Caching various string manipulations

Author: DavidMikeSimon

lib/jsonapi-resources.rb

@@ -1,3 +1,4 @@
+require 'jsonapi/naive_cache'
 require 'jsonapi/resource'
 require 'jsonapi/response_document'
 require 'jsonapi/acts_as_resource_controller'

lib/jsonapi/formatter.rb

@@ -9,9 +9,12 @@ def unformat(arg)
         arg
       end
 
+      @@format_to_formatter_cache = JSONAPI::NaiveCache.new do |format|
+        "#{format.to_s.camelize}Formatter".safe_constantize
+      end
+
       def formatter_for(format)
-        formatter_class_name = "#{format.to_s.camelize}Formatter"
-        formatter_class_name.safe_constantize
+        @@format_to_formatter_cache.calc(format)
       end
     end
   end
@@ -50,9 +53,12 @@ def unformat(value)
         super(value)
       end
 
+      @@value_type_to_formatter_cache = JSONAPI::NaiveCache.new do |type|
+        "#{type.to_s.camelize}ValueFormatter".safe_constantize
+      end
+
       def value_formatter_for(type)
-        formatter_name = "#{type.to_s.camelize}Value"
-        formatter_for(formatter_name)
+        @@value_type_to_formatter_cache.calc(type)
       end
     end
   end
@@ -63,24 +69,38 @@ class UnderscoredKeyFormatter < JSONAPI::KeyFormatter
 
 class CamelizedKeyFormatter < JSONAPI::KeyFormatter
   class << self
+    @@format_cache = JSONAPI::NaiveCache.new do |key|
+      key.to_s.camelize(:lower)
+    end
+    @@unformat_cache = JSONAPI::NaiveCache.new do |formatted_key|
+      formatted_key.to_s.underscore
+    end
+
     def format(key)
-      super.camelize(:lower)
+      @@format_cache.calc(key)
     end
 
     def unformat(formatted_key)
-      formatted_key.to_s.underscore
+      @@unformat_cache.calc(formatted_key)
     end
   end
 end
 
 class DasherizedKeyFormatter < JSONAPI::KeyFormatter
   class << self
+    @@format_cache = JSONAPI::NaiveCache.new do |key|
+      key.to_s.underscore.dasherize
+    end
+    @@unformat_cache = JSONAPI::NaiveCache.new do |formatted_key|
+      formatted_key.to_s.underscore
+    end
+
     def format(key)
-      super.underscore.dasherize
+      @@format_cache.calc(key)
     end
 
     def unformat(formatted_key)
-      formatted_key.to_s.underscore
+      @@unformat_cache.calc(formatted_key)
     end
   end
 end
@@ -107,24 +127,38 @@ class UnderscoredRouteFormatter < JSONAPI::RouteFormatter
 
 class CamelizedRouteFormatter < JSONAPI::RouteFormatter
   class << self
+    @@format_cache = JSONAPI::NaiveCache.new do |route|
+      route.to_s.camelize(:lower)
+    end
+    @@unformat_cache = JSONAPI::NaiveCache.new do |formatted_route|
+      formatted_route.to_s.underscore
+    end
+
     def format(route)
-      super.camelize(:lower)
+      @@format_cache.calc(route)
     end
 
     def unformat(formatted_route)
-      formatted_route.to_s.underscore
+      @@unformat_cache.calc(formatted_route)
     end
   end
 end
 
 class DasherizedRouteFormatter < JSONAPI::RouteFormatter
   class << self
+    @@format_cache = JSONAPI::NaiveCache.new do |route|
+      route.to_s.dasherize
+    end
+    @@unformat_cache = JSONAPI::NaiveCache.new do |formatted_route|
+      formatted_route.to_s.underscore
+    end
+
     def format(route)
-      super.dasherize
+      @@format_cache.calc(route)
     end
 
     def unformat(formatted_route)
-      formatted_route.to_s.underscore
+      @@unformat_cache.calc(formatted_route)
     end
   end
 end

lib/jsonapi/link_builder.rb

@@ -9,6 +9,10 @@ def initialize(config = {})
       @primary_resource_klass = config[:primary_resource_klass]
       @route_formatter        = config[:route_formatter]
       @is_engine              = !!engine_name
+
+      @resources_path_cache   = JSONAPI::NaiveCache.new do |source_klass|
+        formatted_module_path_from_class(source_klass) + format_route(source_klass._type.to_s)
+      end
     end
 
     def engine?
@@ -113,23 +117,20 @@ def module_scopes_from_class(klass)
       klass.name.to_s.split("::")[0...-1]
     end
 
+    def regular_resources_path(source_klass)
+      @resources_path_cache.calc(source_klass)
+    end
+
     def regular_primary_resources_path
-      [
-        formatted_module_path_from_class(primary_resource_klass),
-        format_route(primary_resource_klass._type.to_s),
-      ].join
+      regular_resources_path(primary_resource_klass)
     end
 
     def regular_primary_resources_url
       "#{ base_url }#{ regular_primary_resources_path }"
     end
 
     def regular_resource_path(source)
-      [
-        formatted_module_path_from_class(source.class),
-        format_route(source.class._type.to_s),
-        "/#{ source.id }",
-      ].join
+      "#{regular_resources_path(source.class)}/#{source.id}"
     end
 
     def regular_resource_url(source)

lib/jsonapi/naive_cache.rb

@@ -0,0 +1,19 @@
+module JSONAPI
+  class NaiveCache
+    def initialize(cap = 1024, &calculator)
+      @data = {}
+      @cap = cap
+      @calculator = calculator
+    end
+
+    def calc(key)
+      value = @data.fetch(key, nil)
+      return value unless value.nil?
+      value = @calculator.call(key)
+      raise "Cannot cache nil value (calculated for #{key})" if value.nil?
+      @data[key] = value
+      @data.shift if @data.length > @cap
+      return value
+    end
+  end
+end

lib/jsonapi/resource.rb

@@ -350,16 +350,28 @@ def resource_for_model(model)
         resource_for(resource_type_for(model))
       end
 
-      def _resource_name_from_type(type)
+      @@type_name_to_resource_name_cache = JSONAPI::NaiveCache.new do |type|
         "#{type.to_s.underscore.singularize}_resource".camelize
       end
 
+      def _resource_name_from_type(type)
+        @@type_name_to_resource_name_cache.calc(type)
+      end
+
+      @@model_to_model_name_cache = JSONAPI::NaiveCache.new do |model|
+        model.class.to_s.underscore
+      end
+
+      @@model_name_to_resource_type_cache = JSONAPI::NaiveCache.new do |model_name|
+        model_name.rpartition('/').last
+      end
+
       def resource_type_for(model)
-        model_name = model.class.to_s.underscore
+        model_name = @@model_to_model_name_cache.calc(model)
         if _model_hints[model_name]
           _model_hints[model_name]
         else
-          model_name.rpartition('/').last
+          @@model_name_to_resource_type_cache.calc(model_name)
         end
       end