adapter.rb in flipper-0.5.0

- old
+ new
@@ -1,211 +1,5 @@
-require 'flipper/instrumenters/noop'
-
 module Flipper
-  # Internal: Adapter wrapper that wraps vanilla adapter instances. Adds things
-  # like local caching and convenience methods for adding/reading features from
-  # the adapter.
-  #
-  # So what is this local cache crap?
-  #
-  # The main goal of the local cache is to prevent multiple queries to an
-  # adapter for the same key for a given amount of time (per request, per
-  # background job, etc.).
-  #
-  # To facilitate with this, there is an included local cache middleware
-  # that enables local caching for the length of a web request. The local
-  # cache is enabled and cleared before each request and cleared and reset
-  # to original value after each request.
-  #
-  # Examples
-  #
-  # To see an example adapter that this would wrap, checkout the [memory
-  # adapter included with flipper](https://github.com/jnunemaker/flipper/blob/master/lib/flipper/adapters/memory.rb).
-  class Adapter
-    # Private: The name of instrumentation events.
-    InstrumentationName = "adapter_operation.#{InstrumentationNamespace}"
-
-    # Private: The name of the key that stores the set of known features.
-    FeaturesKey = 'features'
-
-    # Internal: Wraps vanilla adapter instance for use internally in flipper.
-    #
-    # object - Either an instance of Flipper::Adapter or a vanilla adapter instance
-    #
-    # Examples
-    #
-    #   adapter = Flipper::Adapters::Memory.new
-    #   instance = Flipper::Adapter.new(adapter)
-    #
-    #   Flipper::Adapter.wrap(instance)
-    #   # => Flipper::Adapter instance
-    #
-    #   Flipper::Adapter.wrap(adapter)
-    #   # => Flipper::Adapter instance
-    #
-    # Returns Flipper::Adapter instance
-    def self.wrap(object, options = {})
-      if object.is_a?(Flipper::Adapter)
-        object
-      else
-        new(object, options)
-      end
-    end
-
-    # Private: What adapter is being wrapped and will ultimately be used.
-    attr_reader :adapter
-
-    # Private: The name of the adapter. Based on the class name.
-    attr_reader :name
-
-    # Private: What is used to store the local cache.
-    attr_reader :local_cache
-
-    # Private: What is used to instrument all the things.
-    attr_reader :instrumenter
-
-    # Internal: Initializes a new adapter instance.
-    #
-    # adapter - Vanilla adapter instance to wrap. Just needs to respond to
-    #           read, write, delete, set_members, set_add, and set_delete.
-    #
-    # options - The Hash of options.
-    #           :local_cache - Where to store the local cache data (default: {}).
-    #                          Must respond to fetch(key, block), delete(key)
-    #                          and clear.
-    #           :instrumenter - What to use to instrument all the things.
-    #
-    def initialize(adapter, options = {})
-      @adapter = adapter
-      @name = adapter.class.name.split('::').last.downcase.to_sym
-      @local_cache = options[:local_cache] || {}
-      @instrumenter = options.fetch(:instrumenter, Flipper::Instrumenters::Noop)
-    end
-
-    # Public: Turns local caching on/off.
-    #
-    # value - The Boolean that decides if local caching is on.
-    def use_local_cache=(value)
-      local_cache.clear
-      @use_local_cache = value
-    end
-
-    # Public: Returns true for using local cache, false for not.
-    def using_local_cache?
-      @use_local_cache == true
-    end
-
-    # Public: Reads a key.
-    def read(key)
-      perform_read(:read, key)
-    end
-
-    # Public: Set a key to a value.
-    def write(key, value)
-      perform_update(:write, key, value.to_s)
-    end
-
-    # Public: Deletes a key.
-    def delete(key)
-      perform_delete(:delete, key)
-    end
-
-    # Public: Returns the members of a set.
-    def set_members(key)
-      perform_read(:set_members, key)
-    end
-
-    # Public: Adds a value to a set.
-    def set_add(key, value)
-      perform_update(:set_add, key, value.to_s)
-    end
-
-    # Public: Deletes a value from a set.
-    def set_delete(key, value)
-      perform_update(:set_delete, key, value.to_s)
-    end
-
-    # Public: Determines equality for an adapter instance when compared to
-    # another object.
-    def eql?(other)
-      self.class.eql?(other.class) && adapter == other.adapter
-    end
-    alias_method :==, :eql?
-
-    # Public: Returns all the features that the adapter knows of.
-    def features
-      set_members(FeaturesKey)
-    end
-
-    # Internal: Adds a known feature to the set of features.
-    def feature_add(name)
-      set_add(FeaturesKey, name.to_s)
-    end
-
-    # Public: Pretty string version for debugging.
-    def inspect
-      attributes = [
-        "name=#{name.inspect}",
-        "use_local_cache=#{@use_local_cache.inspect}"
-      ]
-      "#<#{self.class.name}:#{object_id} #{attributes.join(', ')}>"
-    end
-
-    # Private
-    def perform_read(operation, key)
-      if using_local_cache?
-        local_cache.fetch(key.to_s) {
-          local_cache[key.to_s] = @adapter.send(operation, key)
-        }
-      else
-        payload = {
-          :key => key,
-          :operation => operation,
-          :adapter_name => @name,
-        }
-
-        @instrumenter.instrument(InstrumentationName, payload) { |payload|
-          payload[:result] = @adapter.send(operation, key)
-        }
-      end
-    end
-
-    # Private
-    def perform_update(operation, key, value)
-      payload = {
-        :key => key,
-        :value => value,
-        :operation => operation,
-        :adapter_name => @name,
-      }
-
-      result = @instrumenter.instrument(InstrumentationName, payload) { |payload|
-        payload[:result] = @adapter.send(operation, key, value)
-      }
-
-      if using_local_cache?
-        local_cache.delete(key.to_s)
-      end
-
-      result
-    end
-
-    # Private
-    def perform_delete(operation, key)
-      payload = {
-        :key => key,
-        :operation => operation,
-        :adapter_name => @name,
-      }
-
-      result = @instrumenter.instrument(InstrumentationName, payload) { |payload|
-        payload[:result] = @adapter.send(operation, key)
-      }
-
-      if using_local_cache?
-        local_cache.delete(key.to_s)
-      end
-
-      result
-    end
+  module Adapter
+    # adding a module include so we have some hooks for stuff down the road
   end
 end