third_party/protobuf/csharp/src/Google.Protobuf/Reflection/OneofDescriptor.cs

   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.Collections.Generic;
  34 using System.Collections.ObjectModel;
  35 using Google.Protobuf.Compatibility;
  36
  37 namespace Google.Protobuf.Reflection
  38 {
  39     /// <summary>
  40     /// Describes a "oneof" field collection in a message type: a set of
  41     /// fields of which at most one can be set in any particular message.
  42     /// </summary>
  43     public sealed class OneofDescriptor : DescriptorBase
  44     {
  45         private readonly OneofDescriptorProto proto;
  46         private MessageDescriptor containingType;
  47         private IList<FieldDescriptor> fields;
  48         private readonly OneofAccessor accessor;
  49
  50         internal OneofDescriptor(OneofDescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int index, string clrName)
  51             : base(file, file.ComputeFullName(parent, proto.Name), index)
  52         {
  53             this.proto = proto;
  54             containingType = parent;
  55
  56             file.DescriptorPool.AddSymbol(this);
  57             accessor = CreateAccessor(clrName);
  58         }
  59
  60         /// <summary>
  61         /// The brief name of the descriptor's target.
  62         /// </summary>
  63         public override string Name { get { return proto.Name; } }
  64
  65         /// <summary>
  66         /// Gets the message type containing this oneof.
  67         /// </summary>
  68         /// <value>
  69         /// The message type containing this oneof.
  70         /// </value>
  71         public MessageDescriptor ContainingType
  72         {
  73             get { return containingType; }
  74         }
  75
  76         /// <summary>
  77         /// Gets the fields within this oneof, in declaration order.
  78         /// </summary>
  79         /// <value>
  80         /// The fields within this oneof, in declaration order.
  81         /// </value>
  82         public IList<FieldDescriptor> Fields { get { return fields; } }
  83
  84         /// <summary>
  85         /// Gets an accessor for reflective access to the values associated with the oneof
  86         /// in a particular message.
  87         /// </summary>
  88         /// <value>
  89         /// The accessor used for reflective access, or <c>null</c> if reflection is not
  90         /// supported by this descriptor.
  91         /// </value>
  92         public OneofAccessor Accessor { get { return accessor; } }
  93
  94         internal void CrossLink()
  95         {
  96             List<FieldDescriptor> fieldCollection = new List<FieldDescriptor>();
  97             foreach (var field in ContainingType.Fields.InDeclarationOrder())
  98             {
  99                 if (field.ContainingOneof == this)
 100                 {
 101                     fieldCollection.Add(field);
 102                 }
 103             }
 104             fields = new ReadOnlyCollection<FieldDescriptor>(fieldCollection);
 105         }
 106
 107         private OneofAccessor CreateAccessor(string clrName)
 108         {
 109             if (containingType.GeneratedType == null || clrName == null)
 110             {
 111                 return null;
 112             }
 113             var caseProperty = containingType.GeneratedType.GetProperty(clrName + "Case");
 114             if (caseProperty == null)
 115             {
 116                 throw new DescriptorValidationException(this, "Property " + clrName + "Case not found in " + containingType.GeneratedType);
 117             }
 118             var clearMethod = containingType.GeneratedType.GetMethod("Clear" + clrName);
 119             if (clearMethod == null)
 120             {
 121                 throw new DescriptorValidationException(this, "Method Clear" + clrName + " not found in " + containingType.GeneratedType);
 122             }
 123
 124             return new OneofAccessor(caseProperty, clearMethod, this);
 125         }
 126     }
 127 }