1 #region Copyright notice and license 2 // Protocol Buffers - Google's data interchange format 3 // Copyright 2008 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 33 using System; 34 using System.IO; 35 using System.Threading; 36 using System.Threading.Tasks; 37 38 namespace Google.Protobuf 39 { 40 /// <summary> 41 /// SecuritySafeCritical attribute can not be placed on types with async methods. 42 /// This class has ByteString's async methods so it can be marked with SecuritySafeCritical. 43 /// </summary> 44 internal static class ByteStringAsync 45 { 46 #if !NET35 FromStreamAsyncCore(Stream stream, CancellationToken cancellationToken)47 internal static async Task<ByteString> FromStreamAsyncCore(Stream stream, CancellationToken cancellationToken) 48 { 49 int capacity = stream.CanSeek ? checked((int)(stream.Length - stream.Position)) : 0; 50 var memoryStream = new MemoryStream(capacity); 51 // We have to specify the buffer size here, as there's no overload accepting the cancellation token 52 // alone. But it's documented to use 81920 by default if not specified. 53 await stream.CopyToAsync(memoryStream, 81920, cancellationToken); 54 #if NETSTANDARD1_1 55 byte[] bytes = memoryStream.ToArray(); 56 #else 57 // Avoid an extra copy if we can. 58 byte[] bytes = memoryStream.Length == memoryStream.Capacity ? memoryStream.GetBuffer() : memoryStream.ToArray(); 59 #endif 60 return ByteString.AttachBytes(bytes); 61 } 62 #endif 63 } 64 }