a few minor performance improvements: fewer strings, fewer range objects, fewer method calls

2 files changed, 13 insertions, 22 deletions

diff --git a/activerecord/lib/active_record/associations/alias_tracker.rb b/activerecord/lib/active_record/associations/alias_tracker.rb
index c14d42dec9..92ed844a2e 100644
--- a/activerecord/lib/active_record/associations/alias_tracker.rb
+++ b/activerecord/lib/active_record/associations/alias_tracker.rb
@@ -9,7 +9,7 @@ module ActiveRecord
 
       # table_joins is an array of arel joins which might conflict with the aliases we assign here
       def initialize(table_joins = [])
-        @aliases     = Hash.new
+        @aliases     = Hash.new { |h,k| h[k] = initial_count_for(k) }
         @table_joins = table_joins
       end
 
@@ -26,8 +26,6 @@ module ActiveRecord
       def aliased_name_for(table_name, aliased_name = nil)
         aliased_name ||= table_name
 
-        initialize_count_for(table_name) if aliases[table_name].nil?
-
         if aliases[table_name].zero?
           # If it's zero, we can have our table_name
           aliases[table_name] = 1
@@ -36,8 +34,6 @@ module ActiveRecord
           # Otherwise, we need to use an alias
           aliased_name = connection.table_alias_for(aliased_name)
 
-          initialize_count_for(aliased_name) if aliases[aliased_name].nil?
-
           # Update the count
           aliases[aliased_name] += 1
 
@@ -51,26 +47,22 @@ module ActiveRecord
 
       private
 
-        def initialize_count_for(name)
-          aliases[name] = 0
+        def initial_count_for(name)
+          return 0 if Arel::Table === table_joins
 
-          unless Arel::Table === table_joins
-            # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase
-            quoted_name = connection.quote_table_name(name).downcase
-
-            aliases[name] += table_joins.map { |join|
-              # Table names + table aliases
-              join.left.downcase.scan(
-                /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/
-              ).size
-            }.sum
-          end
+          # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase
+          quoted_name = connection.quote_table_name(name).downcase
 
-          aliases[name]
+          table_joins.map { |join|
+            # Table names + table aliases
+            join.left.downcase.scan(
+              /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/
+            ).size
+          }.sum
         end
 
         def truncate(name)
-          name[0..connection.table_alias_length-3]
+          name.slice(0, connection.table_alias_length - 2)
         end
 
         def connection
diff --git a/activerecord/lib/active_record/associations/join_helper.rb b/activerecord/lib/active_record/associations/join_helper.rb
index d094a8def3..f83138195c 100644
--- a/activerecord/lib/active_record/associations/join_helper.rb
+++ b/activerecord/lib/active_record/associations/join_helper.rb
@@ -32,8 +32,7 @@ module ActiveRecord
       end
 
       def table_alias_for(reflection, join = false)
-        name = reflection.plural_name.dup
-        name << "_#{alias_suffix}"
+        name = "#{reflection.plural_name}_#{alias_suffix}"
         name << "_join" if join
         name
       end