src/ProtoGen/ServiceInterfaceGenerator.cs

#region Copyright notice and license

// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
// http://github.com/jskeet/dotnet-protobufs/
// Original C++/Java/Python code:
// http://code.google.com/p/protobuf/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#endregion

using System;
using System.Collections.Generic;
using Google.ProtocolBuffers.DescriptorProtos;
using Google.ProtocolBuffers.Descriptors;

namespace Google.ProtocolBuffers.ProtoGen
{
    internal class ServiceGenerator : SourceGeneratorBase<ServiceDescriptor>, ISourceGenerator
    {
        private readonly CSharpServiceType svcType;
        private ISourceGenerator _generator;

        internal ServiceGenerator(ServiceDescriptor descriptor)
            : base(descriptor)
        {
            svcType = descriptor.File.CSharpOptions.ServiceGeneratorType;
            switch (svcType)
            {
                case CSharpServiceType.NONE:
                    _generator = new NoServicesGenerator(descriptor);
                    break;
                case CSharpServiceType.GENERIC:
                    _generator = new GenericServiceGenerator(descriptor);
                    break;
                case CSharpServiceType.INTERFACE:
                    _generator = new ServiceInterfaceGenerator(descriptor);
                    break;
                case CSharpServiceType.IRPCDISPATCH:
                    _generator = new RpcServiceGenerator(descriptor);
                    break;
                default:
                    throw new ApplicationException("Unknown ServiceGeneratorType = " + svcType.ToString());
            }
        }

        public void Generate(TextGenerator writer)
        {
            _generator.Generate(writer);
        }

        private class NoServicesGenerator : SourceGeneratorBase<ServiceDescriptor>, ISourceGenerator
        {
            public NoServicesGenerator(ServiceDescriptor descriptor)
                : base(descriptor)
            {
            }

            public virtual void Generate(TextGenerator writer)
            {
                writer.WriteLine("/*");
                writer.WriteLine("* Service generation is now disabled by default, use the following option to enable:");
                writer.WriteLine("* option (google.protobuf.csharp_file_options).service_generator_type = GENERIC;");
                writer.WriteLine("*/");
            }
        }

        private class ServiceInterfaceGenerator : SourceGeneratorBase<ServiceDescriptor>, ISourceGenerator
        {
            public ServiceInterfaceGenerator(ServiceDescriptor descriptor)
                : base(descriptor)
            {
            }

            public virtual void Generate(TextGenerator writer)
            {
                CSharpServiceOptions options = Descriptor.Options.GetExtension(CSharpOptions.CsharpServiceOptions);
                if (options != null && options.HasInterfaceId)
                {
                    writer.WriteLine("[global::System.Runtime.InteropServices.GuidAttribute(\"{0}\")]",
                                     new Guid(options.InterfaceId));
                }
                writer.WriteLine("{0} partial interface I{1} {{", ClassAccessLevel, Descriptor.Name);
                writer.Indent();

                foreach (MethodDescriptor method in Descriptor.Methods)
                {
                    CSharpMethodOptions mth = method.Options.GetExtension(CSharpOptions.CsharpMethodOptions);
                    if (mth.HasDispatchId)
                    {
                        writer.WriteLine("[global::System.Runtime.InteropServices.DispId({0})]", mth.DispatchId);
                    }
                    writer.WriteLine("{0} {1}({2} {3});", GetClassName(method.OutputType),
                                     NameHelpers.UnderscoresToPascalCase(method.Name), GetClassName(method.InputType),
                                     NameHelpers.UnderscoresToCamelCase(method.InputType.Name));
                }

                writer.Outdent();
                writer.WriteLine("}");
            }
        }

        private class RpcServiceGenerator : ServiceInterfaceGenerator
        {
            public RpcServiceGenerator(ServiceDescriptor descriptor)
                : base(descriptor)
            {
            }

            public override void Generate(TextGenerator writer)
            {
                base.Generate(writer);

                writer.WriteLine();

                // CLIENT Proxy
                {
                    if (Descriptor.File.CSharpOptions.ClsCompliance)
                        writer.WriteLine("[global::System.CLSCompliant(false)]");
                    writer.WriteLine("{0} partial class {1} : I{1}, pb::IRpcDispatch, global::System.IDisposable {{",
                                     ClassAccessLevel, Descriptor.Name);
                    writer.Indent();
                    writer.WriteLine("private readonly bool dispose;");
                    writer.WriteLine("private readonly pb::IRpcDispatch dispatch;");

                    writer.WriteLine("public {0}(pb::IRpcDispatch dispatch) : this(dispatch, true) {{", Descriptor.Name);
                    writer.WriteLine("}");
                    writer.WriteLine("public {0}(pb::IRpcDispatch dispatch, bool dispose) {{", Descriptor.Name);
                    writer.WriteLine(
                        "  if (null == (this.dispatch = dispatch)) throw new global::System.ArgumentNullException();");
                    writer.WriteLine("  this.dispose = dispose && dispatch is global::System.IDisposable;");
                    writer.WriteLine("}");
                    writer.WriteLine();

                    writer.WriteLine("public void Dispose() {");
                    writer.WriteLine("  if (dispose) ((global::System.IDisposable)dispatch).Dispose();");
                    writer.WriteLine("}");
                    writer.WriteLine();
                    writer.WriteLine(
                        "TMessage pb::IRpcDispatch.CallMethod<TMessage, TBuilder>(string method, pb::IMessageLite request, pb::IBuilderLite<TMessage, TBuilder> response) {");
                    writer.WriteLine("  return dispatch.CallMethod(method, request, response);");
                    writer.WriteLine("}");
                    writer.WriteLine();

                    foreach (MethodDescriptor method in Descriptor.Methods)
                    {
                        writer.WriteLine("public {0} {1}({2} {3}) {{", GetClassName(method.OutputType),
                                         NameHelpers.UnderscoresToPascalCase(method.Name),
                                         GetClassName(method.InputType),
                                         NameHelpers.UnderscoresToCamelCase(method.InputType.Name));
                        writer.WriteLine("   return dispatch.CallMethod(\"{0}\", {1}, {2}.CreateBuilder());",
                                         method.Name,
                                         NameHelpers.UnderscoresToCamelCase(method.InputType.Name),
                                         GetClassName(method.OutputType)
                            );
                        writer.WriteLine("}");
                        writer.WriteLine();
                    }
                }
                // SERVER - DISPATCH
                {
                    if (Descriptor.File.CSharpOptions.ClsCompliance)
                        writer.WriteLine("[global::System.CLSCompliant(false)]");
                    writer.WriteLine("public partial class Dispatch : pb::IRpcDispatch, global::System.IDisposable {");
                    writer.Indent();
                    writer.WriteLine("private readonly bool dispose;");
                    writer.WriteLine("private readonly I{0} implementation;", Descriptor.Name);

                    writer.WriteLine("public Dispatch(I{0} implementation) : this(implementation, true) {{",
                                     Descriptor.Name);
                    writer.WriteLine("}");
                    writer.WriteLine("public Dispatch(I{0} implementation, bool dispose) {{", Descriptor.Name);
                    writer.WriteLine(
                        "  if (null == (this.implementation = implementation)) throw new global::System.ArgumentNullException();");
                    writer.WriteLine("  this.dispose = dispose && implementation is global::System.IDisposable;");
                    writer.WriteLine("}");
                    writer.WriteLine();

                    writer.WriteLine("public void Dispose() {");
                    writer.WriteLine("  if (dispose) ((global::System.IDisposable)implementation).Dispose();");
                    writer.WriteLine("}");
                    writer.WriteLine();

                    writer.WriteLine(
                        "public TMessage CallMethod<TMessage, TBuilder>(string methodName, pb::IMessageLite request, pb::IBuilderLite<TMessage, TBuilder> response)");
                    writer.WriteLine("  where TMessage : IMessageLite<TMessage, TBuilder>");
                    writer.WriteLine("  where TBuilder : IBuilderLite<TMessage, TBuilder> {");
                    writer.Indent();
                    writer.WriteLine("switch(methodName) {");
                    writer.Indent();

                    foreach (MethodDescriptor method in Descriptor.Methods)
                    {
                        writer.WriteLine(
                            "case \"{0}\": return response.MergeFrom(implementation.{1}(({2})request)).Build();",
                            method.Name, NameHelpers.UnderscoresToPascalCase(method.Name),
                            GetClassName(method.InputType));
                    }
                    writer.WriteLine(
                        "default: throw new global::System.MissingMethodException(typeof(ISearchService).FullName, methodName);");
                    writer.Outdent();
                    writer.WriteLine("}"); //end switch
                    writer.Outdent();
                    writer.WriteLine("}"); //end invoke
                    writer.Outdent();
                    writer.WriteLine("}"); //end server
                }
                // SERVER - STUB
                {
                    if (Descriptor.File.CSharpOptions.ClsCompliance)
                        writer.WriteLine("[global::System.CLSCompliant(false)]");
                    writer.WriteLine(
                        "public partial class ServerStub : pb::IRpcServerStub, global::System.IDisposable {");
                    writer.Indent();
                    writer.WriteLine("private readonly bool dispose;");
                    writer.WriteLine("private readonly pb::IRpcDispatch implementation;", Descriptor.Name);

                    writer.WriteLine("public ServerStub(I{0} implementation) : this(implementation, true) {{",
                                     Descriptor.Name);
                    writer.WriteLine("}");
                    writer.WriteLine(
                        "public ServerStub(I{0} implementation, bool dispose) : this(new Dispatch(implementation, dispose), dispose) {{",
                        Descriptor.Name);
                    writer.WriteLine("}");

                    writer.WriteLine("public ServerStub(pb::IRpcDispatch implementation) : this(implementation, true) {");
                    writer.WriteLine("}");
                    writer.WriteLine("public ServerStub(pb::IRpcDispatch implementation, bool dispose) {");
                    writer.WriteLine(
                        "  if (null == (this.implementation = implementation)) throw new global::System.ArgumentNullException();");
                    writer.WriteLine("  this.dispose = dispose && implementation is global::System.IDisposable;");
                    writer.WriteLine("}");
                    writer.WriteLine();

                    writer.WriteLine("public void Dispose() {");
                    writer.WriteLine("  if (dispose) ((global::System.IDisposable)implementation).Dispose();");
                    writer.WriteLine("}");
                    writer.WriteLine();

                    writer.WriteLine(
                        "public pb::IMessageLite CallMethod(string methodName, pb::CodedInputStream input, pb::ExtensionRegistry registry) {{",
                        Descriptor.Name);
                    writer.Indent();
                    writer.WriteLine("switch(methodName) {");
                    writer.Indent();

                    foreach (MethodDescriptor method in Descriptor.Methods)
                    {
                        writer.WriteLine(
                            "case \"{0}\": return implementation.CallMethod(methodName, {1}.ParseFrom(input, registry), {2}.CreateBuilder());",
                            method.Name, GetClassName(method.InputType), GetClassName(method.OutputType));
                    }
                    writer.WriteLine(
                        "default: throw new global::System.MissingMethodException(typeof(ISearchService).FullName, methodName);");
                    writer.Outdent();
                    writer.WriteLine("}"); //end switch
                    writer.Outdent();
                    writer.WriteLine("}"); //end invoke
                    writer.Outdent();
                    writer.WriteLine("}"); //end server
                }

                writer.Outdent();
                writer.WriteLine("}");
            }
        }
    }
}