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-rw-r--r--lib/declarative_policy.rb40
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