Riex

Elixir wrapper based on riak-elixir-client

Differences:

• Pool of connections using pooler
• Organization of source and tests;
• Riex.Object is a struct;

#Setup

Prerequisites

You should have at least one Riex node running. If you plan to use secondary indexes, you'll need to have the leveldb backend enabled:

app.config in version 1.4.x-

[
    ...
    {riak_kv, [
        {storage_backend, riak_kv_eleveldb_backend},
        ...
            ]},
    ...
].

or riak.conf in version 2.x.x+

...
storage_backend = leveldb
...

In your Elixir application

Add this project as a depency in your mix.exs

defp deps do
  [{ :riex, github: "edgurgel/riex" }]
end

Also you should add to the list of applications that your project depends on:

def application do
  [applications: [ :riex ]]
end

Install dependencies

mix deps.get

Compile

mix compile

Usage

One can pass the pid of the established connection or just use the pool (provided by pooler). You just need to define your pools using the group "riak. For example having this on your config/config.exs:

[pooler: [pools: [
  [ name: :riaklocal1,
    group: :riak,
    max_count: 10,
    init_count: 5,
    start_mfa: {Riex.Connection, :start_link, []}
  ],
   [ name: :riaklocal2,
    group: :riak,
    max_count: 15,
    init_count: 2,
    start_mfa: {Riex.Connection, :start_link, ['127.0.0.1', 9090]}
  ] ]
]]

Check Riex config/config.exs for an example on the pool configuration for a local Riak. More info about configuration on Elixir website: Application environment and configuration.

After this pool configuration, any call to Riex can omit the pid if you want to use the pool.

For example:

Riex.delete(pid, "user", key)

Riex.delete("user", key)

The first call will use the pid you started using Riex.Connection and the second call will get a connection from the pool of connections provided by pooler.

##Establishing a Riex connection

{:ok, pid} = Riex.Connection.start_link('127.0.0.1', 8087) # Default values

##Save a value

o = Riex.Object.create(bucket: "user", key: "my_key", data: "Drew Kerrigan")
Riex.put(pid, o)

##Find an object

o = Riex.find(pid, "user", "my_key")

##Update an object

o = %{o | data: "Something Else"}
Riex.put(pid, o)

##Delete an object

Using key

Riex.delete(pid, "user", key)

Using object

Riex.delete(pid, o)

CRDTs

Riak Datatypes are avaiable since Riak 2.0. The types included are: maps, sets, counters, registers and flags.

Counters

Considering that you created the "counter_bucket" bucket type using something like:

riak-admin bucket-type create counter_bucket '{"props":{"datatype":"counter"}}'
riak-admin bucket-type activate counter_bucket

One can create a counter (Riex.CRDT.Counter):

Counter.new
  |> Counter.increment
  |> Counter.increment(2)
  |> Riex.update("counter_bucket", "bucketcounter", "my_key")

And fetch the counter:

counter = Riex.find("counter_bucket", "bucketcounter", my_key)
  |> Counter.value

counter will be 3.

Sets

Considering that you created the "set_bucket" bucket type using something like:

riak-admin bucket-type create set_bucket '{"props":{"datatype":"set"}}'
riak-admin bucket-type activate set_bucket

Now one can create a set (Riex.CRDT.Set):

Set.new
  |> Set.put("foo")
  |> Set.put("bar")
  |> Riex.update("set_bucket", "bucketset", "my_key")

And fetch the set:

set = Riex.find("set_bucket", "bucketset", "my_key")
  |> Set.value

Where set is an orddict.

Maps

Maps handle binary keys with any other datatype (map, set, flag, register and counter).

Considering that you created the "map_bucket" bucket type using something like:

riak-admin bucket-type create set_bucket '{"props":{"datatype":"map"}}'
riak-admin bucket-type activate map_bucket

Now one can create a map (Riex.CRDT.Map):

register = Register.new("data")
flag = Flag.new |> Flag.enable
Map.new
  |> Map.put("k1", register)
  |> Map.put("k2", flag)
  |> Riex.update("map_bucket", "bucketmap", "map_key")

And fetch the map:

map = Riex.find("map_bucket", "bucketmap", key) |> Map.value

Where map is an orddict.

For a more functionality, check test/ directory

##Tests

MIX_ENV=test mix do deps.get, test

License

Copyright 2012-2013 Drew Kerrigan.
Copyright 2014 Eduardo Gurgel.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.