Allow to run transformations in parallel.

bt5/erp5_wendelin/SkinTemplateItem/portal_skins/erp5_wendelin/DataStream_readChunkListAndTransform.xml

@@ -55,18 +55,18 @@
 """\n
   Simply a wrapper to real method.\n
 """\n
-data_stream = context\n
-total_stream_length = data_stream.getSize()\n
+\n
+total_stream_length = context.getSize()\n
 \n
 if start > total_stream_length:\n
   # end reached\n
   return\n
 \n
-data_stream_chunk_list = data_stream.readChunkList(start, end)\n
+data_stream_chunk_list = context.readChunkList(start, end)\n
 \n
 # do call transformation script\n
 if transform_script_id is not None:\n
-  transform_script = getattr(data_stream, transform_script_id, None)\n
+  transform_script = getattr(context, transform_script_id, None)\n
   if transform_script is not None:\n
     start, end = transform_script(context, data_stream_chunk_list, \\\n
                                   start, \\\n
@@ -77,7 +77,7 @@ if transform_script_id is not None:\n
 # [warning] store current position offset in Data Stream, this can cause easily \n
 # ConflictErrors and it spawns re-index activities on DataStream. Thus \n
 # disable for now.\n
-#data_stream.setIntOffsetIndex(end)\n
+#context.setIntOffsetIndex(end)\n
 \n
 # start another read in another activity\n
 start += chunk_length\n
@@ -87,13 +87,15 @@ if end > total_stream_length:\n
   # no read beyond end of stream\n
   end = total_stream_length\n
 \n
-# some bytes left ...\n
-data_stream.activate().DataStream_readChunkListAndTransform( \\\n
+if recursive:\n
+  # some bytes left ...\n
+  context.activate().DataStream_readChunkListAndTransform( \\\n
     start, \\\n
     end, \\\n
     chunk_length, \\\n
     transform_script_id,\\\n
     data_array_reference,\\\n
+    recursive = recursive, \\\n
     **kw)\n
 
 
@@ -101,7 +103,7 @@ data_stream.activate().DataStream_readChunkListAndTransform( \\\n
         </item>
         <item>
             <key> <string>_params</string> </key>
-            <value> <string>start, end, chunk_length, transform_script_id=None, data_array_reference=None, **kw</string> </value>
+            <value> <string>start, end, chunk_length, transform_script_id=None, data_array_reference=None, recursive=1,**kw</string> </value>
         </item>
         <item>
             <key> <string>id</string> </key>

bt5/erp5_wendelin/SkinTemplateItem/portal_skins/erp5_wendelin/DataStream_transform.xml

@@ -50,27 +50,55 @@
         </item>
         <item>
             <key> <string>_body</string> </key>
-            <value> <string>""" \n
-  Read entire stream using activities and pass stream\'s data to handler script\n
-  who can transform it.\n
+            <value> <string encoding="cdata"><![CDATA[
+
+""" \n
+  Read entire stream using activities either in a sequence or in a oarallel mode.\n
+  Pass stream\'s data to handler script  who can transform it.\n
   Parameters:\n
     * transform_script_id - the script which will transform data\n
     * chunk_length - the length of a chunk\n
+    * data_array_reference - the reference of the output Data Array\n
+    * parallelize - try to transform in parallel or not, in this case\n
+      developer must carefully choose chunk_length to match record (s) size\n
 """\n
 start = 0\n
 end  = chunk_length\n
-context.activate().DataStream_readChunkListAndTransform( \\\n
+if not parallelize:\n
+  # sequential case\n
+  context.activate().DataStream_readChunkListAndTransform( \\\n
     start, \\\n
     end, \\\n
     chunk_length, \\\n
     transform_script_id, \\\n
     data_array_reference,\\\n
+    recursive =1, \\\n
     **kw)\n
-</string> </value>
+else:\n
+  # parallel case\n
+  total_size =  context.getSize()\n
+  while total_size > start:\n
+    start += chunk_length + 1\n
+    end += chunk_length +1\n
+    if end > total_size:\n
+      end = total_size\n
+      \n
+    # call transformation in an activity\n
+    context.activate(activity=\'SQLQueue\').DataStream_readChunkListAndTransform( \\\n
+      start, \\\n
+      end, \\\n
+      chunk_length, \\\n
+      transform_script_id, \\\n
+      data_array_reference,\\\n
+      recursive = 0, \\\n
+      **kw)\n
+
+
+]]></string> </value>
         </item>
         <item>
             <key> <string>_params</string> </key>
-            <value> <string>chunk_length=1048576, transform_script_id=None, data_array_reference=None, **kw</string> </value>
+            <value> <string>chunk_length=1048576, transform_script_id=None, data_array_reference=None,parallelize=0, **kw</string> </value>
         </item>
         <item>
             <key> <string>id</string> </key>