/// <summary>
/// Decrease the validator balance at index ``index`` by ``delta``, with underflow protection.
/// </summary>
public void DecreaseBalance(BeaconState state, ValidatorIndex index, Gwei delta)
{
Gwei balance = state.Balances[(int)index];
if (delta > balance)
{
state.SetBalance(index, Gwei.Zero);
}
else
{
Gwei newBalance = balance - delta;
state.SetBalance(index, newBalance);
}
}
/// <summary>
/// Increase the validator balance at index ``index`` by ``delta``.
/// </summary>
public void IncreaseBalance(BeaconState state, ValidatorIndex index, Gwei delta)
{
Gwei balance = state.Balances[(int)index];
Gwei newBalance = balance + delta;
state.SetBalance(index, newBalance);
}
public void EffectiveBalanceHysteresis()
{
// Arrange
IServiceProvider testServiceProvider = TestSystem.BuildTestServiceProvider();
BeaconState state = TestState.PrepareTestState(testServiceProvider);
//# Prepare state up to the final-updates.
//# Then overwrite the balances, we only want to focus to be on the hysteresis based changes.
TestProcessUtility.RunEpochProcessingTo(testServiceProvider, state, TestProcessStep.ProcessFinalUpdates);
GweiValues gweiValues = testServiceProvider.GetService <IOptions <GweiValues> >().Value;
BeaconChainUtility beaconChainUtility = testServiceProvider.GetService <BeaconChainUtility>();
BeaconStateAccessor beaconStateAccessor = testServiceProvider.GetService <BeaconStateAccessor>();
BeaconStateTransition beaconStateTransition = testServiceProvider.GetService <BeaconStateTransition>();
// Set some edge cases for balances
Gwei maximum = gweiValues.MaximumEffectiveBalance;
Gwei minimum = gweiValues.EjectionBalance;
Gwei increment = gweiValues.EffectiveBalanceIncrement;
Gwei halfIncrement = increment / 2;
EffectiveBalanceCase[] testCases = new[] {
new EffectiveBalanceCase(maximum, maximum, maximum, "as-is"),
new EffectiveBalanceCase(maximum, (Gwei)(maximum - 1), maximum - increment, "round down, step lower"),
new EffectiveBalanceCase(maximum, (Gwei)(maximum + 1), maximum, "round down"),
new EffectiveBalanceCase(maximum, (Gwei)(maximum - increment), maximum - increment, "exactly 1 step lower"),
new EffectiveBalanceCase(maximum, (Gwei)(maximum - increment - 1), maximum - (increment * 2), "just 1 over 1 step lower"),
new EffectiveBalanceCase(maximum, (Gwei)(maximum - increment + 1), maximum - increment, "close to 1 step lower"),
new EffectiveBalanceCase(minimum, (Gwei)(minimum + (halfIncrement * 3)), minimum, "bigger balance, but not high enough"),
new EffectiveBalanceCase(minimum, (Gwei)(minimum + (halfIncrement * 3) + 1), minimum + increment, "bigger balance, high enough, but small step"),
new EffectiveBalanceCase(minimum, (Gwei)(minimum + (halfIncrement * 4) - 1), minimum + increment, "bigger balance, high enough, close to double step"),
new EffectiveBalanceCase(minimum, (Gwei)(minimum + (halfIncrement * 4)), minimum + (increment * 2), "exact two step balance increment"),
new EffectiveBalanceCase(minimum, (Gwei)(minimum + (halfIncrement * 4) + 1), minimum + (increment * 2), "over two steps, round down"),
};
Epoch currentEpoch = beaconStateAccessor.GetCurrentEpoch(state);
for (int index = 0; index < testCases.Length; index++)
{
Validator validator = state.Validators[index];
bool isActive = beaconChainUtility.IsActiveValidator(validator, currentEpoch);
isActive.ShouldBeTrue();
EffectiveBalanceCase testCase = testCases[index];
validator.SetEffectiveBalance(testCase.PreEffective);
ValidatorIndex validatorIndex = new ValidatorIndex((ulong)index);
state.SetBalance(validatorIndex, testCase.Balance);
}
// Act
beaconStateTransition.ProcessFinalUpdates(state);
// Assert
for (int index = 0; index < testCases.Length; index++)
{
EffectiveBalanceCase testCase = testCases[index];
Validator validator = state.Validators[index];
validator.EffectiveBalance.ShouldBe(testCase.PostEffective, testCase.Name);
}
}