public void Construct_WithClockAndEpoch_ShouldUseThose()
{
var factory = new FluidIdGenerator(isProduction: false, Clock, ApplicationInstanceId, epoch: Epoch, BitDistribution);
var fluid = factory.CreateFluid();
Assert.Equal(GetMilliseconds(ClockValue, factory.Epoch), GetMilliseconds(fluid));
}
public void Construct_WithApplicationInstanceId_ShouldUseThatValue()
{
var factory = new FluidIdGenerator(isProduction: false, FluidIdGenerator.GetUtcNow, applicationInstanceId: ApplicationInstanceId, bitDistribution: BitDistribution);
var fluid = factory.CreateFluid();
Assert.Equal(ApplicationInstanceId, GetApplicationInstanceId(fluid));
}
public void GetUtcNow_WhenInvoked_ShouldReturnUtcNow()
{
var getUtcNowResult = FluidIdGenerator.GetUtcNow();
var utcNow = DateTime.UtcNow;
Assert.True((utcNow - getUtcNowResult) < TimeSpan.FromMilliseconds(1000));
}
public void CreateFluid_TheFirstTime_ShouldUseCounterValue0()
{
var factory = new FluidIdGenerator(isProduction: false, Clock, ApplicationInstanceId, epoch: Epoch, BitDistribution);
var fluid = factory.CreateFluid();
Assert.Equal(0UL, GetCounterValue(fluid));
}
public void GetMillisecondsSinceEpoch_Regularly_ShouldReturnExpectedValue()
{
var factory = new FluidIdGenerator(isProduction: false,
utcClock: () => new DateTime(2020, 01, 01, 0, 0, 0, millisecond: 1, DateTimeKind.Utc),
ApplicationInstanceId,
epoch: new DateTime(2020, 01, 01, 0, 0, 0, DateTimeKind.Utc));
var milliseconds = factory.GetMillisecondsSinceEpoch();
Assert.Equal(1UL, milliseconds);
}
public void Construct_WithClock_ShouldUseThat()
{
var clockValue = FluidIdGenerator.DefaultEpoch;
DateTime FixedClock() => clockValue;
var factory = new FluidIdGenerator(isProduction: false, FixedClock, applicationInstanceId: ApplicationInstanceId, bitDistribution: BitDistribution);
var fluid = factory.CreateFluid();
Assert.Equal(GetMilliseconds(clockValue, factory.Epoch), GetMilliseconds(fluid));
}
private static IIdGenerator CreateIdGenerator(InvocationDetector invocationDetector)
{
return(new FluidIdGenerator(isProduction: false, utcClock: GetUtcNow, applicationInstanceId: 1));
// Local function that acts as the UTC clock and also toggles a ref bool
DateTime GetUtcNow()
{
invocationDetector.WasInvoked = true;
return(FluidIdGenerator.GetUtcNow());
}
}
public void CreateFluid_TwiceWithAdvancingTimestamps_ShouldCount0Twice()
{
var invocationCount = 0;
DateTime AutoAdvancingClock() => Epoch.AddMilliseconds(invocationCount++);
var factory = new FluidIdGenerator(isProduction: false, utcClock: AutoAdvancingClock, ApplicationInstanceId, epoch: Epoch, BitDistribution);
var fluid1 = factory.CreateFluid();
var fluid2 = factory.CreateFluid();
Assert.Equal(0UL, GetCounterValue(fluid1));
Assert.Equal(0UL, GetCounterValue(fluid2));
}
public void CreateFluid_Regularly_ShouldCreateExpectedValue()
{
var factory = new FluidIdGenerator(isProduction: false, Clock, ApplicationInstanceId, Epoch, BitDistribution);
var fluid = factory.CreateFluid();
Debug.Assert((ulong)(ClockValue - Epoch).TotalMilliseconds == 1);
var milliseconds = 1UL << BitDistribution.ApplicationInstanceIdBitCount << BitDistribution.CounterBitCount;
var applicationInstanceId = (ulong)ApplicationInstanceId << BitDistribution.CounterBitCount;
const ulong counterValue = 0;
var expectedValue = milliseconds | applicationInstanceId | counterValue;
Assert.Equal(expectedValue, (ulong)fluid);
}
public void CreateFluid_With10CounterBitsAnd1024Calls_ShouldCountUpTo1023()
{
Debug.Assert(BitDistribution.CounterBitCount == 10);
// Timestamp advances after 1024 invocations
var counter = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: () => Epoch.AddMilliseconds(counter++ >= 1024 ? 2 : 1), ApplicationInstanceId, epoch: Epoch, BitDistribution);
counter = 0; // Reset from initial internal call
for (var i = 0UL; i < 1024; i++)
{
Assert.Equal(i, GetCounterValue(factory.CreateFluid()));
}
}
public void CreateFluid_With10CounterBitsAnd1025Calls_ShouldSleepNoMoreThan1Second()
{
Debug.Assert(BitDistribution.CounterBitCount == 10);
var sleepMs = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: () => Epoch.AddMilliseconds(sleepMs == 0 ? 1 : 2), ApplicationInstanceId, epoch: Epoch, BitDistribution,
sleepAction: ms => sleepMs += ms);
for (var i = 0; i < 1025; i++)
{
factory.CreateFluid();
}
Assert.True(sleepMs <= 1000);
}
public void CreateFluid_With10CounterBitsAnd1024Calls_ShouldNotSleep()
{
Debug.Assert(BitDistribution.CounterBitCount == 10);
var sleepCount = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: () => Epoch.AddMilliseconds(sleepCount == 0 ? 1 : 2), ApplicationInstanceId, epoch: Epoch, BitDistribution,
sleepAction: ms => sleepCount++);
for (var i = 0; i < 1024; i++)
{
factory.CreateFluid();
}
Assert.Equal(0, sleepCount);
}
public void CreateFluid_With10CounterBitsAnd1025CallsAndStuckClock_ShouldThrowOnLastCall()
{
Debug.Assert(BitDistribution.CounterBitCount == 10);
var sleepMs = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: () => Epoch.AddDays(1), ApplicationInstanceId, epoch: Epoch, BitDistribution,
sleepAction: ms => sleepMs += ms);
for (var i = 0; i < 1024; i++)
{
factory.CreateFluid();
}
Assert.Throws <TimeoutException>(() => factory.CreateFluid());
}
public void CreateFluid_TwiceWithRewindingClockMoreThanMaxAllowedMilliseconds_ShouldThrow()
{
var invocationCount = 0UL;
DateTime AutorewindingClock() =>
Epoch.AddDays(1).AddMilliseconds(++invocationCount == 2 ? 0 : (1UL + FluidIdGenerator.MaxClockCatchupSleepMilliseconds) * invocationCount); // E.g. +2001, 0, +4002, +6003, ...
var sleepMs = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: AutorewindingClock, ApplicationInstanceId, epoch: Epoch, BitDistribution,
sleepAction: ms => sleepMs += ms);
invocationCount = 0; // Reset the clock
factory.CreateFluid();
Assert.Throws <TimeoutException>(() => factory.CreateFluid());
}
public void CreateFluid_TwiceWithRewindingClock1Second_ShouldSleep1Second()
{
var invocationCount = 0;
DateTime AutorewindingClock() => Epoch.AddDays(1).AddSeconds(++invocationCount == 2 ? 0 : invocationCount); // +1, 0, +2, +3, +4, ...
var sleepMs = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: AutorewindingClock, ApplicationInstanceId, epoch: Epoch, BitDistribution,
sleepAction: ms => sleepMs += ms);
invocationCount = 0; // Reset the clock
factory.CreateFluid();
factory.CreateFluid();
Assert.Equal(1000, sleepMs); // We would need a minute to catch up, but will never sleep for more than a second
}
public void CreateFluid_TwiceWithRewindingClockMaxAllowedMilliseconds_ShouldSleepThatLong()
{
var invocationCount = 0UL;
DateTime AutorewindingClock() =>
Epoch.AddDays(1).AddMilliseconds(++invocationCount == 2 ? 0 : FluidIdGenerator.MaxClockCatchupSleepMilliseconds * invocationCount); // E.g. +2000, 0, +4000, +6000, ...
var sleepMs = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: AutorewindingClock, ApplicationInstanceId, epoch: Epoch, BitDistribution,
sleepAction: ms => sleepMs += ms);
invocationCount = 0; // Reset the clock
factory.CreateFluid();
factory.CreateFluid();
Assert.Equal(FluidIdGenerator.MaxClockCatchupSleepMilliseconds, (ulong)sleepMs);
}
public void CreateFluid_With10CounterBitsAnd1026Calls_ShouldCount0And1OnTheLastTwoCalls()
{
Debug.Assert(BitDistribution.CounterBitCount == 10);
// Timestamp advances after 1024 invocations
var counter = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: () => Epoch.AddMilliseconds(counter++ >= 1024 ? 2 : 1), ApplicationInstanceId, epoch: Epoch, BitDistribution);
counter = 0;
for (var i = 0UL; i < 1024; i++)
{
factory.CreateFluid();
}
var fluid1024 = factory.CreateFluid();
var fluid1025 = factory.CreateFluid();
Assert.Equal(0UL, GetCounterValue(fluid1024));
Assert.Equal(1UL, GetCounterValue(fluid1025));
}
public void CreateFluid_With10CounterBitsAnd1025CallsAndTemporarilyStuckClock_ShouldSleep1Millisecond()
{
Debug.Assert(BitDistribution.CounterBitCount == 10);
var i = 0;
var lastI = 0;
var clockMilliseconds = 0;
DateTime StuckClockUnlesInvokedAgainBySameIteration() => Epoch.AddMilliseconds(clockMilliseconds += i == lastI ? 1 : (lastI = i) - i); // Advances only when invoked multiple times by same iteration
var sleepMs = 0;
var factory = new FluidIdGenerator(isProduction: false, utcClock: StuckClockUnlesInvokedAgainBySameIteration, ApplicationInstanceId, epoch: Epoch, BitDistribution,
sleepAction: ms => sleepMs += ms);
for (i = 0; i < 1025; i++)
{
factory.CreateFluid();
}
Assert.Equal(1, sleepMs);
}
public void CreateFluid_WithClockThrowingOnSecondInvocationForOneFluid_ShouldNotChangeCounter()
{
var invocationCount = 0;
DateTime ClockThatThrowsOnThirdInvocation()
{
if (++invocationCount == 3)
{
throw new Exception("Deliberately throws on third invocation.");
}
return(ClockValue);
}
var factory = new FluidIdGenerator(isProduction: false, ClockThatThrowsOnThirdInvocation, ApplicationInstanceId, Epoch, BitDistribution);
factory.CreateFluid(); // Ensure that a "previous timestamp" was registered
Assert.Throws <Exception>(() => factory.CreateFluid()); // This one throws
var fluid = factory.CreateFluid(); // This one's counter value should not have been affected by the throwing invocation
Assert.Equal(1UL, GetCounterValue(fluid));
}
public void Construct_WithBitDistribution_ShouldDistributeBitsAsExpected()
{
var factory = new FluidIdGenerator(isProduction: false, FluidIdGenerator.GetUtcNow, ApplicationInstanceId, bitDistribution: BitDistribution);
var maxTimestamp = (ulong)(FluidIdGenerator.DefaultEpoch.AddMilliseconds((1UL << FluidBitDistribution.Default.TimestampBitCount) - 1) - FluidIdGenerator.DefaultEpoch).TotalMilliseconds;
var timestampPartial = factory.GetTimestampPartialFluid(maxTimestamp);
var applicationInstanceIdPartial = factory.GetApplicationInstanceIdPartialFluid();
var counterValuePartial = factory.GetCounterValuePartialFluid(2UL);
var timestampMask = BitDistribution.MaxTimestamp << BitDistribution.ApplicationInstanceIdBitCount << BitDistribution.CounterBitCount;
Assert.Equal(0UL, timestampPartial & ~timestampMask);
Assert.Equal(maxTimestamp, timestampPartial >> BitDistribution.ApplicationInstanceIdBitCount >> BitDistribution.CounterBitCount);
var applicationInstanceIdMask = BitDistribution.MaxApplicationInstanceId << BitDistribution.CounterBitCount;
Assert.Equal(0UL, applicationInstanceIdPartial & ~applicationInstanceIdMask);
Assert.Equal(ApplicationInstanceId, applicationInstanceIdPartial >> BitDistribution.CounterBitCount);
var counterMask = BitDistribution.MaxCounterValue;
Assert.Equal(0UL, counterValuePartial & ~counterMask);
Assert.Equal(2UL, counterValuePartial);
}
public void Construct_WithZeroApplicationInstanceIdOutsideProduction_ShouldSucceed()
{
_ = new FluidIdGenerator(isProduction: false, FluidIdGenerator.GetUtcNow, applicationInstanceId: 0);
}
