rb-redis-cache

A simple framework-agnostic cache with Redis.

⚠️ This gem is still under development, the api is not stable and there might be breaking changes until we reach v1.0.

Installation

Add this line to your application's Gemfile:

gem 'rb-redis-cache'

And then execute:

bundle install

Or install it yourself as:

gem install rb-redis-cache

Usage

Connection

You can connect to Redis by configuring the RedisCache::Store class:

require 'redis_cache'

cache = RedisCache::Store.new(url: REDIS_URL)

Alternatively, you can pass options to the Store instance:

require 'redis_cache'

cache = RedisCache::Store.new(url: REDIS_URL, connect_timeout: 10)

Defaults are defined in lib/redis_cache.rb and can be overrided.

Storing objects

You can store data structures that can be serialized to JSON.

cache.write('my_key', 'my_value')

my_hash = {a: 'a', b: 'b', c: [{ d: 'd' }]}
cache.write('my_key', my_hash)

Optionaly, you can set an expiry time in seconds fot the key.

cache.write('my_key', 'my_value', expires_in: 60)

Retrieving objects

cache.read('my_key')
=> 'my_value'

Incrementing a counter

Increments the number stored at key by increment.

cache.increment('my_key_inc')
=> 1
cache.increment('my_key_inc')
=> 2

Decrementing a counter

Decrements the number stored at key by decrement.

cache.increment('my_key_inc')
=> 1
cache.increment('my_key_inc')
=> 2
cache.decrement('my_key_inc')
=> 1

Testing if a key exist

cache.write('my_key', 'my_value')
cache.exist?('my_key')
=> true

cache.exist?('my_other_key')
=> false

Deleting a key

cache.delete('my_key')

Rails-style fetching

You can fetch a key from the cache, if there is an existing value for a given key, then this value is returned. If there is no value for the given key, and a block parameter has been passed, then the result will be cached and returned.

cache.fetch('my_key', expires_in: 60) do
  block_method_calculation
end
=> 'my_value'

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/jveillet/rb-redis-cache/issues.

License

The gem is available as open source under the terms of the MIT License.