[ActiveSupport::Cache::DalliStore] #fetch patch

CHANGELOG.md

@@ -1,6 +1,12 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## [0.3.1] - 2018-10-08
+### Added
+- patch interface `AnyCache.enable_patch!(:patch_series_name)`:
+  - `ActiveSupport::Cache::DalliStore` patch: now the `#fetch` method provides
+    a cache key attribute to the fallback proc (can be enabled via `.enable(:dalli_store)`);
+
 ## [0.3.0] - 2018-10-06
 ### Added
 - support for `ActiveSupport::Cache::DalliStore` client;

README.md

@@ -60,6 +60,7 @@ require 'any_cache'
     - [Persist](#persist)
     - [Existence](#existence)
     - [Clear](#clear)
+- [Roadmap](#roadmap)
 
 ---
 
@@ -195,6 +196,8 @@ require 'dalli'
 require 'active_support'
 require 'any_cache'
 
+AnyCache.enable_patch!(:dalli_store)
+
 AnyCache.configure do |conf|
   conf.driver = :as_dalli_store
   conf.as_dalli_store.servers = ... # string or array of strings

lib/any_cache.rb

@@ -14,12 +14,14 @@ class AnyCache
   require_relative 'any_cache/adapters'
   require_relative 'any_cache/logging'
   require_relative 'any_cache/delegation'
+  require_relative 'any_cache/patches'
 
   # @since 0.2.0
   include Qonfig::Configurable
-
   # @since 0.3.0
   include Delegation
+  # @since 0.3.1
+  extend Patches::InterfaceAccessMixin
 
   # @since 0.2.0
   # rubocop:disable Metrics/BlockLength

lib/any_cache/error.rb

@@ -8,4 +8,7 @@ class AnyCache
 
   # @since 0.1.0
   UnsupportedDriverError = Class.new(Error)
+
+  # @since 0.3.1
+  NonexistentPatchError = Class.new(ArgumentError)
 end

lib/any_cache/patches.rb

@@ -0,0 +1,41 @@
+# frozen_string_literal: true
+
+# @api private
+# @since 0.3.1
+module AnyCache::Patches
+  # @since 0.3.1
+  require_relative 'patches/dalli_store'
+
+  class << self
+    # @param patch_series [Symbol, String]
+    # @return [void]
+    #
+    # @raise [AnyCache::NonexistentPatchError]
+    #
+    # @api private
+    # @since 0.3.1
+    def enable!(patch_series)
+      case patch_series
+      when :dalli_store, 'dalli_store'
+        AnyCache::Patches::DalliStore.enable!
+      else
+        raise AnyCache::NonexistentPatchError, "Can't enable nonexistnet patch! (#{patch_series})"
+      end
+    end
+  end
+
+  # @api private
+  # @since 0.3.1
+  module InterfaceAccessMixin
+    # @param patch_series [Symbol, String]
+    # @return [void]
+    #
+    # @see AnyCache::Patches#enable!
+    #
+    # @api private
+    # @since 0.3.1
+    def enable_patch!(patch_series)
+      AnyCache::Patches.enable!(patch_series)
+    end
+  end
+end

lib/any_cache/patches/dalli_store.rb

@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+# @api private
+# @since 0.3.1
+module AnyCache::Patches::DalliStore
+  class << self
+    # @return [void]
+    #
+    # @api private
+    # @since 0.3.1
+    def enable!
+      defined?(::Dalli) &&
+      defined?(::ActiveSupport::Cache::DalliStore) &&
+      Gem::Version.new(::Dalli::VERSION) <= Gem::Version.new('2.7.8') &&
+      ::ActiveSupport::Cache::DalliStore.prepend(ActiveSupportFetchWithKey)
+    end
+  end
+
+  # @api private
+  # @since 0.3.1
+  module ActiveSupportFetchWithKey
+    # NOTE: original fetch implementation with my own little fix (see #43 line of code below)
+    # rubocop:disable all
+    def fetch(name, options=nil)
+      options ||= {}
+      options[:cache_nils] = true if @options[:cache_nils]
+      namespaced_name = namespaced_key(name, options)
+      not_found = options[:cache_nils] ? Dalli::Server::NOT_FOUND : nil
+      if block_given?
+        entry = not_found
+        unless options[:force]
+          entry = instrument_with_log(:read, namespaced_name, options) do |payload|
+            read_entry(namespaced_name, options).tap do |result|
+              if payload
+                payload[:super_operation] = :fetch
+                payload[:hit] = not_found != result
+              end
+            end
+          end
+        end
+
+        if not_found == entry
+          result = instrument_with_log(:generate, namespaced_name, options) do |payload|
+            # FIX: https://github.com/petergoldstein/dalli/pull/701
+            yield(name)
+            # FIX: https://github.com/petergoldstein/dalli/pull/701
+          end
+          write(name, result, options)
+          result
+        else
+          instrument_with_log(:fetch_hit, namespaced_name, options) { |payload| }
+          entry
+        end
+      else
+        read(name, options)
+      end
+    end
+    # rubocop:enable all
+  end
+end
+

lib/any_cache/version.rb

@@ -1,6 +1,9 @@
 # frozen_string_literal: true
 
 class AnyCache
+  # @return [String]
+  #
+  # @api public
   # @since 0.1.0
   VERSION = '0.3.0'
 end

spec/features/fetch_multi_spec.rb

@@ -44,23 +44,12 @@
       "#{key}-#{data_stub}"
     end
 
-    unless test_as_dalli_store_cache? # TODO: remove this condition in future
-      # NOTE: entry_2 has especial dynamically calculated value
-      expect(data).to match(
-        entry_1[:key] => entry_1[:value],
-        entry_2[:key] => "#{entry_2[:key]}-#{data_stub}",
-        entry_3[:key] => entry_3[:value]
-      )
-    end
-
-    if test_as_dalli_store_cache? # TODO: remove this block of code in future
-      # NOTE: entry_2 has especial dynamically calculated value
-      expect(data).to match(
-        entry_1[:key] => entry_1[:value],
-        entry_2[:key] => "-#{data_stub}",
-        entry_3[:key] => entry_3[:value]
-      )
-    end
+    # NOTE: entry_2 has especial dynamically calculated value
+    expect(data).to match(
+      entry_1[:key] => entry_1[:value],
+      entry_2[:key] => "#{entry_2[:key]}-#{data_stub}",
+      entry_3[:key] => entry_3[:value]
+    )
 
     # NOTE: force rewrite
     data_stub = SecureRandom.hex(4)
@@ -73,23 +62,12 @@
       "#{key}-#{data_stub}"
     end
 
-    unless test_as_dalli_store_cache? # TODO: remove this condition in future
-      # NOTE: entries with new values (and expiration time)
-      expect(cache_store.fetch_multi(entry_1[:key], entry_2[:key], entry_3[:key])).to match(
-        entry_1[:key] => "#{entry_1[:key]}-#{data_stub}",
-        entry_2[:key] => "#{entry_2[:key]}-#{data_stub}",
-        entry_3[:key] => entry_3[:value]
-      )
-    end
-
-    if test_as_dalli_store_cache? # TODO: remove this block of code in future
-      # NOTE: entries with new values (and expiration time)
-      expect(cache_store.fetch_multi(entry_1[:key], entry_2[:key], entry_3[:key])).to match(
-        entry_1[:key] => "-#{data_stub}",
-        entry_2[:key] => "-#{data_stub}",
-        entry_3[:key] => entry_3[:value]
-      )
-    end
+    # NOTE: entries with new values (and expiration time)
+    expect(cache_store.fetch_multi(entry_1[:key], entry_2[:key], entry_3[:key])).to match(
+      entry_1[:key] => "#{entry_1[:key]}-#{data_stub}",
+      entry_2[:key] => "#{entry_2[:key]}-#{data_stub}",
+      entry_3[:key] => entry_3[:value]
+    )
 
     sleep(expires_in + 1)
 

spec/features/patches_interface_spec.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+describe 'Patches interface' do
+  describe 'patch activation' do
+    it 'fails when the required patch does not exist' do
+      random_nonexistent_patch_name = SecureRandom.hex(rand(1..4)).to_sym
+
+      expect do
+        AnyCache.enable_patch!(random_nonexistent_patch_name)
+      end.to raise_error(AnyCache::NonexistentPatchError)
+    end
+  end
+end

spec/support/spec_support/cache/active_support_dalli_store.rb

@@ -13,6 +13,7 @@ class CacheStore < AnyCache
   class << self
     def build
       load_dependencies!
+      enable_patches!
       build_cache_store
     end
 
@@ -24,6 +25,10 @@ def load_dependencies!
       require 'active_support/cache/dalli_store'
     end
 
+    def enable_patches!
+      AnyCache.enable_patch!(:dalli_store)
+    end
+
     def build_cache_store
       CacheStore.build
     end