StoragePlugin: add method MapToRelativeUTF8()

Replaces map_to_relative_path() from Mapper.cxx.

src/Mapper.cxx

@@ -160,21 +160,6 @@ mapper_get_music_directory_fs(void)
 
 #endif
 
-const char *
-map_to_relative_path(const char *path_utf8)
-{
-#ifdef ENABLE_DATABASE
-	return !music_dir_utf8.empty() &&
-		memcmp(path_utf8, music_dir_utf8.c_str(),
-		       music_dir_utf8_length) == 0 &&
-		PathTraitsUTF8::IsSeparator(path_utf8[music_dir_utf8_length])
-		? path_utf8 + music_dir_utf8_length + 1
-		: path_utf8;
-#else
-	return path_utf8;
-#endif
-}
-
 #ifdef ENABLE_DATABASE
 
 AllocatedPath

src/Mapper.hxx

@@ -71,15 +71,6 @@ mapper_has_music_directory(void)
 
 #endif
 
-/**
- * If the specified absolute path points inside the music directory,
- * this function converts it to a relative path.  If not, it returns
- * the unmodified string pointer.
- */
-gcc_pure
-const char *
-map_to_relative_path(const char *path_utf8);
-
 #ifdef ENABLE_DATABASE
 
 /**

src/SongLoader.cxx

@@ -20,8 +20,8 @@
 #include "config.h"
 #include "SongLoader.hxx"
 #include "client/Client.hxx"
-#include "Mapper.hxx"
 #include "db/DatabaseSong.hxx"
+#include "storage/StorageInterface.hxx"
 #include "ls.hxx"
 #include "fs/AllocatedPath.hxx"
 #include "fs/Traits.hxx"
@@ -45,14 +45,13 @@ DetachedSong *
 SongLoader::LoadFile(const char *path_utf8, Error &error) const
 {
 #ifdef ENABLE_DATABASE
-	/* TODO fs_charset vs utf8? */
-	const char *suffix = map_to_relative_path(path_utf8);
-	assert(suffix != nullptr);
-
-	if (suffix != path_utf8)
-		/* this path was relative to the music directory -
-		   obtain it from the database */
-		return LoadSong(suffix, error);
+	if (storage != nullptr) {
+		const char *suffix = storage->MapToRelativeUTF8(path_utf8);
+		if (suffix != nullptr)
+			/* this path was relative to the music
+			   directory - obtain it from the database */
+			return LoadSong(suffix, error);
+	}
 #endif
 
 	if (client != nullptr) {

src/SongPrint.cxx

@@ -20,10 +20,10 @@
 #include "config.h"
 #include "SongPrint.hxx"
 #include "db/LightSong.hxx"
+#include "storage/StorageInterface.hxx"
 #include "DetachedSong.hxx"
 #include "TimePrint.hxx"
 #include "TagPrint.hxx"
-#include "Mapper.hxx"
 #include "client/Client.hxx"
 #include "util/UriUtil.hxx"
 
@@ -32,12 +32,20 @@
 static void
 song_print_uri(Client &client, const char *uri)
 {
+#ifdef ENABLE_DATABASE
+	const Storage *storage = client.GetStorage();
+	if (storage != nullptr) {
+		const char *suffix = storage->MapToRelativeUTF8(uri);
+		if (suffix != nullptr)
+			uri = suffix;
+	}
+#endif
+
 	const std::string allocated = uri_remove_auth(uri);
 	if (!allocated.empty())
 		uri = allocated.c_str();
 
-	client_printf(client, "%s%s\n", SONG_FILE,
-		      map_to_relative_path(uri));
+	client_printf(client, "%s%s\n", SONG_FILE, uri);
 }
 
 void

src/db/update/Walk.cxx

@@ -29,13 +29,13 @@
 #include "db/Uri.hxx"
 #include "storage/StorageInterface.hxx"
 #include "playlist/PlaylistRegistry.hxx"
-#include "Mapper.hxx"
 #include "ExcludeList.hxx"
 #include "config/ConfigGlobal.hxx"
 #include "config/ConfigOption.hxx"
 #include "fs/AllocatedPath.hxx"
 #include "fs/Traits.hxx"
 #include "fs/FileSystem.hxx"
+#include "fs/Charset.hxx"
 #include "storage/FileInfo.hxx"
 #include "util/Alloc.hxx"
 #include "util/UriUtil.hxx"
@@ -274,8 +274,13 @@ UpdateWalk::SkipSymlink(const Directory *directory,
 	if (PathTraitsFS::IsAbsolute(target_str)) {
 		/* if the symlink points to an absolute path, see if
 		   that path is inside the music directory */
-		const char *relative = map_to_relative_path(target_str);
-		return relative > target_str
+		const auto target_utf8 = PathToUTF8(target_str);
+		if (target_utf8.empty())
+			return true;
+
+		const char *relative =
+			storage.MapToRelativeUTF8(target_utf8.c_str());
+		return relative != nullptr
 			? !follow_inside_symlinks
 			: !follow_outside_symlinks;
 	}

src/storage/StorageInterface.hxx

@@ -68,6 +68,14 @@ public:
 	gcc_pure
 	AllocatedPath MapChildFS(const char *uri_utf8,
 				 const char *child_utf8) const;
+
+	/**
+	 * Check if the given URI points inside this storage.  If yes,
+	 * then it returns a relative URI (pointing inside the given
+	 * string); if not, returns nullptr.
+	 */
+	gcc_pure
+	virtual const char *MapToRelativeUTF8(const char *uri_utf8) const = 0;
 };
 
 #endif

src/storage/plugins/LocalStorage.cxx

@@ -68,6 +68,8 @@ public:
 
 	virtual AllocatedPath MapFS(const char *uri_utf8) const override;
 
+	virtual const char *MapToRelativeUTF8(const char *uri_utf8) const override;
+
 private:
 	AllocatedPath MapFS(const char *uri_utf8, Error &error) const;
 };
@@ -130,6 +132,12 @@ LocalStorage::MapFS(const char *uri_utf8) const
 	return MapFS(uri_utf8, IgnoreError());
 }
 
+const char *
+LocalStorage::MapToRelativeUTF8(const char *uri_utf8) const
+{
+	return PathTraitsUTF8::Relative(base_utf8.c_str(), uri_utf8);
+}
+
 bool
 LocalStorage::GetInfo(const char *uri_utf8, bool follow, FileInfo &info,
 		      Error &error)

src/storage/plugins/SmbclientStorage.cxx

@@ -69,6 +69,8 @@ public:
 						      Error &error) override;
 
 	virtual std::string MapUTF8(const char *uri_utf8) const override;
+
+	virtual const char *MapToRelativeUTF8(const char *uri_utf8) const override;
 };
 
 std::string
@@ -82,6 +84,12 @@ SmbclientStorage::MapUTF8(const char *uri_utf8) const
 	return PathTraitsUTF8::Build(base.c_str(), uri_utf8);
 }
 
+const char *
+SmbclientStorage::MapToRelativeUTF8(const char *uri_utf8) const
+{
+	return PathTraitsUTF8::Relative(base.c_str(), uri_utf8);
+}
+
 static bool
 GetInfo(const char *path, FileInfo &info, Error &error)
 {