calling cache methods against the connection

lib/arel/select_manager.rb

@@ -51,7 +51,7 @@ module Arel
       if $VERBOSE
         warn "(#{caller.first}) where_clauses is deprecated and will be removed in arel 3.0.0 with no replacement"
       end
-      to_sql = Visitors::ToSql.new @engine.connection_pool
+      to_sql = Visitors::ToSql.new @engine.connection
       @ctx.wheres.map { |c| to_sql.accept c }
     end
 
@@ -161,13 +161,13 @@ module Arel
 
     def wheres
       warn "#{caller[0]}: SelectManager#wheres is deprecated and will be removed in ARel 3.0.0 with no replacement"
-      Compatibility::Wheres.new @engine.connection_pool, @ctx.wheres
+      Compatibility::Wheres.new @engine.connection, @ctx.wheres
     end
 
     def where_sql
       return if @ctx.wheres.empty?
 
-      viz = Visitors::WhereSql.new @engine.connection_pool
+      viz = Visitors::WhereSql.new @engine.connection
       Nodes::SqlLiteral.new viz.accept @ctx
     end
 
@@ -222,7 +222,7 @@ module Arel
     end
 
     def order_clauses
-      visitor = Visitors::OrderClauses.new(@engine.connection_pool)
+      visitor = Visitors::OrderClauses.new(@engine.connection)
       visitor.accept(@ast).map { |x|
         Nodes::SqlLiteral.new x
       }

lib/arel/visitors/to_sql.rb

@@ -4,30 +4,22 @@ require 'date'
 module Arel
   module Visitors
     class ToSql < Arel::Visitors::Visitor
-      def initialize pool
-        @pool           = pool
-        @connection     = nil
+      attr_accessor :last_column
+
+      def initialize connection
+        @connection     = connection
+        @schema_cache   = connection.schema_cache
         @quoted_tables  = {}
         @quoted_columns = {}
+        @last_column    = nil
       end
 
       def accept object
         self.last_column = nil
-        @pool.with_connection do |conn|
-          @connection = conn
-          super
-        end
+        super
       end
 
       private
-      def last_column= col
-        Thread.current[:arel_visitors_to_sql_last_column] = col
-      end
-
-      def last_column
-        Thread.current[:arel_visitors_to_sql_last_column]
-      end
-
       def visit_Arel_Nodes_DeleteStatement o
         [
           "DELETE FROM #{visit o.relation}",
@@ -97,7 +89,7 @@ key on UpdateManager using UpdateManager#key=
       end
 
       def table_exists? name
-        @pool.table_exists? name
+        @schema_cache.table_exists? name
       end
 
       def column_for attr
@@ -110,7 +102,7 @@ key on UpdateManager using UpdateManager#key=
       end
 
       def column_cache
-        @pool.columns_hash
+        @schema_cache.columns_hash
       end
 
       def visit_Arel_Nodes_Values o
@@ -387,7 +379,9 @@ key on UpdateManager using UpdateManager#key=
       alias :visit_Bignum                :literal
       alias :visit_Fixnum                :literal
 
-      def quoted o; quote(o, last_column) end
+      def quoted o
+        quote(o, last_column)
+      end
 
       alias :visit_ActiveSupport_Multibyte_Chars :quoted
       alias :visit_ActiveSupport_StringInquirer  :quoted

test/support/fake_record.rb

@@ -3,9 +3,10 @@ module FakeRecord
   end
 
   class Connection
-    attr_reader :tables, :columns_hash, :visitor
+    attr_reader :tables, :columns_hash
+    attr_accessor :visitor
 
-    def initialize(visitor)
+    def initialize(visitor = nil)
       @tables = %w{ users photos developers products}
       @columns = {
         'users' => [
@@ -50,6 +51,10 @@ module FakeRecord
       "\"#{name.to_s}\""
     end
 
+    def schema_cache
+      self
+    end
+
     def quote thing, column = nil
       if column && column.type == :integer
         return 'NULL' if thing.nil?
@@ -79,7 +84,8 @@ module FakeRecord
 
     def initialize
       @spec = Spec.new(:adapter => 'america')
-      @connection = Connection.new(Arel::Visitors::ToSql.new(self))
+      @connection = Connection.new
+      @connection.visitor = Arel::Visitors::ToSql.new(connection)
     end
 
     def with_connection
@@ -93,6 +99,10 @@ module FakeRecord
     def columns_hash
       connection.columns_hash
     end
+
+    def schema_cache
+      connection
+    end
   end
 
   class Base

test/visitors/test_ibm_db.rb

@@ -4,7 +4,7 @@ module Arel
   module Visitors
     describe 'the ibm_db visitor' do
       before do
-        @visitor = IBM_DB.new Table.engine.connection_pool
+        @visitor = IBM_DB.new Table.engine.connection
       end
 
       it 'uses FETCH FIRST n ROWS to limit results' do

test/visitors/test_informix.rb

@@ -4,7 +4,7 @@ module Arel
   module Visitors
     describe 'the informix visitor' do
       before do
-        @visitor = Informix.new Table.engine.connection_pool
+        @visitor = Informix.new Table.engine.connection
       end
 
       it 'uses LIMIT n to limit results' do

test/visitors/test_join_sql.rb

@@ -4,7 +4,7 @@ module Arel
   module Visitors
     describe 'the join_sql visitor' do
       before do
-        @visitor = ToSql.new Table.engine.connection_pool
+        @visitor = ToSql.new Table.engine.connection
         @visitor.extend(JoinSql)
       end
 

test/visitors/test_mssql.rb

@@ -4,7 +4,7 @@ module Arel
   module Visitors
     describe 'the mssql visitor' do
       before do
-        @visitor = MSSQL.new Table.engine.connection_pool
+        @visitor = MSSQL.new Table.engine.connection
         @table = Arel::Table.new "users"
       end
 

test/visitors/test_mysql.rb

@@ -4,7 +4,7 @@ module Arel
   module Visitors
     describe 'the mysql visitor' do
       before do
-        @visitor = MySQL.new Table.engine.connection_pool
+        @visitor = MySQL.new Table.engine.connection
       end
 
       it 'squashes parenthesis on multiple unions' do

test/visitors/test_postgres.rb

@@ -4,7 +4,7 @@ module Arel
   module Visitors
     describe 'the postgres visitor' do
       before do
-        @visitor = PostgreSQL.new Table.engine.connection_pool
+        @visitor = PostgreSQL.new Table.engine.connection
       end
 
       describe 'locking' do

test/visitors/test_to_sql.rb

@@ -1,14 +1,10 @@
 require 'helper'
 
-class Arel::Visitors::ToSql
-  def last_column; Thread.current[:arel_visitors_to_sql_last_column]; end
-end
-
 module Arel
   module Visitors
     describe 'the to_sql visitor' do
       before do
-        @visitor = ToSql.new Table.engine.connection_pool
+        @visitor = ToSql.new Table.engine.connection
         @table = Table.new(:users)
         @attr = @table[:id]
       end
@@ -29,20 +25,6 @@ module Arel
         assert visited, 'hello method was called'
       end
 
-      it "should be thread safe around usage of last_column" do
-        visit_integer_column = Thread.new do
-          Thread.stop
-          @visitor.send(:visit_Arel_Attributes_Attribute, @attr)
-        end
-
-        sleep 0.2
-        @visitor.accept(@table[:name])
-        assert_equal(:string, @visitor.last_column.type)
-        visit_integer_column.run
-        visit_integer_column.join
-        assert_equal(:string, @visitor.last_column.type)
-      end
-
       it 'should not quote sql literals' do
         node = @table[Arel.star]
         sql = @visitor.accept node
@@ -220,7 +202,7 @@ module Arel
             end
           end
           in_node = Nodes::In.new @attr, %w{ a b c }
-          visitor = visitor.new(Table.engine.connection_pool)
+          visitor = visitor.new(Table.engine.connection)
           visitor.expected = Table.engine.connection.columns(:users).find { |x|
             x.name == 'name'
           }
@@ -308,7 +290,7 @@ module Arel
             end
           end
           in_node = Nodes::NotIn.new @attr, %w{ a b c }
-          visitor = visitor.new(Table.engine.connection_pool)
+          visitor = visitor.new(Table.engine.connection)
           visitor.expected = Table.engine.connection.columns(:users).find { |x|
             x.name == 'name'
           }