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Diffstat (limited to 'csharp/src/ProtocolBuffers/GeneratedExtensionBase.cs')
| -rw-r--r-- | csharp/src/ProtocolBuffers/GeneratedExtensionBase.cs | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/csharp/src/ProtocolBuffers/GeneratedExtensionBase.cs b/csharp/src/ProtocolBuffers/GeneratedExtensionBase.cs new file mode 100644 index 00000000..424b981a --- /dev/null +++ b/csharp/src/ProtocolBuffers/GeneratedExtensionBase.cs @@ -0,0 +1,185 @@ +#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;
+using System.Collections.Generic;
+using System.Reflection;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers
+{
+ /// <summary>
+ /// Base type for all generated extensions.
+ /// </summary>
+ /// <remarks>
+ /// The protocol compiler generates a static singleton instance of this
+ /// class for each extension. For exmaple, imagine a .proto file with:
+ /// <code>
+ /// message Foo {
+ /// extensions 1000 to max
+ /// }
+ ///
+ /// extend Foo {
+ /// optional int32 bar;
+ /// }
+ /// </code>
+ /// Then MyProto.Foo.Bar has type GeneratedExtensionBase<MyProto.Foo,int>.
+ /// <para />
+ /// In general, users should ignore the details of this type, and
+ /// simply use the static singletons as parameters to the extension accessors
+ /// in ExtendableMessage and ExtendableBuilder.
+ /// The interface implemented by both GeneratedException and GeneratedRepeatException,
+ /// to make it easier to cope with repeats separately.
+ /// </remarks>
+ public abstract class GeneratedExtensionBase<TExtension>
+ {
+ private readonly FieldDescriptor descriptor;
+ private readonly IMessageLite messageDefaultInstance;
+
+ protected GeneratedExtensionBase(FieldDescriptor descriptor, Type singularExtensionType)
+ {
+ if (!descriptor.IsExtension)
+ {
+ throw new ArgumentException("GeneratedExtension given a regular (non-extension) field.");
+ }
+
+ this.descriptor = descriptor;
+ if (descriptor.MappedType == MappedType.Message)
+ {
+ PropertyInfo defaultInstanceProperty = singularExtensionType
+ .GetProperty("DefaultInstance", BindingFlags.Static | BindingFlags.Public);
+ if (defaultInstanceProperty == null)
+ {
+ throw new ArgumentException("No public static DefaultInstance property for type " +
+ typeof(TExtension).Name);
+ }
+
+ messageDefaultInstance = (IMessageLite) defaultInstanceProperty.GetValue(null, null);
+ }
+ }
+
+ public FieldDescriptor Descriptor
+ {
+ get { return descriptor; }
+ }
+
+ public int Number
+ {
+ get { return Descriptor.FieldNumber; }
+ }
+
+ /// <summary>
+ /// Returns the default message instance for extensions which are message types.
+ /// </summary>
+ public IMessageLite MessageDefaultInstance
+ {
+ get { return messageDefaultInstance; }
+ }
+
+ public object SingularFromReflectionType(object value)
+ {
+ switch (Descriptor.MappedType)
+ {
+ case MappedType.Message:
+ if (value is TExtension)
+ {
+ return value;
+ }
+ else
+ {
+ // It seems the copy of the embedded message stored inside the
+ // extended message is not of the exact type the user was
+ // expecting. This can happen if a user defines a
+ // GeneratedExtension manually and gives it a different type.
+ // This should not happen in normal use. But, to be nice, we'll
+ // copy the message to whatever type the caller was expecting.
+ return MessageDefaultInstance.WeakCreateBuilderForType()
+ .WeakMergeFrom((IMessageLite) value).WeakBuild();
+ }
+ case MappedType.Enum:
+ // Just return a boxed int - that can be unboxed to the enum
+ EnumValueDescriptor enumValue = (EnumValueDescriptor) value;
+ return enumValue.Number;
+ default:
+ return value;
+ }
+ }
+
+ /// <summary>
+ /// Converts from the type used by the native accessors to the type
+ /// used by reflection accessors. For example, the reflection accessors
+ /// for enums use EnumValueDescriptors but the native accessors use
+ /// the generated enum type.
+ /// </summary>
+ public object ToReflectionType(object value)
+ {
+ if (descriptor.IsRepeated)
+ {
+ if (descriptor.MappedType == MappedType.Enum)
+ {
+ // Must convert the whole list.
+ IList<object> result = new List<object>();
+ foreach (object element in (IEnumerable) value)
+ {
+ result.Add(SingularToReflectionType(element));
+ }
+ return result;
+ }
+ else
+ {
+ return value;
+ }
+ }
+ else
+ {
+ return SingularToReflectionType(value);
+ }
+ }
+
+ /// <summary>
+ /// Like ToReflectionType(object) but for a single element.
+ /// </summary>
+ internal Object SingularToReflectionType(object value)
+ {
+ return descriptor.MappedType == MappedType.Enum
+ ? descriptor.EnumType.FindValueByNumber((int) value)
+ : value;
+ }
+
+ public abstract object FromReflectionType(object value);
+ }
+}
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