}null${sp}==${sp}_d${sp}?${sp}(_d${sp}=${sp}newBuilder()."
+          "buildPartial())${sp}:${sp}_d;");
+      out.println("static ${_classname} parseFromBuffer(List<int> i,"
+          "${sp}[ExtensionRegistry r])"
+          "${sp}=>${sp}GeneratedMessage.parseBuffer(newBuilder(),"
+          "${sp}i,${sp}r);");
+      out.println("static Future<${_classname}> parseFromStream("
+          "InputStream i,${sp}[ExtensionRegistry r])${sp}=>${sp}"
+          "GeneratedMessage.parseStream(newBuilder(),${sp}i,${sp}r);");
+      out.println("static ${_classname} parseFromJson("
+          "String i,"
+        "${sp}[ExtensionRegistry r])"
+        "${sp}=>${sp}GeneratedMessage.parseJson(newBuilder(),${sp}i,${sp}r);");
+      out.println("${_classname}._fromBuilder(${_builderClassname} b)"
+          "${sp}:${sp}super(b);");
+      out.println("${_builderClassname} toBuilder()"
+          "${sp}=>${sp}newBuilder().mergeFromMessage(this);");
+
+      generateFields(out);
+    });
+
+    // -------------------------- BUILDER --------------------------
+    out.blankLine();
+    out.addBlock("class ${_builderClassname} extends Builder${sp}{",
+        "}", ()
+      {
+      out.println("static BuilderInfo _i;");
+
+      if (_blankLines) {
+        out.blankLine();
+      }
+      out.addBlock("void initialize_()${sp}{","}",(){
+        out.addBlock("if${sp}(null${sp}==${sp}_i)${sp}{", "}", () {
+          out.println("_i${sp}=${sp}new BuilderInfo(this,${sp}"
+            "\"${_classname}\");");
+
+        for (ProtobufField field in _fieldList) {
+          String type = field.shortTypeName;
+
+          String makeDefault = null;
+          if (field.hasInitialization) {
+            makeDefault = "${field.initialization}";
+          }
+          String subBuilder = null;
+          if (field.message || field.group) {
+            subBuilder = "()${sp}=>${sp}new ${field.baseType}_Builder()";
+          }
+          String valueOf = null;
+          if (field.enum) {
+            valueOf = "(var v)${sp}=>${sp}${field.baseType}.valueOf(v)";
+          }
+          if ("PM" == type) {
+            // Repeated message: default is an empty list
+            out.println("_i.m(${field.number},${sp}'"
+                "${field.externalFieldName}',${sp}$subBuilder,"
+                "${sp}()${sp}=>${sp}new PbList<${field.baseType}>(this));");
+          } else if (type[0] == "P" && type != "PG" && type != "PE") {
+            // Repeated, not a message or enum: default is an empty list,
+            // subBuilder is null, valueOf is null
+            out.println("_i.p(${field.number},${sp}"
+                "'${field.externalFieldName}',${sp}Builder.$type);");
+          } else if (type == "OE" || type == "QE") {
+            out.println("_i.e(${field.number},${sp}"
+                "'${field.externalFieldName}',${sp}Builder.$type,"
+                "${sp}$makeDefault,${sp}$valueOf);");
+          } else {
+            if (makeDefault == null && subBuilder == null && valueOf == null) {
+              out.println("_i.a(${field.number},${sp}"
+                  "'${field.externalFieldName}',${sp}Builder.$type);");
+            } else if (subBuilder == null && valueOf == null) {
+              out.println("_i.a(${field.number},${sp}"
+                  "'${field.externalFieldName}',${sp}Builder.$type,"
+                  "${sp}$makeDefault);");
+            } else if (valueOf == null) {
+              out.println("_i.a(${field.number},${sp}"
+                  "'${field.externalFieldName}',${sp}Builder.$type,"
+                  "${sp}$makeDefault,${sp}$subBuilder);");
+            } else {
+              out.println("_i.a(${field.number},${sp}"
+                  "'${field.externalFieldName}',${sp}Builder.$type,"
+                  "${sp}$makeDefault,${sp}$subBuilder,${sp}$valueOf);");
+            }
+          }
+        }
+
+        if (_descriptor.extensionRange.length > 0) {
+          out.println("_i.hasExtensions${sp}=${sp}true;");
+        }
+        if (!_hasRequiredFields(this, new Set())) {
+          out.println("_i.hasRequiredFields${sp}=${sp}false;");
+        }
+        });
+      });
+
+      if (_blankLines) {
+        out.blankLine();
+      }
+      out.println("$_classname build()${sp}=>${sp}super.build();");
+      out.println("$_classname buildPartial()${sp}=>${sp}"
+          "partial(new ${_classname}._fromBuilder(this));");
+      out.println("BuilderInfo get info_()${sp}=>${sp}_i;");
+
+      generateFieldsAccessorsMutators(out);
+    });
+    out.blankLine();
+  }
+
+  void generateFields(IndentingWriter out) {
+
+//
+// Disable 'noSuchMethod' dependency for now until dart2js code generation
+// improves
+//
+
+//    if (optimizeFor == GoogleProtobuf_FileOptions_OptimizeMode.SPEED) {
+      for (ProtobufField field in _fieldList) {
+        if (_blankLines) {
+          out.blankLine();
+        }
+
+        String label = field.label.name.substring(6).toLowerCase();
+        String type = field.type.name.substring(5).toLowerCase();
+        if ("message" == type || "group" == type) {
+          type = field.typeName.substring(1);
+        }
+        String options = "";
+        if ((field.options != null) && field.options.packed) {
+          if (options.length == 0) {
+            options = " [";
+          }
+          options = "${options}packed=true";
+        }
+        if (options.length > 0) {
+          options = "${options}]";
+        }
+        if (_fieldComments) {
+          out.println("// $label $type ${field.name}${sp}=${sp}"
+              "${field.number}${options};");
+        }
+        out.println(
+            "${field.typeString} get ${field.externalFieldName}()${sp}=>"
+            "${sp}g_(${field.number});");
+        if (field.single) {
+          out.println("bool has${field.titlecaseFieldName}()${sp}=>"
+              "${sp}h_(${field.number});");
+        }
+//      }
+    }
+  }
+
+  // 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 (alreadySeen.contains(type._fqname)) {
+      // 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._fqname);
+    // 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.required) {
+        return true;
+      }
+      if (field.message) {
+        ProtobufContainer messageType = _context[field.typeName];
+        if (messageType != null && messageType is MessageGenerator) {
+          if (_hasRequiredFields(messageType, alreadySeen)) {
+            return true;
+          }
+        }
+      }
+    }
+    return false;
+  }
+
+  void generateFieldsAccessorsMutators(IndentingWriter out) {
+    for (ProtobufField field in _fieldList) {
+//
+// Disable code size optimization for now until dart2js code generation
+// is better able to handle 'noSuchMethod'
+//
+
+//      if (optimizeFor == GoogleProtobuf_FileOptions_OptimizeMode.SPEED) {
+        if (_blankLines) {
+          out.blankLine();
+        }
+        out.println("${field.typeString} get ${field.externalFieldName}()"
+            "${sp}=>${sp}g_(${field.number});");
+        if (field.single) {
+          out.println("void set ${field.externalFieldName}"
+              "(${field.typeString} v)${sp}"
+              "{${sp}s_(${field.number},${sp}v);${sp}}");
+          out.println("bool has${field.titlecaseFieldName}()${sp}=>"
+              "${sp}h_(${field.number});");
+          out.println("void clear${field.titlecaseFieldName}()${sp}=>"
+              "${sp}c_(${field.number});");
+        }
+//      }
+    }
+  }
+}