use the cache mechanism in the connection pool rather than our own cache

3 files changed, 19 insertions, 29 deletions

diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 61f68a8c09..70e10a5e0f 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -11,14 +11,6 @@ module Arel
         @last_column    = nil
         @quoted_tables  = {}
         @quoted_columns = {}
-        @column_cache   = Hash.new { |h,pool|
-          h[pool] = Hash.new { |conn_h,column|
-            conn_h[column] = {}
-          }
-        }
-        @table_exists   = Hash.new { |h,pool|
-          h[pool] = {}
-        }
       end
 
       def accept object
@@ -91,37 +83,20 @@ key on UpdateManager using UpdateManager#key=
       end
 
       def table_exists? name
-        return true if table_exists.key? name
-
-        @connection.tables.each do |table|
-          table_exists[table] = true
-        end
-
-        table_exists.key? name
-      end
-
-      def table_exists
-        @table_exists[@pool]
+        @pool.table_exists? name
       end
 
       def column_for attr
-        name    = attr.name.to_sym
+        name    = attr.name.to_s
         table   = attr.relation.name
 
         return nil unless table_exists? table
 
-        # If we don't have this column cached, get a list of columns and
-        # cache them for this table
-        unless column_cache.key? table
-          columns = @connection.columns(table, "#{table}(#{name}) Columns")
-          column_cache[table] = Hash[columns.map { |c| [c.name.to_sym, c] }]
-        end
-
         column_cache[table][name]
       end
 
       def column_cache
-        @column_cache[@pool]
+        @pool.columns_hash
       end
 
       def visit_Arel_Nodes_Values o
diff --git a/test/support/fake_record.rb b/test/support/fake_record.rb
index 376ed40f2d..54f73489c9 100644
--- a/test/support/fake_record.rb
+++ b/test/support/fake_record.rb
@@ -3,7 +3,7 @@ module FakeRecord
   end
 
   class Connection
-    attr_reader :tables
+    attr_reader :tables, :columns_hash
 
     def initialize
       @tables = %w{ users photos developers }
@@ -15,6 +15,9 @@ module FakeRecord
           Column.new('created_at', :date),
         ]
       }
+      @columns_hash = {
+        'users' => Hash[@columns['users'].map { |x| [x.name, x] }]
+      }
       @primary_keys = {
         'users' => 'id'
       }
@@ -75,6 +78,14 @@ module FakeRecord
     def with_connection
       yield connection
     end
+
+    def table_exists? name
+      connection.tables.include? name.to_s
+    end
+
+    def columns_hash
+      connection.columns_hash
+    end
   end
 
   class Base
diff --git a/test/test_select_manager.rb b/test/test_select_manager.rb
index 3ffdbe2e23..3b5ded8389 100644
--- a/test/test_select_manager.rb
+++ b/test/test_select_manager.rb
@@ -30,6 +30,10 @@ module Arel
       @engine.connection.columns table, message
     end
 
+    def columns_hash
+      @engine.connection.columns_hash
+    end
+
     def table_exists? name
       @engine.connection.table_exists? name
     end