Extract reusable one-shot process runner from backup compressor implementation

Agent/Phantom.Agent.Services/Backups/BackupCompressor.cs

@@ -1,15 +1,17 @@
 using System.Diagnostics;
 using Phantom.Common.Logging;
+using Phantom.Utils.Runtime;
 using Serilog;
 
 namespace Phantom.Agent.Services.Backups; 
 
 static class BackupCompressor {
 	private static ILogger Logger { get; } = PhantomLogger.Create(nameof(BackupCompressor));
+	private static ILogger ZstdLogger { get; } = PhantomLogger.Create(nameof(BackupCompressor), "Zstd");
 	
-	private const int Quality = 10;
-	private const int Memory = 26;
-	private const int Threads = 3;
+	private const string Quality = "-10";
+	private const string Memory = "--long=26";
+	private const string Threads = "-T3";
 	
 	public static async Task<string?> Compress(string sourceFilePath, CancellationToken cancellationToken) {
 		if (sourceFilePath.Contains('"')) {
@@ -38,66 +40,31 @@ static class BackupCompressor {
 			Logger.Error("Invalid destination path: {Path}", destinationFilePath);
 			return false;
 		}
-		
+
 		var startInfo = new ProcessStartInfo {
 			FileName = "zstd",
 			WorkingDirectory = workingDirectory,
-			Arguments = $"-{Quality} --long={Memory} -T{Threads} -c --rm --no-progress -c -o \"{destinationFilePath}\" -- \"{sourceFilePath}\"",
-			RedirectStandardOutput = true,
-			RedirectStandardError = true
+			ArgumentList = {
+				Quality,
+				Memory,
+				Threads,
+				"-c",
+				"--rm",
+				"--no-progress",
+				"-c",
+				"-o", destinationFilePath,
+				"--", sourceFilePath
+			}
 		};
 
-		using var process = new Process { StartInfo = startInfo };
-		process.OutputDataReceived += OnZstdProcessOutput;
-		process.ErrorDataReceived += OnZstdProcessOutput;
-
-		try {
-			process.Start();
-			process.BeginOutputReadLine();
-			process.BeginErrorReadLine();
-		} catch (Exception e) {
-			Logger.Error(e, "Caught exception launching zstd process.");
+		static void OnZstdOutput(object? sender, DataReceivedEventArgs e) {
+			if (!string.IsNullOrWhiteSpace(e.Data)) {
+				ZstdLogger.Verbose("[Output] {Line}", e.Data);
+			}
 		}
 
-		try {
-			await process.WaitForExitAsync(cancellationToken);
-		} catch (OperationCanceledException) {
-			await TryKillProcess(process);
-			return false;
-		} catch (Exception e) {
-			Logger.Error(e, "Caught exception waiting for zstd process to exit.");
-			return false;
-		}
-
-		if (!process.HasExited) {
-			await TryKillProcess(process);
-			return false;
-		}
-
-		if (process.ExitCode != 0) {
-			Logger.Error("Zstd process exited with code {ExitCode}.", process.ExitCode);
-			return false;
-		}
-
-		return true;
-	}
-
-	private static void OnZstdProcessOutput(object sender, DataReceivedEventArgs e) {
-		if (!string.IsNullOrWhiteSpace(e.Data)) {
-			Logger.Verbose("[Zstd] {Line}", e.Data);
-		}
-	}
-
-	private static async Task TryKillProcess(Process process) {
-		CancellationTokenSource timeout = new CancellationTokenSource(TimeSpan.FromSeconds(1));
-
-		try {
-			process.Kill();
-			await process.WaitForExitAsync(timeout.Token);
-		} catch (OperationCanceledException) {
-			Logger.Error("Timed out waiting for killed zstd process to exit.");
-		} catch (Exception e) {
-			Logger.Error(e, "Caught exception killing zstd process.");
-		}
+		var process = new OneShotProcess(ZstdLogger, startInfo);
+		process.Output += OnZstdOutput;
+		return await process.Run(cancellationToken);
 	}
 }

Utils/Phantom.Utils.Runtime/OneShotProcess.cs

@@ -0,0 +1,69 @@
+using System.Diagnostics;
+using Serilog;
+
+namespace Phantom.Utils.Runtime;
+
+public sealed class OneShotProcess {
+	private readonly ILogger logger;
+	private readonly ProcessStartInfo startInfo;
+	
+	public event DataReceivedEventHandler? Output;
+	
+	public OneShotProcess(ILogger logger, ProcessStartInfo startInfo) {
+		this.logger = logger;
+		this.startInfo = startInfo;
+		this.startInfo.RedirectStandardOutput = true;
+		this.startInfo.RedirectStandardError = true;
+	}
+
+	public async Task<bool> Run(CancellationToken cancellationToken) {
+		using var process = new Process { StartInfo = startInfo };
+		process.OutputDataReceived += Output;
+		process.ErrorDataReceived += Output;
+
+		try {
+			process.Start();
+			process.BeginOutputReadLine();
+			process.BeginErrorReadLine();
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception launching process.");
+			return false;
+		}
+
+		try {
+			await process.WaitForExitAsync(cancellationToken);
+		} catch (OperationCanceledException) {
+			await TryKillProcess(process);
+			return false;
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception waiting for process to exit.");
+			return false;
+		}
+
+		if (!process.HasExited) {
+			await TryKillProcess(process);
+			return false;
+		}
+
+		if (process.ExitCode != 0) {
+			logger.Error("Process exited with code {ExitCode}.", process.ExitCode);
+			return false;
+		}
+
+		logger.Verbose("Process finished successfully.");
+		return true;
+	}
+
+	private async Task TryKillProcess(Process process) {
+		using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(2));
+
+		try {
+			process.Kill();
+			await process.WaitForExitAsync(timeout.Token);
+		} catch (OperationCanceledException) {
+			logger.Error("Timed out waiting for killed process to exit.");
+		} catch (Exception e) {
+			logger.Error(e, "Caught exception killing process.");
+		}
+	}
+}