Merge pull request #302 from fxn/cnames

Micro-optimization for explicit namespaces

lib/zeitwerk/cref.rb

@@ -13,6 +13,9 @@
 class Zeitwerk::Cref
   include Zeitwerk::RealModName
 
+  # @sig Module
+  attr_reader :mod
+
   # @sig Symbol
   attr_reader :cname
 

lib/zeitwerk/explicit_namespace.rb

@@ -8,48 +8,56 @@ module Zeitwerk
   # Loaders that reopen namespaces owned by other projects are responsible for
   # loading their constant before setup. This is documented.
   module ExplicitNamespace # :nodoc: all
-    # Maps cpaths of explicit namespaces with their corresponding loader.
-    # Entries are added as the namespaces are found, and removed as they are
-    # autoloaded.
+    # Maps cnames or cpaths of explicit namespaces with their corresponding
+    # loader. They are symbols if the namespace lives in Object, or qualified
+    # paths as strings otherwise. Entries are added as the namespaces are found,
+    # and removed as they are autoloaded.
     #
-    # @sig Hash[String => Zeitwerk::Loader]
-    @cpaths = {}
+    # @sig Hash[(Symbol | String) => Zeitwerk::Loader]
+    @loaders = {}
 
     class << self
       include RealModName
       extend Internal
 
-      # Registers `cpath` as being the constant path of an explicit namespace
+      # Registers `cref` as being the constant path of an explicit namespace
       # managed by `loader`.
       #
       # @sig (String, Zeitwerk::Loader) -> void
-      internal def register(cpath, loader)
-        @cpaths[cpath] = loader
+      internal def register(cref, loader)
+        if Object.equal?(cref.mod)
+          @loaders[cref.cname] = loader
+        else
+          @loaders[cref.path] = loader
+        end
       end
 
       # @sig (String) -> Zeitwerk::Loader?
       internal def loader_for(mod, cname)
-        cpath = Object.equal?(mod) ? cname.name : "#{real_mod_name(mod)}::#{cname}"
-        @cpaths.delete(cpath)
+        if Object.equal?(mod)
+          @loaders.delete(cname)
+        else
+          @loaders.delete("#{real_mod_name(mod)}::#{cname}")
+        end
       end
 
       # @sig (Zeitwerk::Loader) -> void
       internal def unregister_loader(loader)
-        @cpaths.delete_if { _2.equal?(loader) }
+        @loaders.delete_if { _2.equal?(loader) }
       end
 
       # This is an internal method only used by the test suite.
       #
       # @sig (String) -> Zeitwerk::Loader?
-      internal def registered?(cpath)
-        @cpaths[cpath]
+      internal def registered?(cname_or_cpath)
+        @loaders[cname_or_cpath]
       end
 
       # This is an internal method only used by the test suite.
       #
       # @sig () -> void
       internal def clear
-        @cpaths.clear
+        @loaders.clear
       end
 
       module Synchronized

lib/zeitwerk/loader.rb

@@ -553,7 +553,7 @@ def all_dirs
 
     # @sig (Zeitwerk::Cref) -> void
     private def register_explicit_namespace(cref)
-      ExplicitNamespace.__register(cref.path, self)
+      ExplicitNamespace.__register(cref, self)
     end
 
     # @sig (String) -> void

test/lib/zeitwerk/test_autovivification.rb

@@ -63,7 +63,7 @@ module Namespace; end
       ["rd2/admin/y.rb", "Admin::Y = true"]
     ]
     with_setup(files) do
-      assert !Zeitwerk::ExplicitNamespace.__registered?("Admin")
+      assert !Zeitwerk::ExplicitNamespace.__registered?(:Admin)
     end
   end
 

test/lib/zeitwerk/test_unload.rb

@@ -131,14 +131,14 @@ def self.name
     ]
     with_files(files) do
       la = new_loader(dirs: "a")
-      assert Zeitwerk::ExplicitNamespace.__registered?("M") == la
+      assert Zeitwerk::ExplicitNamespace.__registered?(:M) == la
 
       lb = new_loader(dirs: "b")
-      assert Zeitwerk::ExplicitNamespace.__registered?("X") == lb
+      assert Zeitwerk::ExplicitNamespace.__registered?(:X) == lb
 
       la.unload
-      assert_nil Zeitwerk::ExplicitNamespace.__registered?("M")
-      assert Zeitwerk::ExplicitNamespace.__registered?("X") == lb
+      assert_nil Zeitwerk::ExplicitNamespace.__registered?(:M)
+      assert Zeitwerk::ExplicitNamespace.__registered?(:X) == lb
     end
   end
 

test/lib/zeitwerk/test_unregister.rb

@@ -10,29 +10,29 @@ class TestUnregister < LoaderTest
     registry.gem_loaders_by_root_file["dummy1"] = loader1
     registry.register_autoload(loader1, "dummy1")
     registry.register_inception("dummy1", "dummy1", loader1)
-    Zeitwerk::ExplicitNamespace.__register("dummy1", loader1)
+    Zeitwerk::ExplicitNamespace.__register(Zeitwerk::Cref.new(Object, :"dummy"), loader1)
 
     loader2 = Zeitwerk::Loader.new
     registry = Zeitwerk::Registry
     registry.register_loader(loader2)
     registry.gem_loaders_by_root_file["dummy2"] = loader2
     registry.register_autoload(loader2, "dummy2")
     registry.register_inception("dummy2", "dummy2", loader2)
-    Zeitwerk::ExplicitNamespace.__register("dummy2", loader2)
+    Zeitwerk::ExplicitNamespace.__register(Zeitwerk::Cref.new(Object, :"dummy2"), loader2)
 
     loader1.unregister
 
     assert !registry.loaders.include?(loader1)
     assert !registry.gem_loaders_by_root_file.values.include?(loader1)
     assert !registry.autoloads.values.include?(loader1)
     assert !registry.inceptions.values.any? {|_, l| l == loader1}
-    assert !Zeitwerk::ExplicitNamespace.__registered?("dummy1")
+    assert !Zeitwerk::ExplicitNamespace.__registered?(:"dummy1")
 
     assert registry.loaders.include?(loader2)
     assert registry.gem_loaders_by_root_file.values.include?(loader2)
     assert registry.autoloads.values.include?(loader2)
     assert registry.inceptions.values.any? {|_, l| l == loader2}
-    assert Zeitwerk::ExplicitNamespace.__registered?("dummy2") == loader2
+    assert Zeitwerk::ExplicitNamespace.__registered?(:"dummy2") == loader2
   end
 
   test 'with_loader yields and unregisters' do