From 4802806bdccee27cb3d5fa8c2d0dfbdc117fdb4d Mon Sep 17 00:00:00 2001
From: Jordan Brown <Cyberboss@users.noreply.github.com>
Date: Mon, 20 Apr 2020 12:24:42 -0400
Subject: [PATCH] Cleanup repository management code

---
 .../Repository/IRepositoryFactory.cs          |  5 ++-
 .../Repository/RepositoryFactory.cs           | 16 ++++---
 .../Repository/RepositoryManager.cs           | 43 +++++++------------
 3 files changed, 30 insertions(+), 34 deletions(-)

diff --git a/src/Tgstation.Server.Host/Components/Repository/IRepositoryFactory.cs b/src/Tgstation.Server.Host/Components/Repository/IRepositoryFactory.cs
index a4e7d2b4c3..1b9d7b8c41 100644
--- a/src/Tgstation.Server.Host/Components/Repository/IRepositoryFactory.cs
+++ b/src/Tgstation.Server.Host/Components/Repository/IRepositoryFactory.cs
@@ -20,8 +20,9 @@ namespace Tgstation.Server.Host.Components.Repository
 		/// Load a <see cref="LibGit2Sharp.IRepository"/> from a given <paramref name="path"/>.
 		/// </summary>
 		/// <param name="path">The full path to the <see cref="LibGit2Sharp.IRepository"/>.</param>
-		/// <returns>The loaded <see cref="LibGit2Sharp.IRepository"/>.</returns>
-		LibGit2Sharp.IRepository CreateFromPath(string path);
+		/// <param name="cancellationToken">The <see cref="CancellationToken"/> for the operation.</param>
+		/// <returns>A <see cref="Task{TResult}"/> resulting in, the loaded <see cref="LibGit2Sharp.IRepository"/>.</returns>
+		Task<LibGit2Sharp.IRepository> CreateFromPath(string path, CancellationToken cancellationToken);
 
 		/// <summary>
 		/// Clone a remote <see cref="LibGit2Sharp.IRepository"/>.
diff --git a/src/Tgstation.Server.Host/Components/Repository/RepositoryFactory.cs b/src/Tgstation.Server.Host/Components/Repository/RepositoryFactory.cs
index 5c6e4e2667..69865ce950 100644
--- a/src/Tgstation.Server.Host/Components/Repository/RepositoryFactory.cs
+++ b/src/Tgstation.Server.Host/Components/Repository/RepositoryFactory.cs
@@ -28,17 +28,21 @@ namespace Tgstation.Server.Host.Components.Repository
 		/// <inheritdoc />
 		public LibGit2Sharp.IRepository CreateInMemory()
 		{
-			logger.LogTrace("Creating in-memory LibGit2Sharp...");
+			logger.LogTrace("Creating in-memory repository...");
 			return new LibGit2Sharp.Repository();
 		}
 
 		/// <inheritdoc />
-		public LibGit2Sharp.IRepository CreateFromPath(string path)
+		public Task<LibGit2Sharp.IRepository> CreateFromPath(string path, CancellationToken cancellationToken)
 		{
 			if (path == null)
 				throw new ArgumentNullException(nameof(path));
-			logger.LogTrace("Creating LibGit2Sharp Repostory at {0}...", path);
-			return new LibGit2Sharp.Repository(path);
+			logger.LogTrace("Creating repostory at {0}...", path);
+			return Task.Factory.StartNew(
+				() => (LibGit2Sharp.IRepository)new LibGit2Sharp.Repository(path),
+				cancellationToken,
+				TaskCreationOptions.LongRunning,
+				TaskScheduler.Current);
 		}
 
 		/// <inheritdoc />
@@ -46,10 +50,12 @@ namespace Tgstation.Server.Host.Components.Repository
 		{
 			try
 			{
+				logger.LogTrace("Cloning {0} into {1}...", url, path);
 				LibGit2Sharp.Repository.Clone(url.ToString(), path, cloneOptions);
 			}
-			catch (UserCancelledException)
+			catch (UserCancelledException ex)
 			{
+				logger.LogTrace("Suppressing clone cancellation exception: {0}", ex);
 				cancellationToken.ThrowIfCancellationRequested();
 			}
 		}, cancellationToken, TaskCreationOptions.LongRunning, TaskScheduler.Current);
diff --git a/src/Tgstation.Server.Host/Components/Repository/RepositoryManager.cs b/src/Tgstation.Server.Host/Components/Repository/RepositoryManager.cs
index f198ad0b4b..f495a56693 100644
--- a/src/Tgstation.Server.Host/Components/Repository/RepositoryManager.cs
+++ b/src/Tgstation.Server.Host/Components/Repository/RepositoryManager.cs
@@ -94,7 +94,7 @@ namespace Tgstation.Server.Host.Components.Repository
 				throw new ArgumentNullException(nameof(progressReporter));
 
 			logger.LogInformation("Begin clone {0} (Branch: {1})", url, initialBranch);
-			lock (this)
+			lock (semaphore)
 			{
 				if (CloneInProgress)
 					throw new InvalidOperationException("The repository is already being cloned!");
@@ -167,40 +167,29 @@ namespace Tgstation.Server.Host.Components.Repository
 		public async Task<IRepository> LoadRepository(CancellationToken cancellationToken)
 		{
 			logger.LogTrace("Begin LoadRepository...");
-			lock (this)
+			lock (semaphore)
 				if (CloneInProgress)
 					throw new InvalidOperationException("The repository is being cloned!");
-			await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
-			LibGit2Sharp.IRepository repo = null;
-			await Task.Factory.StartNew(() =>
+			try
 			{
-				try
-				{
-					logger.LogTrace("Creating LibGit2Sharp.Repository...");
-					repo = repositoryFactory.CreateFromPath(ioManager.ResolvePath("."));
-				}
-				catch (RepositoryNotFoundException e)
-				{
-					logger.LogDebug("Repository not found!");
-					logger.LogTrace("Exception: {0}", e);
-				}
-				catch
+				using var context = await SemaphoreSlimContext.Lock(semaphore, cancellationToken).ConfigureAwait(false);
+				var repo = await repositoryFactory.CreateFromPath(ioManager.ResolvePath("."), cancellationToken).ConfigureAwait(false);
+
+				if (repo == null)
+					return null;
+
+				return new Repository(repo, ioManager, eventConsumer, repositoryFactory, repositoryLogger, () =>
 				{
+					logger.LogTrace("Releasing semaphore due to Repository disposal...");
 					semaphore.Release();
-					throw;
-				}
-			}, cancellationToken, TaskCreationOptions.LongRunning, TaskScheduler.Current).ConfigureAwait(false);
-			if (repo == null)
+				});
+			}
+			catch (RepositoryNotFoundException e)
 			{
-				semaphore.Release();
+				logger.LogDebug("Repository not found!");
+				logger.LogTrace("Exception: {0}", e);
 				return null;
 			}
-
-			return new Repository(repo, ioManager, eventConsumer, repositoryFactory, repositoryLogger, () =>
-			{
-				logger.LogTrace("Releasing semaphore due to Repository disposal...");
-				semaphore.Release();
-			});
 		}
 
 		/// <inheritdoc />