Class: EppoClient::Client

Inherits:
Object
  • Object
show all
Includes:
Singleton
Defined in:
lib/client.rb

Overview

The main client singleton

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#assignment_logger ⇒ Object

Returns the value of attribute assignment_logger.



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# File 'lib/client.rb', line 16

def assignment_logger
  @assignment_logger
end

#config_requestor ⇒ Object

Returns the value of attribute config_requestor.



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# File 'lib/client.rb', line 16

def config_requestor
  @config_requestor
end

#poller ⇒ Object

Returns the value of attribute poller.



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# File 'lib/client.rb', line 16

def poller
  @poller
end

Instance Method Details

#get_assignment(subject_key, flag_or_experiment_key, subject_attributes = {}) ⇒ Object

rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/MethodLength, Metrics/PerceivedComplexity



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# File 'lib/client.rb', line 23

def get_assignment(subject_key, flag_or_experiment_key, subject_attributes = {})
  EppoClient.validate_not_blank('subject_key', subject_key)
  EppoClient.validate_not_blank('flag_or_experiment_key', flag_or_experiment_key)
  experiment_config = @config_requestor.get_configuration(flag_or_experiment_key)
  override = get_subject_variation_override(experiment_config, subject_key)
  return override unless override.nil?

  if experiment_config.nil? || experiment_config.enabled == false
    EppoClient.logger('out').info(
      "[Eppo SDK] No assigned variation. No active experiment or flag for key: #{flag_or_experiment_key}"
    )
    return nil
  end

  matched_rule = EppoClient.find_matching_rule(subject_attributes, experiment_config.rules)
  if matched_rule.nil?
    EppoClient.logger('out').info(
      "[Eppo SDK] No assigned variation. Subject attributes do not match targeting rules: #{subject_attributes}"
    )
    return nil
  end

  allocation = experiment_config.allocations[matched_rule.allocation_key]
  unless in_experiment_sample?(
    subject_key,
    flag_or_experiment_key,
    experiment_config.subject_shards,
    allocation.percent_exposure
  )
    EppoClient.logger('out').info(
      '[Eppo SDK] No assigned variation. Subject is not part of experiment sample population'
    )
    return nil
  end

  shard = EppoClient.get_shard("assignment-#{subject_key}-#{flag_or_experiment_key}", experiment_config.subject_shards)
  assigned_variation = allocation.variations.find { |var| var.shard_range.shard_in_range?(shard) }.value

  assignment_event = {
    "experiment": flag_or_experiment_key,
    "variation": assigned_variation,
    "subject": subject_key,
    "timestamp": Time.now.utc.iso8601,
    "subjectAttributes": subject_attributes
  }

  begin
    @assignment_logger.log_assignment(assignment_event)
  rescue EppoClient::AssignmentLoggerError => e
    # This error means that log_assignment was not set up. This is okay to ignore.
  rescue StandardError => e
    EppoClient.logger('err').info("[Eppo SDK] Error logging assignment event: #{e}")
  end

  assigned_variation
end

#get_subject_variation_override(experiment_config, subject) ⇒ Object 



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# File 'lib/client.rb', line 85

def get_subject_variation_override(experiment_config, subject)
  subject_hash = Digest::MD5.hexdigest(subject.to_s)
  experiment_config&.overrides && experiment_config.overrides[subject_hash]
end

#in_experiment_sample?(subject, experiment_key, subject_shards, percent_exposure) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/client.rb', line 90

def in_experiment_sample?(subject, experiment_key, subject_shards, percent_exposure)
  shard = EppoClient.get_shard("exposure-#{subject}-#{experiment_key}", subject_shards)
  shard <= percent_exposure * subject_shards
end

#instance ⇒ Object 



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# File 'lib/client.rb', line 18

def instance
  Client.instance
end

#shutdown ⇒ Object

rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/MethodLength, Metrics/PerceivedComplexity



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# File 'lib/client.rb', line 81

def shutdown
  @poller.stop
end