diff --git a/Tests.Vpn.Service/DownloaderTest.cs b/Tests.Vpn.Service/DownloaderTest.cs
index 985e331..8b55f50 100644
--- a/Tests.Vpn.Service/DownloaderTest.cs
+++ b/Tests.Vpn.Service/DownloaderTest.cs
@@ -284,6 +284,34 @@ public async Task Download(CancellationToken ct)
Assert.That(await File.ReadAllTextAsync(destPath, ct), Is.EqualTo("test"));
}
+ [Test(Description = "Perform 2 downloads with the same destination")]
+ [CancelAfter(30_000)]
+ public async Task DownloadSameDest(CancellationToken ct)
+ {
+ using var httpServer = EchoServer();
+ var url0 = new Uri(httpServer.BaseUrl + "/test0");
+ var url1 = new Uri(httpServer.BaseUrl + "/test1");
+ var destPath = Path.Combine(_tempDir, "test");
+
+ var manager = new Downloader(NullLogger<Downloader>.Instance);
+ var startTask0 = manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url0), destPath,
+ NullDownloadValidator.Instance, ct);
+ var startTask1 = manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url1), destPath,
+ NullDownloadValidator.Instance, ct);
+ var dlTask0 = await startTask0;
+ await dlTask0.Task;
+ Assert.That(dlTask0.TotalBytes, Is.EqualTo(5));
+ Assert.That(dlTask0.BytesRead, Is.EqualTo(5));
+ Assert.That(dlTask0.Progress, Is.EqualTo(1));
+ Assert.That(dlTask0.IsCompleted, Is.True);
+ var dlTask1 = await startTask1;
+ await dlTask1.Task;
+ Assert.That(dlTask1.TotalBytes, Is.EqualTo(5));
+ Assert.That(dlTask1.BytesRead, Is.EqualTo(5));
+ Assert.That(dlTask1.Progress, Is.EqualTo(1));
+ Assert.That(dlTask1.IsCompleted, Is.True);
+ }
+
[Test(Description = "Download with custom headers")]
[CancelAfter(30_000)]
public async Task WithHeaders(CancellationToken ct)
@@ -347,17 +375,17 @@ public async Task DownloadExistingDifferentContent(CancellationToken ct)
[Test(Description = "Unexpected response code from server")]
[CancelAfter(30_000)]
- public void UnexpectedResponseCode(CancellationToken ct)
+ public async Task UnexpectedResponseCode(CancellationToken ct)
{
using var httpServer = new TestHttpServer(ctx => { ctx.Response.StatusCode = 404; });
var url = new Uri(httpServer.BaseUrl + "/test");
var destPath = Path.Combine(_tempDir, "test");
var manager = new Downloader(NullLogger<Downloader>.Instance);
- // The "outer" Task should fail.
- var ex = Assert.ThrowsAsync<HttpRequestException>(async () =>
- await manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url), destPath,
- NullDownloadValidator.Instance, ct));
+ // The "inner" Task should fail.
+ var dlTask = await manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url), destPath,
+ NullDownloadValidator.Instance, ct);
+ var ex = Assert.ThrowsAsync<HttpRequestException>(async () => await dlTask.Task);
Assert.That(ex.Message, Does.Contain("404"));
}
@@ -384,22 +412,6 @@ public async Task MismatchedETag(CancellationToken ct)
Assert.That(ex.Message, Does.Contain("ETag does not match SHA1 hash of downloaded file").And.Contains("beef"));
}
- [Test(Description = "Timeout on response headers")]
- [CancelAfter(30_000)]
- public void CancelledOuter(CancellationToken ct)
- {
- using var httpServer = new TestHttpServer(async _ => { await Task.Delay(TimeSpan.FromSeconds(5), ct); });
- var url = new Uri(httpServer.BaseUrl + "/test");
- var destPath = Path.Combine(_tempDir, "test");
-
- var manager = new Downloader(NullLogger<Downloader>.Instance);
- // The "outer" Task should fail.
- var smallerCt = new CancellationTokenSource(TimeSpan.FromSeconds(1)).Token;
- Assert.ThrowsAsync<TaskCanceledException>(
- async () => await manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url), destPath,
- NullDownloadValidator.Instance, smallerCt));
- }
-
[Test(Description = "Timeout on response body")]
[CancelAfter(30_000)]
public async Task CancelledInner(CancellationToken ct)
@@ -451,12 +463,10 @@ public async Task ValidationFailureExistingFile(CancellationToken ct)
await File.WriteAllTextAsync(destPath, "test", ct);
var manager = new Downloader(NullLogger<Downloader>.Instance);
- // The "outer" Task should fail because the inner task never starts.
- var ex = Assert.ThrowsAsync<Exception>(async () =>
- {
- await manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url), destPath,
- new TestDownloadValidator(new Exception("test exception")), ct);
- });
+ var dlTask = await manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url), destPath,
+ new TestDownloadValidator(new Exception("test exception")), ct);
+ // The "inner" Task should fail.
+ var ex = Assert.ThrowsAsync<Exception>(async () => { await dlTask.Task; });
Assert.That(ex.Message, Does.Contain("Existing file failed validation"));
Assert.That(ex.InnerException, Is.Not.Null);
Assert.That(ex.InnerException!.Message, Is.EqualTo("test exception"));
diff --git a/Vpn.Service/Downloader.cs b/Vpn.Service/Downloader.cs
index a37a1ec..6a665ae 100644
--- a/Vpn.Service/Downloader.cs
+++ b/Vpn.Service/Downloader.cs
@@ -3,6 +3,7 @@
using System.Formats.Asn1;
using System.Net;
using System.Runtime.CompilerServices;
+using System.Runtime.ExceptionServices;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using Coder.Desktop.Vpn.Utilities;
@@ -288,7 +289,26 @@ public async Task<DownloadTask> StartDownloadAsync(HttpRequestMessage req, strin
{
var task = _downloads.GetOrAdd(destinationPath,
_ => new DownloadTask(_logger, req, destinationPath, validator));
- await task.EnsureStartedAsync(ct);
+ // EnsureStarted is a no-op if we didn't create a new DownloadTask.
+ // So, we will only remove the destination once for each time we start a new task.
+ task.EnsureStarted(tsk =>
+ {
+ // remove the key first, before checking the exception, to ensure
+ // we still clean up.
+ _downloads.TryRemove(destinationPath, out _);
+ if (tsk.Exception == null)
+ {
+ return;
+ }
+
+ if (tsk.Exception.InnerException != null)
+ {
+ ExceptionDispatchInfo.Capture(tsk.Exception.InnerException).Throw();
+ }
+
+ // not sure if this is hittable, but just in case:
+ throw tsk.Exception;
+ }, ct);
// If the existing (or new) task is for the same URL, return it.
if (task.Request.RequestUri == req.RequestUri)
@@ -357,13 +377,11 @@ internal DownloadTask(ILogger logger, HttpRequestMessage req, string destination
".download-" + Path.GetRandomFileName());
}
- internal async Task<Task> EnsureStartedAsync(CancellationToken ct = default)
+ internal void EnsureStarted(Action<Task> continuation, CancellationToken ct = default)
{
- using var _ = await _semaphore.LockAsync(ct);
+ using var _ = _semaphore.Lock();
if (Task == null!)
- Task = await StartDownloadAsync(ct);
-
- return Task;
+ Task = Start(ct).ContinueWith(continuation, ct);
}
/// <summary>
@@ -371,7 +389,7 @@ internal async Task<Task> EnsureStartedAsync(CancellationToken ct = default)
/// and the download will continue in the background. The provided CancellationToken can be used to cancel the
/// download.
/// </summary>
- private async Task<Task> StartDownloadAsync(CancellationToken ct = default)
+ private async Task Start(CancellationToken ct = default)
{
Directory.CreateDirectory(_destinationDirectory);
@@ -398,8 +416,7 @@ private async Task<Task> StartDownloadAsync(CancellationToken ct = default)
throw new Exception("Existing file failed validation after 304 Not Modified", e);
}
- Task = Task.CompletedTask;
- return Task;
+ return;
}
if (res.StatusCode != HttpStatusCode.OK)
@@ -432,11 +449,11 @@ private async Task<Task> StartDownloadAsync(CancellationToken ct = default)
throw;
}
- Task = DownloadAsync(res, tempFile, ct);
- return Task;
+ await Download(res, tempFile, ct);
+ return;
}
- private async Task DownloadAsync(HttpResponseMessage res, FileStream tempFile, CancellationToken ct)
+ private async Task Download(HttpResponseMessage res, FileStream tempFile, CancellationToken ct)
{
try
{