Add flow logger to help with console output parallelism

build/RepositoryBuild.targets

@@ -29,6 +29,7 @@
     <PropertyGroup>
       <!-- If there are duplicate properties, the properties which are defined later in the order would override the earlier ones -->
       <RepositoryBuildArguments>$(RepositoryBuildArguments) /p:BuildNumber=$(BuildNumber) /p:Configuration=$(Configuration) /p:CommitHash=$(CommitHash)</RepositoryBuildArguments>
+      <RepositoryBuildArguments>$(RepositoryBuildArguments) /noconsolelogger '/l:RepoTasks.FlowLogger,$(MSBuildThisFileDirectory)tasks\bin\publish\RepoTasks.dll;Summary;FlowId=$(RepositoryToBuild)'</RepositoryBuildArguments>
 
       <BuildArguments>$(_RepositoryBuildTargets) $(RepositoryBuildArguments)</BuildArguments>
       <RepositoryArtifactsRoot>$(BuildRepositoryRoot)artifacts</RepositoryArtifactsRoot>
@@ -91,4 +92,4 @@
 
     <Exec Command="$(PinVersionArgs)" />
   </Target>
-</Project>
+</Project>

build/tasks/Logger/DefaultPrefixMessageWriter.cs

@@ -0,0 +1,32 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Logging;
+
+namespace RepoTasks
+{
+    internal class DefaultPrefixMessageWriter : IWriter
+    {
+        private readonly string _flowId;
+
+        public DefaultPrefixMessageWriter(WriteHandler write, string flowId)
+        {
+            _flowId = flowId;
+            var prefix = $"{_flowId,-22}| ";
+            WriteHandler = msg => write(prefix + msg);
+        }
+
+        public WriteHandler WriteHandler { get; }
+
+        public void OnBuildStarted(BuildStartedEventArgs e)
+        {
+            WriteHandler(e.Message + Environment.NewLine);
+        }
+
+        public void OnBuildFinished(BuildFinishedEventArgs e)
+        {
+        }
+    }
+}

build/tasks/Logger/FlowLogger.cs

@@ -0,0 +1,69 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Linq;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Logging;
+
+namespace RepoTasks
+{
+    public class FlowLogger : ConsoleLogger
+    {
+        private static readonly bool IsTeamCity = !string.IsNullOrEmpty(Environment.GetEnvironmentVariable("TEAMCITY_PROJECT_NAME"));
+
+        private volatile bool _initialized;
+
+        public FlowLogger()
+        {
+        }
+
+        public override void Initialize(IEventSource eventSource, int nodeCount)
+        {
+            PreInit(eventSource);
+            base.Initialize(eventSource, nodeCount);
+        }
+
+        public override void Initialize(IEventSource eventSource)
+        {
+            PreInit(eventSource);
+            base.Initialize(eventSource);
+        }
+
+        private void PreInit(IEventSource eventSource)
+        {
+            if (_initialized) return;
+            _initialized = true;
+
+            var _flowId = GetFlowId();
+
+            var writer = IsTeamCity
+                ? (IWriter)new TeamCityMessageWriter(WriteHandler, _flowId)
+                : new DefaultPrefixMessageWriter(WriteHandler, _flowId);
+
+            WriteHandler = writer.WriteHandler;
+            eventSource.BuildStarted += (o, e) =>
+            {
+                writer.OnBuildStarted(e);
+            };
+            eventSource.BuildFinished += (o, e) =>
+            {
+                writer.OnBuildFinished(e);
+            };
+        }
+
+        private string GetFlowId()
+        {
+            var parameters = Parameters?.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
+            if (parameters == null || parameters.Length == 0)
+            {
+                return null;
+            }
+
+            const string flowIdParamName = "FlowId=";
+            return parameters
+                .FirstOrDefault(p => p.StartsWith(flowIdParamName, StringComparison.Ordinal))
+                ?.Substring(flowIdParamName.Length);
+        }
+    }
+}

build/tasks/Logger/IWriter.cs

@@ -0,0 +1,16 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.Build.Framework;
+using Microsoft.Build.Logging;
+
+namespace RepoTasks
+{
+    internal interface IWriter
+    {
+        WriteHandler WriteHandler { get; }
+
+        void OnBuildFinished(BuildFinishedEventArgs e);
+        void OnBuildStarted(BuildStartedEventArgs e);
+    }
+}

build/tasks/Logger/TeamCityMessageWriter.cs

@@ -0,0 +1,107 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Text;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Logging;
+
+namespace RepoTasks
+{
+    /// <summary>
+    /// See https://confluence.jetbrains.com/display/TCD10/Build+Script+Interaction+with+TeamCity
+    /// </summary>
+    internal class TeamCityMessageWriter : IWriter
+    {
+        private const string MessagePrefix = "##teamcity";
+        private static readonly string EOL = Environment.NewLine;
+        private readonly WriteHandler _write;
+        private readonly string _flowIdAttr;
+
+        public TeamCityMessageWriter(WriteHandler write, string flowId)
+        {
+            _write = write;
+            _flowIdAttr = EscapeTeamCityText(flowId);
+
+            WriteHandler = CreateMessageHandler();
+        }
+
+        public WriteHandler WriteHandler { get; }
+
+        public void OnBuildFinished(BuildFinishedEventArgs e)
+        {
+            _write($"##teamcity[blockOpened name='Build {_flowIdAttr}' flowId='{_flowIdAttr}']" + EOL);
+        }
+
+        public void OnBuildStarted(BuildStartedEventArgs e)
+        {
+            _write($"##teamcity[blockClosed name='Build {_flowIdAttr}' flowId='{_flowIdAttr}']" + EOL);
+        }
+
+        private WriteHandler CreateMessageHandler()
+        {
+            var format = "##teamcity[message text='{0}' flowId='" + _flowIdAttr + "']" + EOL;
+            return message =>
+            {
+                if (string.IsNullOrEmpty(message))
+                {
+                    return;
+                }
+
+                if (message.StartsWith(MessagePrefix, StringComparison.Ordinal))
+                {
+                    _write(message);
+                    return;
+                }
+
+                _write(
+                    string.Format(
+                        System.Globalization.CultureInfo.InvariantCulture,
+                        format,
+                        EscapeTeamCityText(message)));
+            };
+        }
+
+        private static string EscapeTeamCityText(string txt)
+        {
+            if (string.IsNullOrEmpty(txt))
+            {
+                return txt;
+            }
+
+            var sb = new StringBuilder(txt.Length);
+            for (var i = 0; i < txt.Length; i++)
+            {
+                var ch = txt[i];
+                switch (ch)
+                {
+                    case '\'':
+                    case '|':
+                    case '[':
+                    case ']':
+                        sb.Append('|').Append(ch);
+                        break;
+                    case '\n':
+                        sb.Append("|n");
+                        break;
+                    case '\r':
+                        sb.Append("|r");
+                        break;
+                    case '\u0085':
+                        sb.Append("|x");
+                        break;
+                    case '\u2028':
+                        sb.Append("|l");
+                        break;
+                    case '\u2029':
+                        sb.Append("|p");
+                        break;
+                    default:
+                        sb.Append(ch);
+                        break;
+                }
+            }
+            return sb.ToString();
+        }
+    }
+}