From 879a0f5e07a05e0c5ceb7572753dfa3be8162b06 Mon Sep 17 00:00:00 2001 From: Jaroslaw Rzeszotko Date: Sat, 27 Dec 2014 12:55:29 +0100 Subject: Flatten the call stacks ActiveSupport::Callbacks produces, fix #18011. --- activesupport/lib/active_support/callbacks.rb | 190 ++++++++++++++++---------- 1 file changed, 116 insertions(+), 74 deletions(-) (limited to 'activesupport/lib/active_support') diff --git a/activesupport/lib/active_support/callbacks.rb b/activesupport/lib/active_support/callbacks.rb index 95dbc9a0cb..d2911a254c 100644 --- a/activesupport/lib/active_support/callbacks.rb +++ b/activesupport/lib/active_support/callbacks.rb @@ -121,22 +121,22 @@ module ActiveSupport ENDING = End.new class Before - def self.build(next_callback, user_callback, user_conditions, chain_config, filter) + def self.build(callback_sequence, user_callback, user_conditions, chain_config, filter) halted_lambda = chain_config[:terminator] if chain_config.key?(:terminator) && user_conditions.any? - halting_and_conditional(next_callback, user_callback, user_conditions, halted_lambda, filter) + halting_and_conditional(callback_sequence, user_callback, user_conditions, halted_lambda, filter) elsif chain_config.key? :terminator - halting(next_callback, user_callback, halted_lambda, filter) + halting(callback_sequence, user_callback, halted_lambda, filter) elsif user_conditions.any? - conditional(next_callback, user_callback, user_conditions) + conditional(callback_sequence, user_callback, user_conditions) else - simple next_callback, user_callback + simple callback_sequence, user_callback end end - def self.halting_and_conditional(next_callback, user_callback, user_conditions, halted_lambda, filter) - lambda { |env| + def self.halting_and_conditional(callback_sequence, user_callback, user_conditions, halted_lambda, filter) + callback_sequence.before do |env| target = env.target value = env.value halted = env.halted @@ -148,13 +148,14 @@ module ActiveSupport target.send :halted_callback_hook, filter end end - next_callback.call env - } + + env + end end private_class_method :halting_and_conditional - def self.halting(next_callback, user_callback, halted_lambda, filter) - lambda { |env| + def self.halting(callback_sequence, user_callback, halted_lambda, filter) + callback_sequence.before do |env| target = env.target value = env.value halted = env.halted @@ -166,57 +167,59 @@ module ActiveSupport target.send :halted_callback_hook, filter end end - next_callback.call env - } + + env + end end private_class_method :halting - def self.conditional(next_callback, user_callback, user_conditions) - lambda { |env| + def self.conditional(callback_sequence, user_callback, user_conditions) + callback_sequence.before do |env| target = env.target value = env.value if user_conditions.all? { |c| c.call(target, value) } user_callback.call target, value end - next_callback.call env - } + + env + end end private_class_method :conditional - def self.simple(next_callback, user_callback) - lambda { |env| + def self.simple(callback_sequence, user_callback) + callback_sequence.before do |env| user_callback.call env.target, env.value - next_callback.call env - } + + env + end end private_class_method :simple end class After - def self.build(next_callback, user_callback, user_conditions, chain_config) + def self.build(callback_sequence, user_callback, user_conditions, chain_config) if chain_config[:skip_after_callbacks_if_terminated] if chain_config.key?(:terminator) && user_conditions.any? - halting_and_conditional(next_callback, user_callback, user_conditions) + halting_and_conditional(callback_sequence, user_callback, user_conditions) elsif chain_config.key?(:terminator) - halting(next_callback, user_callback) + halting(callback_sequence, user_callback) elsif user_conditions.any? - conditional next_callback, user_callback, user_conditions + conditional callback_sequence, user_callback, user_conditions else - simple next_callback, user_callback + simple callback_sequence, user_callback end else if user_conditions.any? - conditional next_callback, user_callback, user_conditions + conditional callback_sequence, user_callback, user_conditions else - simple next_callback, user_callback + simple callback_sequence, user_callback end end end - def self.halting_and_conditional(next_callback, user_callback, user_conditions) - lambda { |env| - env = next_callback.call env + def self.halting_and_conditional(callback_sequence, user_callback, user_conditions) + callback_sequence.after do |env| target = env.target value = env.value halted = env.halted @@ -224,122 +227,124 @@ module ActiveSupport if !halted && user_conditions.all? { |c| c.call(target, value) } user_callback.call target, value end + env - } + end end private_class_method :halting_and_conditional - def self.halting(next_callback, user_callback) - lambda { |env| - env = next_callback.call env + def self.halting(callback_sequence, user_callback) + callback_sequence.after do |env| unless env.halted user_callback.call env.target, env.value end + env - } + end end private_class_method :halting - def self.conditional(next_callback, user_callback, user_conditions) - lambda { |env| - env = next_callback.call env + def self.conditional(callback_sequence, user_callback, user_conditions) + callback_sequence.after do |env| target = env.target value = env.value if user_conditions.all? { |c| c.call(target, value) } user_callback.call target, value end + env - } + end end private_class_method :conditional - def self.simple(next_callback, user_callback) - lambda { |env| - env = next_callback.call env + def self.simple(callback_sequence, user_callback) + callback_sequence.after do |env| user_callback.call env.target, env.value + env - } + end end private_class_method :simple end class Around - def self.build(next_callback, user_callback, user_conditions, chain_config) + def self.build(callback_sequence, user_callback, user_conditions, chain_config) if chain_config.key?(:terminator) && user_conditions.any? - halting_and_conditional(next_callback, user_callback, user_conditions) + halting_and_conditional(callback_sequence, user_callback, user_conditions) elsif chain_config.key? :terminator - halting(next_callback, user_callback) + halting(callback_sequence, user_callback) elsif user_conditions.any? - conditional(next_callback, user_callback, user_conditions) + conditional(callback_sequence, user_callback, user_conditions) else - simple(next_callback, user_callback) + simple(callback_sequence, user_callback) end end - def self.halting_and_conditional(next_callback, user_callback, user_conditions) - lambda { |env| + def self.halting_and_conditional(callback_sequence, user_callback, user_conditions) + callback_sequence.around do |env, &run| target = env.target value = env.value halted = env.halted if !halted && user_conditions.all? { |c| c.call(target, value) } user_callback.call(target, value) { - env = next_callback.call env + env = run.call env env.value } + env else - next_callback.call env + run.call env end - } + end end private_class_method :halting_and_conditional - def self.halting(next_callback, user_callback) - lambda { |env| + def self.halting(callback_sequence, user_callback) + callback_sequence.around do |env, &run| target = env.target value = env.value if env.halted - next_callback.call env + run.call env else user_callback.call(target, value) { - env = next_callback.call env + env = run.call env env.value } env end - } + end end private_class_method :halting - def self.conditional(next_callback, user_callback, user_conditions) - lambda { |env| + def self.conditional(callback_sequence, user_callback, user_conditions) + callback_sequence.around do |env, &run| target = env.target value = env.value if user_conditions.all? { |c| c.call(target, value) } user_callback.call(target, value) { - env = next_callback.call env + env = run.call env env.value } env else - next_callback.call env + run.call env end - } + end end private_class_method :conditional - def self.simple(next_callback, user_callback) - lambda { |env| + def self.simple(callback_sequence, user_callback) + callback_sequence.around do |env, &run| user_callback.call(env.target, env.value) { - env = next_callback.call env + env = run.call env env.value } env - } + end end private_class_method :simple end @@ -392,17 +397,17 @@ module ActiveSupport end # Wraps code with filter - def apply(next_callback) + def apply(callback_sequence) user_conditions = conditions_lambdas user_callback = make_lambda @filter case kind when :before - Filters::Before.build(next_callback, user_callback, user_conditions, chain_config, @filter) + Filters::Before.build(callback_sequence, user_callback, user_conditions, chain_config, @filter) when :after - Filters::After.build(next_callback, user_callback, user_conditions, chain_config) + Filters::After.build(callback_sequence, user_callback, user_conditions, chain_config) when :around - Filters::Around.build(next_callback, user_callback, user_conditions, chain_config) + Filters::Around.build(callback_sequence, user_callback, user_conditions, chain_config) end end @@ -467,6 +472,42 @@ module ActiveSupport end end + # Execute before and after filters in a sequence instead of + # chaining them with nested lambda calls, see: + # https://github.com/rails/rails/issues/18011 + class CallbackSequence + def initialize(&call) + @call = call + @before = [] + @after = [] + end + + def before(&before) + @before.unshift(before) + self + end + + def after(&after) + @after.push(after) + self + end + + def around(&around) + CallbackSequence.new do |*args| + around.call(*args) { + self.call(*args) + } + end + end + + def call(*args) + @before.each { |b| b.call(*args) } + value = @call.call(*args) + @after.each { |a| a.call(*args) } + value + end + end + # An Array with a compile method. class CallbackChain #:nodoc:# include Enumerable @@ -511,8 +552,9 @@ module ActiveSupport def compile @callbacks || @mutex.synchronize do - @callbacks ||= @chain.reverse.inject(Filters::ENDING) do |chain, callback| - callback.apply chain + final_sequence = CallbackSequence.new { |env| Filters::ENDING.call(env) } + @callbacks ||= @chain.reverse.inject(final_sequence) do |callback_sequence, callback| + callback.apply callback_sequence end end end -- cgit v1.2.3