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Add 'unloadable', a method used to mark any constant as requiring an …

…unload after each request.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5307 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
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1 parent fa5080a commit 497b5dcf1965dea95bc59a00214e14c42dba69cc @seckar seckar committed Oct 15, 2006
Showing with 103 additions and 17 deletions.
  1. +2 −0 activesupport/CHANGELOG
  2. +71 −17 activesupport/lib/active_support/dependencies.rb
  3. +30 −0 activesupport/test/dependencies_test.rb
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@@ -1,5 +1,7 @@
*SVN*
+* Add 'unloadable', a method used to mark any constant as requiring an unload after each request. [Nicholas Seckar]
+
* Make core_ext/string/access.rb multibyte safe. Closes #6388 [Manfred Stienstra]
* Make String#chars slicing behaviour consistent with String. Closes #6387 [Manfred Stienstra]
@@ -38,6 +38,11 @@ module Dependencies #:nodoc:
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
@@ -60,7 +65,7 @@ def associate_with(file_name)
def clear
log_call
loaded.clear
- remove_autoloaded_constants!
+ remove_unloadable_constants!
end
def require_or_load(file_name, const_path = nil)
@@ -252,21 +257,12 @@ def load_missing_constant(from_mod, const_name)
end
end
- # Remove the constants that have been autoloaded.
- def remove_autoloaded_constants!
- until autoloaded_constants.empty?
- const = autoloaded_constants.shift
- next unless qualified_const_defined? const
- names = const.split('::')
- if names.size == 1 || names.first.empty? # It's under Object
- parent = Object
- else
- parent = (names[0..-2] * '::').constantize
- end
- log "removing constant #{const}"
- parent.send :remove_const, names.last
- true
- 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.
@@ -276,6 +272,24 @@ def autoloaded?(desc)
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
+
class LoadingModule
# Old style environment.rb referenced this method directly. Please note, it doesn't
# actualy *do* anything any more.
@@ -295,11 +309,28 @@ 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 then desc.name
+ 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
+
+ names = const.split('::')
+ if names.size == 1 || names.first.empty? # 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
@@ -328,6 +359,11 @@ class Module #:nodoc:
def const_missing(class_id)
Dependencies.load_missing_constant self, class_id
end
+
+ def unloadable(const_desc = self)
+ super(const_desc)
+ end
+
end
class Class
@@ -366,6 +402,24 @@ def require(file, *extras)
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
@@ -24,6 +24,7 @@ def with_loading(*from)
ensure
Dependencies.load_paths = prior_load_paths
Dependencies.mechanism = old_mechanism
+ Dependencies.explicitly_unloadable_constants = []
end
def test_tracking_loaded_files
@@ -453,4 +454,33 @@ def test_preexisting_constants_are_not_marked_as_autoloaded
Object.send :remove_const, :E if Object.const_defined?(:E)
end
+ def test_unloadable
+ with_loading 'autoloading_fixtures' do
+ Object.const_set :M, Module.new
+ M.unloadable
+
+ Dependencies.clear
+ assert ! defined?(M)
+
+ Object.const_set :M, Module.new
+ Dependencies.clear
+ assert ! defined?(M), "Dependencies should unload unloadable constants each time"
+ end
+ end
+
+ def test_unloadable_should_fail_with_anonymous_modules
+ with_loading 'autoloading_fixtures' do
+ m = Module.new
+ assert_raises(ArgumentError) { m.unloadable }
+ end
+ end
+
+ def test_unloadable_should_return_change_flag
+ with_loading 'autoloading_fixtures' do
+ Object.const_set :M, Module.new
+ assert_equal true, M.unloadable
+ assert_equal false, M.unloadable
+ end
+ end
+
end

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