1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
using System;
using System.Collections.Generic;
namespace Google.Protobuf
{
/// <summary>
/// Factory methods for <see cref="FieldCodec{T}"/>.
/// </summary>
public static class FieldCodec
{
public static FieldCodec<string> ForString(uint tag)
{
return new FieldCodec<string>(input => input.ReadString(), (output, value) => output.WriteString(value), CodedOutputStream.ComputeStringSize, tag);
}
public static FieldCodec<ByteString> ForBytes(uint tag)
{
return new FieldCodec<ByteString>(input => input.ReadBytes(), (output, value) => output.WriteBytes(value), CodedOutputStream.ComputeBytesSize, tag);
}
public static FieldCodec<bool> ForBool(uint tag)
{
return new FieldCodec<bool>(input => input.ReadBool(), (output, value) => output.WriteBool(value), CodedOutputStream.ComputeBoolSize, tag);
}
public static FieldCodec<int> ForInt32(uint tag)
{
return new FieldCodec<int>(input => input.ReadInt32(), (output, value) => output.WriteInt32(value), CodedOutputStream.ComputeInt32Size, tag);
}
public static FieldCodec<int> ForSInt32(uint tag)
{
return new FieldCodec<int>(input => input.ReadSInt32(), (output, value) => output.WriteSInt32(value), CodedOutputStream.ComputeSInt32Size, tag);
}
public static FieldCodec<uint> ForFixed32(uint tag)
{
return new FieldCodec<uint>(input => input.ReadFixed32(), (output, value) => output.WriteFixed32(value), CodedOutputStream.ComputeFixed32Size, tag);
}
public static FieldCodec<int> ForSFixed32(uint tag)
{
return new FieldCodec<int>(input => input.ReadSFixed32(), (output, value) => output.WriteSFixed32(value), CodedOutputStream.ComputeSFixed32Size, tag);
}
public static FieldCodec<uint> ForUInt32(uint tag)
{
return new FieldCodec<uint>(input => input.ReadUInt32(), (output, value) => output.WriteUInt32(value), CodedOutputStream.ComputeUInt32Size, tag);
}
public static FieldCodec<long> ForInt64(uint tag)
{
return new FieldCodec<long>(input => input.ReadInt64(), (output, value) => output.WriteInt64(value), CodedOutputStream.ComputeInt64Size, tag);
}
public static FieldCodec<long> ForSInt64(uint tag)
{
return new FieldCodec<long>(input => input.ReadSInt64(), (output, value) => output.WriteSInt64(value), CodedOutputStream.ComputeSInt64Size, tag);
}
public static FieldCodec<ulong> ForFixed64(uint tag)
{
return new FieldCodec<ulong>(input => input.ReadFixed64(), (output, value) => output.WriteFixed64(value), CodedOutputStream.ComputeFixed64Size, tag);
}
public static FieldCodec<long> ForSFixed64(uint tag)
{
return new FieldCodec<long>(input => input.ReadSFixed64(), (output, value) => output.WriteSFixed64(value), CodedOutputStream.ComputeSFixed64Size, tag);
}
public static FieldCodec<ulong> ForUInt64(uint tag)
{
return new FieldCodec<ulong>(input => input.ReadUInt64(), (output, value) => output.WriteUInt64(value), CodedOutputStream.ComputeUInt64Size, tag);
}
public static FieldCodec<float> ForFloat(uint tag)
{
return new FieldCodec<float>(input => input.ReadFloat(), (output, value) => output.WriteFloat(value), CodedOutputStream.ComputeFloatSize, tag);
}
public static FieldCodec<double> ForDouble(uint tag)
{
return new FieldCodec<double>(input => input.ReadFloat(), (output, value) => output.WriteDouble(value), CodedOutputStream.ComputeDoubleSize, tag);
}
// Enums are tricky. We can probably use expression trees to build these delegates automatically,
// but it's easy to generate the code fdor it.
public static FieldCodec<T> ForEnum<T>(uint tag, Func<T, int> toInt32, Func<int, T> fromInt32)
{
return new FieldCodec<T>(input => fromInt32(
input.ReadEnum()),
(output, value) => output.WriteEnum(toInt32(value)),
value => CodedOutputStream.ComputeEnumSize(toInt32(value)), tag);
}
public static FieldCodec<T> ForMessage<T>(uint tag, MessageParser<T> parser) where T : IMessage<T>
{
return new FieldCodec<T>(input => { T message = parser.CreateTemplate(); input.ReadMessage(message); return message; },
(output, value) => output.WriteMessage(value), message => CodedOutputStream.ComputeMessageSize(message), tag);
}
}
/// <summary>
/// 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.
/// </summary>
/// <remarks>
/// This never writes default values to the stream, and is not currently designed
/// to play well with packed arrays.
/// </remarks>
public sealed class FieldCodec<T>
{
private static readonly Func<T, bool> IsDefault;
private static readonly T Default;
static FieldCodec()
{
if (typeof(T) == typeof(string))
{
Default = (T)(object)"";
IsDefault = CreateDefaultValueCheck<string>(x => x.Length == 0);
}
else if (typeof(T) == typeof(ByteString))
{
Default = (T)(object)ByteString.Empty;
IsDefault = CreateDefaultValueCheck<ByteString>(x => x.Length == 0);
}
else if (!typeof(T).IsValueType)
{
// Default default
IsDefault = CreateDefaultValueCheck<T>(x => x == null);
}
else
{
// Default default
IsDefault = CreateDefaultValueCheck<T>(x => EqualityComparer<T>.Default.Equals(x, default(T)));
}
}
private static Func<T, bool> CreateDefaultValueCheck<TTmp>(Func<TTmp, bool> check)
{
return (Func<T, bool>)(object)check;
}
private readonly Func<CodedInputStream, T> reader;
private readonly Action<CodedOutputStream, T> writer;
private readonly Func<T, int> sizeComputer;
private readonly uint tag;
private readonly int tagSize;
internal FieldCodec(
Func<CodedInputStream, T> reader,
Action<CodedOutputStream, T> writer,
Func<T, int> sizeComputer,
uint tag)
{
this.reader = reader;
this.writer = writer;
this.sizeComputer = sizeComputer;
this.tag = tag;
tagSize = CodedOutputStream.ComputeRawVarint32Size(tag);
}
public uint Tag { get { return tag; } }
public T DefaultValue { get { return Default; } }
public void Write(CodedOutputStream output, T value)
{
if (!IsDefault(value))
{
output.WriteTag(tag);
writer(output, value);
}
}
public T Read(CodedInputStream input)
{
return reader(input);
}
public int CalculateSize(T value)
{
return IsDefault(value) ? 0 : sizeComputer(value) + CodedOutputStream.ComputeRawVarint32Size(tag);
}
}
}
|
