public void A_TokenBucket_must_work_if_CurrentTime_is_negative()
{
var bucket = new TestBucket(10, 1);
bucket.SetCurrentTime(-100); // Must be set before init()!
bucket.Init();
bucket.Offer(5).ShouldBe(0);
bucket.Offer(10).ShouldBe(5);
bucket.SetCurrentTime(bucket.CurrentTime + 10);
bucket.Offer(5).ShouldBe(0);
}
public void A_TokenBucket_must_work_if_CurrentTime_wraps_over()
{
var bucket = new TestBucket(10, 1);
bucket.SetCurrentTime(long.MaxValue - 5); // Must be set before init()!
bucket.Init();
bucket.Offer(5).ShouldBe(0);
bucket.Offer(10).ShouldBe(5);
bucket.SetCurrentTime(bucket.CurrentTime + 10);
bucket.Offer(5).ShouldBe(0);
}
public void A_TokenBucket_must_allow_sending_elements_larger_than_capacity()
{
var bucket = new TestBucket(10, 2);
bucket.Init();
bucket.Offer(5).ShouldBe(0);
bucket.Offer(20).ShouldBe(30);
bucket.SetCurrentTime(30);
bucket.Offer(1).ShouldBe(2);
bucket.SetCurrentTime(34);
bucket.Offer(1).ShouldBe(0);
bucket.Offer(1).ShouldBe(2);
}
public void A_TokenBucket_must_allow_sending_elements_larger_than_capacity()
{
var bucket = new TestBucket(10, 2);
bucket.Init();
bucket.Offer(5).ShouldBe(0);
bucket.Offer(20).ShouldBe(30);
bucket.SetCurrentTime(30);
bucket.Offer(1).ShouldBe(2);
bucket.SetCurrentTime(34);
bucket.Offer(1).ShouldBe(0);
bucket.Offer(1).ShouldBe(2);
}
public void A_TokenBucket_must_work_with_very_slow_rates()
{
const long t = long.MaxValue >> 10;
var bucket = new TestBucket(10, t);
bucket.Init();
bucket.Offer(20).ShouldBe(10 * t);
bucket.SetCurrentTime(bucket.CurrentTime + 10 * t);
// Collect 5 tokens
bucket.SetCurrentTime(bucket.CurrentTime + 5 * t);
bucket.Offer(4).ShouldBe(0);
bucket.Offer(2).ShouldBe(t);
}
public void A_TokenBucket_must_work_with_zero_capacity()
{
var bucket = new TestBucket(0, 2);
bucket.Init();
bucket.Offer(10).ShouldBe(20);
bucket.SetCurrentTime(40);
bucket.Offer(10).ShouldBe(20);
}
public void A_TokenBucket_must_maintain_equal_time_between_token_renewal_intervals()
{
var bucket = new TestBucket(5, 3);
bucket.Init();
bucket.Offer(10).ShouldBe(15);
bucket.SetCurrentTime(16);
// At this point there is no token in the bucket (we consumed it at T15) but the next token will arrive at T18!
// A naive calculation would consider that there is 1 token needed hence we need to wait 3 units, but in fact
// we only need to wait 2 units, otherwise we shift the whole token arrival sequence resulting in lower rates.
//
// 0 3 9 12 15 18 21 24 27
// +---+---+---+---+---+---+---+---+
// ^ ^
// emitted here --+ +---- currently here (T16)
//
bucket.Offer(1).ShouldBe(2);
bucket.SetCurrentTime(19);
// At 18 bucket is empty, and so is at 19. For a cost of 2 we need to wait until T24 which is 5 units.
//
// 0 3 9 12 15 18 21 24 27
// +---+---+---+---+---+---+---+---+
// ^ ^
// emptied here --+ +---- currently here (T19)
//
bucket.Offer(2).ShouldBe(5);
// Another case
var bucket2 = new TestBucket(10, 3);
bucket2.Init();
bucket2.SetCurrentTime(4);
bucket2.Offer(6).ShouldBe(0);
// 4 tokens remain and new tokens arrive at T6 and T9 so here we have 6 tokens remaining.
// We need 1 more, which will arrive at T12
bucket2.SetCurrentTime(10);
bucket2.Offer(7).ShouldBe(2);
}
public void A_TokenBucket_must_work_with_zero_capacity()
{
var bucket = new TestBucket(0, 2);
bucket.Init();
bucket.Offer(10).ShouldBe(20);
bucket.SetCurrentTime(40);
bucket.Offer(10).ShouldBe(20);
}
public void A_TokenBucket_must_maintain_maximum_capacity()
{
var bucket = new TestBucket(10, 1);
bucket.Init();
bucket.Offer(10).ShouldBe(0);
bucket.SetCurrentTime(100000);
bucket.Offer(20).ShouldBe(10);
}
public void A_TokenBucket_must_not_delay_if_rate_is_higher_than_production()
{
var bucket = new TestBucket(1, 10);
bucket.Init();
for (var time = 0; time <= 100; time += 10)
{
bucket.SetCurrentTime(time);
bucket.Offer(1).ShouldBe(0);
}
}
public void A_TokenBucket_must_calculate_correctly_with_different_rates_and_capacities()
{
var bucketRate2 = new TestBucket(10, 2);
bucketRate2.Init();
bucketRate2.Offer(5).ShouldBe(0);
bucketRate2.Offer(5).ShouldBe(0);
bucketRate2.Offer(5).ShouldBe(10);
var bucketRate3 = new TestBucket(8, 3);
bucketRate3.Init();
bucketRate3.Offer(5).ShouldBe(0);
bucketRate3.Offer(5).ShouldBe(6);
bucketRate3.SetCurrentTime(6);
bucketRate3.Offer(3).ShouldBe(9);
}
public void A_TokenBucket_must_calculate_correctly_with_different_rates_and_capacities()
{
var bucketRate2 = new TestBucket(10, 2);
bucketRate2.Init();
bucketRate2.Offer(5).ShouldBe(0);
bucketRate2.Offer(5).ShouldBe(0);
bucketRate2.Offer(5).ShouldBe(10);
var bucketRate3 = new TestBucket(8, 3);
bucketRate3.Init();
bucketRate3.Offer(5).ShouldBe(0);
bucketRate3.Offer(5).ShouldBe(6);
bucketRate3.SetCurrentTime(6);
bucketRate3.Offer(3).ShouldBe(9);
}
#pragma warning disable 162
public void A_TokenBucket_must_behave_exactly_as_the_ideal_token_bucket_if_offer_is_called_with_perfect_timing()
{
const bool debug = false;
var random = new Random();
foreach (var capacity in new[] {0, 1, 5, 10})
{
foreach (var period in new[] { 1, 3, 5 })
{
foreach (var arrivalPeriod in new[] { 1, 3, 5 })
{
foreach (var startTime in new[] { long.MinValue, -1, 0, long.MaxValue })
{
foreach (var maxCost in new[] { 1, 5, 10 })
{
var bucket = new TestBucket(capacity, period);
bucket.SetCurrentTime(startTime);
bucket.Init();
var idealBucket = capacity;
var untilNextTick = period;
long untilNextElement = random.Next(arrivalPeriod) + 1;
var nextEmit = 0L;
var delaying = false;
for (var time = 0L; time <= 1000; time++)
{
if (untilNextTick == 0)
{
untilNextTick = period;
idealBucket = Math.Min(idealBucket + 1, capacity);
}
if(debug)
_output.WriteLine($"T:{time} bucket:{idealBucket}");
if (delaying && idealBucket == 0)
{
// Actual emit time should equal to what the optimized token bucket calculates
time.ShouldBe(nextEmit);
untilNextElement = time + random.Next(arrivalPeriod);
if(debug)
_output.WriteLine("EMITTING");
delaying = false;
}
if (untilNextElement == 0)
{
//Allow cost of zero
var cost = random.Next(maxCost + 1);
idealBucket -= cost; // This can go negative
bucket.SetCurrentTime(startTime + time);
var delay = bucket.Offer(cost);
nextEmit = time + delay;
if(debug)
_output.WriteLine($"ARRIVAL cost: {cost} at: {nextEmit}");
if (delay == 0)
{
(idealBucket >= 0).ShouldBe(true);
untilNextElement = time + random.Next(arrivalPeriod);
}
else
delaying = true;
}
untilNextTick--;
untilNextElement--;
}
}
}
}
}
}
}
public void A_TokenBucket_must_work_with_very_slow_rates()
{
const long t = long.MaxValue >> 10;
var bucket = new TestBucket(10, t);
bucket.Init();
bucket.Offer(20).ShouldBe(10*t);
bucket.SetCurrentTime(bucket.CurrentTime + 10*t);
// Collect 5 tokens
bucket.SetCurrentTime(bucket.CurrentTime + 5 * t);
bucket.Offer(4).ShouldBe(0);
bucket.Offer(2).ShouldBe(t);
}
public void A_TokenBucket_must_maintain_equal_time_between_token_renewal_intervals()
{
var bucket = new TestBucket(5, 3);
bucket.Init();
bucket.Offer(10).ShouldBe(15);
bucket.SetCurrentTime(16);
// At this point there is no token in the bucket (we consumed it at T15) but the next token will arrive at T18!
// A naive calculation would consider that there is 1 token needed hence we need to wait 3 units, but in fact
// we only need to wait 2 units, otherwise we shift the whole token arrival sequence resulting in lower rates.
//
// 0 3 9 12 15 18 21 24 27
// +---+---+---+---+---+---+---+---+
// ^ ^
// emitted here --+ +---- currently here (T16)
//
bucket.Offer(1).ShouldBe(2);
bucket.SetCurrentTime(19);
// At 18 bucket is empty, and so is at 19. For a cost of 2 we need to wait until T24 which is 5 units.
//
// 0 3 9 12 15 18 21 24 27
// +---+---+---+---+---+---+---+---+
// ^ ^
// emptied here --+ +---- currently here (T19)
//
bucket.Offer(2).ShouldBe(5);
// Another case
var bucket2 = new TestBucket(10, 3);
bucket2.Init();
bucket2.SetCurrentTime(4);
bucket2.Offer(6).ShouldBe(0);
// 4 tokens remain and new tokens arrive at T6 and T9 so here we have 6 tokens remaining.
// We need 1 more, which will arrive at T12
bucket2.SetCurrentTime(10);
bucket2.Offer(7).ShouldBe(2);
}
public void A_TokenBucket_must_work_if_CurrentTime_wraps_over()
{
var bucket = new TestBucket(10, 1);
bucket.SetCurrentTime(long.MaxValue - 5); // Must be set before init()!
bucket.Init();
bucket.Offer(5).ShouldBe(0);
bucket.Offer(10).ShouldBe(5);
bucket.SetCurrentTime(bucket.CurrentTime + 10);
bucket.Offer(5).ShouldBe(0);
}
public void A_TokenBucket_must_work_if_CurrentTime_is_negativ()
{
var bucket = new TestBucket(10, 1);
bucket.SetCurrentTime(-100); // Must be set before init()!
bucket.Init();
bucket.Offer(5).ShouldBe(0);
bucket.Offer(10).ShouldBe(5);
bucket.SetCurrentTime(bucket.CurrentTime + 10);
bucket.Offer(5).ShouldBe(0);
}
#pragma warning disable 162
public void A_TokenBucket_must_behave_exactly_as_the_ideal_token_bucket_if_offer_is_called_with_perfect_timing()
{
const bool debug = false;
var random = new Random();
foreach (var capacity in new[] { 0, 1, 5, 10 })
{
foreach (var period in new[] { 1, 3, 5 })
{
foreach (var arrivalPeriod in new[] { 1, 3, 5 })
{
foreach (var startTime in new[] { long.MinValue, -1, 0, long.MaxValue })
{
foreach (var maxCost in new[] { 1, 5, 10 })
{
var bucket = new TestBucket(capacity, period);
bucket.SetCurrentTime(startTime);
bucket.Init();
var idealBucket = capacity;
var untilNextTick = period;
long untilNextElement = random.Next(arrivalPeriod) + 1;
var nextEmit = 0L;
var delaying = false;
for (var time = 0L; time <= 1000; time++)
{
if (untilNextTick == 0)
{
untilNextTick = period;
idealBucket = Math.Min(idealBucket + 1, capacity);
}
if (debug)
{
_output.WriteLine($"T:{time} bucket:{idealBucket}");
}
if (delaying && idealBucket == 0)
{
// Actual emit time should equal to what the optimized token bucket calculates
time.ShouldBe(nextEmit);
untilNextElement = time + random.Next(arrivalPeriod);
if (debug)
{
_output.WriteLine("EMITTING");
}
delaying = false;
}
if (untilNextElement == 0)
{
//Allow cost of zero
var cost = random.Next(maxCost + 1);
idealBucket -= cost; // This can go negative
bucket.SetCurrentTime(startTime + time);
var delay = bucket.Offer(cost);
nextEmit = time + delay;
if (debug)
{
_output.WriteLine($"ARRIVAL cost: {cost} at: {nextEmit}");
}
if (delay == 0)
{
(idealBucket >= 0).ShouldBe(true);
untilNextElement = time + random.Next(arrivalPeriod);
}
else
{
delaying = true;
}
}
untilNextTick--;
untilNextElement--;
}
}
}
}
}
}
}
public void A_TokenBucket_must_not_delay_if_rate_is_higher_than_production()
{
var bucket = new TestBucket(1, 10);
bucket.Init();
for (var time = 0; time <= 100; time+=10)
{
bucket.SetCurrentTime(time);
bucket.Offer(1).ShouldBe(0);
}
}
public void A_TokenBucket_must_maintain_maximum_capactiy()
{
var bucket = new TestBucket(10, 1);
bucket.Init();
bucket.Offer(10).ShouldBe(0);
bucket.SetCurrentTime(100000);
bucket.Offer(20).ShouldBe(10);
}