Doctrine transaction log implementation - 90%

[scaleupcto]

This allows us to use any Doctrine-compatible db for the tlog (perversely, MongoDB included). The obvious target would be a postgressql, seeing as MongoDB does not work well as an append-(mostly) db

How it's done

1. Create ITransactionLog and have MongoTripod depend on that, not MongoTransactionLog
2. Have MongoTransactionLog extend ITransactionLog
3. Alter MongoTripodConfig object to allow a tlog type which can be MongoTransactionLog (default) or a new DoctrineTransactionLog (only for environments with PHP > 5.3.3)
4. Implement new DoctrineTransactionLog with Doctrine entity TransactionLogEntry that supports squirrelling transactions to SQL
5. Refactor tests - get the unittest suite to run twice, once with the config referencing the MongoTransactionLog, and again with the DoctrineTransactionLog config for Postgres

Todo:

1. Implement replay - 5 failing tests on the Postgres suite at the minute
2. Get the build file to actually set up the Postgres DB for you (will fail unless you have a database called tlog with a user of chris ATM)
3. DSL-based string config for Doctrine, rather than driver, database, user pass
4. Make sure all the various scripts, including processQueue, work. Would prefer to move the queue to resque but that might be a later pull request.
5. Performance tests

[kiyanwang]

why use an underscore ? _unittestPostgresTLog is it because you dont want this target to be called directly by a developer? if thats what you actually want to achieve change the target name to -unittestPostgresTLog the dash makes it impossible for someone to call ant -unittestPostgresTLog directly.

[rgubby]

👍 i like this approach.

I noticed a few commented out bits of code in one of the Doctrine classes to do with MongoDates - I'm guessing they will be removed/replaced at some point.

One final thing - is it even worth having a version > 5.3 in there? Can we make the assumption that it just will be on 5.3? If it's going to make it into prod before the 5.3 kit is ready AND we need to update Tripod then it's worth it - otherwise possibly not.

[scaleupcto]

Thanks for the comments. The commented out code in the Doctrine classes are actually the equiv MongoTransactionLog code to remind me what it does until I have fully implemented Doctrine, after which I'll remove.

On the 5.3 bit, this still needs to work against 5.2 until we've finally migrated, so if we want to merge this to master before that happens we'll need the version checks.

Goes without saying to configure and use against the Doctrine version you'd need to be running 5.3.

[rsinger]

Type hinting for the arrays in the signature?

[scaleupcto]

90% feedback

[rsinger]

So far, I really like the direction of this!

[scaleupcto]

Thanks!