protobuf/csharp/src/Google.Protobuf/Reflection/MethodDescriptor.cs

#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc.  All rights reserved.
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//
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//
//     * Redistributions of source code must retain the above copyright
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// in the documentation and/or other materials provided with the
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// contributors may be used to endorse or promote products derived from
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#endregion

namespace Google.Protobuf.Reflection
{
    /// <summary>
    /// Describes a single method in a service.
    /// </summary>
    public sealed class MethodDescriptor : DescriptorBase
    {
        private readonly MethodDescriptorProto proto;
        private readonly ServiceDescriptor service;
        private MessageDescriptor inputType;
        private MessageDescriptor outputType;

        /// <value>
        /// The service this method belongs to.
        /// </value>
        public ServiceDescriptor Service { get { return service; } }

        /// <value>
        /// The method's input type.
        /// </value>
        public MessageDescriptor InputType { get { return inputType; } }

        /// <value>
        /// The method's input type.
        /// </value>
        public MessageDescriptor OutputType { get { return outputType; } }

        internal MethodDescriptor(MethodDescriptorProto proto, FileDescriptor file,
                                  ServiceDescriptor parent, int index)
            : base(file, parent.FullName + "." + proto.Name, index)
        {
            this.proto = proto;
            service = parent;
            file.DescriptorPool.AddSymbol(this);
        }

        internal MethodDescriptorProto Proto { get { return proto; } }

        /// <summary>
        /// The brief name of the descriptor's target.
        /// </summary>
        public override string Name { get { return proto.Name; } }

        internal void CrossLink()
        {
            IDescriptor lookup = File.DescriptorPool.LookupSymbol(Proto.InputType, this);
            if (!(lookup is MessageDescriptor))
            {
                throw new DescriptorValidationException(this, "\"" + Proto.InputType + "\" is not a message type.");
            }
            inputType = (MessageDescriptor) lookup;

            lookup = File.DescriptorPool.LookupSymbol(Proto.OutputType, this);
            if (!(lookup is MessageDescriptor))
            {
                throw new DescriptorValidationException(this, "\"" + Proto.OutputType + "\" is not a message type.");
            }
            outputType = (MessageDescriptor) lookup;
        }
    }
}