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author | Pratik Naik <pratiknaik@gmail.com> | 2010-02-14 19:28:05 +0000 |
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committer | Pratik Naik <pratiknaik@gmail.com> | 2010-02-14 19:28:05 +0000 |
commit | 6f3c5f67870a625b8be4de6e34e8d0d2f5d2b5e3 (patch) | |
tree | 3da8d75101aabe3c1d90d0582505ec1480c9d885 /activesupport/lib/active_support/dependencies.rb | |
parent | 77bf78b3b78a41d4f2f6e733f5c9c00608c0adba (diff) | |
parent | a1b60696e2b13cbe94d748444cc0da37b190fbb8 (diff) | |
download | rails-6f3c5f67870a625b8be4de6e34e8d0d2f5d2b5e3.tar.gz rails-6f3c5f67870a625b8be4de6e34e8d0d2f5d2b5e3.tar.bz2 rails-6f3c5f67870a625b8be4de6e34e8d0d2f5d2b5e3.zip |
Merge remote branch 'mainstream/master'
Conflicts:
railties/README
railties/guides/source/active_support_core_extensions.textile
railties/guides/source/getting_started.textile
railties/lib/generators/rails/app/templates/README
Diffstat (limited to 'activesupport/lib/active_support/dependencies.rb')
-rw-r--r-- | activesupport/lib/active_support/dependencies.rb | 328 |
1 files changed, 137 insertions, 191 deletions
diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb index 8ded9f8b2d..56de29b730 100644 --- a/activesupport/lib/active_support/dependencies.rb +++ b/activesupport/lib/active_support/dependencies.rb @@ -1,8 +1,10 @@ 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' +require 'active_support/core_ext/module/anonymous' require 'active_support/core_ext/object/blank' require 'active_support/core_ext/load_error' require 'active_support/core_ext/name_error' @@ -58,85 +60,116 @@ module ActiveSupport #: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 +184,23 @@ module ActiveSupport #:nodoc: 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 +243,15 @@ module ActiveSupport #:nodoc: 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 @@ -292,29 +321,22 @@ module ActiveSupport #:nodoc: # 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 @@ -322,29 +344,20 @@ module ActiveSupport #:nodoc: # 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 +406,7 @@ module ActiveSupport #:nodoc: 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) @@ -405,7 +418,7 @@ module ActiveSupport #:nodoc: # 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 @@ -413,38 +426,27 @@ module ActiveSupport #:nodoc: # 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 @@ -471,7 +473,7 @@ module ActiveSupport #:nodoc: # Determine if the given constant has been automatically loaded. def autoloaded?(desc) # No name => anonymous module. - return false if desc.is_a?(Module) && desc.name.blank? + return false if desc.is_a?(Module) && desc.anonymous? name = to_constant_name desc return false unless qualified_const_defined? name return autoloaded_constants.include?(name) @@ -505,79 +507,26 @@ module ActiveSupport #:nodoc: # 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: @@ -595,11 +544,11 @@ module ActiveSupport #:nodoc: # 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 @@ -607,16 +556,13 @@ module ActiveSupport #:nodoc: 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 |