Class: Chokepoint::Limiter

Inherits:
Object
  • Object
show all
Defined in:
lib/chokepoint/limiter.rb

Overview

This is the base class for rate limiter implementations.

Examples:

Defining a rate limiter subclass

class MyLimiter < Limiter
  def allowed?(request)
    # TODO: custom logic goes here
  end
end

Direct Known Subclasses

Interval, TimeWindow

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, options = {}) ⇒ Limiter

Returns a new instance of Limiter.

Parameters:

  • name (String)
  • options (Hash{Symbol => Object}) (defaults to: {})

Options Hash (options):

  • :cache (String) — default: Hash.new
  • :key_prefix (String) — default: nil
  • :code (Integer) — default: 403
  • :message (String) — default: "Rate Limit Exceeded" 


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# File 'lib/chokepoint/limiter.rb', line 23

def initialize(name, options = {})
  @name, @options = name, options
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/chokepoint/limiter.rb', line 13

def name
  @name
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/chokepoint/limiter.rb', line 14

def options
  @options
end

Instance Method Details

#allowed?(context = nil) ⇒ Boolean

Returns false if the rate limit has been exceeded for the given request, or true otherwise.

Override this method in subclasses that implement custom rate limiter strategies.

Parameters:

  • context (Object) (defaults to: nil)

Returns:

  • (Boolean) 


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# File 'lib/chokepoint/limiter.rb', line 40

def allowed?(context = nil)
  case
    when whitelisted?(context) then true
    when blacklisted?(context) then false
    else true # override in subclasses
  end
end

#blacklisted?(context) ⇒ Boolean

This method is abstract.

Returns true if the originator of the given request is blacklisted (not honoring rate limits, and thus permanently forbidden access without the need to maintain further rate limit counters).

The default implementation always returns false. Override this method in a subclass to implement custom blacklisting logic.

Parameters:

  • context (Object)

Returns:

  • (Boolean) 


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# File 'lib/chokepoint/limiter.rb', line 73

def blacklisted?(context)
  false
end

#throttle(context = nil) ⇒ Object 



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# File 'lib/chokepoint/limiter.rb', line 27

def throttle(context = nil)
  allowed?(context) ? yield : rate_limit_exceeded(context)
end

#whitelisted?(context) ⇒ Boolean

This method is abstract.

Returns true if the originator of the given request is whitelisted (not subject to further rate limits).

The default implementation always returns false. Override this method in a subclass to implement custom whitelisting logic.

Parameters:

  • context (Object)

Returns:

  • (Boolean) 


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# File 'lib/chokepoint/limiter.rb', line 58

def whitelisted?(context)
  false
end