[Opensim-dev] Some new code for your review and possible acceptance

[AlexRa]

Hello,

I've been playing around with the database access layer of the code, especially the AssetData plugins
for all 3 supported databases (Sqlite, MySql, and MS SQL) and the underlying classes, and also made
a few other changes:

   git at github.com:AlexRa/opensim-mods-Alex.git

I'd like to invite the developers of the OpenSim team to review the proposed changes
and integrate whatever looks useful into the official repository.

This repository contains the following branches that can be of interest:

The *"master"* contains all my the changes. It is branched off
r/127730 (and with the recent flow of commits I find it difficult to
continue rebasing it to keep up). There is quite a lot of stuff there,
some of it more useful than the other, so if anybody wants to look at
it I'd appreciate that, but that may be too much to ask.

I've been trying to separate particular features and put them into separate
branches. So far, the following branches are fairly independent from
the rest of the stuff and should be easy to integrate into the primary
repo if the team decides to do so:

* The "asset-loader"  branch contains a rewrite of the AssetLoader that
  uses a timestamped asset to determine which of the asset files must
  be loaded. This prevents the lengthy (and unnecessary) re-loading of
  all predefined assets on each server start-up, but does load any
  newly added assets. Status: NOT TESTED (but the logic is quite
  simple, shouldn't have much problems with it(?))

* The "Migrations" branch is a rewrite of the Migrations.cs to support
  single-file migration histories. This way, all those endless
  0xx_StoreName.sql are replaced with a single StoreName.migrations
  file which is more readable and easier to maintain. The new
  migration code supports stored procedures for both MySql and MS SQL.
  It is also fully backward-compatible (does read the old-style
  migration files as well).

  This also includes update of MySql.Data.dll to 6.2.3.0, to avoi a
  known problem with defining stored procs/funcs in earlier versions.

  Status: TESTED and works in all modes.

* The "NUnit-update" touches a lot of test-related code to make it compatible
  with NUnit 2.5.5+. The main advantage is that test classes can be
  made generic and parameterized. This (and the BasicDataServiceTest
  class included in this branch) allows to build DBMS-independent data
  tests. Some samples of such tests are available in my "master"
  branch. The idea is to keep he connection strings for the test
  databases in a single INI file (rather than in each test unit), and
  to keep all data tests in OpenSim.Data.Tests, totally eliminating
  Data.{MySql/MSSQL/SQLite}.Tests. Test sets for a specific DB are
  produced just by adding another [TestFixture(...)] attribute before
  the test class.

The other new stuff that is present in the "master" branch:

* Added Assets.CreatorID support for all dbs;

* A way to keep Asset.AccessTime updated (on MySql, a similar way
  would work on MS SQL) entirely on the SQL server side, without the
  performance costs of a separate UPDATE statement;

* refactored DB-access classes (more code moved to a base class, less stuff is DBMS-specific);

* configurable "keep alive" connection mode (for MySQL/MSSQL) - avoid
  re-creating conn, keep stmts prepared (2x performance gain for MS SQL);

* performance tests for Assets;

* (other changes)  

Best regards,

Alex Rytov  (aka AlexRa)