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// 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 Google.Protobuf.Descriptors;
namespace Google.Protobuf.FieldAccess
{
/// <summary>
/// Provides access to fields in generated messages via reflection.
/// </summary>
public sealed class FieldAccessorTable<T> where T : IMessage<T>
{
private readonly IFieldAccessor<T>[] accessors;
private readonly MessageDescriptor descriptor;
/// <summary>
/// Constructs a FieldAccessorTable for a particular message class.
/// Only one FieldAccessorTable should be constructed per class.
/// </summary>
/// <param name="descriptor">The type's descriptor</param>
/// <param name="propertyNames">The Pascal-case names of all the field-based properties in the message.</param>
public FieldAccessorTable(MessageDescriptor descriptor, string[] propertyNames)
{
this.descriptor = descriptor;
accessors = new IFieldAccessor<T>[descriptor.Fields.Count];
bool supportFieldPresence = descriptor.File.Syntax == FileDescriptor.ProtoSyntax.Proto2;
for (int i = 0; i < accessors.Length; i++)
{
var field = descriptor.Fields[i];
var name = propertyNames[i];
accessors[i] = field.IsRepeated
? (IFieldAccessor<T>) new RepeatedFieldAccessor<T>(propertyNames[i])
: new SingleFieldAccessor<T>(field, name, supportFieldPresence);
}
// TODO(jonskeet): Oneof support
}
internal IFieldAccessor<T> this[int fieldNumber]
{
get
{
FieldDescriptor field = descriptor.FindFieldByNumber(fieldNumber);
// TODO: Handle extensions.
return accessors[field.Index];
}
}
internal IFieldAccessor<T> this[FieldDescriptor field]
{
get
{
if (field.ContainingType != descriptor)
{
throw new ArgumentException("FieldDescriptor does not match message type.");
}
else if (field.IsExtension)
{
// If this type had extensions, it would subclass ExtendableMessage,
// which overrides the reflection interface to handle extensions.
throw new ArgumentException("This type does not have extensions.");
}
return accessors[field.Index];
}
}
}
}
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