From 3239ed48d28f3c0baf4445e6c279107e892b7cab Mon Sep 17 00:00:00 2001 From: Aaron Patterson Date: Thu, 18 Feb 2016 08:23:26 -0800 Subject: [PATCH] move digest cache on to the DetailsKey object This moves digest calculation cache on to the details key object. Before, the digest cache was a class level ivar, and one of the keys was the hash value of the details key object: https://github.com/rails/rails/blob/13c4cc3b5aea02716b7459c0da641438077f5236/actionview/lib/action_view/digestor.rb#L28 An object's hash value is not unique, so it's possible for this cache key to produce colliding keys with no resolution. This commit move cache on to the details key object itself, so we know that the digests are always unique per details key object. --- actionview/lib/action_view/digestor.rb | 16 +++++++--------- actionview/lib/action_view/lookup_context.rb | 16 ++++++++++++++++ actionview/test/template/digestor_test.rb | 5 ++--- .../application/per_request_digest_cache_test.rb | 5 +++-- 4 files changed, 28 insertions(+), 14 deletions(-) diff --git a/actionview/lib/action_view/digestor.rb b/actionview/lib/action_view/digestor.rb index 657026fa14..f3c5d6c8df 100644 --- a/actionview/lib/action_view/digestor.rb +++ b/actionview/lib/action_view/digestor.rb @@ -4,13 +4,11 @@ require 'monitor' module ActionView class Digestor - cattr_reader(:cache) - @@cache = Concurrent::Map.new @@digest_monitor = Monitor.new class PerRequestDigestCacheExpiry < Struct.new(:app) # :nodoc: def call(env) - ActionView::Digestor.cache.clear + ActionView::LookupContext::DetailsKey.clear app.call(env) end end @@ -25,12 +23,12 @@ module ActionView def digest(name:, finder:, **options) options.assert_valid_keys(:dependencies, :partial) - cache_key = ([ name, finder.details_key.hash ].compact + Array.wrap(options[:dependencies])).join('.') + cache_key = ([ name ].compact + Array.wrap(options[:dependencies])).join('.') # this is a correctly done double-checked locking idiom # (Concurrent::Map's lookups have volatile semantics) - @@cache[cache_key] || @@digest_monitor.synchronize do - @@cache.fetch(cache_key) do # re-check under lock + finder.digest_cache[cache_key] || @@digest_monitor.synchronize do + finder.digest_cache.fetch(cache_key) do # re-check under lock compute_and_store_digest(cache_key, name, finder, options) end end @@ -42,16 +40,16 @@ module ActionView # Prevent re-entry or else recursive templates will blow the stack. # There is no need to worry about other threads seeing the +false+ value, # as they will then have to wait for this thread to let go of the @@digest_monitor lock. - pre_stored = @@cache.put_if_absent(cache_key, false).nil? # put_if_absent returns nil on insertion + pre_stored = finder.digest_cache.put_if_absent(cache_key, false).nil? # put_if_absent returns nil on insertion PartialDigestor else Digestor end - @@cache[cache_key] = stored_digest = klass.new(name, finder, options).digest + finder.digest_cache[cache_key] = stored_digest = klass.new(name, finder, options).digest ensure # something went wrong or ActionView::Resolver.caching? is false, make sure not to corrupt the @@cache - @@cache.delete_pair(cache_key, false) if pre_stored && !stored_digest + finder.digest_cache.delete_pair(cache_key, false) if pre_stored && !stored_digest end end diff --git a/actionview/lib/action_view/lookup_context.rb b/actionview/lib/action_view/lookup_context.rb index 2a1f4378f5..86afedaa2d 100644 --- a/actionview/lib/action_view/lookup_context.rb +++ b/actionview/lib/action_view/lookup_context.rb @@ -69,6 +69,18 @@ module ActionView def self.clear @details_keys.clear end + + def self.empty?; @details_keys.empty?; end + + def self.digest_caches + @details_keys.values.map(&:digest_cache) + end + + attr_reader :digest_cache + + def initialize + @digest_cache = Concurrent::Map.new + end end # Add caching behavior on top of Details. @@ -194,6 +206,10 @@ module ActionView self.view_paths = view_paths end + def digest_cache + details_key.digest_cache + end + def initialize_details(target, details) registered_details.each do |k| target[k] = details[k] || Accessors::DEFAULT_PROCS[k].call diff --git a/actionview/test/template/digestor_test.rb b/actionview/test/template/digestor_test.rb index e50caac6d8..9ff5f7126b 100644 --- a/actionview/test/template/digestor_test.rb +++ b/actionview/test/template/digestor_test.rb @@ -33,7 +33,6 @@ class TemplateDigestorTest < ActionView::TestCase def teardown Dir.chdir @cwd FileUtils.rm_r @tmp_dir - ActionView::Digestor.cache.clear end def test_top_level_change_reflected @@ -301,12 +300,12 @@ class TemplateDigestorTest < ActionView::TestCase def assert_digest_difference(template_name, options = {}) previous_digest = digest(template_name, options) - ActionView::Digestor.cache.clear + finder.digest_cache.clear yield assert_not_equal previous_digest, digest(template_name, options), "digest didn't change" - ActionView::Digestor.cache.clear + finder.digest_cache.clear end def digest(template_name, options = {}) diff --git a/railties/test/application/per_request_digest_cache_test.rb b/railties/test/application/per_request_digest_cache_test.rb index 3198e12662..210646c7c0 100644 --- a/railties/test/application/per_request_digest_cache_test.rb +++ b/railties/test/application/per_request_digest_cache_test.rb @@ -50,12 +50,13 @@ class PerRequestDigestCacheTest < ActiveSupport::TestCase get '/customers' assert_equal 200, last_response.status - assert_equal [ '8ba099b7749542fe765ff34a6824d548' ], ActionView::Digestor.cache.values + values = ActionView::LookupContext::DetailsKey.digest_caches.first.values + assert_equal [ '8ba099b7749542fe765ff34a6824d548' ], values assert_equal %w(david dingus), last_response.body.split.map(&:strip) end test "template digests are cleared before a request" do - assert_called(ActionView::Digestor.cache, :clear) do + assert_called(ActionView::LookupContext::DetailsKey, :clear) do get '/customers' assert_equal 200, last_response.status end