Pass data stream start end offset only. Adjust test.

bt5/erp5_wendelin/SkinTemplateItem/portal_skins/erp5_wendelin/DataStream_transformTail.xml

@@ -50,7 +50,9 @@
         </item>
         <item>
             <key> <string>_body</string> </key>
-            <value> <string>"""\n
+            <value> <string encoding="cdata"><![CDATA[
+
+"""\n
   Read tail of a Data Stream and aplly needed transformations.\n
   This script is called every time we appendData to a Stream\n
   using data_stream_interaction_workflow.\n
@@ -58,15 +60,15 @@
   The idea is to provide close to real time data transformations.\n
   As transformation is quite specific we leave this script empty so developers\n
   can hook in and add needed transformations.\n
-  \n
-  Interesting here is to use OffsetIndex property sheet which allows to place\n
-  marker till where a Data Stream has been processed.\n
 """\n
-</string> </value>
+assert start_offset < end_offset\n
+
+
+]]></string> </value>
         </item>
         <item>
             <key> <string>_params</string> </key>
-            <value> <string>*argument_list</string> </value>
+            <value> <string>start_offset, end_offset</string> </value>
         </item>
         <item>
             <key> <string>id</string> </key>

bt5/erp5_wendelin/TestTemplateItem/portal_components/test.erp5.testWendelin.py

@@ -150,7 +150,7 @@ class Test(ERP5TypeTestCase):
     # override DataStream_transformTail to actually do transformation on appenData
     start = data_stream.getSize()
     script_id = 'DataStream_transformTail'
-    script_content_list = ["*argument_list", """
+    script_content_list = ["start_offset, end_offset", """
 # created by testWendelin.test_01_1_IngestionTail
 start = %s
 end  = %s

bt5/erp5_wendelin/WorkflowTemplateItem/portal_workflow/data_stream_interaction_workflow/scripts/DataStream_appendData.xml

@@ -57,11 +57,11 @@ data_stream = state_change[\'object\']\n
 argument_list = state_change[\'kwargs\'][\'workflow_method_args\']\n
 \n
 # call you own script to handle newly appended data which \n
-# is not processed yet\n
-# Note: this will serialize argument_list to activity\'s mysql table\n
-# in case of big packets this can be slow, in =case of small appends it can be \n
-# acceptable.\n
-data_stream.activate().DataStream_transformTail(*argument_list)\n
+# is not processed yet, pass data stream start end offset only\n
+end_offset = data_stream.getSize()\n
+packet_size = len(argument_list[0])\n
+start_offset = end_offset - packet_size\n
+data_stream.activate().DataStream_transformTail(start_offset, end_offset)\n
 </string> </value>
         </item>
         <item>