Class: RateLimit::Htb::Bucket

Inherits:
Object
  • Object
show all
Defined in:
lib/rate_limit/htb.rb

Instance Method Summary collapse

Constructor Details

#initialize(rate, parent = nil) ⇒ Bucket

Attributes

  • rate - Amount of tokens generated every second.

  • parent - Parent of this bucket. Any tokens taken from this bucket will also be taken from parent. When a parent is specified the rate of this bucket will be between the rate of this bucket and the rate of the parent. The parent bucket should have a larger rate than their children.



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# File 'lib/rate_limit/htb.rb', line 54

def initialize(rate, parent = nil)
  @lock = Monitor.new
  @rate = rate || 0
  @bucket_size = rate
  @parent = parent
  @tokens = rate
  @last_update_timestamp = Time.now
end

Instance Method Details

#blocking_take(amount) ⇒ Object

This method takes the specified amount of tokens from the bucket and blocks execution until it was successful.

This method tries to be smart about the amount of time it waits. It will wait the minimum time it takes to replenish enough tokens.



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# File 'lib/rate_limit/htb.rb', line 86

def blocking_take(amount)
  # Try to take amount tokens from this bucket or wait for the tokens to replenish
  # do this until we could get the amount of tokens we wanted
  until take amount
    duration = amount.to_f / rate # rate is a method
    #puts "sleeping for #{duration}"
    sleep duration
  end
end

#take(amount) ⇒ Object

Take the specified amount of tokens from this bucket

If you want your code to block execution until it could take the specified amount of tokens use #blocking_take instead.

  • Returns :

    • true if the amount of tokens could be taken from this bucket or a parent.



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# File 'lib/rate_limit/htb.rb', line 70

def take(amount)
  @lock.synchronize do
    replenish

    could_take = can_take? amount
     amount if could_take

    could_take
  end
end