Mongodb

Features

Supports MongoDB versions 2.4, 2.6, 3.0
Connection pooling
Streaming cursors
Performant ObjectID generation
Follows driver specification set by 10gen
Safe (by default) and unsafe writes
Aggregation pipeline

Immediate Roadmap

Add timeouts for all calls
Bang and non-bang Mongo functions
Move BSON encoding to client process
- Make sure requests don't go over the 16mb limit
Replica sets
- Block in client (and timeout) when waiting for new primary selection
New 2.6 write queries and bulk writes
Reconnect backoffs with https://github.com/ferd/backoff
Lazy connect ? Drop save_* because it was dropped by driver specs

Tentative Roadmap

SSL
Use meta-driver test suite
Server selection / Read preference
- https://www.mongodb.com/blog/post/server-selection-next-generation-mongodb-drivers
- http://docs.mongodb.org/manual/reference/read-preference

Data representation

BSON             	Elixir
----------        	------
double              0.0
string              "Elixir"
document            [{"key", "value"}] | %{"key" => "value"} *
binary              %BSON.Binary{binary: <<42, 43>>, subtype: :generic}
object id           %BSON.ObjectId{value: <<...>>}
boolean             true | false
UTC datetime        %BSON.DateTime{utc: ...}
null                nil
regex               %BSON.Regex{pattern: "..."}
JavaScript          %BSON.JavaScript{code: "..."}
integer             42
symbol              "foo" **
min key             :BSON_min
max key             :BSON_max

Since BSON documents are ordered Elixir maps cannot be used to fully represent them. This driver chose to accept both maps and lists of key-value pairs when encoding but will only decode documents to lists. This has the side-effect that it's impossible to discern empty arrays from empty documents. Additionally the driver will accept both atoms and strings for document keys but will only decode to strings.

** BSON symbols can only be decoded.

Usage

Connection Pools

defmodule MongoPool do
  use Mongo.Pool, name: __MODULE__, adapter: Mongo.Pool.Poolboy
end

# Starts the pool named MongoPool
{:ok, _} = MongoPool.start_link(database: "test")

# Gets an enumerable cursor for the results
cursor = Mongo.find(MongoPool, "test-collection", %{})

Enum.to_list(cursor)
|> IO.inspect

APIs

Mongo.find(MongoPool, "test-collection", %{}, limit: 20)
Mongo.find(MongoPool, "test-collection", %{"field" => %{"$gt" => 0}}, limit: 20, sort: %{"field" => 1})

Mongo.insert_one(MongoPool, "test-collection", %{"field" => 10})

Mongo.insert_many(MongoPool, "test-collection", [%{"field" => 10}, %{"field" => 20}])

Mongo.delete_one(MongoPool, "test-collection", %{"field" => 10})

Mongo.delete_many(MongoPool, "test-collection", %{"field" => 10})

Run on a single pool connection

# Gets a pool process (conn) to run queries on
MongoPool.run(fn (conn) ->
  # Removes 1 result using the query
  Mongo.Connection.remove(conn, "test-collection", %{"field" => 1})

  # Removes all results using the query
  Mongo.Connection.remove(conn, "test-collection", %{"field" => 1, "otherfield" => 1}, multi: true)
end)

License

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.

sean-lin / mongodb