├── CSharp_8_Async_Streams_Demo ├── AsyncStreams │ ├── App.config │ ├── Definitions.cs │ ├── Program.cs │ ├── Properties │ │ └── AssemblyInfo.cs │ ├── Streams.cs │ └── AsyncStreams.csproj └── AsyncStreamsDemo.sln ├── README.md └── .gitignore /CSharp_8_Async_Streams_Demo/AsyncStreams/App.config: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | -------------------------------------------------------------------------------- /CSharp_8_Async_Streams_Demo/AsyncStreams/Definitions.cs: -------------------------------------------------------------------------------- 1 | using System.Threading.Tasks; 2 | 3 | namespace AsyncStreams 4 | { 5 | public interface IAsyncDisposable 6 | { 7 | Task DiskposeAsync(); 8 | } 9 | 10 | public interface IAsyncEnumerable 11 | { 12 | IAsyncEnumerator GetAsyncEnumerator(); 13 | } 14 | 15 | public interface IAsyncEnumerator 16 | { 17 | Task WaitForNextAsync(); 18 | T TryGetNext(out bool success); 19 | } 20 | } -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # CSharp_8_Async_Streams_Demo 2 | C# 8 Demo for the new proposed feature Async Streams 3 | 4 | 5 | Article: https://www.infoq.com/articles/cs8-async-streams 6 | 7 | To be able to test this feature, then you you have to build the roslyn branch: https://github.com/dotnet/roslyn/tree/features/async-streams 8 | 9 | Build the Async Streams Branch 10 | Start the VNext VS 11 | Open and run the project in the VNext VS 12 | Alternatively, you can use sharplab.io 13 | 14 | more info: 15 | https://github.com/dotnet/csharplang/blob/master/proposals/async-streams.md 16 | -------------------------------------------------------------------------------- /CSharp_8_Async_Streams_Demo/AsyncStreams/Program.cs: -------------------------------------------------------------------------------- 1 | using System; 2 | using System.IO; 3 | using System.Threading.Tasks; 4 | 5 | namespace AsyncStreams 6 | { 7 | public class Program 8 | { 9 | private static (Stream stream, long checkSum) CreateStream() 10 | { 11 | long checksum = 0L; 12 | 13 | byte[] bytes = new byte[20000]; 14 | 15 | for (int i = 0; i < bytes.Length; i++) 16 | { 17 | byte value = (byte)(i % byte.MaxValue); 18 | bytes[i] = value; 19 | 20 | unchecked { checksum += value; } 21 | } 22 | 23 | MemoryStream stream = new MemoryStream(bytes); 24 | return (stream, checksum); 25 | } 26 | 27 | private static async Task Main(string[] args) 28 | { 29 | (Stream stream, long checksum) = CreateStream(); 30 | 31 | long c = 0L; 32 | 33 | foreach await (byte b in stream.AsEnumerable()) 34 | { 35 | unchecked { c += b; } 36 | } 37 | 38 | if (c == checksum) 39 | { 40 | Console.WriteLine("Checksums match!"); 41 | } 42 | } 43 | } 44 | } -------------------------------------------------------------------------------- /CSharp_8_Async_Streams_Demo/AsyncStreamsDemo.sln: -------------------------------------------------------------------------------- 1 | 2 | Microsoft Visual Studio Solution File, Format Version 12.00 3 | # Visual Studio 15 4 | VisualStudioVersion = 15.0.27703.1 5 | MinimumVisualStudioVersion = 10.0.40219.1 6 | Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AsyncStreams", "AsyncStreams\AsyncStreams.csproj", "{073CAEFD-1E71-4638-A5AF-27E8CF80B1FD}" 7 | EndProject 8 | Global 9 | GlobalSection(SolutionConfigurationPlatforms) = preSolution 10 | Debug|Any CPU = Debug|Any CPU 11 | Release|Any CPU = Release|Any CPU 12 | EndGlobalSection 13 | GlobalSection(ProjectConfigurationPlatforms) = postSolution 14 | {073CAEFD-1E71-4638-A5AF-27E8CF80B1FD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU 15 | {073CAEFD-1E71-4638-A5AF-27E8CF80B1FD}.Debug|Any CPU.Build.0 = Debug|Any CPU 16 | {073CAEFD-1E71-4638-A5AF-27E8CF80B1FD}.Release|Any CPU.ActiveCfg = Release|Any CPU 17 | {073CAEFD-1E71-4638-A5AF-27E8CF80B1FD}.Release|Any CPU.Build.0 = Release|Any CPU 18 | EndGlobalSection 19 | GlobalSection(SolutionProperties) = preSolution 20 | HideSolutionNode = FALSE 21 | EndGlobalSection 22 | GlobalSection(ExtensibilityGlobals) = postSolution 23 | SolutionGuid = {DF312D44-F3D1-4407-A4C7-050DFA52AE1B} 24 | EndGlobalSection 25 | EndGlobal 26 | -------------------------------------------------------------------------------- /CSharp_8_Async_Streams_Demo/AsyncStreams/Properties/AssemblyInfo.cs: -------------------------------------------------------------------------------- 1 | using System.Reflection; 2 | using System.Runtime.CompilerServices; 3 | using System.Runtime.InteropServices; 4 | 5 | // General Information about an assembly is controlled through the following 6 | // set of attributes. Change these attribute values to modify the information 7 | // associated with an assembly. 8 | [assembly: AssemblyTitle("AsyncStreams")] 9 | [assembly: AssemblyDescription("")] 10 | [assembly: AssemblyConfiguration("")] 11 | [assembly: AssemblyCompany("")] 12 | [assembly: AssemblyProduct("AsyncStreams")] 13 | [assembly: AssemblyCopyright("Copyright © 2018")] 14 | [assembly: AssemblyTrademark("")] 15 | [assembly: AssemblyCulture("")] 16 | 17 | // Setting ComVisible to false makes the types in this assembly not visible 18 | // to COM components. If you need to access a type in this assembly from 19 | // COM, set the ComVisible attribute to true on that type. 20 | [assembly: ComVisible(false)] 21 | 22 | // The following GUID is for the ID of the typelib if this project is exposed to COM 23 | [assembly: Guid("073caefd-1e71-4638-a5af-27e8cf80b1fd")] 24 | 25 | // Version information for an assembly consists of the following four values: 26 | // 27 | // Major Version 28 | // Minor Version 29 | // Build Number 30 | // Revision 31 | // 32 | // You can specify all the values or you can default the Build and Revision Numbers 33 | // by using the '*' as shown below: 34 | // [assembly: AssemblyVersion("1.0.*")] 35 | [assembly: AssemblyVersion("1.0.0.0")] 36 | [assembly: AssemblyFileVersion("1.0.0.0")] 37 | -------------------------------------------------------------------------------- /CSharp_8_Async_Streams_Demo/AsyncStreams/Streams.cs: -------------------------------------------------------------------------------- 1 | using System; 2 | using System.IO; 3 | using System.Threading.Tasks; 4 | 5 | namespace AsyncStreams 6 | { 7 | public class StreamEnumerator : IAsyncEnumerator 8 | { 9 | private readonly Stream _stream; 10 | private readonly byte[] _buffer; 11 | private int _bytesRead; 12 | private int _bufferIndex; 13 | private const int BufferSize = 8000; 14 | 15 | public StreamEnumerator(Stream stream) 16 | { 17 | _stream = stream ?? throw new ArgumentNullException(nameof(stream)); 18 | _buffer = new byte[BufferSize]; 19 | _bytesRead = -1; 20 | } 21 | 22 | public async Task WaitForNextAsync() 23 | { 24 | await Task.Delay(1000); 25 | 26 | _bytesRead = await _stream.ReadAsync(_buffer, 0, BufferSize); 27 | _bufferIndex = 0; 28 | 29 | if (_bytesRead == 0) 30 | { 31 | Console.WriteLine(); 32 | Console.WriteLine("Enumeration complete!"); 33 | return false; 34 | } 35 | 36 | Console.WriteLine($"Read {_bytesRead: 0,0} bytes"); 37 | 38 | return true; 39 | } 40 | 41 | public byte TryGetNext(out bool success) 42 | { 43 | if (_bufferIndex == _bytesRead) 44 | { 45 | success = false; 46 | return 0; 47 | } 48 | 49 | byte result = _buffer[_bufferIndex]; 50 | _bufferIndex++; 51 | 52 | success = true; 53 | return result; 54 | } 55 | 56 | public Task DisposeAsync() 57 | { 58 | _stream.Dispose(); 59 | Console.WriteLine("Stream disposed!"); 60 | return Task.CompletedTask; 61 | } 62 | } 63 | 64 | public class EnumerableStream : IAsyncEnumerable 65 | { 66 | private readonly Stream _stream; 67 | 68 | public EnumerableStream(Stream stream) => _stream = stream ?? throw new ArgumentNullException(nameof(stream)); 69 | 70 | public IAsyncEnumerator GetAsyncEnumerator() => new StreamEnumerator(_stream); 71 | } 72 | 73 | public static class StreamExtensions 74 | { 75 | public static IAsyncEnumerable AsEnumerable(this Stream stream) => new EnumerableStream(stream); 76 | } 77 | } 78 | -------------------------------------------------------------------------------- /CSharp_8_Async_Streams_Demo/AsyncStreams/AsyncStreams.csproj: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | Debug 6 | AnyCPU 7 | {073CAEFD-1E71-4638-A5AF-27E8CF80B1FD} 8 | Exe 9 | AsyncStreams 10 | AsyncStreams 11 | v4.7.2 12 | 512 13 | true 14 | true 15 | publish\ 16 | true 17 | Disk 18 | false 19 | Foreground 20 | 7 21 | Days 22 | false 23 | false 24 | true 25 | 0 26 | 1.0.0.%2a 27 | false 28 | false 29 | true 30 | 31 | 32 | AnyCPU 33 | false 34 | none 35 | false 36 | bin\Debug\ 37 | DEBUG;TRACE 38 | none 39 | 4 40 | Off 41 | false 42 | 7.3 43 | 44 | 45 | AnyCPU 46 | pdbonly 47 | true 48 | bin\Release\ 49 | TRACE 50 | prompt 51 | 4 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | False 65 | Microsoft .NET Framework 4.7.2 %28x86 and x64%29 66 | true 67 | 68 | 69 | False 70 | .NET Framework 3.5 SP1 71 | false 72 | 73 | 74 | 75 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | ## Ignore Visual Studio temporary files, build results, and 2 | ## files generated by popular Visual Studio add-ons. 3 | ## 4 | ## Get latest from https://github.com/github/gitignore/blob/master/VisualStudio.gitignore 5 | 6 | # User-specific files 7 | *.suo 8 | *.user 9 | *.userosscache 10 | *.sln.docstates 11 | 12 | # User-specific files (MonoDevelop/Xamarin Studio) 13 | *.userprefs 14 | 15 | # Build results 16 | [Dd]ebug/ 17 | [Dd]ebugPublic/ 18 | [Rr]elease/ 19 | [Rr]eleases/ 20 | x64/ 21 | x86/ 22 | bld/ 23 | [Bb]in/ 24 | [Oo]bj/ 25 | [Ll]og/ 26 | 27 | # Visual Studio 2015/2017 cache/options directory 28 | .vs/ 29 | # Uncomment if you have tasks that create the project's static files in wwwroot 30 | #wwwroot/ 31 | 32 | # Visual Studio 2017 auto generated files 33 | Generated\ Files/ 34 | 35 | # MSTest test Results 36 | [Tt]est[Rr]esult*/ 37 | [Bb]uild[Ll]og.* 38 | 39 | # NUNIT 40 | *.VisualState.xml 41 | TestResult.xml 42 | 43 | # Build Results of an ATL Project 44 | [Dd]ebugPS/ 45 | [Rr]eleasePS/ 46 | dlldata.c 47 | 48 | # Benchmark Results 49 | BenchmarkDotNet.Artifacts/ 50 | 51 | # .NET Core 52 | project.lock.json 53 | project.fragment.lock.json 54 | artifacts/ 55 | **/Properties/launchSettings.json 56 | 57 | # StyleCop 58 | StyleCopReport.xml 59 | 60 | # Files built by Visual Studio 61 | *_i.c 62 | *_p.c 63 | *_i.h 64 | *.ilk 65 | *.meta 66 | *.obj 67 | *.iobj 68 | *.pch 69 | *.pdb 70 | *.ipdb 71 | *.pgc 72 | *.pgd 73 | *.rsp 74 | *.sbr 75 | *.tlb 76 | *.tli 77 | *.tlh 78 | *.tmp 79 | *.tmp_proj 80 | *.log 81 | *.vspscc 82 | *.vssscc 83 | .builds 84 | *.pidb 85 | *.svclog 86 | *.scc 87 | 88 | # Chutzpah Test files 89 | _Chutzpah* 90 | 91 | # Visual C++ cache files 92 | ipch/ 93 | *.aps 94 | *.ncb 95 | *.opendb 96 | *.opensdf 97 | *.sdf 98 | *.cachefile 99 | *.VC.db 100 | *.VC.VC.opendb 101 | 102 | # Visual Studio profiler 103 | *.psess 104 | *.vsp 105 | *.vspx 106 | *.sap 107 | 108 | # Visual Studio Trace Files 109 | *.e2e 110 | 111 | # TFS 2012 Local Workspace 112 | $tf/ 113 | 114 | # Guidance Automation Toolkit 115 | *.gpState 116 | 117 | # ReSharper is a .NET coding add-in 118 | _ReSharper*/ 119 | *.[Rr]e[Ss]harper 120 | *.DotSettings.user 121 | 122 | # JustCode is a .NET coding add-in 123 | .JustCode 124 | 125 | # TeamCity is a build add-in 126 | _TeamCity* 127 | 128 | # DotCover is a Code Coverage Tool 129 | *.dotCover 130 | 131 | # AxoCover is a Code Coverage Tool 132 | .axoCover/* 133 | !.axoCover/settings.json 134 | 135 | # Visual Studio code coverage results 136 | *.coverage 137 | *.coveragexml 138 | 139 | # NCrunch 140 | _NCrunch_* 141 | .*crunch*.local.xml 142 | nCrunchTemp_* 143 | 144 | # MightyMoose 145 | *.mm.* 146 | AutoTest.Net/ 147 | 148 | # Web workbench (sass) 149 | .sass-cache/ 150 | 151 | # Installshield output folder 152 | [Ee]xpress/ 153 | 154 | # DocProject is a documentation generator add-in 155 | DocProject/buildhelp/ 156 | DocProject/Help/*.HxT 157 | DocProject/Help/*.HxC 158 | DocProject/Help/*.hhc 159 | DocProject/Help/*.hhk 160 | DocProject/Help/*.hhp 161 | DocProject/Help/Html2 162 | DocProject/Help/html 163 | 164 | # Click-Once directory 165 | publish/ 166 | 167 | # Publish Web Output 168 | *.[Pp]ublish.xml 169 | *.azurePubxml 170 | # Note: Comment the next line if you want to checkin your web deploy settings, 171 | # but database connection strings (with potential passwords) will be unencrypted 172 | *.pubxml 173 | *.publishproj 174 | 175 | # Microsoft Azure Web App publish settings. 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