| #region Copyright notice and license |
| // Protocol Buffers - Google's data interchange format |
| // Copyright 2015 Google Inc. All rights reserved. |
| // |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file or at |
| // https://developers.google.com/open-source/licenses/bsd |
| #endregion |
| |
| using Google.Protobuf.Collections; |
| using Google.Protobuf.WellKnownTypes; |
| using System; |
| using System.Collections.Generic; |
| using System.Security; |
| |
| namespace Google.Protobuf |
| { |
| /// <summary> |
| /// Factory methods for <see cref="FieldCodec{T}"/>. |
| /// </summary> |
| public static class FieldCodec |
| { |
| // TODO: Avoid the "dual hit" of lambda expressions: create open delegates instead. (At least test...) |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a string field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<string> ForString(uint tag) => ForString(tag, ""); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a bytes field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<ByteString> ForBytes(uint tag) => ForBytes(tag, ByteString.Empty); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a bool field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<bool> ForBool(uint tag) => ForBool(tag, false); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an int32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<int> ForInt32(uint tag) => ForInt32(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sint32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<int> ForSInt32(uint tag) => ForSInt32(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a fixed32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<uint> ForFixed32(uint tag) => ForFixed32(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sfixed32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<int> ForSFixed32(uint tag) => ForSFixed32(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a uint32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<uint> ForUInt32(uint tag) => ForUInt32(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an int64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<long> ForInt64(uint tag) => ForInt64(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sint64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<long> ForSInt64(uint tag) => ForSInt64(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a fixed64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<ulong> ForFixed64(uint tag) => ForFixed64(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sfixed64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<long> ForSFixed64(uint tag) => ForSFixed64(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a uint64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<ulong> ForUInt64(uint tag) => ForUInt64(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a float field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<float> ForFloat(uint tag) => ForFloat(tag, 0); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a double field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<double> ForDouble(uint tag) => ForDouble(tag, 0); |
| |
| // Enums are tricky. We can probably use expression trees to build these delegates automatically, |
| // but it's easy to generate the code for it. |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an enum field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="toInt32">A conversion function from <see cref="Int32"/> to the enum type.</param> |
| /// <param name="fromInt32">A conversion function from the enum type to <see cref="Int32"/>.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<T> ForEnum<T>(uint tag, Func<T, int> toInt32, Func<int, T> fromInt32) => |
| ForEnum(tag, toInt32, fromInt32, default); |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a string field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<string> ForString(uint tag, string defaultValue) |
| { |
| return new FieldCodec<string>((ref ParseContext ctx) => ctx.ReadString(), (ref WriteContext ctx, string value) => ctx.WriteString(value), CodedOutputStream.ComputeStringSize, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a bytes field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<ByteString> ForBytes(uint tag, ByteString defaultValue) |
| { |
| return new FieldCodec<ByteString>((ref ParseContext ctx) => ctx.ReadBytes(), (ref WriteContext ctx, ByteString value) => ctx.WriteBytes(value), CodedOutputStream.ComputeBytesSize, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a bool field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<bool> ForBool(uint tag, bool defaultValue) |
| { |
| return new FieldCodec<bool>((ref ParseContext ctx) => ctx.ReadBool(), (ref WriteContext ctx, bool value) => ctx.WriteBool(value), CodedOutputStream.BoolSize, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an int32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<int> ForInt32(uint tag, int defaultValue) |
| { |
| return new FieldCodec<int>((ref ParseContext ctx) => ctx.ReadInt32(), (ref WriteContext output, int value) => output.WriteInt32(value), CodedOutputStream.ComputeInt32Size, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sint32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<int> ForSInt32(uint tag, int defaultValue) |
| { |
| return new FieldCodec<int>((ref ParseContext ctx) => ctx.ReadSInt32(), (ref WriteContext output, int value) => output.WriteSInt32(value), CodedOutputStream.ComputeSInt32Size, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a fixed32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<uint> ForFixed32(uint tag, uint defaultValue) |
| { |
| return new FieldCodec<uint>((ref ParseContext ctx) => ctx.ReadFixed32(), (ref WriteContext output, uint value) => output.WriteFixed32(value), 4, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sfixed32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<int> ForSFixed32(uint tag, int defaultValue) |
| { |
| return new FieldCodec<int>((ref ParseContext ctx) => ctx.ReadSFixed32(), (ref WriteContext output, int value) => output.WriteSFixed32(value), 4, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a uint32 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<uint> ForUInt32(uint tag, uint defaultValue) |
| { |
| return new FieldCodec<uint>((ref ParseContext ctx) => ctx.ReadUInt32(), (ref WriteContext output, uint value) => output.WriteUInt32(value), CodedOutputStream.ComputeUInt32Size, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an int64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<long> ForInt64(uint tag, long defaultValue) |
| { |
| return new FieldCodec<long>((ref ParseContext ctx) => ctx.ReadInt64(), (ref WriteContext output, long value) => output.WriteInt64(value), CodedOutputStream.ComputeInt64Size, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sint64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<long> ForSInt64(uint tag, long defaultValue) |
| { |
| return new FieldCodec<long>((ref ParseContext ctx) => ctx.ReadSInt64(), (ref WriteContext output, long value) => output.WriteSInt64(value), CodedOutputStream.ComputeSInt64Size, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a fixed64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<ulong> ForFixed64(uint tag, ulong defaultValue) |
| { |
| return new FieldCodec<ulong>((ref ParseContext ctx) => ctx.ReadFixed64(), (ref WriteContext output, ulong value) => output.WriteFixed64(value), 8, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an sfixed64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<long> ForSFixed64(uint tag, long defaultValue) |
| { |
| return new FieldCodec<long>((ref ParseContext ctx) => ctx.ReadSFixed64(), (ref WriteContext output, long value) => output.WriteSFixed64(value), 8, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a uint64 field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<ulong> ForUInt64(uint tag, ulong defaultValue) |
| { |
| return new FieldCodec<ulong>((ref ParseContext ctx) => ctx.ReadUInt64(), (ref WriteContext output, ulong value) => output.WriteUInt64(value), CodedOutputStream.ComputeUInt64Size, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a float field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<float> ForFloat(uint tag, float defaultValue) |
| { |
| return new FieldCodec<float>((ref ParseContext ctx) => ctx.ReadFloat(), (ref WriteContext output, float value) => output.WriteFloat(value), CodedOutputStream.FloatSize, tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a double field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<double> ForDouble(uint tag, double defaultValue) |
| { |
| return new FieldCodec<double>((ref ParseContext ctx) => ctx.ReadDouble(), (ref WriteContext output, double value) => output.WriteDouble(value), CodedOutputStream.DoubleSize, tag, defaultValue); |
| } |
| |
| // Enums are tricky. We can probably use expression trees to build these delegates automatically, |
| // but it's easy to generate the code for it. |
| |
| /// <summary> |
| /// Retrieves a codec suitable for an enum field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="toInt32">A conversion function from <see cref="Int32"/> to the enum type.</param> |
| /// <param name="fromInt32">A conversion function from the enum type to <see cref="Int32"/>.</param> |
| /// <param name="defaultValue">The default value.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<T> ForEnum<T>(uint tag, Func<T, int> toInt32, Func<int, T> fromInt32, T defaultValue) |
| { |
| return new FieldCodec<T>((ref ParseContext ctx) => fromInt32( |
| ctx.ReadEnum()), |
| (ref WriteContext output, T value) => output.WriteEnum(toInt32(value)), |
| value => CodedOutputStream.ComputeEnumSize(toInt32(value)), tag, defaultValue); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a message field with the given tag. |
| /// </summary> |
| /// <param name="tag">The tag.</param> |
| /// <param name="parser">A parser to use for the message type.</param> |
| /// <returns>A codec for the given tag.</returns> |
| public static FieldCodec<T> ForMessage<T>(uint tag, MessageParser<T> parser) where T : class, IMessage<T> |
| { |
| return new FieldCodec<T>( |
| (ref ParseContext ctx) => |
| { |
| T message = parser.CreateTemplate(); |
| ctx.ReadMessage(message); |
| return message; |
| }, |
| (ref WriteContext output, T value) => output.WriteMessage(value), |
| (ref ParseContext ctx, ref T v) => |
| { |
| if (v == null) |
| { |
| v = parser.CreateTemplate(); |
| } |
| |
| ctx.ReadMessage(v); |
| }, |
| (ref T v, T v2) => |
| { |
| if (v2 == null) |
| { |
| return false; |
| } |
| else if (v == null) |
| { |
| v = v2.Clone(); |
| } |
| else |
| { |
| v.MergeFrom(v2); |
| } |
| return true; |
| }, |
| message => CodedOutputStream.ComputeMessageSize(message), tag); |
| } |
| |
| /// <summary> |
| /// Retrieves a codec suitable for a group field with the given tag. |
| /// </summary> |
| /// <param name="startTag">The start group tag.</param> |
| /// <param name="endTag">The end group tag.</param> |
| /// <param name="parser">A parser to use for the group message type.</param> |
| /// <returns>A codec for given tag</returns> |
| public static FieldCodec<T> ForGroup<T>(uint startTag, uint endTag, MessageParser<T> parser) where T : class, IMessage<T> |
| { |
| return new FieldCodec<T>( |
| (ref ParseContext ctx) => |
| { |
| T message = parser.CreateTemplate(); |
| ctx.ReadGroup(message); |
| return message; |
| }, |
| (ref WriteContext output, T value) => output.WriteGroup(value), |
| (ref ParseContext ctx, ref T v) => |
| { |
| if (v == null) |
| { |
| v = parser.CreateTemplate(); |
| } |
| |
| ctx.ReadGroup(v); |
| }, |
| (ref T v, T v2) => |
| { |
| if (v2 == null) |
| { |
| return v == null; |
| } |
| else if (v == null) |
| { |
| v = v2.Clone(); |
| } |
| else |
| { |
| v.MergeFrom(v2); |
| } |
| return true; |
| }, |
| message => CodedOutputStream.ComputeGroupSize(message), startTag, endTag); |
| } |
| |
| /// <summary> |
| /// Creates a codec for a wrapper type of a class - which must be string or ByteString. |
| /// </summary> |
| public static FieldCodec<T> ForClassWrapper<T>(uint tag) where T : class |
| { |
| var nestedCodec = WrapperCodecs.GetCodec<T>(); |
| return new FieldCodec<T>( |
| (ref ParseContext ctx) => WrapperCodecs.Read<T>(ref ctx, nestedCodec), |
| (ref WriteContext output, T value) => WrapperCodecs.Write<T>(ref output, value, nestedCodec), |
| (ref ParseContext ctx, ref T v) => v = WrapperCodecs.Read<T>(ref ctx, nestedCodec), |
| (ref T v, T v2) => { v = v2; return v == null; }, |
| value => WrapperCodecs.CalculateSize<T>(value, nestedCodec), |
| tag, 0, |
| null); // Default value for the wrapper |
| } |
| |
| /// <summary> |
| /// Creates a codec for a wrapper type of a struct - which must be Int32, Int64, UInt32, UInt64, |
| /// Bool, Single or Double. |
| /// </summary> |
| public static FieldCodec<T?> ForStructWrapper<T>(uint tag) where T : struct |
| { |
| var nestedCodec = WrapperCodecs.GetCodec<T>(); |
| return new FieldCodec<T?>( |
| WrapperCodecs.GetReader<T>(), |
| (ref WriteContext output, T? value) => WrapperCodecs.Write<T>(ref output, value.Value, nestedCodec), |
| (ref ParseContext ctx, ref T? v) => v = WrapperCodecs.Read<T>(ref ctx, nestedCodec), |
| (ref T? v, T? v2) => { if (v2.HasValue) { v = v2; } return v.HasValue; }, |
| value => value == null ? 0 : WrapperCodecs.CalculateSize<T>(value.Value, nestedCodec), |
| tag, 0, |
| null); // Default value for the wrapper |
| } |
| |
| /// <summary> |
| /// Helper code to create codecs for wrapper types. |
| /// </summary> |
| /// <remarks> |
| /// Somewhat ugly with all the static methods, but the conversions involved to/from nullable types make it |
| /// slightly tricky to improve. So long as we keep the public API (ForClassWrapper, ForStructWrapper) in place, |
| /// we can refactor later if we come up with something cleaner. |
| /// </remarks> |
| private static class WrapperCodecs |
| { |
| private static readonly Dictionary<System.Type, object> Codecs = new Dictionary<System.Type, object> |
| { |
| { typeof(bool), ForBool(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) }, |
| { typeof(int), ForInt32(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) }, |
| { typeof(long), ForInt64(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) }, |
| { typeof(uint), ForUInt32(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) }, |
| { typeof(ulong), ForUInt64(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Varint)) }, |
| { typeof(float), ForFloat(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Fixed32)) }, |
| { typeof(double), ForDouble(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.Fixed64)) }, |
| { typeof(string), ForString(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.LengthDelimited)) }, |
| { typeof(ByteString), ForBytes(WireFormat.MakeTag(WrappersReflection.WrapperValueFieldNumber, WireFormat.WireType.LengthDelimited)) } |
| }; |
| |
| private static readonly Dictionary<System.Type, object> Readers = new Dictionary<System.Type, object> |
| { |
| // TODO: Provide more optimized readers. |
| { typeof(bool), (ValueReader<bool?>)ParsingPrimitivesWrappers.ReadBoolWrapper }, |
| { typeof(int), (ValueReader<int?>)ParsingPrimitivesWrappers.ReadInt32Wrapper }, |
| { typeof(long), (ValueReader<long?>)ParsingPrimitivesWrappers.ReadInt64Wrapper }, |
| { typeof(uint), (ValueReader<uint?>)ParsingPrimitivesWrappers.ReadUInt32Wrapper }, |
| { typeof(ulong), (ValueReader<ulong?>)ParsingPrimitivesWrappers.ReadUInt64Wrapper }, |
| { typeof(float), BitConverter.IsLittleEndian ? |
| (ValueReader<float?>)ParsingPrimitivesWrappers.ReadFloatWrapperLittleEndian : |
| (ValueReader<float?>)ParsingPrimitivesWrappers.ReadFloatWrapperSlow }, |
| { typeof(double), BitConverter.IsLittleEndian ? |
| (ValueReader<double?>)ParsingPrimitivesWrappers.ReadDoubleWrapperLittleEndian : |
| (ValueReader<double?>)ParsingPrimitivesWrappers.ReadDoubleWrapperSlow }, |
| // `string` and `ByteString` less performance-sensitive. Do not implement for now. |
| { typeof(string), null }, |
| { typeof(ByteString), null }, |
| }; |
| |
| /// <summary> |
| /// Returns a field codec which effectively wraps a value of type T in a message. |
| /// |
| /// </summary> |
| internal static FieldCodec<T> GetCodec<T>() |
| { |
| if (!Codecs.TryGetValue(typeof(T), out object value)) |
| { |
| throw new InvalidOperationException("Invalid type argument requested for wrapper codec: " + typeof(T)); |
| } |
| return (FieldCodec<T>) value; |
| } |
| |
| internal static ValueReader<T?> GetReader<T>() where T : struct |
| { |
| if (!Readers.TryGetValue(typeof(T), out object value)) |
| { |
| throw new InvalidOperationException("Invalid type argument requested for wrapper reader: " + typeof(T)); |
| } |
| if (value == null) |
| { |
| // Return default unoptimized reader for the wrapper type. |
| var nestedCoded = GetCodec<T>(); |
| return (ref ParseContext ctx) => Read<T>(ref ctx, nestedCoded); |
| } |
| // Return optimized read for the wrapper type. |
| return (ValueReader<T?>)value; |
| } |
| |
| [SecuritySafeCritical] |
| internal static T Read<T>(ref ParseContext ctx, FieldCodec<T> codec) |
| { |
| int length = ctx.ReadLength(); |
| int oldLimit = SegmentedBufferHelper.PushLimit(ref ctx.state, length); |
| |
| uint tag; |
| T value = codec.DefaultValue; |
| while ((tag = ctx.ReadTag()) != 0) |
| { |
| if (tag == codec.Tag) |
| { |
| value = codec.Read(ref ctx); |
| } |
| else |
| { |
| ParsingPrimitivesMessages.SkipLastField(ref ctx.buffer, ref ctx.state); |
| } |
| |
| } |
| ParsingPrimitivesMessages.CheckReadEndOfStreamTag(ref ctx.state); |
| SegmentedBufferHelper.PopLimit(ref ctx.state, oldLimit); |
| |
| return value; |
| } |
| |
| internal static void Write<T>(ref WriteContext ctx, T value, FieldCodec<T> codec) |
| { |
| ctx.WriteLength(codec.CalculateSizeWithTag(value)); |
| codec.WriteTagAndValue(ref ctx, value); |
| } |
| |
| internal static int CalculateSize<T>(T value, FieldCodec<T> codec) |
| { |
| int fieldLength = codec.CalculateSizeWithTag(value); |
| return CodedOutputStream.ComputeLengthSize(fieldLength) + fieldLength; |
| } |
| } |
| } |
| |
| internal delegate TValue ValueReader<out TValue>(ref ParseContext ctx); |
| internal delegate void ValueWriter<T>(ref WriteContext ctx, T value); |
| |
| /// <summary> |
| /// <para> |
| /// An encode/decode pair for a single field. This effectively encapsulates |
| /// all the information needed to read or write the field value from/to a coded |
| /// stream. |
| /// </para> |
| /// <para> |
| /// This class is public and has to be as it is used by generated code, but its public |
| /// API is very limited - just what the generated code needs to call directly. |
| /// </para> |
| /// </summary> |
| /// <remarks> |
| /// This never writes default values to the stream, and does not address "packedness" |
| /// in repeated fields itself, other than to know whether or not the field *should* be packed. |
| /// </remarks> |
| public sealed class FieldCodec<T> |
| { |
| private static readonly EqualityComparer<T> EqualityComparer = ProtobufEqualityComparers.GetEqualityComparer<T>(); |
| private static readonly T DefaultDefault; |
| // Only non-nullable value types support packing. This is the simplest way of detecting that. |
| private static readonly bool TypeSupportsPacking = default(T) != null; |
| |
| /// <summary> |
| /// Merges an input stream into a value |
| /// </summary> |
| internal delegate void InputMerger(ref ParseContext ctx, ref T value); |
| |
| /// <summary> |
| /// Merges a value into a reference to another value, returning a boolean if the value was set |
| /// </summary> |
| internal delegate bool ValuesMerger(ref T value, T other); |
| |
| static FieldCodec() |
| { |
| if (typeof(T) == typeof(string)) |
| { |
| DefaultDefault = (T)(object)""; |
| } |
| else if (typeof(T) == typeof(ByteString)) |
| { |
| DefaultDefault = (T)(object)ByteString.Empty; |
| } |
| // Otherwise it's the default value of the CLR type |
| } |
| |
| internal static bool IsPackedRepeatedField(uint tag) => |
| TypeSupportsPacking && WireFormat.GetTagWireType(tag) == WireFormat.WireType.LengthDelimited; |
| |
| internal bool PackedRepeatedField { get; } |
| |
| /// <summary> |
| /// Returns a delegate to write a value (unconditionally) to a coded output stream. |
| /// </summary> |
| internal ValueWriter<T> ValueWriter { get; } |
| |
| /// <summary> |
| /// Returns the size calculator for just a value. |
| /// </summary> |
| internal Func<T, int> ValueSizeCalculator { get; } |
| |
| /// <summary> |
| /// Returns a delegate to read a value from a coded input stream. It is assumed that |
| /// the stream is already positioned on the appropriate tag. |
| /// </summary> |
| internal ValueReader<T> ValueReader { get; } |
| |
| /// <summary> |
| /// Returns a delegate to merge a value from a coded input stream. |
| /// It is assumed that the stream is already positioned on the appropriate tag |
| /// </summary> |
| internal InputMerger ValueMerger { get; } |
| |
| /// <summary> |
| /// Returns a delegate to merge two values together. |
| /// </summary> |
| internal ValuesMerger FieldMerger { get; } |
| |
| /// <summary> |
| /// Returns the fixed size for an entry, or 0 if sizes vary. |
| /// </summary> |
| internal int FixedSize { get; } |
| |
| /// <summary> |
| /// Gets the tag of the codec. |
| /// </summary> |
| /// <value> |
| /// The tag of the codec. |
| /// </value> |
| internal uint Tag { get; } |
| |
| /// <summary> |
| /// Gets the end tag of the codec or 0 if there is no end tag |
| /// </summary> |
| /// <value> |
| /// The end tag of the codec. |
| /// </value> |
| internal uint EndTag { get; } |
| |
| /// <summary> |
| /// Default value for this codec. Usually the same for every instance of the same type, but |
| /// for string/ByteString wrapper fields the codec's default value is null, whereas for |
| /// other string/ByteString fields it's "" or ByteString.Empty. |
| /// </summary> |
| /// <value> |
| /// The default value of the codec's type. |
| /// </value> |
| internal T DefaultValue { get; } |
| |
| private readonly int tagSize; |
| |
| internal FieldCodec( |
| ValueReader<T> reader, |
| ValueWriter<T> writer, |
| int fixedSize, |
| uint tag, |
| T defaultValue) : this(reader, writer, _ => fixedSize, tag, defaultValue) |
| { |
| FixedSize = fixedSize; |
| } |
| |
| internal FieldCodec( |
| ValueReader<T> reader, |
| ValueWriter<T> writer, |
| Func<T, int> sizeCalculator, |
| uint tag, |
| T defaultValue) : this(reader, writer, (ref ParseContext ctx, ref T v) => v = reader(ref ctx), (ref T v, T v2) => { v = v2; return true; }, sizeCalculator, tag, 0, defaultValue) |
| { |
| } |
| |
| internal FieldCodec( |
| ValueReader<T> reader, |
| ValueWriter<T> writer, |
| InputMerger inputMerger, |
| ValuesMerger valuesMerger, |
| Func<T, int> sizeCalculator, |
| uint tag, |
| uint endTag = 0) : this(reader, writer, inputMerger, valuesMerger, sizeCalculator, tag, endTag, DefaultDefault) |
| { |
| } |
| |
| internal FieldCodec( |
| ValueReader<T> reader, |
| ValueWriter<T> writer, |
| InputMerger inputMerger, |
| ValuesMerger valuesMerger, |
| Func<T, int> sizeCalculator, |
| uint tag, |
| uint endTag, |
| T defaultValue) |
| { |
| ValueReader = reader; |
| ValueWriter = writer; |
| ValueMerger = inputMerger; |
| FieldMerger = valuesMerger; |
| ValueSizeCalculator = sizeCalculator; |
| FixedSize = 0; |
| Tag = tag; |
| EndTag = endTag; |
| DefaultValue = defaultValue; |
| tagSize = CodedOutputStream.ComputeRawVarint32Size(tag); |
| if (endTag != 0) |
| tagSize += CodedOutputStream.ComputeRawVarint32Size(endTag); |
| // Detect packed-ness once, so we can check for it within RepeatedField<T>. |
| PackedRepeatedField = IsPackedRepeatedField(tag); |
| } |
| |
| /// <summary> |
| /// Write a tag and the given value, *if* the value is not the default. |
| /// </summary> |
| public void WriteTagAndValue(CodedOutputStream output, T value) |
| { |
| WriteContext.Initialize(output, out WriteContext ctx); |
| try |
| { |
| WriteTagAndValue(ref ctx, value); |
| } |
| finally |
| { |
| ctx.CopyStateTo(output); |
| } |
| |
| |
| //if (!IsDefault(value)) |
| //{ |
| // output.WriteTag(Tag); |
| // ValueWriter(output, value); |
| // if (EndTag != 0) |
| // { |
| // output.WriteTag(EndTag); |
| // } |
| //} |
| } |
| |
| /// <summary> |
| /// Write a tag and the given value, *if* the value is not the default. |
| /// </summary> |
| public void WriteTagAndValue(ref WriteContext ctx, T value) |
| { |
| if (!IsDefault(value)) |
| { |
| ctx.WriteTag(Tag); |
| ValueWriter(ref ctx, value); |
| if (EndTag != 0) |
| { |
| ctx.WriteTag(EndTag); |
| } |
| } |
| } |
| |
| /// <summary> |
| /// Reads a value of the codec type from the given <see cref="CodedInputStream"/>. |
| /// </summary> |
| /// <param name="input">The input stream to read from.</param> |
| /// <returns>The value read from the stream.</returns> |
| public T Read(CodedInputStream input) |
| { |
| ParseContext.Initialize(input, out ParseContext ctx); |
| try |
| { |
| return ValueReader(ref ctx); |
| } |
| finally |
| { |
| ctx.CopyStateTo(input); |
| } |
| } |
| |
| /// <summary> |
| /// Reads a value of the codec type from the given <see cref="ParseContext"/>. |
| /// </summary> |
| /// <param name="ctx">The parse context to read from.</param> |
| /// <returns>The value read.</returns> |
| public T Read(ref ParseContext ctx) |
| { |
| return ValueReader(ref ctx); |
| } |
| |
| /// <summary> |
| /// Calculates the size required to write the given value, with a tag, |
| /// if the value is not the default. |
| /// </summary> |
| public int CalculateSizeWithTag(T value) => IsDefault(value) ? 0 : ValueSizeCalculator(value) + tagSize; |
| |
| /// <summary> |
| /// Calculates the size required to write the given value, with a tag, even |
| /// if the value is the default. |
| /// </summary> |
| internal int CalculateUnconditionalSizeWithTag(T value) => ValueSizeCalculator(value) + tagSize; |
| |
| private bool IsDefault(T value) => EqualityComparer.Equals(value, DefaultValue); |
| } |
| } |
