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Sprinting

The BoulderSprint is a regular activity of the FrontRangePythoneers. We held six sprints in 2007, and we hope to do this or better in 2008. If you are interested in holding a sprint with us, please contact FRP leader Jim Baker (jbaker AT zyasoft DOT com).

Sprints have both short-term and long-term value. If you attend a sprint, you are going to get an immediate and immersive introduction to an opensource codebase. It's quite possible that code you write that day will get accepted immediately into the project, via its trunk or a branch. And then there is the long-term payoff, where the sprint leads into a longer journey. The newcompiler project for Jython 2.5 (sprints Jan 6, Feb 3, Aug 4) was merged into trunk on Jan 7, 2008, and is part of two students' master and dissertation research respectively. The modern branch (expected to be merged in soon) generated some interest for Django on Jython, and soon perhaps ipython on Jython too (also due to another local Pythoneer) (sprints Sept 14-15; Dec 1); the Boulder-Oracle branch was merged April 19 into the Django trunk for its Oracle support (sprint Nov 4, 2006). (Fill in more long-term stories.)

People planning to participate, either in person or via IRC on #jython (irc.freenode.net):

Charlie Groves

Damien Lejeune

Eric Dobbs

Fernando Perez

Frank Wierzbicki

Ian Kelly

Jim Baker

Kip Lehman

Matt Boersma

Tobias Ivarsson

Neal McBurnett

Philip Jenvey

IPython on Jython

For the Jython sprint on Aug 4, there's strong interest in getting IPython working on jython. Jython's ability to explore the large and complex ecosystem that is Java is one reason it's such a great tool. In particular, I (Jim Baker) like using Jython on Jython, as well as to explore functionality we are in the process of adding. It's much better to use an object shell than the alternatives (mostly painful).

But IPython is a much better object shell, as we know in using it to explore Django and other projects. Hence the sprint. x IPython support: Getting IPython to run on Jython (ideally the upcoming 2.2 release). Fernando Perez will be attending as a domain expert we can tap, although he plans to squash bugs in the CPython version.

Homework

Install Jython 2.2, including source. Will this be RC3?

Get source code for IPython, and otherwise familiarize yourself with the shell.

Jython 2.5

The upcoming Jython 2.2 release represents a huge milestone for the Jython community, but in the next step we want to catch up on 2.5 (or even 2.6) features. The principal reason is to enlarge the community: as long as there's such a lagging between CPython and Jython, it means that supporting even core packages is shouldered by Jython implementers instead of being shared across the Python community. In addition, certain 2.5 functionality addresses portability concerns. Resource Allocation is Initialization (RAII), as enabled by the with-statement, makes it much easier to do the right thing and have deterministic resource destruction instead of relying on reference counting doing this implicitly, but creating an incompatibility with non-refcounting GC as is the case with Java/Jython. 2.6's Class decorators and function annotations, in addition to 2.5's function decorators and 2.2's import hooking, make it possible for Jython to consume and produce annotation metadata and type signatures.

Two of our Google Summer of Code students have confirmed their participation, Damien Lejeune and Tobias Ivarsson. Damien has been working on the new AST parser based on Antlr, and Tobias has been working on a new bytecode compiler based on ASM. In this sprint, we would like to help them out and especially help with their integration of the compilation pipeline. In addition one of us (Jim Baker) is planning on finally getting to work on support for Java annotation metadata.

This shouldn't take more than an hour or two, and will ensure we all have a base level of familiarity with the project that will help us hit the ground running.

In addition, Fernando plans to use Mercurial for distributed version control during the sprint, so you should install and familiarize yourself with that software if time permits.

Jython Sprints

January 6, 2007 (Saturday), 9 AM - 6 PM

February 3, 2007 (Saturday), 9 AM - 6 PM

Update Jython. Brian Zimmer's proposal is an useful outline of what needs to be done technically. Perhaps even more importantly, there are some key engineering challenges to be addressed to ensure overall project success. Because of the scope of the work, we are looking at this as preliminary to a 4-day sprint at PyCon. More here at JythonSprint.

Participants

Eric Dobbs

Bill Simons

Matt Boersma

Kip Lehman

Jim Baker

Django-Oracle Project

November 4, 2006 (Saturday), 9 AM - 6 PM

Complete support for Oracle in Django in time for 1.0. Suggested by Matt Boersma.

UPDATE: Thanks to the hard work of Ian Kelly, this code is basically complete. We're submitting a patch for Oracle support back to the trunk today (April 19, 2007). Lots of people had a hand in these changes, so congratulations are in order for everyone!

Specifically, we would like to build on the good work already done by the Django community to produce a single patch that can be applied to current subversion sources, enabling Django's ORM to pass basic tests against an Oracle database. The current patches available have Oracle-specific conditional tests in many locations; we will try to confine such code to the django.db.backends.oracle package.

References

Preliminary Tasks

(Many of these are refinements and performance improvements that we won't get to, since we're focused only on correct behavior right now. But several of us reviewed the code and didn't want to lose any feedback. After the sprint, we will enter the outstanding issues in the Django project Trac.)

Use ROWNUM, not LIMIT 1. Oracle guru Tom Kyte addresses this in a recent article in Oracle magazine. It boils down to using a doubly nested subquery.

Create LOB columns out-of-line

Need a way to explicitly specify TABLESPACE for table creation

(Done) CREATE [SEQUENCE|CONSTRAINTS] gets logged twice

(Done) backend creates LONG columns, should use CLOBs instead

(Done) backend may create two LONG columns, but Oracle allows one per table (don't use LONG columns... solved by using CLOBs)

In "syncdb", foreign keys should be created as a second pass after table creation, using ALTER statements. Otherwise the DDL will reference tables not yet created, and Oracle throws errors.

(Done) Primary key "id" column (AutoField) is NUMBER(38) in creation.py. Does it need to be that large? No it doesn't.

(Done) Don't use Oracle's non-native Integer and SmallInteger types, which result in a NUMBER(38).

XmlField unimplemented, although Oracle now has native support for this.

In db/models/base.py, should use COUNT(*) instead of Oracle LIMIT 1 conditional test

Create a function-based index on lower() columns, or else check if DB is Oracle 10g

move query.py oracle tests out to the db module

Which versions of Oracle do we need to support? (9i and 10g, hopefully, although old versions of cx_Oracle still support 8i)

Good comment from Winston Lee: "I think the biggest issue is the restriction of only one LONG field type on a table. This means that NCLOB will need to be used for TextField? in creation.py. cx_Oracle will then return NCLOB field as a cx_Oracle.LOB. I thought that it would be possible to use cx_Oracle.Connection.register to hook into the return and read the LOB object but it should really be a lazy fetch."

Add more Monty Python references to the code.

Participants

Jim Baker

Matt Boersma, Aries, the man with the plan

Eric Dobbs

Ian Kelly, Pisces, he who shall do all the work

Matt Drew, Capricorn, master pizza orderer

Michelle Cyr, Cancer, senior ice cream fetcher

Jacob Kaplan-Moss, lead Django developer!

Malcolm Tredinnick (working remotely from Sydney -- with the flu, no less!)

Mitchell W. Smith, Virgo, schwag coordinator

Post Sprint Party

Some of us are planning to go to the Cuban Connection fundraiser, 6 PM - 1 AM, St. Julien Hotel (our favorite meeting place for FrontRangePythoneers). In addition to raising money for a good cause, this will be a chance to stretch our weary coding muscles while dancing salsa to Quemando and Havana NRG.