gistfile1.txt

diff --git a/examples/basic/Gemfile b/examples/basic/Gemfile
index 3e9fbe9..16c32f0 100644
--- a/examples/basic/Gemfile
+++ b/examples/basic/Gemfile
@@ -5,6 +5,6 @@ bundle_path ".gems/bundler_gems"
 
 # List gems to bundle here:
 gem 'appengine-rack', '0.0.7'
-gem 'appengine-apis', '0.0.14'
+gem 'appengine-apis', '0.0.15'
 gem 'sinatra'
 gem 'rack',           '1.0.1'
diff --git a/lib/tiny_ds/base_tx.rb b/lib/tiny_ds/base_tx.rb
index d67a579..6ca17c2 100644
--- a/lib/tiny_ds/base_tx.rb
+++ b/lib/tiny_ds/base_tx.rb
@@ -167,10 +167,24 @@ module TinyDS
 
 # $app_logger.info "BaseTx.apply dest_journal.nil?=#{dest_journal.nil?}"
           if dest_journal.nil?
+            # double-check by '_dsj'
+            if TinyDS::BaseTx.done_src_journal_key_exist?(dest, src_journal.key)
+              raise "why dest_journal is nil? _dsj has key=[#{src_journal.key.inspect}]"
+            end
+
             # TODO if dest.nil? ...
             entities_to_put = dest.send(src_journal.method_name, *(src_journal.args))
             entities_to_put = [entities_to_put] unless entities_to_put.kind_of?(Array)
             entities_to_put << DestJournal.new({}, :key=>src_journal.dest_journal_key)
+
+            # For double-check by '_dsj'
+            _dest = entities_to_put.find{|ent| ent.key==dest.key }
+            unless _dest
+              _dest = dest
+              entities_to_put << _dest
+            end
+            TinyDS::BaseTx.append_done_src_journal_key(_dest, src_journal.key)
+
             TinyDS.batch_save(entities_to_put)
           end
         }
@@ -203,6 +217,26 @@ module TinyDS
         end
         nil
       end
+
+      def done_src_journal_key_exist?(dest, src_journal_key)
+        if dest.class.has_property?(:_dsj) # done src journal
+          sj_key_str = src_journal_key.inspect
+          if dest._dsj.include?(sj_key_str)
+            return true
+          else
+            return false
+          end
+        end
+        return false
+      end
+
+      def append_done_src_journal_key(dest, src_journal_key)
+        if dest.class.has_property?(:_dsj)
+          sj_key_str = src_journal_key.inspect
+          dest._dsj = ([sj_key_str] + dest._dsj)[0,50]
+        end
+        return nil
+      end
     end
   end
 end
diff --git a/spec/base_tx_spec.rb b/spec/base_tx_spec.rb
index 96c4aef..ee9441b 100644
--- a/spec/base_tx_spec.rb
+++ b/spec/base_tx_spec.rb
@@ -9,6 +9,17 @@ class User < TinyDS::Base
   end
 end
 
+class Account < TinyDS::Base
+  property :nickname, :string
+  property :money,    :integer
+  property :_dsj,     :list
+  def apply_recv_money(amount)
+    self.money += amount
+    return [self]
+  end
+end
+
+
 describe "BaseTx" do
   before :all do
     #AppEngine::Testing.install_test_env
@@ -139,4 +150,82 @@ describe "BaseTx" do
   end
 
   describe "should move money AtoB and AtoC"
+
+  describe "_dsj : done_src_journal" do
+    it "incremented twice if dest_journal is not found" do
+      User.has_property?(:_dsj).should    == false
+      Account.has_property?(:_dsj).should == true
+      User.destroy_all
+      Account.destroy_all
+      TinyDS::BaseTx::SrcJournal.destroy_all
+      TinyDS::BaseTx::DestJournal.destroy_all
+
+      [User, Account].each do |klass|
+        @userA = klass.create(:nickname=>"userA", :money=>10000)
+        @userB = klass.create(:nickname=>"userB", :money=>10000)
+        @amount = 500
+        @journal = nil
+        TinyDS.tx do
+          @userA = @userA.reget
+          @userA.money -= @amount
+          @journal = TinyDS::BaseTx.build_journal(
+            @userA,
+            {:class=>klass, :key=>@userB.key}, # @userB,
+             :apply_recv_money,
+            @amount
+          )
+          TinyDS.batch_save([@userA, @journal])
+        end
+        @userA.reget.money.should        ==  9500
+        @userB.reget.money.should        == 10000
+        TinyDS::BaseTx.apply(@journal)
+        @userA.reget.money.should        ==  9500
+        @userB.reget.money.should        == 10500
+
+        TinyDS::BaseTx::DestJournal.destroy_all # delete dest_journal
+        if klass==User
+          TinyDS::BaseTx.apply(@journal)
+          @userA.reget.money.should        ==  9500
+          @userB.reget.money.should        == 11000
+        elsif klass==Account
+          proc{
+            TinyDS::BaseTx.apply(@journal)
+          }.should raise_error(RuntimeError, /why dest_journal is nil/)
+          @userA.reget.money.should        ==  9500
+          @userB.reget.money.should        == 10500
+        else
+          raise
+        end
+      end
+    end
+    it "_dsj.size is upto 50" do
+      @userA = Account.create(:nickname=>"userA", :money=>10000)
+      @userB = Account.create(:nickname=>"userB", :money=>10000)
+      @amount = 100
+      100.times do |n|
+        @journal = nil
+        TinyDS.tx do
+          @userA = @userA.reget
+          @userA.money -= @amount
+          @journal = TinyDS::BaseTx.build_journal(
+            @userA,
+            {:class=>Account, :key=>@userB.key}, # @userB,
+             :apply_recv_money,
+            @amount
+          )
+          TinyDS.batch_save([@userA, @journal])
+        end
+        TinyDS::BaseTx.apply(@journal)
+        @userA.reget.money.should        == 10000-(n+1)*@amount
+        @userB.reget.money.should        == 10000+(n+1)*@amount
+        @userA.reget._dsj.size.should    == 0
+        if n<50
+          @userB.reget._dsj.size.should    == n+1
+        else
+          @userB.reget._dsj.size.should    == 50
+        end
+        TinyDS::BaseTx.done_src_journal_key_exist?(@userB.reget, @journal.key).should == true
+      end
+    end
+  end
 end