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.

src/update.c

@@ -23,6 +23,7 @@
 #include "song.h"
 #include "log.h"
 #include "ls.h"
+#include "mapper.h"
 #include "path.h"
 #include "playlist.h"
 #include "utils.h"
@@ -150,11 +151,11 @@ static int
 delete_song_if_removed(struct song *song, void *_data)
 {
 	struct delete_data *data = _data;
+	const char *path;
+	struct stat st;
 
-	data->tmp = song_get_url(song, data->tmp);
-	assert(data->tmp);
-
-	if (!isFile(data->tmp, NULL)) {
+	if ((path = map_song_fs(song, data->tmp)) == NULL ||
+	    stat(data->tmp, &st) < 0 || !S_ISREG(st.st_mode)) {
 		delete_song(data->dir, song);
 		modified = true;
 	}
@@ -169,7 +170,12 @@ removeDeletedFromDirectory(char *path_max_tmp, struct directory *directory)
 	struct delete_data data;
 
 	for (i = dv->nr; --i >= 0; ) {
-		if (isDir(dv->base[i]->path))
+		const char *path_fs;
+		struct stat st;
+
+		path_fs = map_directory_fs(dv->base[i], path_max_tmp);
+		if (path_fs == NULL || (stat(path_fs, &st) == 0 &&
+					S_ISDIR(st.st_mode)))
 			continue;
 		LOG("removing directory: %s\n", dv->base[i]->path);
 		dirvec_delete(dv, dv->base[i]);
@@ -181,12 +187,26 @@ removeDeletedFromDirectory(char *path_max_tmp, struct directory *directory)
 	songvec_for_each(&directory->songs, delete_song_if_removed, &data);
 }
 
-static const char *opendir_path(char *path_max_tmp, const char *dirname)
+static int
+stat_directory(const struct directory *directory, struct stat *st)
 {
-	if (*dirname != '\0')
-		return rmp2amp_r(path_max_tmp,
-		                 utf8_to_fs_charset(path_max_tmp, dirname));
-	return musicDir;
+	char buffer[MPD_PATH_MAX];
+	const char *path_fs;
+
+	path_fs = map_directory_fs(directory, buffer);
+	if (path_fs == NULL)
+		return -1;
+	return stat(path_fs, st);
+}
+
+static int
+stat_directory_child(const struct directory *parent, const char *name,
+		     struct stat *st)
+{
+	char path_fs[MPD_PATH_MAX];
+
+	map_directory_child_fs(parent, name, path_fs);
+	return stat(path_fs, st);
 }
 
 static int
@@ -194,7 +214,7 @@ statDirectory(struct directory *dir)
 {
 	struct stat st;
 
-	if (myStat(directory_get_path(dir), &st) < 0)
+	if (stat_directory(dir, &st) < 0)
 		return -1;
 
 	directory_set_stat(dir, &st);
@@ -296,15 +316,19 @@ static bool
 updateDirectory(struct directory *directory, const struct stat *st)
 {
 	DIR *dir;
-	const char *dirname = directory_get_path(directory);
 	struct dirent *ent;
 	char path_max_tmp[MPD_PATH_MAX];
+	const char *path_fs;
 
 	assert(S_ISDIR(st->st_mode));
 
 	directory_set_stat(directory, st);
 
-	dir = opendir(opendir_path(path_max_tmp, dirname));
+	path_fs = map_directory_fs(directory, path_max_tmp);
+	if (path_fs == NULL)
+		return false;
+
+	dir = opendir(path_fs);
 	if (!dir)
 		return false;
 
@@ -321,15 +345,11 @@ updateDirectory(struct directory *directory, const struct stat *st)
 		if (!utf8)
 			continue;
 
-		if (!isRootDirectory(directory->path))
-			utf8 = pfx_dir(path_max_tmp, utf8, strlen(utf8),
-			               dirname, strlen(dirname));
-
-		if (myStat(path_max_tmp, &st2) == 0)
+		if (stat_directory_child(directory, utf8, &st2) == 0)
 			updateInDirectory(directory,
-					  mpd_basename(path_max_tmp), &st2);
+					  path_max_tmp, &st2);
 		else
-			delete_name_in(directory, mpd_basename(path_max_tmp));
+			delete_name_in(directory, path_max_tmp);
 	}
 
 	closedir(dir);
@@ -348,7 +368,7 @@ directory_make_child_checked(struct directory *parent, const char *path)
 	if (directory != NULL)
 		return directory;
 
-	if (myStat(path, &st) < 0 ||
+	if (stat_directory_child(parent, mpd_basename(path), &st) < 0 ||
 	    inodeFoundInParent(parent, st.st_ino, st.st_dev))
 		return NULL;
 
@@ -398,7 +418,7 @@ updatePath(const char *path)
 
 	name = mpd_basename(path);
 
-	if (myStat(path, &st) == 0)
+	if (stat_directory_child(parent, name, &st) == 0)
 		updateInDirectory(parent, name, &st);
 	else
 		delete_name_in(parent, name);
@@ -413,7 +433,7 @@ static void * update_task(void *_path)
 		struct directory *directory = db_get_root();
 		struct stat st;
 
-		if (myStat(directory_get_path(directory), &st) == 0)
+		if (stat_directory(directory, &st) == 0)
 			updateDirectory(directory, &st);
 	}