class ActionDispatch::Session::CacheStore

Action Dispatch `Session` `CacheStore`

A session store that uses an ActiveSupport::Cache::Store to store the sessions. This store is most useful if you don’t store critical data in your sessions and you don’t need them to live for extended periods of time.

Options

cache - The cache to use. If it is not specified, Rails.cache will be used.
expire_after - The length of time a session will be stored before automatically expiring. By default, the :expires_in option of the cache is used.
check_collisions - Check if newly generated session ids aren’t already in use. If for some reason 128 bits of randomness aren’t considered secure enough to avoid collisions, this option can be enabled to ensure newly generated ids aren’t in use. By default, it is set to false to avoid additional cache write operations.

Public Class Methods

new (app, options = {})

Source

# File lib/action_dispatch/middleware/session/cache_store.rb, line 27
def initialize(app, options = {})
  @cache = options[:cache] || Rails.cache
  options[:expire_after] ||= @cache.options[:expires_in]
  @check_collisions = options[:check_collisions] || false
  super
end

Calls superclass method ActionDispatch::Session::Compatibility::new

Public Instance Methods

delete_session (env, sid, options)

Source

# File lib/action_dispatch/middleware/session/cache_store.rb, line 54
def delete_session(env, sid, options)
  @cache.delete(cache_key(sid.private_id))
  @cache.delete(cache_key(sid.public_id))
  generate_sid
end

Remove a session from the cache.

find_session (env, sid)

Source

# File lib/action_dispatch/middleware/session/cache_store.rb, line 35
def find_session(env, sid)
  unless sid && (session = get_session_with_fallback(sid))
    sid, session = generate_sid, {}
  end
  [sid, session]
end

Get a session from the cache.

write_session (env, sid, session, options)

Source

# File lib/action_dispatch/middleware/session/cache_store.rb, line 43
def write_session(env, sid, session, options)
  key = cache_key(sid.private_id)
  if session
    @cache.write(key, session, expires_in: options[:expire_after])
  else
    @cache.delete(key)
  end
  sid
end

Set a session in the cache.

Private Instance Methods

cache_key (id)

Source

# File lib/action_dispatch/middleware/session/cache_store.rb, line 62
def cache_key(id)
  "_session_id:#{id}"
end

Turn the session id into a cache key.

generate_sid ()

Source

# File lib/action_dispatch/middleware/session/cache_store.rb, line 70
def generate_sid
  if @check_collisions
    loop do
      sid = super
      key = cache_key(sid.private_id)
      break sid if @cache.write(key, {}, unless_exist: true, expires_in: default_options[:expire_after])
    end
  else
    super
  end
end

Calls superclass method ActionDispatch::Session::AbstractSecureStore#generate_sid

get_session_with_fallback (sid)

Source

# File lib/action_dispatch/middleware/session/cache_store.rb, line 66
def get_session_with_fallback(sid)
  @cache.read(cache_key(sid.private_id)) || @cache.read(cache_key(sid.public_id))
end

class ActionDispatch::Session::CacheStore

Action Dispatch Session CacheStore

Options

Action Dispatch `Session` `CacheStore`