lib/active_support/dependencies.rb in activesupport-1.3.1 vs lib/active_support/dependencies.rb in activesupport-1.4.0
- old
+ new
@@ -19,68 +19,426 @@
self.loaded = Set.new
# Should we load files or require them?
mattr_accessor :mechanism
self.mechanism = :load
-
+
+ # The set of directories from which we may automatically load files. Files
+ # under these directories will be reloaded on each request in development mode,
+ # unless the directory also appears in load_once_paths.
+ mattr_accessor :load_paths
+ self.load_paths = []
+
+ # The set of directories from which automatically loaded constants are loaded
+ # only once. All directories in this set must also be present in +load_paths+.
+ mattr_accessor :load_once_paths
+ self.load_once_paths = []
+
+ # An array of qualified constant names that have been loaded. Adding a name to
+ # this array will cause it to be unloaded the next time Dependencies are cleared.
+ mattr_accessor :autoloaded_constants
+ self.autoloaded_constants = []
+
+ # An array of constant names that need to be unloaded on every request. Used
+ # to allow arbitrary constants to be marked for unloading.
+ mattr_accessor :explicitly_unloadable_constants
+ self.explicitly_unloadable_constants = []
+
+ # Set to true to enable logging of const_missing and file loads
+ mattr_accessor :log_activity
+ self.log_activity = false
+
+ # :nodoc:
+ # An internal stack used to record which constants are loaded by any block.
+ mattr_accessor :constant_watch_stack
+ self.constant_watch_stack = []
+
def load?
mechanism == :load
end
def depend_on(file_name, swallow_load_errors = false)
- require_or_load(file_name)
+ path = search_for_file(file_name)
+ require_or_load(path || file_name)
rescue LoadError
raise unless swallow_load_errors
end
def associate_with(file_name)
depend_on(file_name, true)
end
def clear
+ log_call
loaded.clear
+ remove_unloadable_constants!
end
- def require_or_load(file_name)
+ def require_or_load(file_name, const_path = nil)
+ log_call file_name, const_path
file_name = $1 if file_name =~ /^(.*)\.rb$/
- return if loaded.include?(file_name)
+ expanded = File.expand_path(file_name)
+ return if loaded.include?(expanded)
# Record that we've seen this file *before* loading it to avoid an
# infinite loop with mutual dependencies.
- loaded << file_name
-
+ loaded << expanded
+
if load?
+ log "loading #{file_name}"
begin
# Enable warnings iff this file has not been loaded before and
# warnings_on_first_load is set.
- if !warnings_on_first_load or history.include?(file_name)
- load "#{file_name}.rb"
+ load_args = ["#{file_name}.rb"]
+ load_args << const_path unless const_path.nil?
+
+ if !warnings_on_first_load or history.include?(expanded)
+ result = load_file(*load_args)
else
- enable_warnings { load "#{file_name}.rb" }
+ enable_warnings { result = load_file(*load_args) }
end
- rescue
- loaded.delete file_name
+ rescue Exception
+ loaded.delete expanded
raise
end
else
- require file_name
+ log "requiring #{file_name}"
+ result = require file_name
end
# Record history *after* loading so first load gets warnings.
- history << file_name
+ history << expanded
+ return result
end
+ # 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.split('::')
+ names.shift if names.first.empty?
+
+ # 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 mod.const_defined? name
+ mod.const_get name
+ end
+ return true
+ 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.camelize,
+ # Special case: application.rb might define ApplicationControlller.
+ ('ApplicationController' if nesting == 'application')
+ ]
+ end.flatten.compact.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.ends_with? '.rb'
+ load_paths.each do |root|
+ path = File.join(root, path_suffix)
+ return path if File.file? path
+ end
+ nil # Gee, I sure wish we had first_match ;-)
+ end
+
+ # Does the provided path_suffix correspond to an autoloadable module?
+ # Instead of returning a boolean, the autoload base for this module is returned.
+ def autoloadable_module?(path_suffix)
+ load_paths.each do |load_path|
+ return load_path if File.directory? File.join(load_path, path_suffix)
+ end
+ nil
+ end
+
+ def load_once_path?(path)
+ load_once_paths.any? { |base| path.starts_with? base }
+ end
+
+ # Attempt to autoload the provided module name by searching for a directory
+ # matching the expect path suffix. If found, the module is created and assigned
+ # to +into+'s constants with the name +const_name+. Provided that the directory
+ # was loaded from a reloadable base path, it is added to the set of constants
+ # that are to be unloaded.
+ def autoload_module!(into, const_name, qualified_name, path_suffix)
+ return nil unless base_path = autoloadable_module?(path_suffix)
+ mod = Module.new
+ into.const_set const_name, mod
+ autoloaded_constants << qualified_name unless load_once_paths.include?(base_path)
+ return mod
+ end
+
+ # Load the file at the provided path. +const_paths+ is a set of qualified
+ # constant names. When loading the file, Dependencies will watch for the
+ # addition of these constants. Each that is defined will be marked as
+ # autoloaded, and will be removed when Dependencies.clear is next called.
+ #
+ # If the second parameter is left off, then Dependencies will construct a set
+ # of names that the file at +path+ may define. See
+ # +loadable_constants_for_path+ for more details.
+ def load_file(path, const_paths = loadable_constants_for_path(path))
+ log_call path, const_paths
+ const_paths = [const_paths].compact unless const_paths.is_a? Array
+ parent_paths = const_paths.collect { |const_path| /(.*)::[^:]+\Z/ =~ const_path ? $1 : :Object }
+
+ result = nil
+ newly_defined_paths = new_constants_in(*parent_paths) do
+ result = load_without_new_constant_marking path
+ end
+
+ autoloaded_constants.concat newly_defined_paths unless load_once_path?(path)
+ autoloaded_constants.uniq!
+ log "loading #{path} defined #{newly_defined_paths * ', '}" unless newly_defined_paths.empty?
+ return result
+ end
+
+ # 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}"
+ end
+
+ # Load the constant named +const_name+ which is missing from +from_mod+. If
+ # it is not possible to laod 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.empty?
+
+ unless qualified_const_defined?(from_mod.name) && from_mod.name.constantize.object_id == from_mod.object_id
+ 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 from_mod.const_defined?(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 from_mod.const_defined?(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| p.const_defined?(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
+ # return constants from from_mod's parents.
+ begin
+ return parent.const_missing(const_name)
+ rescue NameError => e
+ raise unless e.missing_name? qualified_name_for(parent, const_name)
+ raise name_error
+ end
+ else
+ raise name_error
+ end
+ end
+
+ # Remove the constants that have been autoloaded, and those that have been
+ # marked for unloading.
+ def remove_unloadable_constants!
+ autoloaded_constants.each { |const| remove_constant const }
+ autoloaded_constants.clear
+ explicitly_unloadable_constants.each { |const| remove_constant const }
+ end
+
+ # 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?
+ name = to_constant_name desc
+ return false unless qualified_const_defined? name
+ return autoloaded_constants.include?(name)
+ end
+
+ # Will the provided constant descriptor be unloaded?
+ def will_unload?(const_desc)
+ autoloaded?(desc) ||
+ explicitly_unloadable_constants.include?(to_constant_name(const_desc))
+ end
+
+ # Mark the provided constant name for unloading. This constant will be
+ # unloaded on each request, not just the next one.
+ def mark_for_unload(const_desc)
+ name = to_constant_name const_desc
+ if explicitly_unloadable_constants.include? name
+ return false
+ else
+ explicitly_unloadable_constants << name
+ return true
+ end
+ end
+
+ # Run the provided block and detect the new constants that were loaded during
+ # its execution. Constants may only be regarded as 'new' once -- so if the
+ # block calls +new_constants_in+ again, then the constants defined within the
+ # inner call will not be reported in this one.
+ #
+ # If the provided block does not run to completion, and instead raises an
+ # exception, any new constants are regarded as being only partially defined
+ # 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.constants
+ 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)
+ mod_name.constantize.constants
+ else
+ []
+ end
+ else
+ raise Argument, "#{desc.inspect} does not describe a module!"
+ end
+
+ [mod_name, initial_constants]
+ end
+
+ constant_watch_stack.concat watch_frames
+
+ 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 = mod_name.constantize
+ next [] unless mod.is_a? Module
+ new_constants = mod.constants - prior_constants
+
+ # Make sure no other frames takes credit for these constants.
+ constant_watch_stack.each do |frame_name, constants|
+ constants.concat new_constants if frame_name == mod_name
+ end
+
+ new_constants.collect do |suffix|
+ mod_name == "Object" ? suffix : "#{mod_name}::#{suffix}"
+ end
+ end.flatten
+
+ log "New constants: #{new_constants * ', '}"
+
+ if aborting
+ log "Error during loading, removing partially loaded constants "
+ new_constants.each { |name| remove_constant name }
+ new_constants.clear
+ end
+ end
+
+ return new_constants
+ ensure
+ # Remove the stack frames that we added.
+ if defined?(watch_frames) && ! watch_frames.empty?
+ frame_ids = watch_frames.collect(&:object_id)
+ constant_watch_stack.delete_if do |watch_frame|
+ frame_ids.include? watch_frame.object_id
+ end
+ end
+ end
+
class LoadingModule
# Old style environment.rb referenced this method directly. Please note, it doesn't
# actualy *do* anything any more.
def self.root(*args)
if defined?(RAILS_DEFAULT_LOGGER)
RAILS_DEFAULT_LOGGER.warn "Your environment.rb uses the old syntax, it may not continue to work in future releases."
RAILS_DEFAULT_LOGGER.warn "For upgrade instructions please see: http://manuals.rubyonrails.com/read/book/19"
end
end
end
+
+protected
+
+ # Convert the provided const desc to a qualified constant name (as a string).
+ # A module, class, symbol, or string may be provided.
+ def to_constant_name(desc)
+ name = case desc
+ when String then desc.starts_with?('::') ? desc[2..-1] : desc
+ 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
+ else raise TypeError, "Not a valid constant descriptor: #{desc.inspect}"
+ end
+ end
+
+ def remove_constant(const)
+ return false unless qualified_const_defined? const
+
+ const = $1 if /\A::(.*)\Z/ =~ const.to_s
+ names = const.split('::')
+ if names.size == 1 # It's under Object
+ parent = Object
+ else
+ parent = (names[0..-2] * '::').constantize
+ end
+
+ log "removing constant #{const}"
+ parent.send :remove_const, names.last
+ return true
+ end
+
+ def log_call(*args)
+ arg_str = args.collect(&:inspect) * ', '
+ /in `([a-z_\?\!]+)'/ =~ caller(1).first
+ selector = $1 || '<unknown>'
+ log "called #{selector}(#{arg_str})"
+ end
+
+ def log(msg)
+ if defined?(RAILS_DEFAULT_LOGGER) && RAILS_DEFAULT_LOGGER && log_activity
+ RAILS_DEFAULT_LOGGER.debug "Dependencies: #{msg}"
+ end
+ end
+
end
Object.send(:define_method, :require_or_load) { |file_name| Dependencies.require_or_load(file_name) } unless Object.respond_to?(:require_or_load)
Object.send(:define_method, :require_dependency) { |file_name| Dependencies.depend_on(file_name) } unless Object.respond_to?(:require_dependency)
Object.send(:define_method, :require_association) { |file_name| Dependencies.associate_with(file_name) } unless Object.respond_to?(:require_association)
@@ -90,67 +448,76 @@
alias :rails_original_const_missing :const_missing
# Use const_missing to autoload associations so we don't have to
# require_association when using single-table inheritance.
def const_missing(class_id)
- file_name = class_id.to_s.demodulize.underscore
- file_path = as_load_path.empty? ? file_name : "#{as_load_path}/#{file_name}"
- begin
- require_dependency(file_path)
- brief_name = self == Object ? '' : "#{name}::"
- raise NameError.new("uninitialized constant #{brief_name}#{class_id}") unless const_defined?(class_id)
- return const_get(class_id)
- rescue MissingSourceFile => e
- # Re-raise the error if it does not concern the file we were trying to load.
- raise unless e.is_missing? file_path
-
- # Look for a directory in the load path that we ought to load.
- if $LOAD_PATH.any? { |base| File.directory? "#{base}/#{file_path}" }
- mod = Module.new
- const_set class_id, mod # Create the new module
- return mod
- end
-
- # Attempt to access the name from the parent, unless we don't have a valid
- # parent, or the constant is already defined in the parent. If the latter
- # is the case, then we are being queried via self::class_id, and we should
- # avoid returning the constant from the parent if possible.
- if parent && parent != self && ! parents.any? { |p| p.const_defined?(class_id) }
- suppress(NameError) do
- return parent.send(:const_missing, class_id)
- end
- end
-
- raise NameError.new("uninitialized constant #{class_id}").copy_blame!(e)
- end
+ Dependencies.load_missing_constant self, class_id
end
+
+ def unloadable(const_desc = self)
+ super(const_desc)
+ end
+
end
class Class
def const_missing(class_id)
if [Object, Kernel].include?(self) || parent == self
super
else
- parent.send :const_missing, class_id
+ begin
+ begin
+ Dependencies.load_missing_constant self, class_id
+ rescue NameError
+ parent.send :const_missing, class_id
+ end
+ 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, class_id
+ raise unless e.missing_name? parent_qualified_name
+ qualified_name = Dependencies.qualified_name_for self, class_id
+ raise NameError.new("uninitialized constant #{qualified_name}").copy_blame!(e)
+ end
end
end
end
class Object #:nodoc:
+
+ alias_method :load_without_new_constant_marking, :load
+
def load(file, *extras)
- super(file, *extras)
- rescue Object => exception
+ Dependencies.new_constants_in(Object) { super(file, *extras) }
+ rescue Exception => exception # errors from loading file
exception.blame_file! file
raise
end
def require(file, *extras)
- super(file, *extras)
- rescue Object => exception
+ Dependencies.new_constants_in(Object) { super(file, *extras) }
+ rescue Exception => exception # errors from required file
exception.blame_file! file
raise
end
+
+ # Mark the given constant as unloadable. Unloadable constants are removed each
+ # time dependencies are cleared.
+ #
+ # Note that marking a constant for unloading need only be done once. Setup
+ # or init scripts may list each unloadable constant that may need unloading;
+ # each constant will be removed for every subsequent clear, as opposed to for
+ # the first clear.
+ #
+ # The provided constant descriptor may be a (non-anonymous) module or class,
+ # or a qualified constant name as a string or symbol.
+ #
+ # Returns true if the constant was not previously marked for unloading, false
+ # otherwise.
+ def unloadable(const_desc)
+ Dependencies.mark_for_unload const_desc
+ end
+
end
# Add file-blaming to exceptions
class Exception #:nodoc:
def blame_file!(file)
@@ -161,13 +528,13 @@
@blamed_files ||= []
end
def describe_blame
return nil if blamed_files.empty?
- "This error occured while loading the following files:\n #{blamed_files.join "\n "}"
+ "This error occurred while loading the following files:\n #{blamed_files.join "\n "}"
end
def copy_blame!(exc)
@blamed_files = exc.blamed_files.clone
self
end
-end
\ No newline at end of file
+end