new concept of session boundaries

8 files changed, 53 insertions, 17 deletions

diff --git a/lib/active_relation/extensions/object.rb b/lib/active_relation/extensions/object.rb
index 0cc87bf262..c8a0ff49e5 100644
--- a/lib/active_relation/extensions/object.rb
+++ b/lib/active_relation/extensions/object.rb
@@ -14,4 +14,10 @@ class Object
   def strategy
     ActiveRelation::Sql::Scalar.new
   end
+  
+  def metaclass
+    class << self
+      self
+    end
+  end
 end
\ No newline at end of file
diff --git a/lib/active_relation/predicates.rb b/lib/active_relation/predicates.rb
index 2a36e65042..ddc6eab02b 100644
--- a/lib/active_relation/predicates.rb
+++ b/lib/active_relation/predicates.rb
@@ -17,7 +17,7 @@ module ActiveRelation
     end
     
     def bind(relation)
-      descend{ |x| x.bind(relation) }
+      descend { |x| x.bind(relation) }
     end
     
     def qualify
diff --git a/lib/active_relation/primitives/attribute.rb b/lib/active_relation/primitives/attribute.rb
index 75f19605c7..a72acb0c34 100644
--- a/lib/active_relation/primitives/attribute.rb
+++ b/lib/active_relation/primitives/attribute.rb
@@ -49,13 +49,10 @@ module ActiveRelation
       def self.included(klass)
         klass.class_eval do
           alias_method :eql?, :==
+          delegate :hash, :to => :name
         end
       end
       
-      def hash
-        relation.hash + name.hash
-      end
-      
       def history
         [self] + (ancestor ? [ancestor, ancestor.send(:history)].flatten : [])
       end
diff --git a/lib/active_relation/relations/compound.rb b/lib/active_relation/relations/compound.rb
index 115315a76a..4e583e61e8 100644
--- a/lib/active_relation/relations/compound.rb
+++ b/lib/active_relation/relations/compound.rb
@@ -3,6 +3,7 @@ module ActiveRelation
     attr_reader :relation
     delegate :joins, :selects, :orders, :groupings, :table_sql, :inserts, :limit,
              :offset, :name, :alias, :aggregation?, :alias?, :prefix_for, :column_for,
+             :hash,
              :to => :relation
     
     def attributes
diff --git a/lib/active_relation/relations/relation.rb b/lib/active_relation/relations/relation.rb
index 7536390aca..889cf59d3a 100644
--- a/lib/active_relation/relations/relation.rb
+++ b/lib/active_relation/relations/relation.rb
@@ -3,7 +3,7 @@ module ActiveRelation
     include Sql::Quoting
 
     def session
-      Session.instance
+      Session.new
     end
 
     module Enumerable
@@ -103,6 +103,10 @@ module ActiveRelation
     def alias?
       false
     end
+    
+    def eql?(other)
+      self == other
+    end
 
     def to_sql(strategy = Sql::Relation.new)
       strategy.select [
@@ -117,10 +121,6 @@ module ActiveRelation
       ].compact.join("\n"), self.alias
     end
     alias_method :to_s, :to_sql
-  
-    def descend
-      yield self
-    end
     
     def connection
       ActiveRecord::Base.connection
diff --git a/lib/active_relation/relations/table.rb b/lib/active_relation/relations/table.rb
index 5720be30e3..271e76f362 100644
--- a/lib/active_relation/relations/table.rb
+++ b/lib/active_relation/relations/table.rb
@@ -1,7 +1,8 @@
 module ActiveRelation
   class Table < Relation
     attr_reader :name
-
+    delegate :hash, :to => :name
+    
     def initialize(name)
       @name = name.to_s
     end
@@ -21,17 +22,25 @@ module ActiveRelation
     end
     
     def column_for(attribute)
-      self[attribute] and columns.detect { |c| c.name == attribute.name }
+      self[attribute] and columns.detect { |c| c.name == attribute.name.to_s }
     end
     
     def ==(other)
       self.class == other.class and
       name       == other.name
     end
-        
+    
     def columns
       @columns ||= connection.columns(name, "#{name} Columns")
     end
+    
+    def descend
+      yield self
+    end
+    
+    def reset
+      @attributes = @columns = nil
+    end
 
     protected    
     def table_sql
diff --git a/lib/active_relation/sessions/session.rb b/lib/active_relation/sessions/session.rb
index d6e2ae7169..7eb66a1395 100644
--- a/lib/active_relation/sessions/session.rb
+++ b/lib/active_relation/sessions/session.rb
@@ -2,8 +2,29 @@ require 'singleton'
 
 module ActiveRelation
   class Session
-    include Singleton
-        
+    class << self
+      def start
+        if @started
+          yield
+        else
+          begin
+            @started = true
+            @instance = new
+            manufacture = method(:new)
+            metaclass.class_eval do
+              define_method(:new) { @instance }
+            end
+            yield
+          ensure
+            metaclass.class_eval do
+              define_method(:new, &manufacture)
+            end
+            @started = false
+          end
+        end
+      end
+    end
+    
     module CRUD
       def connection
         ActiveRecord::Base.connection
@@ -14,7 +35,8 @@ module ActiveRelation
       end
       
       def read(select)
-        connection.select_all(select.to_sql)
+        @read ||= {}
+        @read.has_key?(select) ? @read[select] : (@read[select] = connection.select_all(select.to_sql))
       end
       
       def update(update)
diff --git a/lib/active_relation/sql.rb b/lib/active_relation/sql.rb
index 49ced3cbaa..0fc8b3e1be 100644
--- a/lib/active_relation/sql.rb
+++ b/lib/active_relation/sql.rb
@@ -2,12 +2,13 @@ module ActiveRelation
   module Sql
     module Quoting
       def connection
-        Session.instance.connection
+        Session.new.connection
       end
   
       delegate :quote_table_name, :quote_column_name, :quote, :to => :connection
     end
     
+    # module Formatting Context / Strategy # unit test me!!!
     class Strategy
       include Quoting
     end