1 #region Copyright notice and license 2 // Protocol Buffers - Google's data interchange format 3 // Copyright 2015 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 using System.Reflection; 35 using Google.Protobuf.Compatibility; 36 37 namespace Google.Protobuf.Reflection 38 { 39 /// <summary> 40 /// Reflection access for a oneof, allowing clear and "get case" actions. 41 /// </summary> 42 public sealed class OneofAccessor 43 { 44 private readonly Func<IMessage, int> caseDelegate; 45 private readonly Action<IMessage> clearDelegate; 46 private OneofDescriptor descriptor; 47 OneofAccessor(PropertyInfo caseProperty, MethodInfo clearMethod, OneofDescriptor descriptor)48 internal OneofAccessor(PropertyInfo caseProperty, MethodInfo clearMethod, OneofDescriptor descriptor) 49 { 50 if (!caseProperty.CanRead) 51 { 52 throw new ArgumentException("Cannot read from property"); 53 } 54 this.descriptor = descriptor; 55 caseDelegate = ReflectionUtil.CreateFuncIMessageT<int>(caseProperty.GetGetMethod()); 56 57 this.descriptor = descriptor; 58 clearDelegate = ReflectionUtil.CreateActionIMessage(clearMethod); 59 } 60 61 /// <summary> 62 /// Gets the descriptor for this oneof. 63 /// </summary> 64 /// <value> 65 /// The descriptor of the oneof. 66 /// </value> 67 public OneofDescriptor Descriptor { get { return descriptor; } } 68 69 /// <summary> 70 /// Clears the oneof in the specified message. 71 /// </summary> Clear(IMessage message)72 public void Clear(IMessage message) 73 { 74 clearDelegate(message); 75 } 76 77 /// <summary> 78 /// Indicates which field in the oneof is set for specified message 79 /// </summary> GetCaseFieldDescriptor(IMessage message)80 public FieldDescriptor GetCaseFieldDescriptor(IMessage message) 81 { 82 int fieldNumber = caseDelegate(message); 83 if (fieldNumber > 0) 84 { 85 return descriptor.ContainingType.FindFieldByNumber(fieldNumber); 86 } 87 return null; 88 } 89 } 90 } 91