Merge pull request rails#54129 from ermolaev/perf-file-cheker

perf FileUpdateChecker, ignore gems paths

Author: byroot

activesupport/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   FileUpdateChecker and EventedFileUpdateChecker ignore changes in Gem.path now.
+
+    *Ermolaev Andrey*, *zzak*
+
 *   The new method `ActiveSupport::BacktraceCleaner#first_clean_frame` returns
     the first clean frame of the caller's backtrace, or `nil`. Useful when you
     want to report the application-level location where something happened.

activesupport/lib/active_support/evented_file_update_checker.rb

@@ -73,9 +73,13 @@ class Core
       attr_reader :updated, :files
 
       def initialize(files, dirs)
-        @files = files.map { |file| Pathname(file).expand_path }.to_set
+        gem_paths = Gem.path
+        files = files.map { |f| Pathname(f).expand_path }
+        files.reject! { |f| f.to_s.start_with?(*gem_paths) }
+        @files = files.to_set
 
         @dirs = dirs.each_with_object({}) do |(dir, exts), hash|
+          next if dir.start_with?(*gem_paths)
           hash[Pathname(dir).expand_path] = Array(exts).map { |ext| ext.to_s.sub(/\A\.?/, ".") }.to_set
         end
 

activesupport/lib/active_support/file_update_checker.rb

@@ -46,8 +46,11 @@ def initialize(files, dirs = {}, &block)
         raise ArgumentError, "A block is required to initialize a FileUpdateChecker"
       end
 
-      @files = files.freeze
-      @globs = compile_glob(dirs)
+      gem_paths = Gem.path
+      @files = files.reject { |file| File.expand_path(file).start_with?(*gem_paths) }.freeze
+
+      @globs = compile_glob(dirs)&.reject { |dir| dir.start_with?(*gem_paths) }
+
       @block = block
 
       @watched    = nil

activesupport/lib/active_support/i18n_railtie.rb

@@ -66,8 +66,7 @@ def self.initialize_i18n(app)
 
       if app.config.reloading_enabled?
         directories = watched_dirs_with_extensions(reloadable_paths)
-        root_load_paths = I18n.load_path.select { |path| path.to_s.start_with?(Rails.root.to_s) }
-        reloader = app.config.file_watcher.new(root_load_paths, directories) do
+        reloader = app.config.file_watcher.new(I18n.load_path, directories) do
           I18n.load_path.delete_if { |path| path.to_s.start_with?(Rails.root.to_s) && !File.exist?(path) }
           I18n.load_path |= reloadable_paths.flat_map(&:existent)
         end

activesupport/test/file_update_checker_shared_tests.rb

@@ -33,6 +33,51 @@ def run(*args)
     assert_equal 0, i
   end
 
+  test "should exclude files in gem path" do
+    fake_gem_dir = File.join(tmpdir, "gemdir")
+    FileUtils.mkdir_p(fake_gem_dir)
+    gem_file = File.join(fake_gem_dir, "foo.rb")
+    local_file = tmpfile("bar.rb")
+    touched = []
+
+    Gem.stub(:path, [fake_gem_dir]) do
+      checker = new_checker([gem_file, local_file]) { touched << :called }
+
+      touch(local_file)
+      assert checker.execute_if_updated
+      assert_equal [:called], touched
+
+      touched.clear
+      touch(gem_file)
+      assert_not checker.execute_if_updated
+      assert_empty touched
+    end
+  end
+
+  test "should exclude directories in gem path" do
+    local_dir = Dir.mktmpdir
+    fake_gem_dir = Dir.mktmpdir
+    local_file = File.join(local_dir, "foo.rb")
+    gem_file = File.join(fake_gem_dir, "bar.rb")
+    touched = []
+
+    Gem.stub(:path, [fake_gem_dir]) do
+      checker = new_checker([], { fake_gem_dir => [], local_dir => [] }) { touched << :called }
+
+      touch(local_file)
+      assert checker.execute_if_updated
+      assert_equal [:called], touched
+
+      touched.clear
+      touch(gem_file)
+      assert_not checker.execute_if_updated
+      assert_empty touched
+    end
+  ensure
+    FileUtils.remove_entry(local_dir)
+    FileUtils.remove_entry(fake_gem_dir)
+  end
+
   test "should not execute the block if no files change" do
     i = 0