Connection cache to speed up retrieve_connection and get rid of dirty...

Connection cache to speed up retrieve_connection and get rid of dirty connection marking.  References #428.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3218 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/lib/active_record/base.rb

@@ -243,11 +243,17 @@ class Base
     # on to any new database connections made and which can be retrieved on both a class and instance level by calling +logger+.
     cattr_accessor :logger
 
+    @@connection_cache = Hash.new { |h, k| h[k] = Hash.new }
+
     # Returns the connection currently associated with the class. This can
     # also be used to "borrow" the connection to do database work unrelated
     # to any of the specific Active Records.
     def self.connection
-      retrieve_connection
+      @@connection_cache[Thread.current.object_id][name] ||= retrieve_connection
+    end
+
+    def self.clear_connection_cache!
+      @@connection_cache.clear
     end
 
     # Returns the connection currently associated with the class. This can

activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb

 module ActiveRecord
-  module ConnectionAdapters
-    module ConnectionManagement
-      # Check whether the connection should be checked for activity before use.
-      def needs_verification?
-        @needs_verification == true
-      end
-
-      # Flag the connection for an activity check before use.
-      def needs_verification!
-        @needs_verification = true
-      end
-
-      # If the connection is flagged for an activity check, check whether
-      # it is active and reconnect if not.
-      def verify!
-        if needs_verification?
-          reconnect! unless active?
-          @needs_verification = false
-        end
-        self
-      end
-    end
-  end
-
   # The root class of all active record objects.
   class Base
     class ConnectionSpecification #:nodoc:
@@ -102,8 +78,8 @@ def self.retrieve_connection #:nodoc:
       ar_super = ActiveRecord::Base.superclass
       until klass == ar_super
         if conn = active_connections[klass.name]
-          # Validate the active connection before returning it.
-          conn.verify!
+          # Reconnect if the connection is inactive.
+          conn.reconnect! unless conn.active?
           return conn
         elsif conn = @@defined_connections[klass.name]
           # Activate this connection specification.
@@ -152,10 +128,5 @@ def self.connection=(spec)
         establish_connection spec
       end
     end
-
-    # Mark active connections for verification on next retrieve_connection.
-    def self.mark_active_connections_for_verification! #:nodoc:
-      active_connections.values.each { |conn| conn.needs_verification! }
-    end
   end
 end

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -19,7 +19,7 @@ module ConnectionAdapters # :nodoc:
     # SchemaStatements#add_column, SchemaStatements#change_column and
     # SchemaStatements#remove_column are very useful.
     class AbstractAdapter
-      include Quoting, DatabaseStatements, SchemaStatements, ConnectionManagement
+      include Quoting, DatabaseStatements, SchemaStatements
       @@row_even = true
 
       def initialize(connection, logger = nil) #:nodoc:
@@ -69,9 +69,6 @@ def log(sql, name)
             nil
           end
         rescue Exception => e
-          # Flag connection as possibly dirty; needs verification before use.
-          self.needs_verification!
-
           # Log message and raise exception.
           message = "#{e.class.name}: #{e.message}: #{sql}"
           log_info(message, name, 0)

activerecord/lib/active_record/fixtures.rb

@@ -503,6 +503,8 @@ def setup_with_fixtures
       alias_method :setup, :setup_with_fixtures
 
       def teardown_with_fixtures
+        ActiveRecord::Base.clear_connection_cache!
+      ensure
         # Rollback changes.
         if use_transactional_fixtures?
           ActiveRecord::Base.connection.rollback_db_transaction

railties/lib/dispatcher.rb

@@ -73,7 +73,7 @@ def prepare_application
     
       def reset_after_dispatch
         reset_application! if Dependencies.load?
-        ActiveRecord::Base.mark_active_connections_for_verification!
+        ActiveRecord::Base.clear_connection_cache!
         Breakpoint.deactivate_drb if defined?(BREAKPOINT_SERVER_PORT)
       end