ATAS.DataFeedsCore.RequestLimiter Class Reference

Token bucket bounding the rate of requests sent to a broker: Capacity is the largest burst allowed at once, RefillPerSecond the sustained ceiling. The bucket starts full, refills continuously (fractional tokens) and never accumulates more than Capacity. Refill is computed from a TimeProvider on demand, so the limiter owns no timer and no background thread and is fully testable with a fake time provider. More...

Public Member Functions
	RequestLimiter (int capacity, double refillPerSecond, TimeProvider? timeProvider=null)
	Creates a full bucket.
bool	TryTake (int tokens=1)
	Takes tokens tokens if the bucket holds enough, atomically.
TimeSpan	GetWaitTime (int tokens=1)
	How long to wait before TryTake of the same amount can succeed, assuming nobody else takes tokens meanwhile. Takes nothing itself.
async Task	WaitAsync (int tokens=1, CancellationToken cancellationToken=default)
	Waits until tokens tokens could be taken and takes them. Not fair - see the remarks on the class.
void	Reset ()
	Fills the bucket again, dropping the accumulated debt. Used when the state the limiter protects is gone (connector disconnect), not as a way around the budget.

Properties
int	Capacity [get]
	Bucket size: the number of tokens available at once after an idle period, and the largest amount a single TryTake may ask for.
double	RefillPerSecond [get]
	Tokens added per second, fractional. Together with Capacity it defines the sustained request ceiling.
double	AvailableTokens [get]
	Tokens available at this moment, refill included. Fractional and immediately stale; meant for tests and telemetry, not for deciding whether a request may be sent - use TryTake for that.

Detailed Description

Token bucket bounding the rate of requests sent to a broker: Capacity is the largest burst allowed at once, RefillPerSecond the sustained ceiling. The bucket starts full, refills continuously (fractional tokens) and never accumulates more than Capacity. Refill is computed from a TimeProvider on demand, so the limiter owns no timer and no background thread and is fully testable with a fake time provider.

Every member is thread-safe. WaitAsync is a plain retry loop and does not queue its callers: waiters are not served in arrival order and a caller asking for many tokens can be overtaken by a caller asking for one. That is intentional - the only waiter is the single option subscription pump of one connector (PLAT-5011), and a fair queue would be dead weight; the connector-level OptionRequestGuard only calls TryTake. A future consumer with several concurrent waiters must not rely on fairness here.

Constructor & Destructor Documentation

RequestLimiter()

ATAS.DataFeedsCore.RequestLimiter.RequestLimiter	(	int	capacity,
		double	refillPerSecond,
		TimeProvider?	timeProvider = null
	)

Creates a full bucket.

Parameters

capacity	Bucket size in tokens, at least 1.
refillPerSecond	Tokens added per second, greater than 0.
timeProvider	Time source; TimeProvider.System when omitted.

Member Function Documentation

GetWaitTime()

TimeSpan ATAS.DataFeedsCore.RequestLimiter.GetWaitTime

(

int

tokens = 1

)

How long to wait before TryTake of the same amount can succeed, assuming nobody else takes tokens meanwhile. Takes nothing itself.

Parameters

tokens

Tokens to account for, within [1; Capacity].

Returns

TimeSpan.Zero when the bucket already holds enough.

Reset()

void ATAS.DataFeedsCore.RequestLimiter.Reset

(

)

Fills the bucket again, dropping the accumulated debt. Used when the state the limiter protects is gone (connector disconnect), not as a way around the budget.

TryTake()

bool ATAS.DataFeedsCore.RequestLimiter.TryTake

(

int

tokens = 1

)

Takes tokens tokens if the bucket holds enough, atomically.

Parameters

tokens

Tokens to take, within [1; Capacity].

Returns

true when the tokens were taken, false when the bucket is short.

WaitAsync()

async Task ATAS.DataFeedsCore.RequestLimiter.WaitAsync	(	int	tokens = 1,
		CancellationToken	cancellationToken = default
	)

Waits until tokens tokens could be taken and takes them. Not fair - see the remarks on the class.

Parameters

tokens	Tokens to take, within [1; Capacity].
cancellationToken	Cancels the wait; no tokens are taken then.

Property Documentation

AvailableTokens

double ATAS.DataFeedsCore.RequestLimiter.AvailableTokens

get

Tokens available at this moment, refill included. Fractional and immediately stale; meant for tests and telemetry, not for deciding whether a request may be sent - use TryTake for that.

Capacity

int ATAS.DataFeedsCore.RequestLimiter.Capacity

get

Bucket size: the number of tokens available at once after an idle period, and the largest amount a single TryTake may ask for.

RefillPerSecond

double ATAS.DataFeedsCore.RequestLimiter.RefillPerSecond

get

Tokens added per second, fractional. Together with Capacity it defines the sustained request ceiling.

---

The documentation for this class was generated from the following file:

• RequestLimiter.cs