// Protocol Buffers - Google's data interchange format
// Copyright 2015 Google Inc. All rights reserved.
// Author: jieluo@google.com (Jie Luo)
//
// 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,
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
using System;
using System.Reflection;
using Google.ProtocolBuffers.Descriptors;
namespace Google.ProtocolBuffers.FieldAccess
{
///
/// Access for an oneof
///
internal class OneofAccessor
where TMessage : IMessage
where TBuilder : IBuilder
{
private readonly Func caseDelegate;
private readonly Func clearDelegate;
private MessageDescriptor descriptor;
internal OneofAccessor(MessageDescriptor descriptor, string name)
{
this.descriptor = descriptor;
MethodInfo clearMethod = typeof(TBuilder).GetMethod("Clear" + name);
PropertyInfo caseProperty = typeof(TMessage).GetProperty(name + "Case");
if (clearMethod == null || caseProperty == null)
{
throw new ArgumentException("Not all required properties/methods available for oneof");
}
clearDelegate = ReflectionUtil.CreateDelegateFunc(clearMethod);
caseDelegate = ReflectionUtil.CreateUpcastDelegate(caseProperty.GetGetMethod());
}
///
/// Indicates whether the specified message has set any field in the oneof.
///
public bool Has(TMessage message)
{
return ((int) caseDelegate(message) != 0);
}
///
/// Clears the oneof in the specified builder.
///
public void Clear(TBuilder builder)
{
clearDelegate(builder);
}
///
/// Indicates which field in the oneof is set for specified message
///
public virtual FieldDescriptor GetOneofFieldDescriptor(TMessage message)
{
int fieldNumber = (int) caseDelegate(message);
if (fieldNumber > 0)
{
return descriptor.FindFieldByNumber(fieldNumber);
}
return null;
}
}
}