Class: Trevosdk::Client

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

Overview

Server client: deterministic assignment and event tracking for any Ruby runtime.

Evaluation reads an immutable config snapshot and never touches the network, so calls are safe from Rails controllers, Sidekiq jobs, and scripts alike.

Constant Summary collapse

EXPOSURE_EVENT = 
"$experiment_exposure"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(secret_key, bootstrap_config: nil, config_url: CONFIG_URL, ingestion_url: INGESTION_URL, alias_url: nil, poll_interval_s: DEFAULT_POLL_INTERVAL_S, flush_interval_s: DEFAULT_FLUSH_INTERVAL_S, max_batch_size: DEFAULT_MAX_BATCH_SIZE, force_variants: nil, transport: nil, on_error: nil) ⇒ Client

Returns a new instance of Client.

Raises:

  • (ArgumentError) 


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# File 'lib/trevosdk/client.rb', line 20

def initialize(secret_key, bootstrap_config: nil, config_url: CONFIG_URL,
  ingestion_url: INGESTION_URL, alias_url: nil,
  poll_interval_s: DEFAULT_POLL_INTERVAL_S, flush_interval_s: DEFAULT_FLUSH_INTERVAL_S,
  max_batch_size: DEFAULT_MAX_BATCH_SIZE, force_variants: nil,
  transport: nil, on_error: nil)
  raise ArgumentError, "Trevosdk::Client requires a secret_key" if secret_key.to_s.empty?
  if !bootstrap_config.nil? && !bootstrap_config.is_a?(Array)
    raise ArgumentError,
      "bootstrap_config must be an array of experiment configs — pass " \
      'response["experiments"], not the whole config response'
  end

  @secret_key = secret_key
  @transport = transport || DEFAULT_TRANSPORT
  @on_error = on_error || ->(error) { warn("[Trevo] #{error.message}") }
  @alias_url = alias_url || self.class.derive_alias_url(ingestion_url)

  @experiments = (bootstrap_config || []).to_h { |config| [config["experimentKey"], config] }
  @exposures = ExposureDeduper.new(SERVER_EXPOSURE_DEDUP_MAX_KEYS)
  @exposures_mutex = Mutex.new
  @forced = self.class.parse_force_variants(ENV[FORCE_VARIANTS_ENV])
    .merge((force_variants || {}).transform_keys(&:to_s))

  @batcher = EventBatcher.new(
    ingestion_url: ingestion_url,
    secret_key: secret_key,
    max_batch_size: [1, max_batch_size].max,
    flush_interval_s: [MIN_FLUSH_INTERVAL_S, flush_interval_s].max,
    transport: @transport,
    on_error: @on_error
  )
  @poller = ConfigPoller.new(
    config_url: config_url,
    secret_key: secret_key,
    interval_s: [MIN_POLL_INTERVAL_S, poll_interval_s].max,
    transport: @transport,
    on_config: ->(configs) { swap_config(configs) },
    on_error: @on_error
  )

  @start_mutex = Mutex.new
  @started = false
  @closed = false
end

Class Method Details

.derive_alias_url(ingestion_url) ⇒ Object

Alias lives on the same service as events, so an ingestion override must move alias too.



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# File 'lib/trevosdk/client.rb', line 66

def self.derive_alias_url(ingestion_url)
  return ALIAS_URL if ingestion_url == INGESTION_URL
  trimmed = ingestion_url.sub(%r{/+\z}, "")
  return "#{trimmed.delete_suffix("/events")}/alias" if trimmed.end_with?("/events")
  ALIAS_URL
end

.parse_force_variants(raw) ⇒ Object 



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# File 'lib/trevosdk/client.rb', line 73

def self.parse_force_variants(raw)
  return {} if raw.nil? || raw.empty?
  raw.split(",").each_with_object({}) do |pair, parsed|
    separator = pair.index(":")
    next if separator.nil? || separator.zero? || separator == pair.length - 1
    key = pair[...separator].strip
    variant = pair[(separator + 1)..].strip
    parsed[key] = variant unless key.empty? || variant.empty?
  end
end

Instance Method Details

#alias(anonymous_id, user_id) ⇒ Object 



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# File 'lib/trevosdk/client.rb', line 124

def alias(anonymous_id, user_id)
  ensure_started
  if anonymous_id.to_s.empty? || user_id.to_s.empty?
    raise ArgumentError, "alias requires both an anonymous_id and a user_id"
  end

  response = @transport.call(
    TransportRequest.new(
      method: "POST",
      url: @alias_url,
      headers: Trevosdk.auth_headers(@secret_key),
      body: JSON.generate({anonymousId: anonymous_id, userId: user_id})
    )
  )
  if response.status == 409
    raise "Trevo alias rejected: anonymousId \"#{anonymous_id}\" is already linked to a different user"
  end
  raise "Trevo alias failed with status #{response.status}" unless (200..299).cover?(response.status)
  nil
end

#close ⇒ Object 



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# File 'lib/trevosdk/client.rb', line 154

def close
  return if @closed
  @closed = true
  @poller.stop
  @batcher.shutdown
end

#flush ⇒ Object 



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# File 'lib/trevosdk/client.rb', line 150

def flush
  @batcher.flush
end

#get_variant(experiment_key, user_id: nil, anonymous_id: nil, track_exposure: true) ⇒ Object 



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# File 'lib/trevosdk/client.rb', line 84

def get_variant(experiment_key, user_id: nil, anonymous_id: nil, track_exposure: true)
  return Core::CONTROL_VARIANT if experiment_key.to_s.empty?
  ensure_started

  config = @experiments[experiment_key]

  # Overrides win, but only for a variant the experiment has, and never
  # record an exposure — see docs/sdk/bucketing-spec.md §6.
  override = @forced[experiment_key]
  if override && config && config["variants"].any? { |v| v["name"] == override }
    return override
  end

  # An empty-string user_id must fall through to the anonymous id the
  # browser is bucketing with.
  bucketing_id = user_id.to_s.empty? ? anonymous_id : user_id
  return Core::CONTROL_VARIANT if bucketing_id.to_s.empty? || config.nil?

  variant = Core.assign_variant(bucketing_id, config)

  if track_exposure
    now_ms = (Time.now.to_f * 1000).to_i
    should_log = @exposures_mutex.synchronize do
      @exposures.should_log?(bucketing_id, experiment_key, variant, now_ms)
    end
    if should_log
      enqueue_event(
        EXPOSURE_EVENT, user_id, anonymous_id,
        {"experimentKey" => experiment_key, "variantName" => variant}, nil
      )
    end
  end

  variant
end

#ready(timeout_s = nil) ⇒ Object 



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# File 'lib/trevosdk/client.rb', line 145

def ready(timeout_s = nil)
  ensure_started
  @poller.wait_ready(timeout_s)
end

#track(event_name, user_id: nil, anonymous_id: nil, properties: nil, insert_id: nil) ⇒ Object 



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# File 'lib/trevosdk/client.rb', line 120

def track(event_name, user_id: nil, anonymous_id: nil, properties: nil, insert_id: nil)
  enqueue_event(event_name, user_id, anonymous_id, properties, insert_id)
end