mapper: new song-to-filesystem mapper library

The mapper library maps directory and song objects to file system
paths.  With this central library, the code mixture in path.c should
be cleaned up, and we will be able to add neat features like aliasing.

1 files changed, 77 insertions, 0 deletions

diff --git a/src/mapper.c b/src/mapper.c
new file mode 100644
index 00000000..39221121
--- /dev/null
+++ b/src/mapper.c
@@ -0,0 +1,77 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2008 Max Kellermann <max@duempel.org>
+ * This project's homepage is: http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*
+ * Maps directory and song objects to file system paths.
+ */
+
+#include "mapper.h"
+#include "directory.h"
+#include "song.h"
+#include "path.h"
+
+const char *
+map_directory_fs(const struct directory *directory, char *buffer)
+{
+	const char *dirname = directory_get_path(directory);
+	if (isRootDirectory(dirname))
+	    return musicDir;
+
+	return rmp2amp_r(buffer, utf8_to_fs_charset(buffer, dirname));
+}
+
+const char *
+map_directory_child_fs(const struct directory *directory, const char *name,
+		       char *buffer)
+{
+	char buffer2[MPD_PATH_MAX];
+	const char *parent_fs;
+
+	parent_fs = map_directory_fs(directory, buffer2);
+	if (parent_fs == NULL)
+		return NULL;
+
+	utf8_to_fs_charset(buffer, name);
+	pfx_dir(buffer, name, strlen(name),
+		parent_fs, strlen(parent_fs));
+	return buffer;
+}
+
+const char *
+map_song_fs(const struct song *song, char *buffer)
+{
+	assert(song->parent != NULL);
+
+	return map_directory_child_fs(song->parent, song->url, buffer);
+}
+
+const char *
+map_fs_to_utf8(const char *path_fs, char *buffer)
+{
+	size_t music_path_length = strlen(musicDir);
+
+	if (strncmp(path_fs, musicDir, music_path_length) == 0 &&
+	    path_fs[music_path_length] == '/')
+		/* remove musicDir prefix */
+		path_fs += music_path_length;
+	else if (path_fs[0] == '/')
+		/* not within musicDir */
+		return NULL;
+
+	return fs_charset_to_utf8(buffer, path_fs);
+}