AS::Concern is not really needed for AR::Explain

activerecord/lib/active_record/base.rb

@@ -699,7 +699,7 @@ module ActiveRecord #:nodoc:
     include Associations
     include IdentityMap
     include ActiveModel::SecurePassword
-    include Explain
+    extend Explain
 
     # AutosaveAssociation needs to be included before Transactions, because we want
     # #save_with_autosave_associations to be wrapped inside a transaction.

activerecord/lib/active_record/explain.rb

@@ -1,85 +1,83 @@
-require 'active_support/concern'
+require 'active_support/core_ext/class/attribute'
 
 module ActiveRecord
   module Explain
-    extend ActiveSupport::Concern
-
-    included do
-      # If a query takes longer than these many seconds we log its query plan
-      # automatically. nil disables this feature.
-      class_attribute :auto_explain_threshold_in_seconds, :instance_writer => false
-      self.auto_explain_threshold_in_seconds = nil
+    def self.extended(base)
+      base.class_eval do
+        # If a query takes longer than these many seconds we log its query plan
+        # automatically. nil disables this feature.
+        class_attribute :auto_explain_threshold_in_seconds, :instance_writer => false
+        self.auto_explain_threshold_in_seconds = nil
+      end
     end
 
-    module ClassMethods
-      # If auto explain is enabled, this method triggers EXPLAIN logging for the
-      # queries triggered by the block if it takes more than the threshold as a
-      # whole. That is, the threshold is not checked against each individual
-      # query, but against the duration of the entire block. This approach is
-      # convenient for relations.
-      #
-      # The available_queries_for_explain thread variable collects the queries
-      # to be explained. If the value is nil, it means queries are not being
-      # currently collected. A false value indicates collecting is turned
-      # off. Otherwise it is an array of queries.
-      def logging_query_plan # :nodoc:
-        threshold = auto_explain_threshold_in_seconds
-        current   = Thread.current
-        if threshold && current[:available_queries_for_explain].nil?
-          begin
-            queries = current[:available_queries_for_explain] = []
-            start = Time.now
-            result = yield
-            logger.warn(exec_explain(queries)) if Time.now - start > threshold
-            result
-          ensure
-            current[:available_queries_for_explain] = nil
-          end
-        else
-          yield
+    # If auto explain is enabled, this method triggers EXPLAIN logging for the
+    # queries triggered by the block if it takes more than the threshold as a
+    # whole. That is, the threshold is not checked against each individual
+    # query, but against the duration of the entire block. This approach is
+    # convenient for relations.
+    #
+    # The available_queries_for_explain thread variable collects the queries
+    # to be explained. If the value is nil, it means queries are not being
+    # currently collected. A false value indicates collecting is turned
+    # off. Otherwise it is an array of queries.
+    def logging_query_plan # :nodoc:
+      threshold = auto_explain_threshold_in_seconds
+      current   = Thread.current
+      if threshold && current[:available_queries_for_explain].nil?
+        begin
+          queries = current[:available_queries_for_explain] = []
+          start = Time.now
+          result = yield
+          logger.warn(exec_explain(queries)) if Time.now - start > threshold
+          result
+        ensure
+          current[:available_queries_for_explain] = nil
         end
-      end
-
-      # Relation#explain needs to be able to collect the queries regardless of
-      # whether auto explain is enabled. This method serves that purpose.
-      def collecting_queries_for_explain # :nodoc:
-        current = Thread.current
-        original, current[:available_queries_for_explain] = current[:available_queries_for_explain], []
-        return yield, current[:available_queries_for_explain]
-      ensure
-        # Note that the return value above does not depend on this assigment.
-        current[:available_queries_for_explain] = original
-      end
-
-      # Makes the adapter execute EXPLAIN for the tuples of queries and bindings.
-      # Returns a formatted string ready to be logged.
-      def exec_explain(queries) # :nodoc:
-        queries && queries.map do |sql, bind|
-          [].tap do |msg|
-            msg << "EXPLAIN for: #{sql}"
-            unless bind.empty?
-              bind_msg = bind.map {|col, val| [col.name, val]}.inspect
-              msg.last << " #{bind_msg}"
-            end
-            msg << connection.explain(sql, bind)
-          end.join("\n")
-        end.join("\n")
-      end
-
-      # Silences automatic EXPLAIN logging for the duration of the block.
-      #
-      # This has high priority, no EXPLAINs will be run even if downwards
-      # the threshold is set to 0.
-      #
-      # As the name of the method suggests this only applies to automatic
-      # EXPLAINs, manual calls to +ActiveRecord::Relation#explain+ run.
-      def silence_auto_explain
-        current = Thread.current
-        original, current[:available_queries_for_explain] = current[:available_queries_for_explain], false
+      else
         yield
-      ensure
-        current[:available_queries_for_explain] = original
       end
     end
+
+    # Relation#explain needs to be able to collect the queries regardless of
+    # whether auto explain is enabled. This method serves that purpose.
+    def collecting_queries_for_explain # :nodoc:
+      current = Thread.current
+      original, current[:available_queries_for_explain] = current[:available_queries_for_explain], []
+      return yield, current[:available_queries_for_explain]
+    ensure
+      # Note that the return value above does not depend on this assigment.
+      current[:available_queries_for_explain] = original
+    end
+
+    # Makes the adapter execute EXPLAIN for the tuples of queries and bindings.
+    # Returns a formatted string ready to be logged.
+    def exec_explain(queries) # :nodoc:
+      queries && queries.map do |sql, bind|
+        [].tap do |msg|
+          msg << "EXPLAIN for: #{sql}"
+          unless bind.empty?
+            bind_msg = bind.map {|col, val| [col.name, val]}.inspect
+            msg.last << " #{bind_msg}"
+          end
+          msg << connection.explain(sql, bind)
+        end.join("\n")
+      end.join("\n")
+    end
+
+    # Silences automatic EXPLAIN logging for the duration of the block.
+    #
+    # This has high priority, no EXPLAINs will be run even if downwards
+    # the threshold is set to 0.
+    #
+    # As the name of the method suggests this only applies to automatic
+    # EXPLAINs, manual calls to +ActiveRecord::Relation#explain+ run.
+    def silence_auto_explain
+      current = Thread.current
+      original, current[:available_queries_for_explain] = current[:available_queries_for_explain], false
+      yield
+    ensure
+      current[:available_queries_for_explain] = original
+    end
   end
 end

activerecord/lib/active_record/relation.rb

@@ -9,7 +9,7 @@ module ActiveRecord
     MULTI_VALUE_METHODS = [:select, :group, :order, :joins, :where, :having, :bind]
     SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reorder, :reverse_order, :uniq]
 
-    include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain::ClassMethods, Delegation
+    include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation
 
     attr_reader :table, :klass, :loaded
     attr_accessor :extensions, :default_scoped