Class: Flipper::Adapters::Memoizable

Inherits:
SimpleDelegator
  • Object
show all
Includes:
Flipper::Adapter
Defined in:
lib/flipper/adapters/memoizable.rb

Overview

Internal: Adapter that wraps another adapter with the ability to memoize adapter calls in memory. Used by flipper dsl and the memoizer middleware to make it possible to memoize adapter calls for the duration of a request.

Constant Summary collapse

FeaturesKey = 
:flipper_features
GetAllKey = 
:all_memoized

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Flipper::Adapter

#default_config, #import, included

Constructor Details

#initialize(adapter, cache = nil) ⇒ Memoizable

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 29

def initialize(adapter, cache = nil)
  super(adapter)
  @adapter = adapter
  @name = :memoizable
  @cache = cache || {}
  @memoize = false
end

Instance Attribute Details

#adapter ⇒ Object (readonly)

Internal: The adapter this adapter is wrapping.



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# File 'lib/flipper/adapters/memoizable.rb', line 21

def adapter
  @adapter
end

#cache ⇒ Object (readonly)

Internal



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# File 'lib/flipper/adapters/memoizable.rb', line 15

def cache
  @cache
end

#name ⇒ Object (readonly)

Public: The name of the adapter.



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# File 'lib/flipper/adapters/memoizable.rb', line 18

def name
  @name
end

Class Method Details

.key_for(key) ⇒ Object

Private



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# File 'lib/flipper/adapters/memoizable.rb', line 24

def self.key_for(key)
  "feature/#{key}"
end

Instance Method Details

#add(feature) ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 47

def add(feature)
  result = @adapter.add(feature)
  expire_features_set
  result
end

#clear(feature) ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 62

def clear(feature)
  result = @adapter.clear(feature)
  expire_feature(feature)
  result
end

#disable(feature, gate, thing) ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 133

def disable(feature, gate, thing)
  result = @adapter.disable(feature, gate, thing)
  expire_feature(feature)
  result
end

#enable(feature, gate, thing) ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 126

def enable(feature, gate, thing)
  result = @adapter.enable(feature, gate, thing)
  expire_feature(feature)
  result
end

#features ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 38

def features
  if memoizing?
    cache.fetch(FeaturesKey) { cache[FeaturesKey] = @adapter.features }
  else
    @adapter.features
  end
end

#get(feature) ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 69

def get(feature)
  if memoizing?
    cache.fetch(key_for(feature.key)) { cache[key_for(feature.key)] = @adapter.get(feature) }
  else
    @adapter.get(feature)
  end
end

#get_all ⇒ Object 



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# File 'lib/flipper/adapters/memoizable.rb', line 99

def get_all
  if memoizing?
    response = nil
    if cache[GetAllKey]
      response = {}
      cache[FeaturesKey].each do |key|
        response[key] = cache[key_for(key)]
      end
    else
      response = @adapter.get_all
      response.each do |key, value|
        cache[key_for(key)] = value
      end
      cache[FeaturesKey] = response.keys.to_set
      cache[GetAllKey] = true
    end

    # Ensures that looking up other features that do not exist doesn't
    # result in N+1 adapter calls.
    response.default_proc = ->(memo, key) { memo[key] = default_config }
    response
  else
    @adapter.get_all
  end
end

#get_multi(features) ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 78

def get_multi(features)
  if memoizing?
    uncached_features = features.reject { |feature| cache[key_for(feature.key)] }

    if uncached_features.any?
      response = @adapter.get_multi(uncached_features)
      response.each do |key, hash|
        cache[key_for(key)] = hash
      end
    end

    result = {}
    features.each do |feature|
      result[feature.key] = cache[key_for(feature.key)]
    end
    result
  else
    @adapter.get_multi(features)
  end
end

#memoize=(value) ⇒ Object

Internal: Turns local caching on/off.

value - The Boolean that decides if local caching is on.



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# File 'lib/flipper/adapters/memoizable.rb', line 142

def memoize=(value)
  cache.clear
  @memoize = value
end

#memoizing? ⇒ Boolean

Internal: Returns true for using local cache, false for not.

Returns:

  • (Boolean) 


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# File 'lib/flipper/adapters/memoizable.rb', line 148

def memoizing?
  !!@memoize
end

#remove(feature) ⇒ Object

Public



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# File 'lib/flipper/adapters/memoizable.rb', line 54

def remove(feature)
  result = @adapter.remove(feature)
  expire_features_set
  expire_feature(feature)
  result
end