playlist_queue: resolve relative URIs, database lookup

Prepend the playlist's base URI to relative song URIs.  Look up songs
in the database (if the URI refers to a local song file).  Merge
existing database metadata with metadata from the playlist plugin.

src/playlist_queue.c

@@ -22,43 +22,139 @@
 #include "playlist_list.h"
 #include "playlist_plugin.h"
 #include "stored_playlist.h"
+#include "database.h"
 #include "mapper.h"
 #include "song.h"
+#include "tag.h"
 #include "uri.h"
 #include "ls.h"
 #include "input_stream.h"
 
-/**
- * Determins if it's allowed to add this song to the playlist.  For
- * safety reasons, we disallow local files.
- */
-static inline bool
-accept_song(const struct song *song)
+static void
+merge_song_metadata(struct song *dest, const struct song *base,
+		    const struct song *add)
 {
-	return !song_is_file(song) && uri_has_scheme(song->uri) &&
-		uri_supported_scheme(song->uri);
+	dest->tag = base->tag != NULL
+		? (add->tag != NULL
+		   ? tag_merge(base->tag, add->tag)
+		   : tag_dup(base->tag))
+		: (add->tag != NULL
+		   ? tag_dup(add->tag)
+		   : NULL);
+
+	dest->mtime = base->mtime;
+	dest->start_ms = add->start_ms;
+	dest->end_ms = add->end_ms;
+}
+
+static struct song *
+apply_song_metadata(struct song *dest, const struct song *src)
+{
+	struct song *tmp;
+
+	assert(dest != NULL);
+	assert(src != NULL);
+
+	if (src->tag == NULL && src->start_ms == 0 && src->end_ms == 0)
+		return dest;
+
+	if (song_in_database(dest)) {
+		char *path_fs = map_song_fs(dest);
+		if (path_fs == NULL)
+			return dest;
+
+		tmp = song_file_new(path_fs, NULL);
+		merge_song_metadata(tmp, dest, src);
+	} else {
+		tmp = song_file_new(dest->uri, NULL);
+		merge_song_metadata(tmp, dest, src);
+		song_free(dest);
+	}
+
+	return tmp;
+}
+
+/**
+ * Verifies the song, returns NULL if it is unsafe.  Translate the
+ * song to a new song object within the database, if it is a local
+ * file.  The old song object is freed.
+ */
+static struct song *
+check_translate_song(struct song *song, const char *base_uri)
+{
+	struct song *dest;
+	char *uri;
+
+	if (song_in_database(song))
+		/* already ok */
+		return song;
+
+	if (uri_has_scheme(song->uri)) {
+		if (uri_supported_scheme(song->uri))
+			/* valid remote song */
+			return song;
+		else {
+			/* unsupported remote song */
+			song_free(song);
+			return NULL;
+		}
+	}
+
+	if (g_path_is_absolute(song->uri)) {
+		/* local files must be relative to the music
+		   directory */
+		song_free(song);
+		return NULL;
+	}
+
+	if (base_uri != NULL)
+		uri = g_build_filename(base_uri, song->uri, NULL);
+	else
+		uri = g_strdup(song->uri);
+
+	if (uri_has_scheme(base_uri)) {
+		dest = song_remote_new(uri);
+		g_free(uri);
+	} else {
+		dest = db_get_song(uri);
+		g_free(uri);
+		if (dest == NULL) {
+			/* not found in database */
+			song_free(song);
+			return dest;
+		}
+	}
+
+	dest = apply_song_metadata(dest, song);
+	song_free(song);
+
+	return dest;
 }
 
 enum playlist_result
-playlist_load_into_queue(struct playlist_provider *source,
+playlist_load_into_queue(const char *uri, struct playlist_provider *source,
 			 struct playlist *dest)
 {
 	enum playlist_result result;
 	struct song *song;
+	char *base_uri = uri != NULL ? g_path_get_dirname(uri) : NULL;
 
 	while ((song = playlist_plugin_read(source)) != NULL) {
-		if (!accept_song(song)) {
-			song_free(song);
+		song = check_translate_song(song, base_uri);
+		if (song == NULL)
 			continue;
-		}
 
 		result = playlist_append_song(dest, song, NULL);
 		if (result != PLAYLIST_RESULT_SUCCESS) {
-			song_free(song);
+			if (!song_in_database(song))
+				song_free(song);
+			g_free(base_uri);
 			return result;
 		}
 	}
 
+	g_free(base_uri);
+
 	return PLAYLIST_RESULT_SUCCESS;
 }
 
@@ -93,7 +189,7 @@ playlist_open_remote_into_queue(const char *uri, struct playlist *dest)
 		}
 	}
 
-	result = playlist_load_into_queue(playlist, dest);
+	result = playlist_load_into_queue(uri, playlist, dest);
 	playlist_plugin_close(playlist);
 
 	if (stream)
@@ -103,16 +199,17 @@ playlist_open_remote_into_queue(const char *uri, struct playlist *dest)
 }
 
 static enum playlist_result
-playlist_open_path_into_queue(const char *path_fs, struct playlist *dest)
+playlist_open_path_into_queue(const char *path_fs, const char *uri,
+			      struct playlist *dest)
 {
 	struct playlist_provider *playlist;
 	struct input_stream is;
 	enum playlist_result result;
 
 	if ((playlist = playlist_list_open_uri(path_fs)) != NULL)
-		result = playlist_load_into_queue(playlist, dest);
+		result = playlist_load_into_queue(uri, playlist, dest);
 	else if ((playlist = playlist_list_open_path(&is, path_fs)) != NULL) {
-		result = playlist_load_into_queue(playlist, dest);
+		result = playlist_load_into_queue(uri, playlist, dest);
 		input_stream_close(&is);
 	} else
 		return PLAYLIST_RESULT_NO_SUCH_LIST;
@@ -139,7 +236,7 @@ playlist_open_local_into_queue(const char *uri, struct playlist *dest)
 		return PLAYLIST_RESULT_DISABLED;
 
 	path_fs = g_build_filename(playlist_directory_fs, uri, NULL);
-	result = playlist_open_path_into_queue(path_fs, dest);
+	result = playlist_open_path_into_queue(path_fs, NULL, dest);
 	g_free(path_fs);
 
 	return result;
@@ -160,7 +257,7 @@ playlist_open_local_into_queue2(const char *uri, struct playlist *dest)
 	if (path_fs == NULL)
 		return PLAYLIST_RESULT_NO_SUCH_LIST;
 
-	result = playlist_open_path_into_queue(path_fs, dest);
+	result = playlist_open_path_into_queue(path_fs, uri, dest);
 	g_free(path_fs);
 
 	return result;

src/playlist_queue.h

@@ -32,9 +32,12 @@ struct playlist;
 /**
  * Loads the contents of a playlist and append it to the specified
  * play queue.
+ *
+ * @param uri the URI of the playlist, used to resolve relative song
+ * URIs
  */
 enum playlist_result
-playlist_load_into_queue(struct playlist_provider *source,
+playlist_load_into_queue(const char *uri, struct playlist_provider *source,
 			 struct playlist *dest);
 
 /**