public async Task RefreshValueNotifiesChannelSubscribers()
{
RedisHelper.FlushDatabase();
var connection = RedisHelper.GetConnection();
var cacheStackMock = new Mock <ICacheStack>();
var extension = new RedisLockExtension(connection, RedisLockOptions.Default);
extension.Register(cacheStackMock.Object);
var completionSource = new TaskCompletionSource <bool>();
await connection.GetSubscriber().SubscribeAsync("CacheTower.CacheLock", (channel, value) =>
{
if (value == "TestKey")
{
completionSource.SetResult(true);
}
else
{
completionSource.SetResult(false);
}
});
var cacheEntry = new CacheEntry <int>(13, TimeSpan.FromDays(1));
await extension.RefreshValueAsync("TestKey",
() => new ValueTask <CacheEntry <int> >(cacheEntry), new CacheSettings(TimeSpan.FromDays(1)));
var succeedingTask = await Task.WhenAny(completionSource.Task, Task.Delay(TimeSpan.FromSeconds(10)));
Assert.AreEqual(completionSource.Task, succeedingTask, "Subscriber response took too long");
Assert.IsTrue(completionSource.Task.Result, "Subscribers were not notified about the refreshed value");
}
public async Task CustomLockTimeout()
{
RedisHelper.FlushDatabase();
var extension = new RedisLockExtension(RedisHelper.GetConnection(), new RedisLockOptions(lockTimeout: TimeSpan.FromDays(1)));
var refreshWaiterTask = new TaskCompletionSource <bool>();
var lockWaiterTask = new TaskCompletionSource <bool>();
var refreshTask = extension.RefreshValueAsync("TestLock", async() =>
{
lockWaiterTask.SetResult(true);
await refreshWaiterTask.Task;
return(new CacheEntry <int>(5, TimeSpan.FromDays(1)));
}, new CacheSettings(TimeSpan.FromHours(3)));
await lockWaiterTask.Task;
var database = RedisHelper.GetConnection().GetDatabase();
var keyWithExpiry = await database.StringGetWithExpiryAsync("Lock:TestLock");
refreshWaiterTask.SetResult(true);
var lockTimeout = TimeSpan.FromDays(1);
var actualExpiry = keyWithExpiry.Expiry.Value;
//Due to the logistics of the wait etc, we can't do an exact comparison
//Instead, we can safely say the above code should be completed within a minute
//With that in mind, remove that from the set lock timeout and compare the expiry
//is greater than this new "comparison timeout".
var comparisonTimeout = lockTimeout - TimeSpan.FromMinutes(1);
Assert.IsTrue(comparisonTimeout < keyWithExpiry.Expiry.Value);
}
public async Task ObservedLockMultiple()
{
RedisHelper.FlushDatabase();
var connection = RedisHelper.GetConnection();
var cacheStackMock = new Mock <ICacheStack>();
var extension = new RedisLockExtension(connection, RedisLockOptions.Default);
extension.Register(cacheStackMock.Object);
var cacheEntry = new CacheEntry <int>(13, TimeSpan.FromDays(1));
//Establish lock
await connection.GetDatabase().StringSetAsync("Lock:TestKey", RedisValue.EmptyString);
var refreshTask1 = extension.RefreshValueAsync("TestKey",
() =>
{
return(new ValueTask <CacheEntry <int> >(cacheEntry));
},
new CacheSettings(TimeSpan.FromDays(1))
).AsTask();
var refreshTask2 = extension.RefreshValueAsync("TestKey",
() =>
{
return(new ValueTask <CacheEntry <int> >(cacheEntry));
},
new CacheSettings(TimeSpan.FromDays(1))
).AsTask();
//Delay to allow for Redis check and self-entry into lock
await Task.Delay(TimeSpan.FromSeconds(2));
Assert.IsTrue(extension.LockedOnKeyRefresh.ContainsKey("TestKey"), "Lock was not established");
//Trigger the end of the lock
await connection.GetSubscriber().PublishAsync("CacheTower.CacheLock", "TestKey");
var whenAllRefreshesTask = Task.WhenAll(refreshTask1, refreshTask2);
var succeedingTask = await Task.WhenAny(whenAllRefreshesTask, Task.Delay(TimeSpan.FromSeconds(10)));
Assert.AreEqual(whenAllRefreshesTask, succeedingTask, "Refresh has timed out - something has gone very wrong");
cacheStackMock.Verify(c => c.GetAsync <int>("TestKey"), Times.Exactly(4), "Two checks to the cache stack are expected");
}
public async Task WaitingTaskInSameInstanceUnlocksAndCompletes()
{
var connection = RedisHelper.GetConnection();
var cacheStackMock = new Mock <ICacheStack>();
var extension = new RedisLockExtension(connection);
extension.Register(cacheStackMock.Object);
var cacheEntry = new CacheEntry <int>(13, TimeSpan.FromDays(1));
var secondaryTaskKickoff = new TaskCompletionSource <bool>();
var primaryTask = extension.RefreshValueAsync("TestKey",
async() =>
{
secondaryTaskKickoff.SetResult(true);
await Task.Delay(3000);
return(cacheEntry);
},
new CacheSettings(TimeSpan.FromDays(1))
).AsTask();
await secondaryTaskKickoff.Task;
var secondaryTask = extension.RefreshValueAsync("TestKey",
() =>
{
return(new ValueTask <CacheEntry <int> >(cacheEntry));
},
new CacheSettings(TimeSpan.FromDays(1))
).AsTask();
var succeedingTask = await Task.WhenAny(primaryTask, secondaryTask);
Assert.AreEqual(await primaryTask, await succeedingTask, "Processing task call didn't complete first - something has gone very wrong.");
//Let the secondary task finish before we verify ICacheStack method calls
await secondaryTask;
cacheStackMock.Verify(c => c.GetAsync <int>("TestKey"), Times.Exactly(2), "Missed checks whether waiting was required or retrieving the updated value");
}
public async Task RefreshValueNotifiesChannelSubscribers()
{
var connection = RedisHelper.GetConnection();
var taskCompletionSource = new TaskCompletionSource <bool>();
await connection.GetSubscriber().SubscribeAsync("CacheTower.CacheLock", (channel, value) =>
{
if (value == "TestKey")
{
taskCompletionSource.SetResult(true);
}
Assert.Fail($"Unexpected value '{value}'");
taskCompletionSource.SetResult(false);
});
var cacheStackMock = new Mock <ICacheStack>();
var extension = new RedisLockExtension(connection);
extension.Register(cacheStackMock.Object);
var cacheEntry = new CacheEntry <int>(13, TimeSpan.FromDays(1));
await extension.RefreshValueAsync("TestKey",
() => new ValueTask <CacheEntry <int> >(cacheEntry), new CacheSettings(TimeSpan.FromDays(1)));
var waitTask = taskCompletionSource.Task;
await Task.WhenAny(waitTask, Task.Delay(TimeSpan.FromSeconds(10)));
if (!waitTask.IsCompleted)
{
Assert.Fail("Subscriber response took too long");
}
Assert.IsTrue(waitTask.Result, "Subscribers were not notified about the refreshed value");
}