1 files changed, 26 insertions, 35 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/schema_cache.rb b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
index 5839d1d3b4..37ff4e4613 100644
--- a/activerecord/lib/active_record/connection_adapters/schema_cache.rb
+++ b/activerecord/lib/active_record/connection_adapters/schema_cache.rb
@@ -1,7 +1,7 @@
 module ActiveRecord
   module ConnectionAdapters
     class SchemaCache
-      attr_reader :primary_keys, :tables, :version
+      attr_reader :version
       attr_accessor :connection
 
       def initialize(conn)
@@ -11,11 +11,15 @@ module ActiveRecord
         @columns_hash = {}
         @primary_keys = {}
         @tables       = {}
-        prepare_default_proc
+      end
+
+      def primary_keys(table_name)
+        @primary_keys[table_name] ||= table_exists?(table_name) ? connection.primary_key(table_name) : nil
       end
 
       # A cached lookup for table existence.
       def table_exists?(name)
+        prepare_tables if @tables.empty?
         return @tables[name] if @tables.key? name
 
         @tables[name] = connection.table_exists?(name)
@@ -24,29 +28,27 @@ module ActiveRecord
       # Add internal cache for table with +table_name+.
       def add(table_name)
         if table_exists?(table_name)
-          @primary_keys[table_name]
-          @columns[table_name]
-          @columns_hash[table_name]
+          primary_keys(table_name)
+          columns(table_name)
+          columns_hash(table_name)
         end
       end
 
+      def tables(name)
+        @tables[name]
+      end
+
       # Get the columns for a table
-      def columns(table = nil)
-        if table
-          @columns[table]
-        else
-          @columns
-        end
+      def columns(table_name)
+        @columns[table_name] ||= connection.columns(table_name)
       end
 
       # Get the columns for a table as a hash, key is the column name
       # value is the column object.
-      def columns_hash(table = nil)
-        if table
-          @columns_hash[table]
-        else
-          @columns_hash
-        end
+      def columns_hash(table_name)
+        @columns_hash[table_name] ||= Hash[columns(table_name).map { |col|
+          [col.name, col]
+        }]
       end
 
       # Clears out internal caches
@@ -58,6 +60,10 @@ module ActiveRecord
         @version = nil
       end
 
+      def size
+        [@columns, @columns_hash, @primary_keys, @tables].map(&:size).inject :+
+      end
+
       # Clear out internal caches for table with +table_name+.
       def clear_table_cache!(table_name)
         @columns.delete table_name
@@ -69,33 +75,18 @@ module ActiveRecord
       def marshal_dump
         # if we get current version during initialization, it happens stack over flow.
         @version = ActiveRecord::Migrator.current_version
-        [@version] + [:@columns, :@columns_hash, :@primary_keys, :@tables].map do |val|
-          self.instance_variable_get(val).inject({}) { |h, v| h[v[0]] = v[1]; h }
-        end
+        [@version, @columns, @columns_hash, @primary_keys, @tables]
       end
 
       def marshal_load(array)
         @version, @columns, @columns_hash, @primary_keys, @tables = array
-        prepare_default_proc
       end
 
       private
 
-      def prepare_default_proc
-        @columns.default_proc = Proc.new do |h, table_name|
-          h[table_name] = connection.columns(table_name)
-        end
-
-        @columns_hash.default_proc = Proc.new do |h, table_name|
-          h[table_name] = Hash[columns[table_name].map { |col|
-            [col.name, col]
-          }]
+        def prepare_tables
+          connection.tables.each { |table| @tables[table] = true }
         end
-
-        @primary_keys.default_proc = Proc.new do |h, table_name|
-          h[table_name] = table_exists?(table_name) ? connection.primary_key(table_name) : nil
-        end
-      end
     end
   end
 end