src/ProtocolBuffers/ExtendableBuilder.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.Descriptors;

namespace Google.ProtocolBuffers
{
    public abstract class ExtendableBuilder<TMessage, TBuilder> : GeneratedBuilder<TMessage, TBuilder>
        where TMessage : ExtendableMessage<TMessage, TBuilder>
        where TBuilder : GeneratedBuilder<TMessage, TBuilder>, new()
    {
        protected ExtendableBuilder()
        {
        }

        /// <summary>
        /// Checks if a singular extension is present
        /// </summary>
        public bool HasExtension<TExtension>(GeneratedExtensionBase<TExtension> extension)
        {
            return MessageBeingBuilt.HasExtension(extension);
        }

        /// <summary>
        /// Returns the number of elements in a repeated extension.
        /// </summary>
        public int GetExtensionCount<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension)
        {
            return MessageBeingBuilt.GetExtensionCount(extension);
        }

        /// <summary>
        /// Returns the value of an extension.
        /// </summary>
        public TExtension GetExtension<TExtension>(GeneratedExtensionBase<TExtension> extension)
        {
            return MessageBeingBuilt.GetExtension(extension);
        }

        /// <summary>
        /// Returns one element of a repeated extension.
        /// </summary>
        public TExtension GetExtension<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension, int index)
        {
            return MessageBeingBuilt.GetExtension(extension, index);
        }

        /// <summary>
        /// Sets the value of an extension.
        /// </summary>
        public TBuilder SetExtension<TExtension>(GeneratedExtensionBase<TExtension> extension, TExtension value)
        {
            ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
            message.VerifyExtensionContainingType(extension);
            message.Extensions[extension.Descriptor] = extension.ToReflectionType(value);
            return ThisBuilder;
        }

        /// <summary>
        /// Sets the value of one element of a repeated extension.
        /// </summary>
        public TBuilder SetExtension<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension, int index,
                                                 TExtension value)
        {
            ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
            message.VerifyExtensionContainingType(extension);
            message.Extensions[extension.Descriptor, index] = extension.SingularToReflectionType(value);
            return ThisBuilder;
        }

        /// <summary>
        /// Appends a value to a repeated extension.
        /// </summary>
        public TBuilder AddExtension<TExtension>(GeneratedExtensionBase<IList<TExtension>> extension, TExtension value)
        {
            ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
            message.VerifyExtensionContainingType(extension);
            message.Extensions.AddRepeatedField(extension.Descriptor, extension.SingularToReflectionType(value));
            return ThisBuilder;
        }

        /// <summary>
        /// Clears an extension.
        /// </summary>
        public TBuilder ClearExtension<TExtension>(GeneratedExtensionBase<TExtension> extension)
        {
            ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
            message.VerifyExtensionContainingType(extension);
            message.Extensions.ClearField(extension.Descriptor);
            return ThisBuilder;
        }

        /// <summary>
        /// Called by subclasses to parse an unknown field or an extension.
        /// </summary>
        /// <returns>true unless the tag is an end-group tag</returns>
        [CLSCompliant(false)]
        protected override bool ParseUnknownField(ICodedInputStream input, UnknownFieldSet.Builder unknownFields,
                                                  ExtensionRegistry extensionRegistry, uint tag, string fieldName)
        {
            return unknownFields.MergeFieldFrom(input, extensionRegistry, this, tag, fieldName);
        }

        // ---------------------------------------------------------------
        // Reflection


        public override object this[FieldDescriptor field, int index]
        {
            set
            {
                if (field.IsExtension)
                {
                    ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
                    message.VerifyContainingType(field);
                    message.Extensions[field, index] = value;
                }
                else
                {
                    base[field, index] = value;
                }
            }
        }


        public override object this[FieldDescriptor field]
        {
            set
            {
                if (field.IsExtension)
                {
                    ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
                    message.VerifyContainingType(field);
                    message.Extensions[field] = value;
                }
                else
                {
                    base[field] = value;
                }
            }
        }

        public override TBuilder ClearField(FieldDescriptor field)
        {
            if (field.IsExtension)
            {
                ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
                message.VerifyContainingType(field);
                message.Extensions.ClearField(field);
                return ThisBuilder;
            }
            else
            {
                return base.ClearField(field);
            }
        }

        public override TBuilder AddRepeatedField(FieldDescriptor field, object value)
        {
            if (field.IsExtension)
            {
                ExtendableMessage<TMessage, TBuilder> message = MessageBeingBuilt;
                message.VerifyContainingType(field);
                message.Extensions.AddRepeatedField(field, value);
                return ThisBuilder;
            }
            else
            {
                return base.AddRepeatedField(field, value);
            }
        }

        protected void MergeExtensionFields(ExtendableMessage<TMessage, TBuilder> other)
        {
            MessageBeingBuilt.Extensions.MergeFrom(other.Extensions);
        }
    }
}