diff options
Diffstat (limited to 'csharp/ProtocolBuffers/UnknownFieldSet.cs')
| -rw-r--r-- | csharp/ProtocolBuffers/UnknownFieldSet.cs | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/csharp/ProtocolBuffers/UnknownFieldSet.cs b/csharp/ProtocolBuffers/UnknownFieldSet.cs index a7d19945..468970e5 100644 --- a/csharp/ProtocolBuffers/UnknownFieldSet.cs +++ b/csharp/ProtocolBuffers/UnknownFieldSet.cs @@ -17,6 +17,7 @@ using System; using System.Collections.Generic; using System.IO; using Google.ProtocolBuffers.Collections; +using Google.ProtocolBuffers.Descriptors; namespace Google.ProtocolBuffers { /// <summary> @@ -430,6 +431,191 @@ namespace Google.ProtocolBuffers { return this; } + internal void MergeFrom(CodedInputStream input, ExtensionRegistry extensionRegistry, IBuilder builder) { + while (true) { + uint tag = input.ReadTag(); + if (tag == 0) { + break; + } + if (!MergeFieldFrom(input, extensionRegistry, builder, tag)) { + // end group tag + break; + } + } + } + + /// <summary> + /// Like <see cref="MergeFrom(CodedInputStream, ExtensionRegistry, IBuilder)" /> + /// but parses a single field. + /// </summary> + /// <param name="input">The input to read the field from</param> + /// <param name="extensionRegistry">Registry to use when an extension field is encountered</param> + /// <param name="builder">Builder to merge field into, if it's a known field</param> + /// <param name="tag">The tag, which should already have been read from the input</param> + /// <returns>true unless the tag is an end-group tag</returns> + internal bool MergeFieldFrom(CodedInputStream input, + ExtensionRegistry extensionRegistry, IBuilder builder, uint tag) { + MessageDescriptor type = builder.DescriptorForType; + if (type.Options.MessageSetWireFormat && tag == WireFormat.MessageSetTag.ItemStart) { + MergeMessageSetExtensionFromCodedStream(input, extensionRegistry, builder); + return true; + } + + WireFormat.WireType wireType = WireFormat.GetTagWireType(tag); + int fieldNumber = WireFormat.GetTagFieldNumber(tag); + + FieldDescriptor field; + IMessage defaultFieldInstance = null; + + if (type.IsExtensionNumber(fieldNumber)) { + ExtensionInfo extension = extensionRegistry[type, fieldNumber]; + if (extension == null) { + field = null; + } else { + field = extension.Descriptor; + defaultFieldInstance = extension.DefaultInstance; + } + } else { + field = type.FindFieldByNumber(fieldNumber); + } + + // Unknown field or wrong wire type. Skip. + if (field == null || wireType != WireFormat.FieldTypeToWireFormatMap[field.FieldType]) { + return MergeFieldFrom(tag, input); + } + + object value; + switch (field.FieldType) { + case FieldType.Group: + case FieldType.Message: { + IBuilder subBuilder; + if (defaultFieldInstance != null) { + subBuilder = defaultFieldInstance.WeakCreateBuilderForType(); + } else { + subBuilder = builder.CreateBuilderForField(field); + } + if (!field.IsRepeated) { + subBuilder.WeakMergeFrom((IMessage)builder[field]); + } + if (field.FieldType == FieldType.Group) { + input.ReadGroup(field.FieldNumber, subBuilder, extensionRegistry); + } else { + input.ReadMessage(subBuilder, extensionRegistry); + } + value = subBuilder.WeakBuild(); + break; + } + case FieldType.Enum: { + int rawValue = input.ReadEnum(); + value = field.EnumType.FindValueByNumber(rawValue); + // If the number isn't recognized as a valid value for this enum, + // drop it. + if (value == null) { + MergeVarintField(fieldNumber, (ulong)rawValue); + return true; + } + break; + } + default: + value = input.ReadPrimitiveField(field.FieldType); + break; + } + if (field.IsRepeated) { + builder.WeakAddRepeatedField(field, value); + } else { + builder[field] = value; + } + return true; + } + + /// <summary> + /// Called by MergeFieldFrom to parse a MessageSet extension. + /// </summary> + private void MergeMessageSetExtensionFromCodedStream(CodedInputStream input, + ExtensionRegistry extensionRegistry, IBuilder builder) { + MessageDescriptor type = builder.DescriptorForType; + + // The wire format for MessageSet is: + // message MessageSet { + // repeated group Item = 1 { + // required int32 typeId = 2; + // required bytes message = 3; + // } + // } + // "typeId" is the extension's field number. The extension can only be + // a message type, where "message" contains the encoded bytes of that + // message. + // + // In practice, we will probably never see a MessageSet item in which + // the message appears before the type ID, or where either field does not + // appear exactly once. However, in theory such cases are valid, so we + // should be prepared to accept them. + + int typeId = 0; + ByteString rawBytes = null; // If we encounter "message" before "typeId" + IBuilder subBuilder = null; + FieldDescriptor field = null; + + while (true) { + uint tag = input.ReadTag(); + if (tag == 0) { + break; + } + + if (tag == WireFormat.MessageSetTag.TypeID) { + typeId = input.ReadInt32(); + // Zero is not a valid type ID. + if (typeId != 0) { + ExtensionInfo extension = extensionRegistry[type, typeId]; + if (extension != null) { + field = extension.Descriptor; + subBuilder = extension.DefaultInstance.WeakCreateBuilderForType(); + IMessage originalMessage = (IMessage)builder[field]; + if (originalMessage != null) { + subBuilder.WeakMergeFrom(originalMessage); + } + if (rawBytes != null) { + // We already encountered the message. Parse it now. + // TODO(jonskeet): Check this is okay. It's subtly different from the Java, as it doesn't create an input stream from rawBytes. + // In fact, why don't we just call MergeFrom(rawBytes)? And what about the extension registry? + subBuilder.WeakMergeFrom(rawBytes.CreateCodedInput()); + rawBytes = null; + } + } else { + // Unknown extension number. If we already saw data, put it + // in rawBytes. + if (rawBytes != null) { + MergeField(typeId, UnknownField.CreateBuilder().AddLengthDelimited(rawBytes).Build()); + rawBytes = null; + } + } + } + } else if (tag == WireFormat.MessageSetTag.Message) { + if (typeId == 0) { + // We haven't seen a type ID yet, so we have to store the raw bytes for now. + rawBytes = input.ReadBytes(); + } else if (subBuilder == null) { + // We don't know how to parse this. Ignore it. + MergeField(typeId, UnknownField.CreateBuilder().AddLengthDelimited(input.ReadBytes()).Build()); + } else { + // We already know the type, so we can parse directly from the input + // with no copying. Hooray! + input.ReadMessage(subBuilder, extensionRegistry); + } + } else { + // Unknown tag. Skip it. + if (!input.SkipField(tag)) { + break; // end of group + } + } + } + + input.CheckLastTagWas(WireFormat.MessageSetTag.ItemEnd); + + if (subBuilder != null) { + builder[field] = subBuilder.WeakBuild(); + } + } } } } |