#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2015 Google Inc. All rights reserved.
// https://developers.google.com/protocol-buffers/
//
// 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.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Reflection;
using Google.Protobuf.Compatibility;
namespace Google.Protobuf.Reflection
{
/// <summary>
/// Accessor for single fields.
/// </summary>
internal sealed class SingleFieldAccessor : FieldAccessorBase
{
// All the work here is actually done in the constructor - it creates the appropriate delegates.
// There are various cases to consider, based on the property type (message, string/bytes, or "genuine" primitive)
// and proto2 vs proto3 for non-message types, as proto3 doesn't support "full" presence detection or default
// values.
private readonly Action<IMessage, object> setValueDelegate;
private readonly Action<IMessage> clearDelegate;
private readonly Func<IMessage, bool> hasDelegate;
internal SingleFieldAccessor(
[DynamicallyAccessedMembers(GeneratedClrTypeInfo.MessageAccessibility)]
Type messageType, PropertyInfo property, FieldDescriptor descriptor) : base(property, descriptor)
{
if (!property.CanWrite)
{
throw new ArgumentException("Not all required properties/methods available");
}
setValueDelegate = ReflectionUtil.CreateActionIMessageObject(property.GetSetMethod());
// Note: this looks worrying in that we access the containing oneof, which isn't valid until cross-linking
// is complete... but field accessors aren't created until after cross-linking.
// The oneof itself won't be cross-linked yet, but that's okay: the oneof accessor is created
// earlier.
// Message fields always support presence, via null checks.
if (descriptor.FieldType == FieldType.Message)
{
hasDelegate = message => GetValue(message) != null;
clearDelegate = message => SetValue(message, null);
}
// Oneof fields always support presence, via case checks.
// Note that clearing the field is a no-op unless that specific field is the current "case".
else if (descriptor.RealContainingOneof != null)
{
var oneofAccessor = descriptor.RealContainingOneof.Accessor;
hasDelegate = message => oneofAccessor.GetCaseFieldDescriptor(message) == descriptor;
clearDelegate = message =>
{
// Clear on a field only affects the oneof itself if the current case is the field we're accessing.
if (oneofAccessor.GetCaseFieldDescriptor(message) == descriptor)
{
oneofAccessor.Clear(message);
}
};
}
// Primitive fields always support presence in proto2, and support presence in proto3 for optional fields.
else if (descriptor.File.Syntax == Syntax.Proto2 || descriptor.Proto.Proto3Optional)
{
MethodInfo hasMethod = messageType.GetRuntimeProperty("Has" + property.Name).GetMethod;
if (hasMethod == null)
{
throw new ArgumentException("Not all required properties/methods are available");
}
hasDelegate = ReflectionUtil.CreateFuncIMessageBool(hasMethod);
MethodInfo clearMethod = messageType.GetRuntimeMethod("Clear" + property.Name, ReflectionUtil.EmptyTypes);
if (clearMethod == null)
{
throw new ArgumentException("Not all required properties/methods are available");
}
clearDelegate = ReflectionUtil.CreateActionIMessage(clearMethod);
}
// What's left?
// Primitive proto3 fields without the optional keyword, which aren't in oneofs.
else
{
hasDelegate = message => { throw new InvalidOperationException("Presence is not implemented for this field"); };
// While presence isn't supported, clearing still is; it's just setting to a default value.
object defaultValue = GetDefaultValue(descriptor);
clearDelegate = message => SetValue(message, defaultValue);
}
}
private static object GetDefaultValue(FieldDescriptor descriptor)
{
switch (descriptor.FieldType)
{
case FieldType.Bool:
return false;
case FieldType.Bytes:
return ByteString.Empty;
case FieldType.String:
return "";
case FieldType.Double:
return 0.0;
case FieldType.SInt32:
case FieldType.Int32:
case FieldType.SFixed32:
case FieldType.Enum:
return 0;
case FieldType.Fixed32:
case FieldType.UInt32:
return (uint)0;
case FieldType.Fixed64:
case FieldType.UInt64:
return 0UL;
case FieldType.SFixed64:
case FieldType.Int64:
case FieldType.SInt64:
return 0L;
case FieldType.Float:
return 0f;
case FieldType.Message:
case FieldType.Group: // Never expect to get this, but...
return null;
default:
throw new ArgumentException("Invalid field type");
}
}
public override void Clear(IMessage message) => clearDelegate(message);
public override bool HasValue(IMessage message) => hasDelegate(message);
public override void SetValue(IMessage message, object value) => setValueDelegate(message, value);
}
}
Codebase Browser
chromium