Class: Ihasa::Bucket

Inherits:
Object
  • Object
show all
Defined in:
lib/ihasa/bucket.rb

Overview

Bucket class. That bucket fills up to burst, by rate per second. Each accept? or accept?! call decrement it from 1.

Defined Under Namespace

Classes: EmptyBucket, Implementation, LegacyImplementation, RedisNamespaceSetupError

Constant Summary collapse

REDIS_VERSION_WITH_REPLICATE_COMMANDS_SUPPORT = 
3.2
SETUP_ADVICE = 
'Ensure that the method '\
'Ihasa::Bucket#save was called.'.freeze
SETUP_ERROR = 
('Redis raised an error: %{msg}. ' + SETUP_ADVICE).freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(rate, burst, prefix, redis) ⇒ Bucket

Returns a new instance of Bucket.



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# File 'lib/ihasa/bucket.rb', line 25

def initialize(rate, burst, prefix, redis)
  @implementation =
    if self.class.legacy_mode?(redis)
      require 'ihasa/bucket/legacy_implementation'
      LegacyImplementation.instance
    else
      require 'ihasa/bucket/implementation'
      Implementation.instance
    end
  @prefix = prefix
  @keys = Ihasa::OPTIONS.map { |opt| "#{prefix}:#{opt.upcase}" }
  @redis = redis
  @rate = Float rate
  @burst = Float burst
end

Instance Attribute Details

#burst ⇒ Object (readonly)

Returns the value of attribute burst.



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# File 'lib/ihasa/bucket.rb', line 24

def burst
  @burst
end

#keys ⇒ Object (readonly)

Returns the value of attribute keys.



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# File 'lib/ihasa/bucket.rb', line 24

def keys
  @keys
end

#prefix ⇒ Object (readonly)

Returns the value of attribute prefix.



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# File 'lib/ihasa/bucket.rb', line 24

def prefix
  @prefix
end

#rate ⇒ Object (readonly)

Returns the value of attribute rate.



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# File 'lib/ihasa/bucket.rb', line 24

def rate
  @rate
end

#redis ⇒ Object (readonly)

Returns the value of attribute redis.



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# File 'lib/ihasa/bucket.rb', line 24

def redis
  @redis
end

Class Method Details

.create(*args) ⇒ Object 



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# File 'lib/ihasa/bucket.rb', line 7

def create(*args)
  new(*args).tap(&:save)
end

.legacy_mode?(redis) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ihasa/bucket.rb', line 13

def legacy_mode?(redis)
  redis_version(redis) < REDIS_VERSION_WITH_REPLICATE_COMMANDS_SUPPORT
end

Instance Method Details

#accept! ⇒ Object

Raises:



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# File 'lib/ihasa/bucket.rb', line 56

def accept!
  result = (block_given? ? accept?(&Proc.new) : accept?)
  raise EmptyBucket, "Bucket #{prefix} throttle limit" unless result
  result
end

#accept? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ihasa/bucket.rb', line 46

def accept?
  result = @implementation.accept?(self) == OK
  return yield if result && block_given?
  result
rescue Redis::CommandError => e
  raise RedisNamespaceSetupError, SETUP_ERROR % { msg: e.message }
end

#delete ⇒ Object 



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# File 'lib/ihasa/bucket.rb', line 66

def delete
  redis.del(keys)
end

#save ⇒ Object 



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# File 'lib/ihasa/bucket.rb', line 62

def save
  @implementation.save(self)
end