An EventMachine interface to the HyperDex NoSQL data store.

It's a gem:

gem install em-hyperdex-client

If you're the sturdy type that likes to run from git:

rake build; gem install pkg/em-hyperdex-client-<whatever>.gem

Or, if you've eschewed the convenience of Rubygems, then you presumably know what to do already.

To use any of these methods, you will want to add the following require:

require 'em-hyperdex-client'

Somewhere inside your EM.run block, create a client object:

c = EM::HyperDex::Client.new('localhost', 1982)

Then, call any (synchronous) method you normally would on a regular HyperDex::Client::Client instance, but instead of having the result returned to you, you use #callback to handle the response:

c.get(:kv, "foo").callback do |r|
  puts "The value of foo is #{r}"
end

To specify the proper order of operations, you need to nest your callbacks:

c.get(:kv, "foo").callback do |r|
  c.put(:kv, "foo", r.merge(:baz => "wombat")).callback do
    c.get(:kv, "bar").callback do |r|
      puts "Ohai!"
    end
  end
end

To handle errors, you specify an #errback callback:

c.get(:kv, "foo").callback do |r|
  c.put(:kv, "foo", r.merge(:baz => "wombat")).callback do
    puts "Completed successfully"
  end.errback do |ex|
    puts "Error on put: #{ex.message}"
  end
end.errback do |ex|
  puts "Error on get: #{ex.message}"
end

What gets yielded to your #errback block is the same exception that would otherwise have been raised by the operation you performed -- typically, that'll be a HyperDex::Client::HyperDexClientException.

Bug reports should be sent to the Github issue tracker, or e-mailed. Patches can be sent as a Github pull request, or e-mailed.