Monga

Yet another MongoDB Ruby Client.

It supports three kind of interfaces:

Asynchronous over EventMachine
Synchronous (on Fibers)
Blocking (over TCPSocket, kgio actually)

Introduction

Asynchronous API will be familiar to Node.js developers. Instead of Deferrable Object you will receive err, response into callback.

EM.run do
  client = Monga::Client.new(type: :em)
  db = client["testDb"]
  collection = db["testCollection"]

  # Fire and forget
  collection.insert(artist: "Madonna", title: "Frozen")

  # Safe method
  collection.safe_insert(artist: "Madonna", title: "Burning Up") do |err, response|
    if err
      puts "Ha, an error! #{err.message}"
    else
      puts "Job is done. Let's do more job"

      # Cursor
      collection.find.batch_size(100).limit(500).each_doc do |err, doc, iter|
        if iter
          puts "What have we got here: #{doc['title']}"
          iter.next
        else
          puts "No more documents in collection"
          EM.stop
        end
      end
      # Yes, you should call `iter.next`, welcome to callback world!
    end
  end
end

Synchronous mode is more simple. It is just like blocking mode, but you can use pool of fibers to make it as fast as lightning.

EM.synchrony do
  client = Monga::Client.new(type: :sync)
  db = client["testDb"]
  collection = db["testCollection"]

  # Fire and forget
  collection.insert(artist: "Madonna", title: "Frozen")

  # Safe method
  collection.safe_insert(artist: "Madonna", title: "Burning Up")
  puts "Job is done"

  # Cursor
  docs = []
  collection.find.batch_size(100).limit(500).each_doc do |doc|
    puts "What have we got here: #{doc['title']}"
    docs << doc
  end
  puts "We have got #{docs.size} documents in this pretty array"

  EM.stop
end

Blocking mode is as simple as a potato

# client = Monga::Client.new(type: :block)
client = Monga::Client.new
db = client["testDb"]
collection = db["testCollection"]

# Fire and forget
collection.insert(artist: "Madonna", title: "Frozen")

# Safe method
collection.safe_insert(artist: "Madonna", title: "Burning Up")
puts "Job is done"

# Cursor
docs = []
collection.find.batch_size(100).limit(500).each_doc do |doc|
  puts "What have we got here: #{doc['title']}"
  docs << doc
end
puts "We have got #{docs.size} documents in this pretty array"

To Do List

[ ] Write a Wiki
[ ] Write comments
[ ] Grammar improvement ;)

Clients

[x] Client (Single instance connection)
[x] ReplicaSetClient
[ ] MasterSlaveClient
[x] ReadPref
[ ] Sharding Support

Connection

[x] Connection
[x] Autoreconnect
[x] Connection Pool

Protocol

[x] OP_QUERY
[x] OP_GET_MORE
[x] OP_KILL_CURSORS
[x] OP_INSERT
[x] OP_UPDATE
[x] OP_DELETE
[x] OP_REPLY

Database

[x] create_collection
[x] drop_collection
[x] get_last_error
[x] drop_indexes
[x] get_indexes
Authentication
- [ ] login
- [ ] logout
- [ ] add_user
[ ] check maxBsonSize / validate
[x] cmd
[x] eval
[x] aggregate
[x] distinct
[x] group
[x] mapReduce
[x] text
[ ] gridfs?

Collection

QUERY_OP
- [x] find
- [x] find_one (first)
- [x] sorting
INSERT_OP
- [x] insert (single)
- [x] insert (batch)
- [x] safe_insert
- FLAGS
  - [x] continue_on_error
UPDATE_OP
- [x] update
- [x] safe_update
- FLAGS
  - [x] upsert
  - [x] multi_update
DELETE_OP
- [x] delete
- [x] safe_delete
- FLAGS
  - [x] single_remove
INDEXES
- [x] ensure_index
- [x] drop_index
- [x] drop_indexes
- [x] get_indexes
[x] count
[x] all
[x] cursor
[ ] DBRef

Cursor

[x] limit
[x] skip
[x] batch_size
[x] get_more
[x] next_document
[x] next_batch
[x] each_doc
[x] kill
[x] mark_to_kill
[x] batch_kill
[x] explain
[x] hint
Flags
- [x] tailable_cursor
- [x] slave_ok
- [x] no_cursor_timeout
- [x] await_data
- [x] exhaust
- [x] partial

ISSUES handled with

Some commands, such as db.getLastError, db.count and other db.commands requires numberToReturn in OP_QUERY to be setted as -1. Also this commands should return a response. If nothing returned it should be interpreted as an Exception. Also, in contrast to the other queries it could return errmsg which should be interpreted as an Exception too. Other query methods could return err response.

To create index you can't call any db.ensureIndex command but you should insert a document into sytem.indexes collection manually. To get list of indexes you should fetch all documents from this collection. But to drop index you should call specific db.dropIndexes command.

multi_update flag works only with $ commands (i.e. $set: { title: "blahblah" })