directory: added "mtime" property

Remember the modification time of each directory.  This is important
for archives (which are virtual directories right now), but may also
be useful for an automatic update mechanism.

3 files changed, 17 insertions, 3 deletions

diff --git a/src/directory.h b/src/directory.h
index 7ffb87d5e..9321e9530 100644
--- a/src/directory.h
+++ b/src/directory.h
@@ -33,6 +33,7 @@ struct directory {
 	struct dirvec children;
 	struct songvec songs;
 	struct directory *parent;
+	time_t mtime;
 	ino_t inode;
 	dev_t device;
 	unsigned stat; /* not needed if ino_t == dev_t == 0 is impossible */
diff --git a/src/directory_save.c b/src/directory_save.c
index 7b2668bc7..b009b1ef5 100644
--- a/src/directory_save.c
+++ b/src/directory_save.c
@@ -28,7 +28,7 @@
 #include <assert.h>
 #include <string.h>
 
-#define DIRECTORY_MTIME "mtime: " /* DEPRECATED, noop-read-only */
+#define DIRECTORY_MTIME "mtime: "
 #define DIRECTORY_BEGIN "begin: "
 #define DIRECTORY_END "end: "
 
@@ -41,6 +41,9 @@ directory_save(FILE *fp, struct directory *directory)
 	int retv;
 
 	if (!directory_is_root(directory)) {
+		fprintf(fp, DIRECTORY_MTIME "%lu\n",
+			(unsigned long)directory->mtime);
+
 		retv = fprintf(fp, "%s%s\n", DIRECTORY_BEGIN,
 			       directory_get_path(directory));
 		if (retv < 0)
@@ -84,8 +87,12 @@ directory_load(FILE *fp, struct directory *directory)
 			strcpy(key, &(buffer[strlen(DIRECTORY_DIR)]));
 			if (!fgets(buffer, sizeof(buffer), fp))
 				FATAL("Error reading db, fgets\n");
-			/* for compatibility with db's prior to 0.11 */
+
 			if (g_str_has_prefix(buffer, DIRECTORY_MTIME)) {
+				directory->mtime =
+					g_ascii_strtoull(buffer + sizeof(DIRECTORY_MTIME) - 1,
+							 NULL, 10);
+
 				if (!fgets(buffer, sizeof(buffer), fp))
 					FATAL("Error reading db, fgets\n");
 			}
diff --git a/src/update.c b/src/update.c
index d03fc7cb4..78929f7d2 100644
--- a/src/update.c
+++ b/src/update.c
@@ -360,10 +360,12 @@ update_archive_tree(struct directory *directory, char *name)
  *
  * @param parent the parent directory the archive file resides in
  * @param name the UTF-8 encoded base name of the archive file
+ * @param st stat() information on the archive file
  * @param plugin the archive plugin which fits this archive type
  */
 static void
 update_archive_file(struct directory *parent, const char *name,
+		    const struct stat *st,
 		    const struct archive_plugin *plugin)
 {
 	char *path_fs;
@@ -393,6 +395,8 @@ update_archive_file(struct directory *parent, const char *name,
 		directory->device = DEVICE_INARCHIVE;
 	}
 
+	directory->mtime = st->st_mtime;
+
 	plugin->scan_reset(file);
 
 	while ((filepath = plugin->scan_next(file)) != NULL) {
@@ -438,7 +442,7 @@ update_regular_file(struct directory *directory,
 		}
 #ifdef ENABLE_ARCHIVE
 	} else if ((archive = archive_plugin_from_suffix(suffix))) {
-		update_archive_file(directory, name, archive);
+		update_archive_file(directory, name, st, archive);
 #endif
 	}
 }
@@ -593,6 +597,8 @@ updateDirectory(struct directory *directory, const struct stat *st)
 
 	closedir(dir);
 
+	directory->mtime = st->st_mtime;
+
 	return true;
 }