directory: make music_root global and avoid runtime initialization

mpd can't function without music_root; so don't bother
allocating it on the heap nor checking to see if it's
initialized.

Don't allow directory_new() to create a directory w/o a parent
or with an empty path, either: root is root and there can
be only one</highlander>.

4 files changed, 21 insertions, 34 deletions

diff --git a/src/database.c b/src/database.c
index dde57ce6a..a9e80f425 100644
--- a/src/database.c
+++ b/src/database.c
@@ -32,14 +32,10 @@
 #include "os_compat.h"
 #include "myfprintf.h"
 
-static struct directory *music_root;
-
 static time_t directory_dbModTime;
 
 void db_init(void)
 {
-	music_root = directory_new("", NULL);
-
 	if (!directory_update_init(NULL))
 		FATAL("directory update failed\n");
 
@@ -54,22 +50,12 @@ void db_init(void)
 
 void db_finish(void)
 {
-	directory_free(music_root);
-}
-
-struct directory * db_get_root(void)
-{
-	assert(music_root != NULL);
-
-	return music_root;
+	directory_free(&music_root);
 }
 
 struct directory * db_get_directory(const char *name)
 {
-	if (name == NULL)
-		return music_root;
-
-	return directory_get_subdir(music_root, name);
+	return name ? directory_get_subdir(&music_root, name) : &music_root;
 }
 
 struct mpd_song *db_get_song(const char *file)
@@ -195,11 +181,11 @@ int db_save(void)
 	struct stat st;
 
 	DEBUG("removing empty directories from DB\n");
-	directory_prune_empty(music_root);
+	directory_prune_empty(&music_root);
 
 	DEBUG("sorting DB\n");
 
-	directory_sort(music_root);
+	directory_sort(&music_root);
 
 	DEBUG("writing DB\n");
 
@@ -220,7 +206,7 @@ int db_save(void)
 	         DIRECTORY_FS_CHARSET "%s\n"
 	         DIRECTORY_INFO_END "\n", getFsCharset());
 
-	if (directory_save(fd, music_root) < 0) {
+	if (directory_save(fd, &music_root) < 0) {
 		ERROR("Failed to write to database file: %s\n",
 		      strerror(errno));
 		xclose(fd);
@@ -243,8 +229,6 @@ int db_load(void)
 	int foundFsCharset = 0;
 	int foundVersion = 0;
 
-	if (!music_root)
-		music_root = directory_new("", NULL);
 	while (!(fp = fopen(dbFile, "r")) && errno == EINTR) ;
 	if (fp == NULL) {
 		ERROR("unable to open db file \"%s\": %s\n",
@@ -296,7 +280,7 @@ int db_load(void)
 
 	DEBUG("reading DB\n");
 
-	directory_load(fp, music_root);
+	directory_load(fp, &music_root);
 	while (fclose(fp) && errno == EINTR) ;
 
 	stats.numberOfSongs = countSongsIn(NULL);
diff --git a/src/directory.c b/src/directory.c
index 699b6fbc1..846f2510a 100644
--- a/src/directory.c
+++ b/src/directory.c
@@ -23,14 +23,18 @@
 #include "myfprintf.h"
 #include "dirvec.h"
 
+struct directory music_root;
+
 struct directory * directory_new(const char *path, struct directory * parent)
 {
 	struct directory *dir;
-	size_t pathlen = strlen(path);
+	size_t pathlen;
 
-	assert(path != NULL);
-	assert((*path == 0) == (parent == NULL));
+	assert(path);
+	assert(*path);
+	assert(parent);
 
+	pathlen = strlen(path);
 	dir = xcalloc(1, sizeof(*dir) - sizeof(dir->path) + pathlen + 1);
 	memcpy(dir->path, path, pathlen + 1);
 	dir->parent = parent;
@@ -42,9 +46,8 @@ void directory_free(struct directory *dir)
 {
 	dirvec_destroy(&dir->children);
 	songvec_destroy(&dir->songs);
-	free(dir);
-	/* this resets last dir returned */
-	/*directory_get_path(NULL); */
+	if (dir != &music_root)
+		free(dir);
 }
 
 void directory_prune_empty(struct directory *dir)
diff --git a/src/directory.h b/src/directory.h
index 546e55183..9c3063d75 100644
--- a/src/directory.h
+++ b/src/directory.h
@@ -43,6 +43,8 @@ struct directory {
 	char path[mpd_sizeof_str_flex_array];
 } mpd_packed;
 
+extern struct directory music_root;
+
 static inline int isRootDirectory(const char *name)
 {
 	/* TODO: verify and remove !name check */
diff --git a/src/update.c b/src/update.c
index ca3640b73..3f6fa15ed 100644
--- a/src/update.c
+++ b/src/update.c
@@ -317,10 +317,9 @@ directory_make_child_checked(struct directory *parent, const char *path)
 	return dir;
 }
 
-static struct directory *
-addParentPathToDB(const char *utf8path)
+static struct directory * addParentPathToDB(const char *utf8path)
 {
-	struct directory *dir = db_get_root();
+	struct directory *dir = &music_root;
 	char *duplicated = xstrdup(utf8path);
 	char *slash = duplicated;
 
@@ -354,11 +353,10 @@ static void * update_task(void *_path)
 		updatePath((char *)_path);
 		free(_path);
 	} else {
-		struct directory *dir = db_get_root();
 		struct stat st;
 
-		if (myStat(directory_get_path(dir), &st) == 0)
-			updateDirectory(dir, &st);
+		if (myStat(directory_get_path(&music_root), &st) == 0)
+			updateDirectory(&music_root, &st);
 	}
 
 	if (modified)