public override async Task GetStatisticsWithZeroPermitCount()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 100,
QueueProcessingOrder = QueueProcessingOrder.OldestFirst,
QueueLimit = 50,
Window = TimeSpan.Zero,
SegmentsPerWindow = 3,
AutoReplenishment = false
});
var lease = limiter.AttemptAcquire(0);
Assert.True(lease.IsAcquired);
Assert.Equal(1, limiter.GetStatistics().TotalSuccessfulLeases);
Assert.Equal(100, limiter.GetStatistics().CurrentAvailablePermits);
lease = await limiter.AcquireAsync(0);
Assert.True(lease.IsAcquired);
Assert.Equal(2, limiter.GetStatistics().TotalSuccessfulLeases);
Assert.Equal(100, limiter.GetStatistics().CurrentAvailablePermits);
lease = limiter.AttemptAcquire(100);
Assert.True(lease.IsAcquired);
Assert.Equal(3, limiter.GetStatistics().TotalSuccessfulLeases);
Assert.Equal(0, limiter.GetStatistics().CurrentAvailablePermits);
var lease2 = limiter.AttemptAcquire(0);
Assert.False(lease2.IsAcquired);
Assert.Equal(3, limiter.GetStatistics().TotalSuccessfulLeases);
Assert.Equal(1, limiter.GetStatistics().TotalFailedLeases);
Assert.Equal(0, limiter.GetStatistics().CurrentAvailablePermits);
}
public void TryReplenishWithAutoReplenish_ReturnsFalse()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 2,
QueueProcessingOrder = QueueProcessingOrder.OldestFirst,
QueueLimit = 1,
Window = TimeSpan.FromSeconds(1),
SegmentsPerWindow = 1,
AutoReplenishment = true
});
Assert.Equal(2, limiter.GetStatistics().CurrentAvailablePermits);
Assert.False(limiter.TryReplenish());
Assert.Equal(2, limiter.GetStatistics().CurrentAvailablePermits);
}
public override async Task CanAcquireResourcesWithAcquireAsyncWithQueuedItemsIfNewestFirst()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 2,
QueueProcessingOrder = QueueProcessingOrder.NewestFirst,
QueueLimit = 2,
Window = TimeSpan.Zero,
SegmentsPerWindow = 3,
AutoReplenishment = false
});
var lease = limiter.AttemptAcquire(1);
Assert.True(lease.IsAcquired);
var wait = limiter.AcquireAsync(2);
Assert.False(wait.IsCompleted);
Assert.Equal(1, limiter.GetStatistics().CurrentAvailablePermits);
lease = await limiter.AcquireAsync(1);
Assert.True(lease.IsAcquired);
Assert.False(wait.IsCompleted);
limiter.TryReplenish();
Assert.True(limiter.TryReplenish());
Assert.False(wait.IsCompleted);
Assert.True(limiter.TryReplenish());
lease = await wait;
Assert.True(lease.IsAcquired);
}
public override async Task CancelUpdatesQueueLimit()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 2,
QueueProcessingOrder = QueueProcessingOrder.NewestFirst,
QueueLimit = 1,
Window = TimeSpan.Zero,
SegmentsPerWindow = 2,
AutoReplenishment = false
});
var lease = limiter.AttemptAcquire(2);
Assert.True(lease.IsAcquired);
var cts = new CancellationTokenSource();
var wait = limiter.AcquireAsync(1, cts.Token);
cts.Cancel();
var ex = await Assert.ThrowsAsync<TaskCanceledException>(() => wait.AsTask());
Assert.Equal(cts.Token, ex.CancellationToken);
wait = limiter.AcquireAsync(1);
Assert.False(wait.IsCompleted);
limiter.TryReplenish();
limiter.TryReplenish();
lease = await wait;
Assert.True(lease.IsAcquired);
Assert.Equal(1, limiter.GetStatistics().CurrentAvailablePermits);
}
public override async Task GetStatisticsHasCorrectValues()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 100,
QueueProcessingOrder = QueueProcessingOrder.OldestFirst,
QueueLimit = 50,
Window = TimeSpan.Zero,
SegmentsPerWindow = 2,
AutoReplenishment = false
});
var stats = limiter.GetStatistics();
Assert.Equal(100, stats.CurrentAvailablePermits);
Assert.Equal(0, stats.CurrentQueuedCount);
Assert.Equal(0, stats.TotalFailedLeases);
Assert.Equal(0, stats.TotalSuccessfulLeases);
var lease1 = limiter.AttemptAcquire(60);
stats = limiter.GetStatistics();
Assert.Equal(40, stats.CurrentAvailablePermits);
Assert.Equal(0, stats.CurrentQueuedCount);
Assert.Equal(0, stats.TotalFailedLeases);
Assert.Equal(1, stats.TotalSuccessfulLeases);
var lease2Task = limiter.AcquireAsync(50);
stats = limiter.GetStatistics();
Assert.Equal(40, stats.CurrentAvailablePermits);
Assert.Equal(50, stats.CurrentQueuedCount);
Assert.Equal(0, stats.TotalFailedLeases);
Assert.Equal(1, stats.TotalSuccessfulLeases);
limiter.TryReplenish();
var lease3 = await limiter.AcquireAsync(1);
Assert.False(lease3.IsAcquired);
stats = limiter.GetStatistics();
Assert.Equal(40, stats.CurrentAvailablePermits);
Assert.Equal(50, stats.CurrentQueuedCount);
Assert.Equal(1, stats.TotalFailedLeases);
Assert.Equal(1, stats.TotalSuccessfulLeases);
var lease4 = limiter.AttemptAcquire(100);
Assert.False(lease4.IsAcquired);
stats = limiter.GetStatistics();
Assert.Equal(40, stats.CurrentAvailablePermits);
Assert.Equal(50, stats.CurrentQueuedCount);
Assert.Equal(2, stats.TotalFailedLeases);
Assert.Equal(1, stats.TotalSuccessfulLeases);
limiter.TryReplenish();
await lease2Task;
stats = limiter.GetStatistics();
Assert.Equal(50, stats.CurrentAvailablePermits);
Assert.Equal(0, stats.CurrentQueuedCount);
Assert.Equal(2, stats.TotalFailedLeases);
Assert.Equal(2, stats.TotalSuccessfulLeases);
}
public override void GetStatisticsReturnsNewInstances()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 1,
QueueProcessingOrder = QueueProcessingOrder.OldestFirst,
QueueLimit = 1,
Window = TimeSpan.Zero,
SegmentsPerWindow = 2,
AutoReplenishment = false
});
var stats = limiter.GetStatistics();
Assert.Equal(1, stats.CurrentAvailablePermits);
var lease = limiter.AttemptAcquire(1);
var stats2 = limiter.GetStatistics();
Assert.NotSame(stats, stats2);
Assert.Equal(1, stats.CurrentAvailablePermits);
Assert.Equal(0, stats2.CurrentAvailablePermits);
}
public async Task AutoReplenish_ReplenishesCounters()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 2,
QueueProcessingOrder = QueueProcessingOrder.OldestFirst,
QueueLimit = 1,
Window = TimeSpan.FromMilliseconds(1000),
SegmentsPerWindow = 2,
AutoReplenishment = true
});
Assert.Equal(2, limiter.GetStatistics().CurrentAvailablePermits);
limiter.AttemptAcquire(2);
var lease = await limiter.AcquireAsync(1);
Assert.True(lease.IsAcquired);
}
public async Task CanAcquireMultipleRequestsAsync()
{
// This test verifies the following behavior
// 1. when we have available permits after replenish to serve the queued requests
// 2. when the oldest item from queue is remove to accommodate new requests (QueueProcessingOrder: NewestFirst)
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 4,
QueueProcessingOrder = QueueProcessingOrder.NewestFirst,
QueueLimit = 4,
Window = TimeSpan.Zero,
SegmentsPerWindow = 3,
AutoReplenishment = false
});
using var lease = await limiter.AcquireAsync(2);
Assert.True(lease.IsAcquired);
var wait = limiter.AcquireAsync(3);
Assert.False(wait.IsCompleted);
Assert.True(limiter.TryReplenish());
Assert.False(wait.IsCompleted);
var wait2 = limiter.AcquireAsync(2);
Assert.True(wait2.IsCompleted);
Assert.True(limiter.TryReplenish());
var wait3 = limiter.AcquireAsync(2);
Assert.False(wait3.IsCompleted);
Assert.True(limiter.TryReplenish());
Assert.True((await wait3).IsAcquired);
Assert.False((await wait).IsAcquired);
Assert.Equal(0, limiter.GetStatistics().CurrentAvailablePermits);
}
public override async Task CanAcquireResourceAsync_QueuesAndGrabsNewest()
{
var limiter = new SlidingWindowRateLimiter(new SlidingWindowRateLimiterOptions
{
PermitLimit = 2,
QueueProcessingOrder = QueueProcessingOrder.NewestFirst,
QueueLimit = 3,
Window = TimeSpan.FromMinutes(0),
SegmentsPerWindow = 2,
AutoReplenishment = false
});
var lease = await limiter.AcquireAsync(2);
Assert.True(lease.IsAcquired);
var wait1 = limiter.AcquireAsync(2);
var wait2 = limiter.AcquireAsync();
Assert.False(wait1.IsCompleted);
Assert.False(wait2.IsCompleted);
lease.Dispose();
Assert.True(limiter.TryReplenish());
Assert.False(wait2.IsCompleted);
Assert.True(limiter.TryReplenish());
// second queued item completes first with NewestFirst
lease = await wait2;
Assert.True(lease.IsAcquired);
Assert.False(wait1.IsCompleted);
lease.Dispose();
Assert.Equal(1, limiter.GetStatistics().CurrentAvailablePermits);
Assert.True(limiter.TryReplenish());
Assert.True(limiter.TryReplenish());
lease = await wait1;
Assert.True(lease.IsAcquired);
}
