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Simplify dependencies.rb some. Remove alias of Kernel::Foo to Object:…

…:Foo as it was not used and breaks Ruby semantics.
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1 parent d68f8ba commit 4da45060a2e839fec4a7e9238cbc9d8de62b1b69 Yehuda Katz committed Feb 14, 2010
Showing with 141 additions and 201 deletions.
  1. +135 −190 activesupport/lib/active_support/dependencies.rb
  2. +6 −11 activesupport/test/dependencies_test.rb
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325 activesupport/lib/active_support/dependencies.rb
@@ -1,5 +1,6 @@
require 'set'
require 'thread'
+require 'pathname'
require 'active_support/core_ext/module/aliasing'
require 'active_support/core_ext/module/attribute_accessors'
require 'active_support/core_ext/module/introspection'
@@ -58,85 +59,116 @@ module Dependencies #:nodoc:
mattr_accessor :log_activity
self.log_activity = false
+ class WatchStack < Array
+ def initialize
+ @mutex = Mutex.new
+ end
+
+ def self.locked(*methods)
+ methods.each { |m| class_eval "def #{m}(*) lock { super } end" }
+ end
+
+ def get(key)
+ (val = assoc(key)) ? val[1] : []
+ end
+
+ locked :concat, :each, :delete_if, :<<
+
+ def new_constants_for(frames)
+ frames.map do |mod_name, prior_constants|
+ mod = Inflector.constantize(mod_name)
+ next unless mod.is_a?(Module)
+
+ new_constants = mod.local_constant_names - prior_constants
+ get(mod_name).concat(new_constants)
+
+ new_constants.map do |suffix|
+ ([mod_name, suffix] - ["Object"]).join("::")
+ end
+ end.flatten
+ end
+
+ # Add a set of modules to the watch stack, remembering the initial constants
+ def add_modules(modules)
+ list = modules.map do |desc|
+ name = Dependencies.to_constant_name(desc)
+ consts = Dependencies.qualified_const_defined?(name) ?
+ Inflector.constantize(name).local_constant_names : []
+ [name, consts]
+ end
+ concat(list)
+ list
+ end
+
+ def lock
+ @mutex.synchronize { yield self }
+ end
+ end
+
# An internal stack used to record which constants are loaded by any block.
mattr_accessor :constant_watch_stack
- self.constant_watch_stack = []
-
- mattr_accessor :constant_watch_stack_mutex
- self.constant_watch_stack_mutex = Mutex.new
+ self.constant_watch_stack = WatchStack.new
# Module includes this module
module ModuleConstMissing #:nodoc:
- def self.included(base) #:nodoc:
+ def self.append_features(base)
base.class_eval do
- unless defined? const_missing_without_dependencies
- alias_method_chain :const_missing, :dependencies
- end
+ # Emulate #exclude via an ivar
+ return if @_const_missing
+ @_const_missing = method(:const_missing)
+ remove_method(:const_missing)
end
+ super
end
- def self.excluded(base) #:nodoc:
+ def self.exclude_from(base)
base.class_eval do
- if defined? const_missing_without_dependencies
- undef_method :const_missing
- alias_method :const_missing, :const_missing_without_dependencies
- undef_method :const_missing_without_dependencies
- end
+ define_method :const_missing, @_const_missing
+ @_const_missing = nil
end
end
# Use const_missing to autoload associations so we don't have to
# require_association when using single-table inheritance.
- def const_missing_with_dependencies(class_id)
- ActiveSupport::Dependencies.load_missing_constant self, class_id
- end
+ def const_missing(const_name, nesting = nil)
+ klass_name = name.presence || "Object"
+
+ if !nesting
+ # We'll assume that the nesting of Foo::Bar is ["Foo::Bar", "Foo"]
+ # even though it might not be, such as in the case of
+ # class Foo::Bar; Baz; end
+ nesting = []
+ klass_name.to_s.scan(/::|$/) { nesting.unshift $` }
+ end
- def unloadable(const_desc = self)
- super(const_desc)
- end
- end
+ # If there are multiple levels of nesting to search under, the top
+ # level is the one we want to report as the lookup fail.
+ error = nil
- # Class includes this module
- module ClassConstMissing #:nodoc:
- def const_missing(const_name)
- if [Object, Kernel].include?(self) || parent == self
- super
- else
+ nesting.each do |namespace|
begin
- begin
- Dependencies.load_missing_constant self, const_name
- rescue NameError
- parent.send :const_missing, const_name
- end
+ return Dependencies.load_missing_constant namespace.constantize, const_name
+ rescue NoMethodError then raise
rescue NameError => e
- # Make sure that the name we are missing is the one that caused the error
- parent_qualified_name = Dependencies.qualified_name_for parent, const_name
- raise unless e.missing_name? parent_qualified_name
- qualified_name = Dependencies.qualified_name_for self, const_name
- raise NameError.new("uninitialized constant #{qualified_name}").copy_blame!(e)
+ error ||= e
end
end
+
+ # Raise the first error for this set. If this const_missing came from an
+ # earlier const_missing, this will result in the real error bubbling
+ # all the way up
+ raise error
+ end
+
+ def unloadable(const_desc = self)
+ super(const_desc)
end
end
# Object includes this module
module Loadable #:nodoc:
- def self.included(base) #:nodoc:
- base.class_eval do
- unless defined? load_without_new_constant_marking
- alias_method_chain :load, :new_constant_marking
- end
- end
- end
-
- def self.excluded(base) #:nodoc:
- base.class_eval do
- if defined? load_without_new_constant_marking
- undef_method :load
- alias_method :load, :load_without_new_constant_marking
- undef_method :load_without_new_constant_marking
- end
- end
+ def self.exclude_from(base)
+ base.class_eval { define_method(:load, Kernel.instance_method(:load)) }
end
def require_or_load(file_name)
@@ -151,26 +183,23 @@ def require_association(file_name)
Dependencies.associate_with(file_name)
end
- def load_with_new_constant_marking(file, *extras) #:nodoc:
+ def load_dependency(file)
if Dependencies.load?
- Dependencies.new_constants_in(Object) { load_without_new_constant_marking(file, *extras) }
+ Dependencies.new_constants_in(Object) { yield }.presence
else
- load_without_new_constant_marking(file, *extras)
+ yield
end
rescue Exception => exception # errors from loading file
exception.blame_file! file
raise
end
- def require(file, *extras) #:nodoc:
- if Dependencies.load?
- Dependencies.new_constants_in(Object) { super }
- else
- super
- end
- rescue Exception => exception # errors from required file
- exception.blame_file! file
- raise
+ def load(file, *)
+ load_dependency(file) { super }
+ end
+
+ def require(file, *)
+ load_dependency(file) { super }
end
# Mark the given constant as unloadable. Unloadable constants are removed each
@@ -213,16 +242,15 @@ def copy_blame!(exc)
end
def hook!
- Object.instance_eval { include Loadable }
- Module.instance_eval { include ModuleConstMissing }
- Class.instance_eval { include ClassConstMissing }
- Exception.instance_eval { include Blamable }
+ Object.class_eval { include Loadable }
+ Module.class_eval { include ModuleConstMissing }
+ Exception.class_eval { include Blamable }
true
end
def unhook!
- ModuleConstMissing.excluded(Module)
- Loadable.excluded(Object)
+ ModuleConstMissing.exclude_from(Module)
+ Loadable.exclude_from(Object)
true
end
@@ -292,59 +320,43 @@ def require_or_load(file_name, const_path = nil)
# Is the provided constant path defined?
def qualified_const_defined?(path)
- raise NameError, "#{path.inspect} is not a valid constant name!" unless
- /^(::)?([A-Z]\w*)(::[A-Z]\w*)*$/ =~ path
-
- names = path.to_s.split('::')
- names.shift if names.first.empty?
+ names = path.sub(/^::/, '').to_s.split('::')
- # We can't use defined? because it will invoke const_missing for the parent
- # of the name we are checking.
names.inject(Object) do |mod, name|
- return false unless uninherited_const_defined?(mod, name)
+ return false unless local_const_defined?(mod, name)
mod.const_get name
end
- return true
end
if Module.method(:const_defined?).arity == 1
# Does this module define this constant?
# Wrapper to accomodate changing Module#const_defined? in Ruby 1.9
- def uninherited_const_defined?(mod, const)
+ def local_const_defined?(mod, const)
mod.const_defined?(const)
end
else
- def uninherited_const_defined?(mod, const) #:nodoc:
+ def local_const_defined?(mod, const) #:nodoc:
mod.const_defined?(const, false)
end
end
# Given +path+, a filesystem path to a ruby file, return an array of constant
# paths which would cause Dependencies to attempt to load this file.
def loadable_constants_for_path(path, bases = load_paths)
- path = $1 if path =~ /\A(.*)\.rb\Z/
- expanded_path = File.expand_path(path)
-
- bases.collect do |root|
- expanded_root = File.expand_path(root)
- next unless %r{\A#{Regexp.escape(expanded_root)}(/|\\)} =~ expanded_path
-
- nesting = expanded_path[(expanded_root.size)..-1]
- nesting = nesting[1..-1] if nesting && nesting[0] == ?/
- next if nesting.blank?
- nesting_camel = nesting.camelize
- begin
- qualified_const_defined?(nesting_camel)
- rescue NameError
- next
- end
- [ nesting_camel ]
- end.compact.flatten.compact.uniq
+ expanded_path = Pathname.new(path[/\A(.*?)(\.rb)?\Z/, 1]).expand_path
+
+ bases.inject([]) do |paths, root|
+ expanded_root = Pathname.new(root).expand_path
+ nesting = expanded_path.relative_path_from(expanded_root).to_s
+ next paths if nesting =~ /\.\./
+ paths << nesting.camelize
+ end.uniq
end
# Search for a file in load_paths matching the provided suffix.
def search_for_file(path_suffix)
- path_suffix = "#{path_suffix}.rb" unless path_suffix =~ /\.rb\Z/
+ path_suffix = path_suffix.sub(/(\.rb)?$/, ".rb")
+
load_paths.each do |root|
path = File.join(root, path_suffix)
return path if File.file? path
@@ -393,7 +405,7 @@ def load_file(path, const_paths = loadable_constants_for_path(path))
result = nil
newly_defined_paths = new_constants_in(*parent_paths) do
- result = load_without_new_constant_marking path
+ result = Kernel.load path
end
autoloaded_constants.concat newly_defined_paths unless load_once_path?(path)
@@ -405,46 +417,35 @@ def load_file(path, const_paths = loadable_constants_for_path(path))
# Return the constant path for the provided parent and constant name.
def qualified_name_for(mod, name)
mod_name = to_constant_name mod
- (%w(Object Kernel).include? mod_name) ? name.to_s : "#{mod_name}::#{name}"
+ mod_name == "Object" ? name.to_s : "#{mod_name}::#{name}"
end
# Load the constant named +const_name+ which is missing from +from_mod+. If
# it is not possible to load the constant into from_mod, try its parent module
# using const_missing.
def load_missing_constant(from_mod, const_name)
log_call from_mod, const_name
- if from_mod == Kernel
- if ::Object.const_defined?(const_name)
- log "Returning Object::#{const_name} for Kernel::#{const_name}"
- return ::Object.const_get(const_name)
- else
- log "Substituting Object for Kernel"
- from_mod = Object
- end
- end
-
- # If we have an anonymous module, all we can do is attempt to load from Object.
- from_mod = Object if from_mod.name.blank?
- unless qualified_const_defined?(from_mod.name) && Inflector.constantize(from_mod.name).object_id == from_mod.object_id
+ unless qualified_const_defined?(from_mod.name) && Inflector.constantize(from_mod.name).equal?(from_mod)
raise ArgumentError, "A copy of #{from_mod} has been removed from the module tree but is still active!"
end
- raise ArgumentError, "#{from_mod} is not missing constant #{const_name}!" if uninherited_const_defined?(from_mod, const_name)
+ raise ArgumentError, "#{from_mod} is not missing constant #{const_name}!" if local_const_defined?(from_mod, const_name)
qualified_name = qualified_name_for from_mod, const_name
path_suffix = qualified_name.underscore
name_error = NameError.new("uninitialized constant #{qualified_name}")
file_path = search_for_file(path_suffix)
+
if file_path && ! loaded.include?(File.expand_path(file_path)) # We found a matching file to load
require_or_load file_path
- raise LoadError, "Expected #{file_path} to define #{qualified_name}" unless uninherited_const_defined?(from_mod, const_name)
+ raise LoadError, "Expected #{file_path} to define #{qualified_name}" unless local_const_defined?(from_mod, const_name)
return from_mod.const_get(const_name)
elsif mod = autoload_module!(from_mod, const_name, qualified_name, path_suffix)
return mod
elsif (parent = from_mod.parent) && parent != from_mod &&
- ! from_mod.parents.any? { |p| uninherited_const_defined?(p, const_name) }
+ ! from_mod.parents.any? { |p| local_const_defined?(p, const_name) }
# If our parents do not have a constant named +const_name+ then we are free
# to attempt to load upwards. If they do have such a constant, then this
# const_missing must be due to from_mod::const_name, which should not
@@ -505,79 +506,26 @@ def mark_for_unload(const_desc)
# and will be removed immediately.
def new_constants_in(*descs)
log_call(*descs)
-
- # Build the watch frames. Each frame is a tuple of
- # [module_name_as_string, constants_defined_elsewhere]
- watch_frames = descs.collect do |desc|
- if desc.is_a? Module
- mod_name = desc.name
- initial_constants = desc.local_constant_names
- elsif desc.is_a?(String) || desc.is_a?(Symbol)
- mod_name = desc.to_s
-
- # Handle the case where the module has yet to be defined.
- initial_constants = if qualified_const_defined?(mod_name)
- Inflector.constantize(mod_name).local_constant_names
- else
- []
- end
- else
- raise Argument, "#{desc.inspect} does not describe a module!"
- end
-
- [mod_name, initial_constants]
- end
-
- constant_watch_stack_mutex.synchronize do
- constant_watch_stack.concat watch_frames
- end
+ watch_frames = constant_watch_stack.add_modules(descs)
aborting = true
begin
yield # Now yield to the code that is to define new constants.
aborting = false
ensure
- # Find the new constants.
- new_constants = watch_frames.collect do |mod_name, prior_constants|
- # Module still doesn't exist? Treat it as if it has no constants.
- next [] unless qualified_const_defined?(mod_name)
-
- mod = Inflector.constantize(mod_name)
- next [] unless mod.is_a? Module
- new_constants = mod.local_constant_names - prior_constants
-
- # Make sure no other frames takes credit for these constants.
- constant_watch_stack_mutex.synchronize do
- constant_watch_stack.each do |frame_name, constants|
- constants.concat new_constants if frame_name == mod_name
- end
- end
-
- new_constants.collect do |suffix|
- mod_name == "Object" ? suffix : "#{mod_name}::#{suffix}"
- end
- end.flatten
+ new_constants = constant_watch_stack.new_constants_for(watch_frames)
log "New constants: #{new_constants * ', '}"
+ return new_constants unless aborting
- if aborting
- log "Error during loading, removing partially loaded constants "
- new_constants.each { |name| remove_constant name }
- new_constants.clear
- end
+ log "Error during loading, removing partially loaded constants "
+ new_constants.each {|c| remove_constant(c) }.clear
end
- return new_constants
+ return []
ensure
# Remove the stack frames that we added.
- if defined?(watch_frames) && ! watch_frames.blank?
- frame_ids = watch_frames.collect { |frame| frame.object_id }
- constant_watch_stack_mutex.synchronize do
- constant_watch_stack.delete_if do |watch_frame|
- frame_ids.include? watch_frame.object_id
- end
- end
- end
+ watch_frames.each {|f| constant_watch_stack.delete(f) } if watch_frames.present?
end
class LoadingModule #:nodoc:
@@ -595,28 +543,25 @@ def self.root(*args)
# A module, class, symbol, or string may be provided.
def to_constant_name(desc) #:nodoc:
name = case desc
- when String then desc.starts_with?('::') ? desc[2..-1] : desc
+ when String then desc.sub(/^::/, '')
when Symbol then desc.to_s
when Module
- raise ArgumentError, "Anonymous modules have no name to be referenced by" if desc.name.blank?
- desc.name
+ desc.name.presence ||
+ raise(ArgumentError, "Anonymous modules have no name to be referenced by")
else raise TypeError, "Not a valid constant descriptor: #{desc.inspect}"
end
end
def remove_constant(const) #:nodoc:
return false unless qualified_const_defined? const
- const = $1 if /\A::(.*)\Z/ =~ const.to_s
- names = const.to_s.split('::')
- if names.size == 1 # It's under Object
- parent = Object
- else
- parent = Inflector.constantize(names[0..-2] * '::')
- end
+ # Normalize ::Foo, Foo, Object::Foo, and ::Object::Foo to Object::Foo
+ names = const.to_s.sub(/^::(Object)?/, 'Object::').split("::")
+ to_remove = names.pop
+ parent = Inflector.constantize(names * '::')
log "removing constant #{const}"
- parent.instance_eval { remove_const names.last }
+ parent.instance_eval { remove_const to_remove }
return true
end
View
17 activesupport/test/dependencies_test.rb
@@ -291,14 +291,18 @@ def test_qualified_const_defined
assert ActiveSupport::Dependencies.qualified_const_defined?("::Test::Unit::TestCase")
end
- def test_qualified_const_defined_should_not_call_method_missing
+ def test_qualified_const_defined_should_not_call_const_missing
ModuleWithMissing.missing_count = 0
assert ! ActiveSupport::Dependencies.qualified_const_defined?("ModuleWithMissing::A")
assert_equal 0, ModuleWithMissing.missing_count
assert ! ActiveSupport::Dependencies.qualified_const_defined?("ModuleWithMissing::A::B")
assert_equal 0, ModuleWithMissing.missing_count
end
+ def test_qualified_const_defined_explodes_with_invalid_const_name
+ assert_raises(NameError) { ActiveSupport::Dependencies.qualified_const_defined?("invalid") }
+ end
+
def test_autoloaded?
with_autoloading_fixtures do
assert ! ActiveSupport::Dependencies.autoloaded?("ModuleFolder")
@@ -333,7 +337,6 @@ def test_qualified_name_for
assert_equal "A", ActiveSupport::Dependencies.qualified_name_for(:Object, :A)
assert_equal "A", ActiveSupport::Dependencies.qualified_name_for("Object", :A)
assert_equal "A", ActiveSupport::Dependencies.qualified_name_for("::Object", :A)
- assert_equal "A", ActiveSupport::Dependencies.qualified_name_for("::Kernel", :A)
assert_equal "ActiveSupport::Dependencies::A", ActiveSupport::Dependencies.qualified_name_for(:'ActiveSupport::Dependencies', :A)
assert_equal "ActiveSupport::Dependencies::A", ActiveSupport::Dependencies.qualified_name_for(ActiveSupport::Dependencies, :A)
@@ -460,14 +463,6 @@ def test_application_should_special_case_application_controller
end
end
- def test_const_missing_on_kernel_should_fallback_to_object
- with_autoloading_fixtures do
- kls = Kernel::E
- assert_equal "E", kls.name
- assert_equal kls.object_id, Kernel::E.object_id
- end
- end
-
def test_preexisting_constants_are_not_marked_as_autoloaded
with_autoloading_fixtures do
require_dependency 'e'
@@ -711,7 +706,7 @@ def test_autoload_doesnt_shadow_error_when_mechanism_not_set_to_load
def test_autoload_doesnt_shadow_name_error
with_autoloading_fixtures do
Object.send(:remove_const, :RaisesNameError) if defined?(::RaisesNameError)
- 2.times do
+ 2.times do |i|
begin
::RaisesNameError::FooBarBaz.object_id
flunk 'should have raised NameError when autoloaded file referenced FooBarBaz'

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