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
#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2008 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 System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
namespace Google.Protobuf
{
/// <summary>
/// SecuritySafeCritical attribute can not be placed on types with async methods.
/// This class has ByteString's async methods so it can be marked with SecuritySafeCritical.
/// </summary>
internal static class ByteStringAsync
{
internal static async Task<ByteString> FromStreamAsyncCore(Stream stream, CancellationToken cancellationToken)
{
int capacity = stream.CanSeek ? checked((int)(stream.Length - stream.Position)) : 0;
var memoryStream = new MemoryStream(capacity);
// We have to specify the buffer size here, as there's no overload accepting the cancellation token
// alone. But it's documented to use 81920 by default if not specified.
await stream.CopyToAsync(memoryStream, 81920, cancellationToken);
#if NETSTANDARD1_1
byte[] bytes = memoryStream.ToArray();
#else
// Avoid an extra copy if we can.
byte[] bytes = memoryStream.Length == memoryStream.Capacity ? memoryStream.GetBuffer() : memoryStream.ToArray();
#endif
return ByteString.AttachBytes(bytes);
}
}
}