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
33using Google.Protobuf.Reflection;
34using System.Buffers;
35using System.Collections;
36using System;
37using System.IO;
38using System.Linq;
39using System.Security;
40
41namespace Google.Protobuf
42{
43    /// <summary>
44    /// Extension methods on <see cref="IMessage"/> and <see cref="IMessage{T}"/>.
45    /// </summary>
46    public static class MessageExtensions
47    {
48        /// <summary>
49        /// Merges data from the given byte array into an existing message.
50        /// </summary>
51        /// <param name="message">The message to merge the data into.</param>
52        /// <param name="data">The data to merge, which must be protobuf-encoded binary data.</param>
53        public static void MergeFrom(this IMessage message, byte[] data) =>
54            MergeFrom(message, data, false, null);
55
56        /// <summary>
57        /// Merges data from the given byte array slice into an existing message.
58        /// </summary>
59        /// <param name="message">The message to merge the data into.</param>
60        /// <param name="data">The data containing the slice to merge, which must be protobuf-encoded binary data.</param>
61        /// <param name="offset">The offset of the slice to merge.</param>
62        /// <param name="length">The length of the slice to merge.</param>
63        public static void MergeFrom(this IMessage message, byte[] data, int offset, int length) =>
64            MergeFrom(message, data, offset, length, false, null);
65
66        /// <summary>
67        /// Merges data from the given byte string into an existing message.
68        /// </summary>
69        /// <param name="message">The message to merge the data into.</param>
70        /// <param name="data">The data to merge, which must be protobuf-encoded binary data.</param>
71        public static void MergeFrom(this IMessage message, ByteString data) =>
72            MergeFrom(message, data, false, null);
73
74        /// <summary>
75        /// Merges data from the given stream into an existing message.
76        /// </summary>
77        /// <param name="message">The message to merge the data into.</param>
78        /// <param name="input">Stream containing the data to merge, which must be protobuf-encoded binary data.</param>
79        public static void MergeFrom(this IMessage message, Stream input) =>
80            MergeFrom(message, input, false, null);
81
82        /// <summary>
83        /// Merges length-delimited data from the given stream into an existing message.
84        /// </summary>
85        /// <remarks>
86        /// The stream is expected to contain a length and then the data. Only the amount of data
87        /// specified by the length will be consumed.
88        /// </remarks>
89        /// <param name="message">The message to merge the data into.</param>
90        /// <param name="input">Stream containing the data to merge, which must be protobuf-encoded binary data.</param>
91        public static void MergeDelimitedFrom(this IMessage message, Stream input) =>
92            MergeDelimitedFrom(message, input, false, null);
93
94        /// <summary>
95        /// Converts the given message into a byte array in protobuf encoding.
96        /// </summary>
97        /// <param name="message">The message to convert.</param>
98        /// <returns>The message data as a byte array.</returns>
99        public static byte[] ToByteArray(this IMessage message)
100        {
101            ProtoPreconditions.CheckNotNull(message, "message");
102            byte[] result = new byte[message.CalculateSize()];
103            CodedOutputStream output = new CodedOutputStream(result);
104            message.WriteTo(output);
105            output.CheckNoSpaceLeft();
106            return result;
107        }
108
109        /// <summary>
110        /// Writes the given message data to the given stream in protobuf encoding.
111        /// </summary>
112        /// <param name="message">The message to write to the stream.</param>
113        /// <param name="output">The stream to write to.</param>
114        public static void WriteTo(this IMessage message, Stream output)
115        {
116            ProtoPreconditions.CheckNotNull(message, "message");
117            ProtoPreconditions.CheckNotNull(output, "output");
118            CodedOutputStream codedOutput = new CodedOutputStream(output);
119            message.WriteTo(codedOutput);
120            codedOutput.Flush();
121        }
122
123        /// <summary>
124        /// Writes the length and then data of the given message to a stream.
125        /// </summary>
126        /// <param name="message">The message to write.</param>
127        /// <param name="output">The output stream to write to.</param>
128        public static void WriteDelimitedTo(this IMessage message, Stream output)
129        {
130            ProtoPreconditions.CheckNotNull(message, "message");
131            ProtoPreconditions.CheckNotNull(output, "output");
132            CodedOutputStream codedOutput = new CodedOutputStream(output);
133            codedOutput.WriteLength(message.CalculateSize());
134            message.WriteTo(codedOutput);
135            codedOutput.Flush();
136        }
137
138        /// <summary>
139        /// Converts the given message into a byte string in protobuf encoding.
140        /// </summary>
141        /// <param name="message">The message to convert.</param>
142        /// <returns>The message data as a byte string.</returns>
143        public static ByteString ToByteString(this IMessage message)
144        {
145            ProtoPreconditions.CheckNotNull(message, "message");
146            return ByteString.AttachBytes(message.ToByteArray());
147        }
148
149        /// <summary>
150        /// Writes the given message data to the given buffer writer in protobuf encoding.
151        /// </summary>
152        /// <param name="message">The message to write to the stream.</param>
153        /// <param name="output">The stream to write to.</param>
154        [SecuritySafeCritical]
155        public static void WriteTo(this IMessage message, IBufferWriter<byte> output)
156        {
157            ProtoPreconditions.CheckNotNull(message, nameof(message));
158            ProtoPreconditions.CheckNotNull(output, nameof(output));
159
160            WriteContext.Initialize(output, out WriteContext ctx);
161            WritingPrimitivesMessages.WriteRawMessage(ref ctx, message);
162            ctx.Flush();
163        }
164
165        /// <summary>
166        /// Writes the given message data to the given span in protobuf encoding.
167        /// The size of the destination span needs to fit the serialized size
168        /// of the message exactly, otherwise an exception is thrown.
169        /// </summary>
170        /// <param name="message">The message to write to the stream.</param>
171        /// <param name="output">The span to write to. Size must match size of the message exactly.</param>
172        [SecuritySafeCritical]
173        public static void WriteTo(this IMessage message, Span<byte> output)
174        {
175            ProtoPreconditions.CheckNotNull(message, nameof(message));
176
177            WriteContext.Initialize(ref output, out WriteContext ctx);
178            WritingPrimitivesMessages.WriteRawMessage(ref ctx, message);
179            ctx.CheckNoSpaceLeft();
180        }
181
182        /// <summary>
183        /// Checks if all required fields in a message have values set. For proto3 messages, this returns true
184        /// </summary>
185        public static bool IsInitialized(this IMessage message)
186        {
187            if (message.Descriptor.File.Syntax == Syntax.Proto3)
188            {
189                return true;
190            }
191
192            if (!message.Descriptor.IsExtensionsInitialized(message))
193            {
194                return false;
195            }
196
197            return message.Descriptor
198                .Fields
199                .InDeclarationOrder()
200                .All(f =>
201                {
202                    if (f.IsMap)
203                    {
204                        var valueField = f.MessageType.Fields[2];
205                        if (valueField.FieldType == FieldType.Message)
206                        {
207                            var map = (IDictionary)f.Accessor.GetValue(message);
208                            return map.Values.Cast<IMessage>().All(IsInitialized);
209                        }
210                        else
211                        {
212                            return true;
213                        }
214                    }
215                    else if (f.IsRepeated && f.FieldType == FieldType.Message || f.FieldType == FieldType.Group)
216                    {
217                        var enumerable = (IEnumerable)f.Accessor.GetValue(message);
218                        return enumerable.Cast<IMessage>().All(IsInitialized);
219                    }
220                    else if (f.FieldType == FieldType.Message || f.FieldType == FieldType.Group)
221                    {
222                        if (f.Accessor.HasValue(message))
223                        {
224                            return ((IMessage)f.Accessor.GetValue(message)).IsInitialized();
225                        }
226                        else
227                        {
228                            return !f.IsRequired;
229                        }
230                    }
231                    else if (f.IsRequired)
232                    {
233                        return f.Accessor.HasValue(message);
234                    }
235                    else
236                    {
237                        return true;
238                    }
239                });
240        }
241
242        // Implementations allowing unknown fields to be discarded.
243        internal static void MergeFrom(this IMessage message, byte[] data, bool discardUnknownFields, ExtensionRegistry registry)
244        {
245            ProtoPreconditions.CheckNotNull(message, "message");
246            ProtoPreconditions.CheckNotNull(data, "data");
247            CodedInputStream input = new CodedInputStream(data);
248            input.DiscardUnknownFields = discardUnknownFields;
249            input.ExtensionRegistry = registry;
250            message.MergeFrom(input);
251            input.CheckReadEndOfStreamTag();
252        }
253
254        internal static void MergeFrom(this IMessage message, byte[] data, int offset, int length, bool discardUnknownFields, ExtensionRegistry registry)
255        {
256            ProtoPreconditions.CheckNotNull(message, "message");
257            ProtoPreconditions.CheckNotNull(data, "data");
258            CodedInputStream input = new CodedInputStream(data, offset, length);
259            input.DiscardUnknownFields = discardUnknownFields;
260            input.ExtensionRegistry = registry;
261            message.MergeFrom(input);
262            input.CheckReadEndOfStreamTag();
263        }
264
265        internal static void MergeFrom(this IMessage message, ByteString data, bool discardUnknownFields, ExtensionRegistry registry)
266        {
267            ProtoPreconditions.CheckNotNull(message, "message");
268            ProtoPreconditions.CheckNotNull(data, "data");
269            CodedInputStream input = data.CreateCodedInput();
270            input.DiscardUnknownFields = discardUnknownFields;
271            input.ExtensionRegistry = registry;
272            message.MergeFrom(input);
273            input.CheckReadEndOfStreamTag();
274        }
275
276        internal static void MergeFrom(this IMessage message, Stream input, bool discardUnknownFields, ExtensionRegistry registry)
277        {
278            ProtoPreconditions.CheckNotNull(message, "message");
279            ProtoPreconditions.CheckNotNull(input, "input");
280            CodedInputStream codedInput = new CodedInputStream(input);
281            codedInput.DiscardUnknownFields = discardUnknownFields;
282            codedInput.ExtensionRegistry = registry;
283            message.MergeFrom(codedInput);
284            codedInput.CheckReadEndOfStreamTag();
285        }
286
287        [SecuritySafeCritical]
288        internal static void MergeFrom(this IMessage message, ReadOnlySequence<byte> data, bool discardUnknownFields, ExtensionRegistry registry)
289        {
290            ParseContext.Initialize(data, out ParseContext ctx);
291            ctx.DiscardUnknownFields = discardUnknownFields;
292            ctx.ExtensionRegistry = registry;
293            ParsingPrimitivesMessages.ReadRawMessage(ref ctx, message);
294            ParsingPrimitivesMessages.CheckReadEndOfStreamTag(ref ctx.state);
295        }
296
297        internal static void MergeDelimitedFrom(this IMessage message, Stream input, bool discardUnknownFields, ExtensionRegistry registry)
298        {
299            ProtoPreconditions.CheckNotNull(message, "message");
300            ProtoPreconditions.CheckNotNull(input, "input");
301            int size = (int) CodedInputStream.ReadRawVarint32(input);
302            Stream limitedStream = new LimitedInputStream(input, size);
303            MergeFrom(message, limitedStream, discardUnknownFields, registry);
304        }
305    }
306}
307