Class: Magick::Adapters::Registry

Inherits:
Object
  • Object
show all
Defined in:
lib/magick/adapters/registry.rb

Constant Summary collapse

CACHE_INVALIDATION_CHANNEL = 
'magick:cache:invalidate'
LOCAL_WRITE_TTL =

seconds to ignore self-invalidation after a local write

2.0
FEATURE_NAME_PATTERN =

Accept only conservative feature identifiers coming off the wire. Anything outside this alphabet (newlines, spaces, Unicode punctuation, 200-char garbage) is a sign of a malformed or malicious publisher and must not be fed back into Magick.features / feature.reload.

/\A[a-zA-Z0-9_\-.:]{1,120}\z/.freeze

Instance Method Summary collapse

Constructor Details

#initialize(memory_adapter, redis_adapter = nil, active_record_adapter: nil, circuit_breaker: nil, async: false, primary: nil) ⇒ Registry

Returns a new instance of Registry.



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# File 'lib/magick/adapters/registry.rb', line 16

def initialize(memory_adapter, redis_adapter = nil, active_record_adapter: nil, circuit_breaker: nil,
               async: false, primary: nil)
  @memory_adapter = memory_adapter
  @redis_adapter = redis_adapter
  @active_record_adapter = active_record_adapter
  @circuit_breaker = circuit_breaker || Magick::CircuitBreaker.new
  @async = async
  @primary = primary || :memory # :memory, :redis, or :active_record
  @subscriber_thread = nil
  @subscriber = nil
  @refresh_thread = nil
  @local_writes = {} # Track recent local writes to skip self-invalidation
  @reload_mutex = Mutex.new
  @stopping = false
  @shutdown_mutex = Mutex.new
  @owner_pid = Process.pid
  # Only start Pub/Sub subscriber if Redis is available
  # In memory-only mode, each process has isolated cache (no cross-process invalidation)
  start_cache_invalidation_subscriber if redis_adapter
end

Instance Method Details

#all_features ⇒ Object 



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# File 'lib/magick/adapters/registry.rb', line 174

def all_features
  features = []
  features += memory_adapter.all_features if memory_adapter
  features += redis_adapter.all_features if redis_adapter
  features += active_record_adapter.all_features if active_record_adapter
  features.uniq
end

#authoritative_get_all_data(feature_name) ⇒ Object

Read a feature’s complete data straight from the shared, authoritative backend — ActiveRecord first (it is written synchronously on every set/set_all_data), then Redis — bypassing this process’s local memory cache, and refresh memory with the result.

The Admin UI uses this so a toggle is reflected immediately on whichever process/container serves the (load-balanced) request after the write, instead of rendering this process’s possibly-stale memory cache while it waits for Pub/Sub invalidation to arrive.



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# File 'lib/magick/adapters/registry.rb', line 228

def authoritative_get_all_data(feature_name)
  data = read_from_source(feature_name)
  if data && !data.empty?
    memory_adapter&.set_all_data(feature_name, data)
    return data
  end

  # Source unavailable (Redis/AR down, or feature absent there) — fall back
  # to whatever this process already has rather than wiping a usable cache.
  memory_adapter ? memory_adapter.get_all_data(feature_name) : {}
end

#delete(feature_name) ⇒ Object 



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# File 'lib/magick/adapters/registry.rb', line 144

def delete(feature_name)
  memory_adapter&.delete(feature_name)

  if redis_adapter
    begin
      redis_adapter.delete(feature_name)
      # Publish cache invalidation message
      publish_cache_invalidation(feature_name)
    rescue AdapterError
      # Continue even if Redis fails
    end
  end

  return unless active_record_adapter

  begin
    active_record_adapter.delete(feature_name)
  rescue AdapterError
    # Continue even if Active Record fails
  end
end

#ensure_subscriber! ⇒ Object

Restart the Pub/Sub subscriber after a fork. The subscriber thread is not carried into child processes, so a worker inheriting a stale reference must re-create its own subscription. Safe to call on every request; it only does work when Process.pid changes.



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# File 'lib/magick/adapters/registry.rb', line 41

def ensure_subscriber!
  return if @owner_pid == Process.pid

  @shutdown_mutex.synchronize do
    return if @owner_pid == Process.pid

    @subscriber_thread = nil
    @subscriber = nil
    @owner_pid = Process.pid
    @stopping = false
  end

  start_cache_invalidation_subscriber if redis_adapter
end

#exists?(feature_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magick/adapters/registry.rb', line 166

def exists?(feature_name)
  return true if memory_adapter&.exists?(feature_name)
  return true if redis_adapter&.exists?(feature_name) == true
  return true if active_record_adapter&.exists?(feature_name) == true

  false
end

#get(feature_name, key) ⇒ Object 



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# File 'lib/magick/adapters/registry.rb', line 77

def get(feature_name, key)
  # Try memory first (fastest) - no Redis calls needed thanks to Pub/Sub invalidation
  value = memory_adapter.get(feature_name, key) if memory_adapter
  return value unless value.nil?

  # Fall back to Redis if available
  if redis_adapter
    begin
      value = redis_adapter.get(feature_name, key)
      if !value.nil? && memory_adapter
        memory_adapter.set(feature_name, key, value)
        return value
      end
    rescue StandardError, AdapterError
      # Redis failed, continue to next adapter
    end
  end

  # Fall back to Active Record if available
  if active_record_adapter
    begin
      value = active_record_adapter.get(feature_name, key)
      memory_adapter.set(feature_name, key, value) if !value.nil? && memory_adapter
      return value
    rescue StandardError, AdapterError
      nil
    end
  end

  nil
end

#get_all_data(feature_name) ⇒ Object

Load all keys for a single feature in one call instead of N separate get() calls



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# File 'lib/magick/adapters/registry.rb', line 183

def get_all_data(feature_name)
  # Try memory first
  if memory_adapter
    data = memory_adapter.get_all_data(feature_name)
    return data unless data.nil? || data.empty?
  end

  # Fall back to Redis
  if redis_adapter
    begin
      data = redis_adapter.get_all_data(feature_name)
      if data && !data.empty?
        memory_adapter.set_all_data(feature_name, data) if memory_adapter
        return data
      end
    rescue StandardError, AdapterError
      # Redis failed, continue
    end
  end

  # Fall back to Active Record
  if active_record_adapter
    begin
      data = active_record_adapter.get_all_data(feature_name)
      if data && !data.empty?
        memory_adapter.set_all_data(feature_name, data) if memory_adapter
        return data
      end
    rescue StandardError, AdapterError
      # AR failed
    end
  end

  {}
end

#invalidate_cache(feature_name) ⇒ Object

Explicitly trigger cache invalidation for a feature This is useful for targeting updates that need immediate cache invalidation Invalidates memory cache in current process AND publishes to Redis for other processes



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# File 'lib/magick/adapters/registry.rb', line 325

def invalidate_cache(feature_name)
  # Invalidate memory cache in current process immediately
  memory_adapter&.delete(feature_name)

  # Publish to Redis Pub/Sub to invalidate cache in other processes
  publish_cache_invalidation(feature_name)
end

#preload! ⇒ Object

Bulk load ALL features into memory cache in minimal queries. Call this after configuration to warm the cache.



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# File 'lib/magick/adapters/registry.rb', line 254

def preload!
  all_data = {}

  # Load from ActiveRecord first (source of truth for persistence)
  if active_record_adapter
    begin
      all_data = active_record_adapter.load_all_features_data
    rescue StandardError, AdapterError
      # AR failed, try Redis
    end
  end

  # Merge/override with Redis data (more up-to-date than AR in most setups)
  if redis_adapter
    begin
      redis_data = redis_adapter.load_all_features_data
      redis_data.each do |feature_name, data|
        all_data[feature_name] ||= {}
        all_data[feature_name].merge!(data)
      end
    rescue StandardError, AdapterError
      # Redis failed, use what we have from AR
    end
  end

  # Populate memory cache in bulk
  if memory_adapter && !all_data.empty?
    all_data.each do |feature_name, data|
      memory_adapter.set_all_data(feature_name, data)
    end
  end

  all_data
end

#publish_cache_invalidation(feature_name) ⇒ Object

Publish cache invalidation message to Redis Pub/Sub (without deleting local memory cache) This is useful when you’ve just updated the cache and want to notify other processes but keep the local memory cache intact



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# File 'lib/magick/adapters/registry.rb', line 348

def publish_cache_invalidation(feature_name)
  return unless redis_adapter

  begin
    redis_client = redis_adapter.client
    redis_client&.publish(CACHE_INVALIDATION_CHANNEL, feature_name.to_s)
  rescue StandardError => e
    # Silently fail - cache invalidation is best effort
    warn "Failed to publish cache invalidation: #{e.message}" if defined?(Rails) && Rails.env.development?
  end
end

#redis_available? ⇒ Boolean

Check if Redis adapter is available

Returns:

  • (Boolean) 


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# File 'lib/magick/adapters/registry.rb', line 334

def redis_available?
  !redis_adapter.nil?
end

#redis_client ⇒ Object

Get Redis client (public method for use by other classes)



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# File 'lib/magick/adapters/registry.rb', line 339

def redis_client
  return nil unless redis_adapter

  redis_adapter.client
end

#refresh_all_from_source ⇒ Object

Bulk variant of #authoritative_get_all_data: refresh the local memory cache for EVERY feature from the shared backend in 1-2 queries. Returns the loaded data. Used by the Admin UI index so the full list reflects authoritative state regardless of which container serves it.



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# File 'lib/magick/adapters/registry.rb', line 244

def refresh_all_from_source
  data = load_all_from_source
  if memory_adapter && !data.empty?
    data.each { |feature_name, feature_data| memory_adapter.set_all_data(feature_name, feature_data) }
  end
  data
end

#set(feature_name, key, value) ⇒ Object 



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# File 'lib/magick/adapters/registry.rb', line 109

def set(feature_name, key, value)
  # Update memory first (always synchronous)
  memory_adapter&.set(feature_name, key, value)

  # Record local write so the subscriber skips self-invalidation
  record_local_write(feature_name)

  # Update Redis if available
  if redis_adapter
    update_redis = proc do
      circuit_breaker.call do
        redis_adapter.set(feature_name, key, value)
      end
    rescue AdapterError => e
      warn "Failed to update Redis: #{e.message}" if defined?(Rails) && Rails.env.development?
    end

    if @async && defined?(Thread)
      spawn_async_write(feature_name, update_redis)
    else
      update_redis.call
      publish_cache_invalidation(feature_name)
    end
  end

  # Always update Active Record if available (as fallback/persistence layer)
  return unless active_record_adapter

  begin
    active_record_adapter.set(feature_name, key, value)
  rescue AdapterError => e
    warn "Failed to update Active Record: #{e.message}" if defined?(Rails) && Rails.env.development?
  end
end

#set_all_data(feature_name, data_hash) ⇒ Object

Bulk set multiple keys for a feature in one call (1 query instead of N)



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# File 'lib/magick/adapters/registry.rb', line 290

def set_all_data(feature_name, data_hash)
  memory_adapter&.set_all_data(feature_name, data_hash)

  # Record local write so the subscriber skips self-invalidation
  record_local_write(feature_name)

  if redis_adapter
    update_redis = proc do
      circuit_breaker.call do
        redis_adapter.set_all_data(feature_name, data_hash)
      end
    rescue AdapterError => e
      warn "Failed to bulk update Redis: #{e.message}" if defined?(Rails) && Rails.env.development?
    end

    if @async && defined?(Thread)
      spawn_async_write(feature_name, update_redis)
    else
      update_redis.call
      publish_cache_invalidation(feature_name)
    end
  end

  if active_record_adapter
    begin
      active_record_adapter.set_all_data(feature_name, data_hash)
    rescue AdapterError => e
      warn "Failed to bulk update Active Record: #{e.message}" if defined?(Rails) && Rails.env.development?
    end
  end
end

#shutdown(timeout: 5) ⇒ Object

Gracefully terminate the Pub/Sub subscriber thread and its Redis connection. Without this, Ruby/Puma shutdown waits on the blocking ‘subscribe` call.



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# File 'lib/magick/adapters/registry.rb', line 58

def shutdown(timeout: 5)
  @shutdown_mutex.synchronize do
    return if @stopping

    @stopping = true
  end

  close_subscriber_connection(@subscriber)
  terminate_subscriber_thread(@subscriber_thread, timeout)

  @subscriber = nil
  @subscriber_thread = nil
  true
end

#stopping? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/magick/adapters/registry.rb', line 73

def stopping?
  @stopping == true
end