public void Should_EmptySnapshotBeThreadSafe()
{
var target = new HdrHistogramReservoir(1, 1000, 3, 10000);
Parallel.ForEach(Enumerable.Range(1, 100000), i => AssertEmptySnapshot(target.GetSnapshot(false)));
target.Reset();
Parallel.ForEach(Enumerable.Range(1, 100000), i => AssertEmptySnapshot(target.GetSnapshot(false)));
Parallel.ForEach(Enumerable.Range(1, 1000), i => AssertEmptySnapshot(target.GetSnapshot(true)));
}
public async Task Should_ReturnEmptyHistogram_When_ResetIsCalled()
{
var target = new HdrHistogramReservoir(1, 1000000000000, 3, 2000);
var tcs = new CancellationTokenSource();
AssertEmptySnapshot(target.GetSnapshot(false));
Parallel.ForEach(Enumerable.Range(1, 100), i => target.Update(i));
AssertEmptySnapshot(target.GetSnapshot(false));
await Task.Yield();
AssertEmptySnapshot(target.GetSnapshot(false));
TestHelper.RetryAssert(
() =>
{
AssertFirstSnapshot(target.GetSnapshot(false));
},
200,
20);
var tasks = Enumerable.Range(0, 4).Select(i => Task.Run(async() =>
{
var current = i * 100000;
while (!tcs.IsCancellationRequested)
{
if (current == int.MaxValue)
{
current = 0;
}
target.Update(++current);
await Task.Yield();
}
})).ToList();
try
{
AssertFirstSnapshot(target.GetSnapshot(false));
await Task.Yield();
AssertFirstSnapshot(target.GetSnapshot(false));
// reset
AssertFirstSnapshot(target.GetSnapshot(true));
AssertEmptySnapshot(target.GetSnapshot(false));
await Task.Yield();
AssertEmptySnapshot(target.GetSnapshot(false));
}
finally
{
tcs.Cancel();
await Task.WhenAll(tasks).ConfigureAwait(false);
}
}
public void Should_RefreshEntireHistogramAfterRefreshInterval()
{
var target = new HdrHistogramReservoir(1, 30000, 3, 1000);
Parallel.ForEach(Enumerable.Range(1, 100), i => target.Update(i));
AssertEmptySnapshot(target.GetSnapshot(false));
AssertEmptySnapshot(target.GetSnapshot(false));
TestHelper.RetryAssert(
() =>
{
AssertFirstSnapshot(target.GetSnapshot(false));
},
200,
15);
Parallel.ForEach(Enumerable.Range(201, 100), i => target.Update(i));
AssertFirstSnapshot(target.GetSnapshot(false));
AssertFirstSnapshot(target.GetSnapshot(false));
TestHelper.RetryAssert(
() =>
{
AssertSecondSnapshot(target.GetSnapshot(false));
},
200,
15);
AssertSecondSnapshot(target.GetSnapshot(false));
AssertSecondSnapshot(target.GetSnapshot(false));
}
public void can_records_user_value()
{
var reservoir = new HdrHistogramReservoir(new Recorder(2));
reservoir.Update(2L, "B");
reservoir.Update(1L, "A");
var snapshot = reservoir.GetSnapshot();
snapshot.MinUserValue.Should().Be("A");
snapshot.Min.Should().Be(1L);
snapshot.MaxUserValue.Should().Be("B");
snapshot.Max.Should().Be(2L);
}
public void snap_shot_reflects_what_was_recorded()
{
var reservoir = new HdrHistogramReservoir(new Recorder(2));
for (var i = 0; i < 1000; i++)
{
reservoir.Update(i);
}
var snapshot = reservoir.GetSnapshot();
snapshot.Count.Should().Be(1000);
snapshot.Median.Should().Be(499);
snapshot.Mean.Should().BeApproximately(499, 1);
snapshot.Min.Should().Be(0);
snapshot.Max.Should().Be(999);
snapshot.Size.Should().Be(4608);
snapshot.Percentile75.Should().Be(751);
snapshot.Percentile95.Should().Be(951);
snapshot.Percentile98.Should().Be(979);
snapshot.Percentile99.Should().Be(991);
snapshot.Percentile999.Should().Be(999);
}