1 #region Copyright notice and license 2 // Protocol Buffers - Google's data interchange format 3 // Copyright 2008 Google Inc. All rights reserved. 4 // https://developers.google.com/protocol-buffers/ 5 // 6 // Redistribution and use in source and binary forms, with or without 7 // modification, are permitted provided that the following conditions are 8 // met: 9 // 10 // * Redistributions of source code must retain the above copyright 11 // notice, this list of conditions and the following disclaimer. 12 // * Redistributions in binary form must reproduce the above 13 // copyright notice, this list of conditions and the following disclaimer 14 // in the documentation and/or other materials provided with the 15 // distribution. 16 // * Neither the name of Google Inc. nor the names of its 17 // contributors may be used to endorse or promote products derived from 18 // this software without specific prior written permission. 19 // 20 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 #endregion 32 33 using System; 34 35 namespace Google.Protobuf 36 { 37 /// <summary> 38 /// Represents a non-generic extension definition. This API is experimental and subject to change. 39 /// </summary> 40 public abstract class Extension 41 { 42 internal abstract Type TargetType { get; } 43 44 /// <summary> 45 /// Internal use. Creates a new extension with the specified field number. 46 /// </summary> Extension(int fieldNumber)47 protected Extension(int fieldNumber) 48 { 49 FieldNumber = fieldNumber; 50 } 51 CreateValue()52 internal abstract IExtensionValue CreateValue(); 53 54 /// <summary> 55 /// Gets the field number of this extension 56 /// </summary> 57 public int FieldNumber { get; } 58 59 internal abstract bool IsRepeated { get; } 60 } 61 62 /// <summary> 63 /// Represents a type-safe extension identifier used for getting and setting single extension values in <see cref="IExtendableMessage{T}"/> instances. 64 /// This API is experimental and subject to change. 65 /// </summary> 66 /// <typeparam name="TTarget">The message type this field applies to</typeparam> 67 /// <typeparam name="TValue">The field value type of this extension</typeparam> 68 public sealed class Extension<TTarget, TValue> : Extension where TTarget : IExtendableMessage<TTarget> 69 { 70 private readonly FieldCodec<TValue> codec; 71 72 /// <summary> 73 /// Creates a new extension identifier with the specified field number and codec 74 /// </summary> Extension(int fieldNumber, FieldCodec<TValue> codec)75 public Extension(int fieldNumber, FieldCodec<TValue> codec) : base(fieldNumber) 76 { 77 this.codec = codec; 78 } 79 80 internal TValue DefaultValue => codec.DefaultValue; 81 82 internal override Type TargetType => typeof(TTarget); 83 84 internal override bool IsRepeated => false; 85 CreateValue()86 internal override IExtensionValue CreateValue() 87 { 88 return new ExtensionValue<TValue>(codec); 89 } 90 } 91 92 /// <summary> 93 /// Represents a type-safe extension identifier used for getting repeated extension values in <see cref="IExtendableMessage{T}"/> instances. 94 /// This API is experimental and subject to change. 95 /// </summary> 96 /// <typeparam name="TTarget">The message type this field applies to</typeparam> 97 /// <typeparam name="TValue">The repeated field value type of this extension</typeparam> 98 public sealed class RepeatedExtension<TTarget, TValue> : Extension where TTarget : IExtendableMessage<TTarget> 99 { 100 private readonly FieldCodec<TValue> codec; 101 102 /// <summary> 103 /// Creates a new repeated extension identifier with the specified field number and codec 104 /// </summary> RepeatedExtension(int fieldNumber, FieldCodec<TValue> codec)105 public RepeatedExtension(int fieldNumber, FieldCodec<TValue> codec) : base(fieldNumber) 106 { 107 this.codec = codec; 108 } 109 110 internal override Type TargetType => typeof(TTarget); 111 112 internal override bool IsRepeated => true; 113 CreateValue()114 internal override IExtensionValue CreateValue() 115 { 116 return new RepeatedExtensionValue<TValue>(codec); 117 } 118 } 119 } 120