rufus-cloche¶ ↑

A very stupid local JSON store.

It’s built on top of yajl-ruby and File.lock. Defaults to ‘json’ (or ‘json_pure’) if yajl-ruby is not present (it’s probably just a “gem install yajl-ruby” away.

Strives to be process-safe and thread-safe.

The philosophy here is : every document has a revision number. You have to provide the latest revision number in order to update sucessfully a document (else the ‘put’ will fail and you’ll return the latest version of the document (as a new starting point)).

A cloche assumes your documents have a ‘type’ and it stores documents in separate dirs, one per type.

WARNING : this library works on windows but without locking (only thread sync).

Basic operations :

require 'rubygems'
require 'rufus-cloche' # gem install rufus-cloche

c = Rufus::Cloche.new(:dir => 'my_cloche')

doc = { '_id' => 'invitation05', 'type' => 'letter', 'to' => 'The Duke' }
  # documents are Hash instances, with an '_id' and a 'type' key.

d = c.put(doc)

p d
  # => nil
  # #put returned nil, the 'insertion' was successful

p doc['_rev']
  # => 0
  # Cloche added the '_rev' key and set its value to 0.

# ... meanwhile, someone in another process upated the document
# we're trying to put an updated version ...

doc['body'] = "Dear Monty, it's been a while since El Alamein..."

d = c.put(doc)

p d
  # => { "_id" => "invitation05", "type"=>"letter", "to" => "The Count", "_rev" => 1 }
  #
  # the update failed, the method returned the current version of the document

It’s OK to get a document, but it’s sometimes better to get many of them :

docs = get_many('letter')
  # returns an array containing *all* the documents with the type 'letter'

docs = get_many('letter', /^invitation/)
  # returns all the documents whose _id begins with "invitation"

docs = get_many('letter', /\/2009\//)
  # returns all the 2009 letters (assuming their _id contains the string "/2009/"

On the rufus-ruby list :

groups.google.com/group/rufus-ruby

github.com/jmettraux/rufus-cloche/issues

irc.freenode.net #ruote

rufus.rubyforge.org

• John Mettraux, jmettraux@gmail.com, jmettraux.wordpress.com

MIT