public class TokenBucket
extends Object 

• Nested Class Summary

  Nested Classes

  Modifier and Type	Class and Description
  static interface	TokenBucket.Clock

• Constructor Summary

  Constructors

  Constructor and Description
  TokenBucket ()

• Method Summary

  All Methods

  Modifier and Type	Method and Description
  boolean	acquire (double amount) Acquire tokens from the bucket.
  boolean	acquire (double amount, boolean fastFail) Acquire tokens from the bucket.
  void	updateClientSendingRate (boolean throttlingResponse) _UpdateClientSendingRate(response) _UpdateMeasuredRate() if IsThrottlingError(response) if not enabled rate_to_use = measured_tx_rate else rate_to_use = min(measured_tx_rate, fill_rate) # The fill_rate is from the token bucket.

  • Methods inherited from class java.lang.Object

    equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

• Constructor Detail

  • TokenBucket

    public TokenBucket()

• Method Detail

  • acquire

    public boolean acquire(double amount)

    Acquire tokens from the bucket. If the bucket contains enough capacity to satisfy the request, this method will return immediately, otherwise the method will block the calling thread until enough tokens are refilled.

     _TokenBucketAcquire(amount)
     # Client side throttling is not enabled until we see a throttling error.
     if not enabled
     return
     _TokenBucketRefill()
     # Next see if we have enough capacity for the requested amount.
     if amount <= current_capacity current_capacity = current_capacity - amount else sleep((amount - current_capacity) / fill_rate) current_capacity = current_capacity - amount return 

    This is equivalent to acquire(amount, false).

    Parameters:

    amount - The amount of tokens to acquire.

    Returns:

    Whether the amount was successfully acquired.

  • acquire

    public boolean acquire(double amount,
     boolean fastFail)

    Acquire tokens from the bucket. If the bucket contains enough capacity to satisfy the request, this method will return immediately. Otherwise, the behavior depends on the value of fastFail. If it is true, then it will return false immediately, signaling that enough capacity could not be acquired. Otherwise if fastFail is false, then it will wait the required amount of time to fill the bucket with enough tokens to satisfy amount.

     _TokenBucketAcquire(amount)
     # Client side throttling is not enabled until we see a throttling error.
     if not enabled
     return
     _TokenBucketRefill()
     # Next see if we have enough capacity for the requested amount.
     if amount <= current_capacity current_capacity = current_capacity - amount else sleep((amount - current_capacity) / fill_rate) current_capacity = current_capacity - amount return 

    Parameters:

    amount - The amount of tokens to acquire.

    fastFail - Whether this method should return immediately instead of waiting if amount exceeds the current capacity.

    Returns:

    Whether the amount was successfully acquired.

  • updateClientSendingRate

    public void updateClientSendingRate(boolean throttlingResponse)

     _UpdateClientSendingRate(response)
     _UpdateMeasuredRate()
     if IsThrottlingError(response)
     if not enabled
     rate_to_use = measured_tx_rate
     else
     rate_to_use = min(measured_tx_rate, fill_rate)
     # The fill_rate is from the token bucket.
     last_max_rate = rate_to_use
     _CalculateTimeWindow()
     last_throttle_time = time()
     calculated_rate = _CUBICThrottle(rate_to_use)
     TokenBucketEnable()
     else
     _CalculateTimeWindow()
     calculated_rate = _CUBICSuccess(time())
     new_rate = min(calculated_rate, 2 * measured_tx_rate)
     _TokenBucketUpdateRate(new_rate)