pirate

A simple key-value storage interface with adapters for different databases

Argh! What's This?

Pirate provides a simple key-value storage interface with adapters for different storage systems. Pirate currently supports Redis and in-memory storage, with MongoDB and ElasticSearch adapters under development.

Important Pirate 1.0 is backwards incompatible with Pirate 0.9.x due to the change to an ES6-friendly Promise-based interfaces.

Here's a simple program to put and get and object from Redis.

assert = require "asssert"
{call} = require "when/generator"
{Redis} = require "pirate"
 
adapter = new Redis.Adapter
  port: 6379
  host: "127.0.0.1"
 
book =
  key: "war-and-peace"
  title: "War and Peace"
  author: "Leo Tolstoy"
  published: "1969"
 
call ->
  # connect to the data store 
  yield adapter.connect()
 
  # get a collection 
  books = yield adapter.collection "books"
 
  # store things in it 
  yield books.put book.keybook
 
  # get them back out 
  assert.deepEqual (yield books.get book.key)book
 
  # update them 
  yield books.patch book.keypublished: "1869"
  book.published = "1869"
  assert.deepEqual (yield books.get book.key)book

Adapter API

The elements of the interface are:

  • get key Returns the object associated with the key or null.

  • put key, object Overwrites the object associated with key with object. Returns the updated object.

  • delete key Deletes the object associated with key. Returns nothing.

  • patch key, patch Updates the object associated with key by overlaying patch. Returns the updated object.

  • all Returns all the objects in the collection.

  • count Returns a count of all the objects in the collection.

All API methods return an Promise object.

The benefits of this approach are:

  • Simplify your code. The Pareto Principle often applies to storage systems, where you only need 20% of the features 80% of the time. Pirate optimizes that 80% while still allowing you to extend adapters to handle the other 20%, specific to your requirements.

  • Eliminate the impedance mismatch between HTTP and storage. Pirate follows a similar interface to that supported by HTTP: get, put, patch, and delete. There's no equivalent to post and there are a few additional methods, but semantically, they're very close.

  • Easily switch between storage implementations. Pirate's adapters not only hide the complexity of the underlying storage implementation, they make it much easier to change it. You can prototype using an in-memory solution, then use a database and later partition your data across servers.

  • Make use of promise-based interfaces. Node-style callbacks provide a reasonable least-common-denominator, but for more sophisticated applications, they can be tedious. Pirate uses promises to provide a generator-friendly interface, so you can just make your database calls using yield expressions.