Reimplement dynamic metadata handling

This has been tested for both playback of streams and
outputting to streams, and seems to work fine with minimal
locking.  This reuses the sequence number infrastructure
in OutputBuffer for synchronizing metadata payloads; so
(IMNSHO) should be much more understandable than various
flags being set here and there..

It could still use some cleanup and much testing, but
synchronization issues should be minimal.

1 files changed, 24 insertions, 19 deletions

diff --git a/src/playlist.c b/src/playlist.c
index 4b1042409..48db355a8 100644
--- a/src/playlist.c
+++ b/src/playlist.c
@@ -32,6 +32,7 @@
 #include "myfprintf.h"
 #include "os_compat.h"
 #include "main_notify.h"
+#include "metadata_pipe.h"
 
 enum _playlist_state {
 	PLAYLIST_STATE_STOP = 0,
@@ -966,31 +967,34 @@ int playPlaylistById(int fd, int id, int stopOnError)
 	return playPlaylist(fd, playlist.idToPosition[id], stopOnError);
 }
 
-static void syncCurrentPlayerDecodeMetadata(void)
+/* This is used when we stream data out to shout while playing static files */
+MpdTag *playlist_current_tag(void)
+{
+	Song *song = song_at(playlist.current);
+
+	/* Non-file song tags can get swept out from under us */
+	return (song && song->type == SONG_TYPE_FILE) ? song->tag : NULL;
+}
+
+/* This receives dynamic metadata updates from streams */
+static void sync_metadata(void)
 {
-	Song *songPlayer = song_at(playlist.current);
 	Song *song;
-	int songNum;
-	char path_max_tmp[MPD_PATH_MAX];
+	MpdTag *tag;
 
-	if (!songPlayer)
+	if (!(tag = metadata_pipe_current()))
 		return;
-
-	if (playlist_state != PLAYLIST_STATE_PLAY)
+	song = song_at(playlist.current);
+	if (!song || song->type != SONG_TYPE_URL ||
+	    mpdTagsAreEqual(song->tag, tag)) {
+		freeMpdTag(tag);
 		return;
-
-	songNum = playlist.order[playlist.current];
-	song = playlist.songs[songNum];
-
-	if (song->type == SONG_TYPE_URL &&
-	    0 == strcmp(get_song_url(path_max_tmp, song), songPlayer->url) &&
-	    !mpdTagsAreEqual(song->tag, songPlayer->tag)) {
-		if (song->tag)
-			freeMpdTag(song->tag);
-		song->tag = mpdTagDup(songPlayer->tag);
-		playlist.songMod[songNum] = playlist.version;
-		incrPlaylistVersion();
 	}
+	if (song->tag)
+		freeMpdTag(song->tag);
+	song->tag = tag;
+	playlist.songMod[playlist.order[playlist.current]] = playlist.version;
+	incrPlaylistVersion();
 }
 
 void syncPlayerAndPlaylist(void)
@@ -998,6 +1002,7 @@ void syncPlayerAndPlaylist(void)
 	if (playlist_state != PLAYLIST_STATE_PLAY)
 		return;
 	syncPlaylistWithQueue();
+	sync_metadata();
 	/* DEBUG("queued:%d current:%d\n", playlist.queued, playlist.current); */
 	if (playlist_state == PLAYLIST_STATE_PLAY &&
 	    playlist.queued >= 0 &&