From 2a15051a1e101ea58d7d2e262aa79c7c21f23266 Mon Sep 17 00:00:00 2001 From: Jon Skeet Date: Fri, 13 Nov 2015 20:04:03 +0000 Subject: Introduce a Parser property into MessageDescriptor, and populate it from generated types. Generated code coming in next commit - in a subsequent PR I want to do a bit of renaming and redocumenting around this, in anticipation of DynamicMessage. --- csharp/src/Google.Protobuf/JsonParser.cs | 6 +- csharp/src/Google.Protobuf/MessageParser.cs | 123 +++++++++++++++++++-- .../Reflection/GeneratedCodeInfo.cs | 10 +- .../Reflection/MessageDescriptor.cs | 11 ++ 4 files changed, 134 insertions(+), 16 deletions(-) (limited to 'csharp/src/Google.Protobuf') diff --git a/csharp/src/Google.Protobuf/JsonParser.cs b/csharp/src/Google.Protobuf/JsonParser.cs index 9e1c83cc..b4a35d7c 100644 --- a/csharp/src/Google.Protobuf/JsonParser.cs +++ b/csharp/src/Google.Protobuf/JsonParser.cs @@ -555,14 +555,10 @@ namespace Google.Protobuf /// /// Creates a new instance of the message type for the given field. - /// This method is mostly extracted so we can replace it in one go when we work out - /// what we want to do instead of Activator.CreateInstance. /// private static IMessage NewMessageForField(FieldDescriptor field) { - // TODO: Create an instance in a better way ? - // (We could potentially add a Parser property to MessageDescriptor... see issue 806.) - return (IMessage) Activator.CreateInstance(field.MessageType.GeneratedType); + return field.MessageType.Parser.CreateTemplate(); } private static T ParseNumericString(string text, Func parser, bool floatingPoint) diff --git a/csharp/src/Google.Protobuf/MessageParser.cs b/csharp/src/Google.Protobuf/MessageParser.cs index 8f2717c5..f911c9dd 100644 --- a/csharp/src/Google.Protobuf/MessageParser.cs +++ b/csharp/src/Google.Protobuf/MessageParser.cs @@ -35,6 +35,109 @@ using System.IO; namespace Google.Protobuf { + /// + /// A general message parser, typically used by reflection-based code as all the methods + /// return simple . + /// + public class MessageParser + { + private Func factory; + + internal MessageParser(Func factory) + { + this.factory = factory; + } + + /// + /// Creates a template instance ready for population. + /// + /// An empty message. + internal IMessage CreateTemplate() + { + return factory(); + } + + /// + /// Parses a message from a byte array. + /// + /// The byte array containing the message. Must not be null. + /// The newly parsed message. + public IMessage ParseFrom(byte[] data) + { + Preconditions.CheckNotNull(data, "data"); + IMessage message = factory(); + message.MergeFrom(data); + return message; + } + + /// + /// Parses a message from the given byte string. + /// + /// The data to parse. + /// The parsed message. + public IMessage ParseFrom(ByteString data) + { + Preconditions.CheckNotNull(data, "data"); + IMessage message = factory(); + message.MergeFrom(data); + return message; + } + + /// + /// Parses a message from the given stream. + /// + /// The stream to parse. + /// The parsed message. + public IMessage ParseFrom(Stream input) + { + IMessage message = factory(); + message.MergeFrom(input); + return message; + } + + /// + /// Parses a length-delimited message from the given stream. + /// + /// + /// The stream is expected to contain a length and then the data. Only the amount of data + /// specified by the length will be consumed. + /// + /// The stream to parse. + /// The parsed message. + public IMessage ParseDelimitedFrom(Stream input) + { + IMessage message = factory(); + message.MergeDelimitedFrom(input); + return message; + } + + /// + /// Parses a message from the given coded input stream. + /// + /// The stream to parse. + /// The parsed message. + public IMessage ParseFrom(CodedInputStream input) + { + IMessage message = factory(); + message.MergeFrom(input); + return message; + } + + /// + /// Parses a message from the given JSON. + /// + /// The JSON to parse. + /// The parsed message. + /// The JSON does not comply with RFC 7159 + /// The JSON does not represent a Protocol Buffers message correctly + public IMessage ParseJson(string json) + { + IMessage message = factory(); + JsonParser.Default.Merge(message, json); + return message; + } + } + /// /// A parser for a specific message type. /// @@ -51,8 +154,10 @@ namespace Google.Protobuf ///

/// /// The type of message to be parsed. - public sealed class MessageParser where T : IMessage + public sealed class MessageParser : MessageParser where T : IMessage { + // Implementation note: all the methods here *could* just delegate up to the base class and cast the result. + // The private readonly Func factory; /// @@ -63,7 +168,7 @@ namespace Google.Protobuf /// to require a parameterless constructor: delegates are significantly faster to execute. /// /// Function to invoke when a new, empty message is required. - public MessageParser(Func factory) + public MessageParser(Func factory) : base(() => factory()) { this.factory = factory; } @@ -72,7 +177,7 @@ namespace Google.Protobuf /// Creates a template instance ready for population. /// /// An empty message. - internal T CreateTemplate() + internal new T CreateTemplate() { return factory(); } @@ -82,7 +187,7 @@ namespace Google.Protobuf /// /// The byte array containing the message. Must not be null. /// The newly parsed message. - public T ParseFrom(byte[] data) + public new T ParseFrom(byte[] data) { Preconditions.CheckNotNull(data, "data"); T message = factory(); @@ -95,7 +200,7 @@ namespace Google.Protobuf /// /// The data to parse. /// The parsed message. - public T ParseFrom(ByteString data) + public new T ParseFrom(ByteString data) { Preconditions.CheckNotNull(data, "data"); T message = factory(); @@ -108,7 +213,7 @@ namespace Google.Protobuf /// /// The stream to parse. /// The parsed message. - public T ParseFrom(Stream input) + public new T ParseFrom(Stream input) { T message = factory(); message.MergeFrom(input); @@ -124,7 +229,7 @@ namespace Google.Protobuf /// /// The stream to parse. /// The parsed message. - public T ParseDelimitedFrom(Stream input) + public new T ParseDelimitedFrom(Stream input) { T message = factory(); message.MergeDelimitedFrom(input); @@ -136,7 +241,7 @@ namespace Google.Protobuf /// /// The stream to parse. /// The parsed message. - public T ParseFrom(CodedInputStream input) + public new T ParseFrom(CodedInputStream input) { T message = factory(); message.MergeFrom(input); @@ -150,7 +255,7 @@ namespace Google.Protobuf /// The parsed message. /// The JSON does not comply with RFC 7159 /// The JSON does not represent a Protocol Buffers message correctly - public T ParseJson(string json) + public new T ParseJson(string json) { T message = factory(); JsonParser.Default.Merge(message, json); diff --git a/csharp/src/Google.Protobuf/Reflection/GeneratedCodeInfo.cs b/csharp/src/Google.Protobuf/Reflection/GeneratedCodeInfo.cs index 8c52cd12..ff4ad0aa 100644 --- a/csharp/src/Google.Protobuf/Reflection/GeneratedCodeInfo.cs +++ b/csharp/src/Google.Protobuf/Reflection/GeneratedCodeInfo.cs @@ -17,6 +17,11 @@ namespace Google.Protobuf.Reflection /// public Type ClrType { get; private set; } + /// + /// Irrelevant for file descriptors; the parser for message descriptors. + /// + public MessageParser Parser { get; private set; } + /// /// Irrelevant for file descriptors; the CLR property names (in message descriptor field order) /// for fields in the message for message descriptors. @@ -46,11 +51,12 @@ namespace Google.Protobuf.Reflection /// Each array parameter may be null, to indicate a lack of values. /// The parameter order is designed to make it feasible to format the generated code readably. /// - public GeneratedCodeInfo(Type clrType, string[] propertyNames, string[] oneofNames, Type[] nestedEnums, GeneratedCodeInfo[] nestedTypes) + public GeneratedCodeInfo(Type clrType, MessageParser parser, string[] propertyNames, string[] oneofNames, Type[] nestedEnums, GeneratedCodeInfo[] nestedTypes) { NestedTypes = nestedTypes ?? EmptyCodeInfo; NestedEnums = nestedEnums ?? ReflectionUtil.EmptyTypes; ClrType = clrType; + Parser = parser; PropertyNames = propertyNames ?? EmptyNames; OneofNames = oneofNames ?? EmptyNames; } @@ -59,7 +65,7 @@ namespace Google.Protobuf.Reflection /// Creates a GeneratedCodeInfo for a file descriptor, with only types and enums. /// public GeneratedCodeInfo(Type[] nestedEnums, GeneratedCodeInfo[] nestedTypes) - : this(null, null, null, nestedEnums, nestedTypes) + : this(null, null, null, null, nestedEnums, nestedTypes) { } } diff --git a/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs b/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs index e599998e..65040e42 100644 --- a/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs +++ b/csharp/src/Google.Protobuf/Reflection/MessageDescriptor.cs @@ -67,11 +67,13 @@ namespace Google.Protobuf.Reflection private readonly IList oneofs; // CLR representation of the type described by this descriptor, if any. private readonly Type generatedType; + private readonly MessageParser parser; internal MessageDescriptor(DescriptorProto proto, FileDescriptor file, MessageDescriptor parent, int typeIndex, GeneratedCodeInfo generatedCodeInfo) : base(file, file.ComputeFullName(parent, proto.Name), typeIndex) { this.proto = proto; + parser = generatedCodeInfo == null ? null : generatedCodeInfo.Parser; generatedType = generatedCodeInfo == null ? null : generatedCodeInfo.ClrType; containingType = parent; @@ -122,6 +124,15 @@ namespace Google.Protobuf.Reflection /// public Type GeneratedType { get { return generatedType; } } + /// + /// A parser for this message type. + /// + /// + /// As is not generic, this cannot be statically + /// typed to the relevant type, but if returns a non-null value, the parser returned + /// + public MessageParser Parser { get { return parser; } } + /// /// Returns whether this message is one of the "well known types" which may have runtime/protoc support. /// -- cgit v1.2.3