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 /// Accessor for single fields. 41 /// </summary> 42 internal sealed class SingleFieldAccessor : FieldAccessorBase 43 { 44 // All the work here is actually done in the constructor - it creates the appropriate delegates. 45 // There are various cases to consider, based on the property type (message, string/bytes, or "genuine" primitive) 46 // and proto2 vs proto3 for non-message types, as proto3 doesn't support "full" presence detection or default 47 // values. 48 49 private readonly Action<IMessage, object> setValueDelegate; 50 private readonly Action<IMessage> clearDelegate; 51 SingleFieldAccessor(PropertyInfo property, FieldDescriptor descriptor)52 internal SingleFieldAccessor(PropertyInfo property, FieldDescriptor descriptor) : base(property, descriptor) 53 { 54 if (!property.CanWrite) 55 { 56 throw new ArgumentException("Not all required properties/methods available"); 57 } 58 setValueDelegate = ReflectionUtil.CreateActionIMessageObject(property.GetSetMethod()); 59 60 var clrType = property.PropertyType; 61 62 // TODO: Validate that this is a reasonable single field? (Should be a value type, a message type, or string/ByteString.) 63 object defaultValue = 64 descriptor.FieldType == FieldType.Message ? null 65 : clrType == typeof(string) ? "" 66 : clrType == typeof(ByteString) ? ByteString.Empty 67 : Activator.CreateInstance(clrType); 68 clearDelegate = message => SetValue(message, defaultValue); 69 } 70 Clear(IMessage message)71 public override void Clear(IMessage message) 72 { 73 clearDelegate(message); 74 } 75 SetValue(IMessage message, object value)76 public override void SetValue(IMessage message, object value) 77 { 78 setValueDelegate(message, value); 79 } 80 } 81 } 82