Hello David, Thanks for your help so far. But I have problem with the activity behaviour. The data read from the iterative reading activity arrives at the downstream activities accumulative. I mean if I divide my file i.e. into parts of size 50 the downstream activities get then first 50 then 100, 150, ... elements. Have you an idea what is the mistake I have made? Furthermore the complete workbench freezes after a while.
Regards Andreas David Withers schrieb: > On 06/07/2010 15:21, Andreas Truszkowski wrote: > >> David Withers schrieb: >> >>> On 06/07/2010 14:41, Andreas Truszkowski wrote: >>> >>> >>>> David Withers schrieb: >>>> >>>> >>>>> On 05/07/2010 18:33, Andreas Truszkowski wrote: >>>>> >>>>> >>>>> >>>>>> Hi! >>>>>> >>>>>> I have to write an iterative filereader activitie. Is there >>>>>> any documentation about writing iterative activies or can >>>>>> anyone give me a short description? >>>>>> >>>>>> >>>>>> >>>>> Hi Andreas, >>>>> >>>>> There is a tutorial for writing activities here: >>>>> http://www.mygrid.org.uk/dev/wiki/display/developer/Tutorial+-+Service+invocation+plugin >>>>> >>>>> >>>>> >>>>> > David. > >>>>> >>>>> >>>> Hi David, >>>> >>>> writing an activitie is not the problem. I need to develope an >>>> activitie which is able to read i.e. a big file iterative. >>>> However that is not described in the wiki documentation. >>>> >>>> >>> Hi Andreas, >>> >>> I don't understand what you mean by iterative in this context. What >>> type of file do you want to read? Do you need to process the file >>> stream as it's being read? >>> >>> David. >>> >> The file should be read in small pieces so that every piece is >> processed separatly within the underlying workflow. If my file ist >> several GBs big or maybe a database it is not possible to load the >> data into the memory at once. I have read somewhere that the API of >> taverna is be able to do so but I can't find any longer the source. >> > > Your activity needs to read a file stream and output a list where each > element of the list is part of the file. There's an example of an > activity that does this at > http://code.google.com/p/taverna-plugins/source/browse/trunk/sequencefile/sequencefile-activity/src/main/java/net/sf/taverna/t2/activities/sequencefile/SequenceFileActivity.java > > If you look at lines 126 to 132 of the file, callback.receiveResult is > called for each part of the input file. (Note that the complete list is > also output at line 140). > > You also need to specify that the activity output port has a granular > depth of 0 (see line 161). > > David. > > ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ taverna-hackers mailing list [email protected] Web site: http://www.taverna.org.uk Mailing lists: http://www.taverna.org.uk/about/contact-us/ Developers Guide: http://www.taverna.org.uk/developers/
