Class: FeatureHub::Sdk::Impl::ApplyFeature

Inherits:
Object
  • Object
show all
Defined in:
lib/feature_hub/sdk/impl/apply_features.rb

Overview

full mechanism for applying client side evaluation

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(percent_calculator = nil, matcher_repository = nil) ⇒ ApplyFeature

Returns a new instance of ApplyFeature.



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# File 'lib/feature_hub/sdk/impl/apply_features.rb', line 20

def initialize(percent_calculator = nil, matcher_repository = nil)
  @percentage_calculator = percent_calculator || FeatureHub::Sdk::Impl::Murmur3PercentageCalculator.new
  @matcher_repository = matcher_repository || FeatureHub::Sdk::Impl::MatcherRegistry.new
end

Class Method Details

.determine_percentage_key(context, rsi) ⇒ Object 



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# File 'lib/feature_hub/sdk/impl/apply_features.rb', line 99

def self.determine_percentage_key(context, rsi)
  if rsi.percentage_attributes?
    rsi.percentage_attributes.map { |attr| context.get_attr(attr, "<none>") }.join("$")
  else
    context.default_percentage_key
  end
end

Instance Method Details

#apply(strategies, _key, feature_value_id, context) ⇒ Object 



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# File 'lib/feature_hub/sdk/impl/apply_features.rb', line 25

def apply(strategies, _key, feature_value_id, context)
  return Applied.new(false, nil) if context.nil? || strategies.nil? || strategies.empty?

  percentage = nil
  percentage_key = nil
  base_percentage = {}
  default_percentage_key = context.default_percentage_key

  strategies.each do |rsi|
    if (rsi.percentage != 0) && (!default_percentage_key.nil? || rsi.percentage_attributes?)
      new_percentage_key = ApplyFeature.determine_percentage_key(context, rsi)

      base_percentage[new_percentage_key] = 0 if base_percentage[new_percentage_key].nil?

      base_percentage_val = base_percentage[new_percentage_key]

      if percentage.nil? || new_percentage_key != percentage_key
        percentage_key = new_percentage_key
        percentage = @percentage_calculator.determine_client_percentage(percentage_key, feature_value_id)
        use_base_percentage = rsi.attributes? ? 0 : base_percentage_val

        # rubocop:disable Layout/MultilineOperationIndentation
        if percentage <= (use_base_percentage + rsi.percentage) &&
          (!rsi.attributes? || (rsi.attributes? && match_attribute(context, rsi)))
          return Applied.new(true, rsi.value)
        end

        # rubocop:enable Layout/MultilineOperationIndentation

        unless rsi.attributes?
          base_percentage[percentage_key] =
            base_percentage[percentage_key] + rsi.percentage
        end
      end
    end

    return Applied.new(true, rsi.value) if rsi.percentage.zero? && rsi.attributes? && match_attribute(context,
                                                                                                      rsi)
  end

  Applied.new(false, nil)
end

#match_attribute(context, rs_attr) ⇒ Object 



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# File 'lib/feature_hub/sdk/impl/apply_features.rb', line 68

def match_attribute(context, rs_attr)
  rs_attr.attributes.each do |attr|
    supplied_values = context.get_attr(attr.field_name)
    if supplied_values.empty? && attr.field_name.downcase == "now"
      case attr.field_type
      when "DATE"
        supplied_values = [Time.new.utc.iso8601[0..9]]
      when "DATETIME"
        supplied_values = [Time.new.utc.iso8601]
      end
    end

    if attr.values.nil? && supplied_values.empty?
      return false unless attr.conditional.equals?

      next
    end

    return false if attr.values.nil? || supplied_values.empty?

    # this attribute has to match or we failed
    match = supplied_values.any? do |supplied_value|
      @matcher_repository.find_matcher(attr).match(supplied_value, attr)
    end

    return false unless match
  end

  true
end