diff options
Diffstat (limited to 'lib/declarative_policy.rb')
| -rw-r--r-- | lib/declarative_policy.rb | 40 |
1 files changed, 35 insertions, 5 deletions
diff --git a/lib/declarative_policy.rb b/lib/declarative_policy.rb index d9959bc1aff..b1eb1a6cef1 100644 --- a/lib/declarative_policy.rb +++ b/lib/declarative_policy.rb @@ -8,7 +8,12 @@ require_dependency 'declarative_policy/step' require_dependency 'declarative_policy/base' +require 'thread' + module DeclarativePolicy + CLASS_CACHE_MUTEX = Mutex.new + CLASS_CACHE_IVAR = :@__DeclarativePolicy_CLASS_CACHE + class << self def policy_for(user, subject, opts = {}) cache = opts[:cache] || {} @@ -23,7 +28,36 @@ module DeclarativePolicy subject = find_delegate(subject) - subject.class.ancestors.each do |klass| + class_for_class(subject.class) + end + + private + + # This method is heavily cached because there are a lot of anonymous + # modules in play in a typical rails app, and #name performs quite + # slowly for anonymous classes and modules. + # + # See https://bugs.ruby-lang.org/issues/11119 + # + # if the above bug is resolved, this caching could likely be removed. + def class_for_class(subject_class) + unless subject_class.instance_variable_defined?(CLASS_CACHE_IVAR) + CLASS_CACHE_MUTEX.synchronize do + # re-check in case of a race + break if subject_class.instance_variable_defined?(CLASS_CACHE_IVAR) + + policy_class = compute_class_for_class(subject_class) + subject_class.instance_variable_set(CLASS_CACHE_IVAR, policy_class) + end + end + + policy_class = subject_class.instance_variable_get(CLASS_CACHE_IVAR) + raise "no policy for #{subject.class.name}" if policy_class.nil? + policy_class + end + + def compute_class_for_class(subject_class) + subject_class.ancestors.each do |klass| next unless klass.name begin @@ -37,12 +71,8 @@ module DeclarativePolicy nil end end - - raise "no policy for #{subject.class.name}" end - private - def find_delegate(subject) seen = Set.new |