Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP

Ruby: Caching library to simplify and organize caching

branch: master

v0.4.0

latest commit c2abef6a5b
Michael Grosser authored
Octocat-spinner-32 lib v0.4.0
Octocat-spinner-32 spec fix memcached wrapper
Octocat-spinner-32 .travis.yml use ruby 2
Octocat-spinner-32 Gemfile fix
Octocat-spinner-32 Gemfile.lock v0.4.0
Octocat-spinner-32 Rakefile bump
Octocat-spinner-32 Readme.md removing extra 'all' in readme
Octocat-spinner-32 cachy.gemspec fix
Octocat-spinner-32 gem-public_cert.pem fix up gemspec
Readme.md

Caching library to simplify and organize caching.

  • I18n (seperate caches by locale / expires all locales)
  • Generation based (your able expire all caches of one type)
  • Simultanouse caching (handle multiple processes trying to write same expensive cache at once)
  • Dependent caches (x caches result of cache z+y -> z changes -> x changes)
  • Hashed keys (optional -> short/unreadable)
  • Global cache_version (expire everything Cachy cached, but not e.g. sessions)
  • ...
  • works out of the box with Rails
  • works with pure Memcache, Redis and Moneta(-> Tokyo Cabinet / CouchDB / S3 / Berkeley DB / DataMapper / Memory store)

Install

As Gem: sudo gem install cachy Or as Rails plugin: script/plugins install git://github.com/grosser/cachy.git

Usage

Cachy.cache

result = Cachy.cache(:a_key){ expensive() }
result = Cachy.cache(:a_key, :expires_in => 1.minute){ expensive() }
result = Cachy.cache(:a_key, 'something else', Date.today.day){ expensive() }

Cache expensive operation that is run many times by many processes

Example: at application startup 20 processes try to set the same cache -> 20 heavy database requests -> database timeout -> cache still empty -> ... -> death

# 19 Processes get [], 1 makes the request -- when cached all get the same result
result = Cachy.cache(:a_key, :while_running=>[]){ block_db_for_5_seconds }

Seperate version for each key

Expire all caches of one kind when code inside the cache has been updated

100.times{ Cachy.cache(:a_key, rand(100000) ){ expensive() } }
Cachy.increment_key(:a_key) --> everything expired

Uses I18n.locale if available

Cachy.cache(:a_key){ 'English' }
I18n.locale = :de
Cachy.cache(:a_key){ 'German' } != 'English'

Explicitly not use I18n.locale

Cachy.cache(:a_key, :witout_locale=>true){ 'English' }
I18n.locale = :de
Cachy.cache(:a_key, :witout_locale=>true){ 'German' } == 'English'

Caching results of other caches

When inner cache is expired outer cache would normally still shows old results.
--> expire outer cache when inner cache is expired.

a = Cachy.cache(:a, :expires_in=>1.day){ expensive() }
b = Cachy.cache(:b, :expires_in=>1.week){ expensive_2() }
Cachy.cache(:surrounding, :expires_in=>5.hours, :keys=>[:a, :b]){ a + b * c }
Cachy.increment_key(:b) -->  expires :b and :surrounding

Hashing keys

In case they get to long for your caching backend, makes them short but unreadable.

Cachy.hash_keys = true  # global
Cachy.cache(:a_key, :hash_key=>true){ expensive } # per call

Uses .cache_key when available

E.g. ActiveRecord objects are stored in the key with their updated_at timestamp.
When they are updated the cache is automatically expired.

Cachy.cache(:my_key, User.first){ expensive }

Uses CACHE_VERSION if defined

Use a global CACHE_VERSION=1 so that all caches can be expired when something big changes. The cache server does not need to be restarted and session data(Rails) is saved.

Does not cache nil

If you want to cache a falsy result, use false (same goes for :while_running) Cachy.cache(:x){ expensive || false } Cachy.cache(:x, :while_running=>false){ expensive }

Cachy.cache_if

Only caches if condition is fulfilled Cachy.cache_if(condition, :foo, 'bar', :expires_in => 1.minute){do_something}

Cachy.expire / .expire_view

Expires all locales of a key Cachy.locales = [:de, :en] # by default filled with I18n.available_locales Cachy.expire(:my_key) -> expires for :de, :en and no-locale

#expire "views/#{key}" (counterpart for Rails-view-caching)
Cachy.expire_view(:my_key)
Cachy.expire(:my_key, :prefix=>'views/')

Cachy.key

Use to cache e.g. Erb output <% cache Cachy.key(:a_key), :expires_in=>1.hour do %> More html ... <% end %>

Cachy.cache_store

No ActionController::Base.cache_store ?
Give me something that responds to read/write(Rails style) or []/store(Moneta) or get/set(Memcached) Cachy.cache_store = some_cache

Cachy.locales

No I18n.available_locales ? Cachy.locales = [:de, :en, :fr]

Memcache timeout protection

If Memcache timeouts keep killing your pages -> catch MemCache timeouts

TODO

  • optionally store dependent keys (:keys=>xxx), so that they can be setup up once and do not need to be remembered

Authors

Contributors

Michael Grosser
michael@grosser.it
License: MIT
Build Status

Something went wrong with that request. Please try again.