reaper/TreeWatch: move code to FindDirectory()

Author: MaxKellermann

src/reaper/TreeWatch.cxx

@@ -118,8 +118,8 @@ TreeWatch::Add(std::string_view relative_path)
 	}
 }
 
-FileDescriptor
-TreeWatch::Find(std::string_view relative_path) const noexcept
+const TreeWatch::Directory *
+TreeWatch::FindDirectory(std::string_view relative_path) const noexcept
 {
 	assert(root.IsOpen());
 
@@ -131,12 +131,12 @@ TreeWatch::Find(std::string_view relative_path) const noexcept
 
 		const auto i = directory->children.find(name);
 		if (i == directory->children.end())
-			return FileDescriptor::Undefined();
+			return nullptr;
 
 		directory = &i->second;
 	}
 
-	return directory->fd;
+	return directory;
 }
 
 TreeWatch::Directory &

src/reaper/TreeWatch.hxx

@@ -69,9 +69,21 @@ public:
 	 * #FileDescriptor.
 	 */
 	[[gnu::pure]]
-	FileDescriptor Find(std::string_view relative_path) const noexcept;
+	FileDescriptor Find(std::string_view relative_path) const noexcept {
+		const auto *directory = FindDirectory(relative_path);
+		return directory != nullptr
+			? FileDescriptor{directory->fd}
+			: FileDescriptor::Undefined();
+	}
 
 private:
+	/**
+	 * Look up a #Directory object.  Returns nullptr if the
+	 * specified path is not being watched.
+	 */
+	[[gnu::pure]]
+	const Directory *FindDirectory(std::string_view relative_path) const noexcept;
+
 	Directory &MakeChild(Directory &parent, std::string_view name,
 			     bool persist, bool all) noexcept;