Support for DBConnection

[ghost]

Ecto 2.0 requires adapters to support DBConnection (https://github.com/elixir-lang/ecto/issues/1215). The support for DBConnection has already been implemented quiet well in my fork of the RethinkDB driver.

Still, some features are missing (SSL support) and i some tests (connection_test.exs) have to be adjusted/rewritten. I will also talk with @hamiltop to see if he agrees to make the change (I think having support for different pool libraries in the driver could be a good thing).

[Lida]

Any progress on Ecto 2.0 support? Now that Phoenix 1.2 is out and requires Ecto 2.0 by default.

[ghost]

I have been working on Ecto 2 support for some time now. Currently, here what has been done so far:

• Fork of :rethinkdb package to support DBConnection (using multiplexed connections).
• Port of 1.x codebase to 2.x. (basically, most of the work is for connection pool integrating).
• Better support for types such as Ecto.UUID and Ecto.DateTime.
• Support for Ecto integration tests (only 1/3 currently passing).

I'm working on failing integration tests (only migrator.exs is 100% passing currently). The Ecto provided integration tests cover most of the edge cases I did not even thought about. So it might take a while until everything works as excepted.

Currently, you should be able to work with basic DB queries (changesets, insert, update, delete and their *_all counterparts). Ecto.preload/2 should also work as excepted.

I have swapped ecto_2 and master branch. This means that currently, the Ecto 2.x branch is master and 1.x is in the ecto_1 branch.

• For using the adapter for Ecto 1.x, you should use the published hex package.
• For using the adapter for Ecto 2.x, you should use the master branch as follow:

def deps do
  [{:rethinkdb_ecto, github: "almightycouch/rethinkdb_ecto"}]
end

[hamiltop]

Is your fork ready for a discussion of merging into the mainline?

[ghost]

Hi @hamiltop, The fork is ready to be merged without conflics.

All the tests are passing successfully with the exception of 5 tests in test/connection_test.exs which must be rewritten to work with the DBConnection behaviour. Some new test should also be written to test the connection pools.

There are a few implementation details that should be discussed thought:

• The connection logic is implemented in the Multiplexer module.
  • Each connection has two processes, for sending and receiving (see recv_loop/2).
  • Calling send_recv/3 function blocks until the response is received (or connection timeout) without blocking the connection. This is done using GenServer.call/3 and GenServer.reply/3.
  • Only the latest authentication method (server >= 2.3) has been implemented. Older authentication methods must be implemented if required.
• To use a specific pool backend, pass the module to the :pool option:
  • Within a supervision tree: supervisor(MyApp.Repo, [[pool: DBConnection.Poolboy]])
  • For available options, check: DBConnection.start_link/2.
  • Default is DBConnection.Connection, :poolboy and :sbroker are optional dependencies.