Wolverine is a simple library to allow you to manage and run redis server-side lua scripts from a rails app, or other ruby code.

Redis versions 2.6 and up allow lua scripts to be run on the server that execute atomically and very quickly.

This is extremely useful.

Wolverine is a wrapper around that functionality, to package it up in a format more familiar to a Rails codebase.

1. Make sure you have redis 2.6 or higher installed. As of now, that means compiling from source:

git clone https://github.com/antirez/redis.git
cd redis && make
./src/redis-server

2. Add wolverine to your Gemfile:

gem 'wolverine'

3. Add your lua scripts to app/wolverine:

-- app/wolverine/util/mexists.lua
local exists = {}
local existence
for _, key in ipairs(KEYS) do
  table.insert(exists, redis.call('exists', key))
end
return exists

4. Call wolverine from your code:

Wolverine.util.mexists(['key1', 'key2', 'key3']) #=> [0, 1, 0]

Or

Wolverine.util.mexists(:keys => ['key1', 'key2', 'key3']) #=> [0, 1, 0]

Methods are available on Wolverine paralleling the directory structure of wolverine's script_path.

Available configuration options:

• Wolverine.config.redis (default Redis.new)
• Wolverine.config.script_path (default Rails.root + 'app/wolverine')
• Wolverine.config.instrumentation (default none)

If you want to override one or more of these, doing so in an initializer is recommended but not required. See the full documentation for more details.

For more information on scripting redis with lua, refer to redis' excellent documentation: http://redis.io/commands/eval

Copyright (C) 2012 Shopify by Burke Libbey

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