Implement caching in .NET info resolver (Buildalyzer#267)

Author: Corniel

src/Buildalyzer/Environment/DotNetInfoResolver.cs

@@ -0,0 +1,65 @@
+using System.Collections.Concurrent;
+using Buildalyzer.IO;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
+
+namespace Buildalyzer.Environment;
+
+internal sealed class DotNetInfoResolver(ILoggerFactory? factory)
+{
+    private static readonly TimeSpan FallbackWaitTime = TimeSpan.FromSeconds(10);
+    private readonly ILoggerFactory Factory = factory ?? NullLoggerFactory.Instance;
+    private readonly ILogger Logger = (factory ?? NullLoggerFactory.Instance).CreateLogger<DotNetInfoResolver>();
+
+    [Pure]
+    public DotNetInfo Resolve(IOPath projectPath, IOPath dotNetExePath)
+        => Cache.TryGetValue(projectPath, out var info)
+            ? info
+            : Execute(projectPath, dotNetExePath);
+
+    [Pure]
+    private DotNetInfo Execute(IOPath projectPath, IOPath dotNetExePath)
+    {
+        // Ensure that we set the DOTNET_CLI_UI_LANGUAGE environment variable to "en-US" before
+        // running 'dotnet --info'. Otherwise, we may get localized results
+        // Also unset some MSBuild variables, see https://github.com/OmniSharp/omnisharp-roslyn/blob/df160f86ce906bc566fe3e04e38a4077bd6023b4/src/OmniSharp.Abstractions/Services/DotNetCliService.cs#L36
+        var environmentVariables = new Dictionary<string, string?>
+        {
+            [EnvironmentVariables.DOTNET_CLI_UI_LANGUAGE] /*.*/ = "en-US",
+            [EnvironmentVariables.MSBUILD_EXE_PATH] /*.......*/ = null,
+            [EnvironmentVariables.COREHOST_TRACE] /*.........*/ = "0",
+            [MsBuildProperties.MSBuildExtensionsPath] /*.....*/ = null,
+        };
+
+        // global.json may change the version, so need to set working directory
+        using var processRunner = new ProcessRunner(
+            dotNetExePath.ToString(),
+            "--info",
+            projectPath.File().Directory!.FullName,
+            environmentVariables,
+            Factory);
+
+        processRunner.Start();
+        processRunner.WaitForExit(GetWaitTime());
+
+        var info = DotNetInfo.Parse(processRunner.Output);
+        Cache[projectPath] = info;
+        return info;
+    }
+
+    [Pure]
+    private int GetWaitTime()
+    {
+        if (int.TryParse(System.Environment.GetEnvironmentVariable(EnvironmentVariables.DOTNET_INFO_WAIT_TIME), out int waitTime))
+        {
+            Logger?.LogInformation("dotnet --info wait time is {WaitTime}ms", waitTime);
+            return waitTime;
+        }
+        else
+        {
+            return (int)FallbackWaitTime.TotalMilliseconds;
+        }
+    }
+
+    private readonly ConcurrentDictionary<IOPath, DotNetInfo> Cache = new();
+}

src/Buildalyzer/Environment/DotnetPathResolver.cs

@@ -1,7 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.IO;
-using System.Linq;
+using System.IO;
 using System.Runtime.InteropServices;
 using Buildalyzer.Construction;
 using Microsoft.Build.Utilities;
@@ -23,19 +20,19 @@ internal EnvironmentFactory(IAnalyzerManager manager, IProjectFile projectFile)
         _logger = _manager.LoggerFactory?.CreateLogger<EnvironmentFactory>();
     }
 
-    public BuildEnvironment GetBuildEnvironment() =>
+    public BuildEnvironment? GetBuildEnvironment() =>
         GetBuildEnvironment(null, null);
 
-    public BuildEnvironment GetBuildEnvironment(string targetFramework) =>
+    public BuildEnvironment? GetBuildEnvironment(string? targetFramework) =>
         GetBuildEnvironment(targetFramework, null);
 
-    public BuildEnvironment GetBuildEnvironment(EnvironmentOptions options) =>
+    public BuildEnvironment? GetBuildEnvironment(EnvironmentOptions? options) =>
         GetBuildEnvironment(null, options);
 
-    public BuildEnvironment GetBuildEnvironment(string targetFramework, EnvironmentOptions options)
+    public BuildEnvironment? GetBuildEnvironment(string? targetFramework, EnvironmentOptions? options)
     {
         options ??= new EnvironmentOptions();
-        BuildEnvironment buildEnvironment;
+        BuildEnvironment? buildEnvironment;
 
         // Use the .NET Framework if that's the preference
         // ...or if this project file uses a target known to require .NET Framework
@@ -57,18 +54,20 @@ public BuildEnvironment GetBuildEnvironment(string targetFramework, EnvironmentO
 
     // Based on code from OmniSharp
     // https://github.com/OmniSharp/omnisharp-roslyn/blob/78ccc8b4376c73da282a600ac6fb10fce8620b52/src/OmniSharp.Abstractions/Services/DotNetCliService.cs
-    private BuildEnvironment CreateCoreEnvironment(EnvironmentOptions options)
+    private BuildEnvironment? CreateCoreEnvironment(EnvironmentOptions options)
     {
         // Get paths
-        DotnetPathResolver pathResolver = new DotnetPathResolver(_manager.LoggerFactory);
-        string dotnetPath = pathResolver.ResolvePath(_projectFile.Path, options.DotnetExePath);
-        if (dotnetPath == null)
+        var resolver = new DotNetInfoResolver(_manager.LoggerFactory);
+        var info = resolver.Resolve(IO.IOPath.Parse(_projectFile.Path), IO.IOPath.Parse(options.DotnetExePath));
+
+        if ((info.BasePath ?? info.Runtimes.Values.FirstOrDefault()) is not { } dotnetPath)
         {
+            _logger?.LogWarning("Could not locate SDK path in `{DotnetPath} --info` results", options.DotnetExePath);
             return null;
         }
 
         string msBuildExePath = Path.Combine(dotnetPath, "MSBuild.dll");
-        if (options != null && options.EnvironmentVariables.ContainsKey(EnvironmentVariables.MSBUILD_EXE_PATH))
+        if (options.EnvironmentVariables.ContainsKey(EnvironmentVariables.MSBUILD_EXE_PATH))
         {
             msBuildExePath = options.EnvironmentVariables[EnvironmentVariables.MSBUILD_EXE_PATH];
         }
@@ -121,7 +120,7 @@ private BuildEnvironment CreateCoreEnvironment(EnvironmentOptions options)
             options.WorkingDirectory);
     }
 
-    private BuildEnvironment CreateFrameworkEnvironment(EnvironmentOptions options)
+    private BuildEnvironment? CreateFrameworkEnvironment(EnvironmentOptions options)
     {
         // Clone the options global properties dictionary so we can add to it
         Dictionary<string, string> additionalGlobalProperties = new Dictionary<string, string>(options.GlobalProperties);
@@ -135,7 +134,7 @@ private BuildEnvironment CreateFrameworkEnvironment(EnvironmentOptions options)
         }
 
         string msBuildExePath;
-        if (options != null && options.EnvironmentVariables.ContainsKey(EnvironmentVariables.MSBUILD_EXE_PATH))
+        if (options.EnvironmentVariables.ContainsKey(EnvironmentVariables.MSBUILD_EXE_PATH))
         {
             msBuildExePath = options.EnvironmentVariables[EnvironmentVariables.MSBUILD_EXE_PATH];
         }
@@ -194,7 +193,7 @@ private bool GetFrameworkMsBuildExePath(out string msBuildExePath)
         return !string.IsNullOrEmpty(msBuildExePath);
     }
 
-    private bool OnlyTargetsFramework(string targetFramework)
+    private bool OnlyTargetsFramework(string? targetFramework)
         => targetFramework == null
             ? _projectFile.TargetFrameworks.TrueForAll(IsFrameworkTargetFramework)
             : IsFrameworkTargetFramework(targetFramework);

src/Buildalyzer/Environment/EnvironmentFactory.cs

@@ -1,6 +1,3 @@
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
 using Microsoft.Extensions.Logging;
 
 namespace Buildalyzer.Environment;
@@ -21,8 +18,8 @@ public ProcessRunner(
         string fileName,
         string arguments,
         string workingDirectory,
-        Dictionary<string, string> environmentVariables,
-        ILoggerFactory loggerFactory)
+        Dictionary<string, string?> environmentVariables,
+        ILoggerFactory? loggerFactory)
     {
         _logger = loggerFactory?.CreateLogger<ProcessRunner>();
         Process = new Process