// 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.
using System;
using System.Reflection;
namespace Google.ProtocolBuffers.FieldAccess
{
///
/// Accessor for fields representing a non-repeated message value.
///
internal sealed class SingleMessageAccessor : SinglePrimitiveAccessor
where TMessage : IMessage
where TBuilder : IBuilder
{
///
/// The static method to create a builder for the property type. For example,
/// in a message type "Foo", a field called "bar" might be of type "Baz". This
/// method is Baz.CreateBuilder.
///
private readonly Func createBuilderDelegate;
internal SingleMessageAccessor(string name) : base(name)
{
MethodInfo createBuilderMethod = ClrType.GetMethod("CreateBuilder", ReflectionUtil.EmptyTypes);
if (createBuilderMethod == null)
{
throw new ArgumentException("No public static CreateBuilder method declared in " + ClrType.Name);
}
createBuilderDelegate = ReflectionUtil.CreateStaticUpcastDelegate(createBuilderMethod);
}
///
/// Creates a message of the appropriate CLR type from the given value,
/// which may already be of the right type or may be a dynamic message.
///
private object CoerceType(object value)
{
ThrowHelper.ThrowIfNull(value, "value");
// If it's already of the right type, we're done
if (ClrType.IsInstanceOfType(value))
{
return value;
}
// No... so let's create a builder of the right type, and merge the value in.
IMessageLite message = (IMessageLite) value;
return CreateBuilder().WeakMergeFrom(message).WeakBuild();
}
public override void SetValue(TBuilder builder, object value)
{
base.SetValue(builder, CoerceType(value));
}
public override IBuilder CreateBuilder()
{
return createBuilderDelegate();
}
}
}