decoder_plugin: added method stream_tag()

This is like tag_dup(), but works with an input_stream object instead
of a file path.

2 files changed, 23 insertions, 1 deletions

diff --git a/src/decoder/sidplay_plugin.cxx b/src/decoder/sidplay_plugin.cxx
index 9bfe98f3d..79cd9cb03 100644
--- a/src/decoder/sidplay_plugin.cxx
+++ b/src/decoder/sidplay_plugin.cxx
@@ -411,6 +411,7 @@ const struct decoder_plugin sidplay_decoder_plugin = {
 	NULL, /* stream_decode() */
 	sidplay_file_decode,
 	sidplay_tag_dup,
+	NULL, /* stream_tag() */
 	sidplay_container_scan,
 	sidplay_suffixes,
 	NULL, /* mime_types */
diff --git a/src/decoder_plugin.h b/src/decoder_plugin.h
index a078540a6..3f0fde3d8 100644
--- a/src/decoder_plugin.h
+++ b/src/decoder_plugin.h
@@ -77,6 +77,13 @@ struct decoder_plugin {
 	struct tag *(*tag_dup)(const char *path_fs);
 
 	/**
+	 * Read the tags of a stream.
+	 *
+	 * @return NULL if the operation has failed
+	 */
+	struct tag *(*stream_tag)(struct input_stream *is);
+
+	/**
 	 * @brief Return a "virtual" filename for subtracks in
 	 * container formats like flac
 	 * @param const char* pathname full pathname for the file on fs
@@ -147,7 +154,21 @@ static inline struct tag *
 decoder_plugin_tag_dup(const struct decoder_plugin *plugin,
 		       const char *path_fs)
 {
-	return plugin->tag_dup(path_fs);
+	return plugin->tag_dup != NULL
+		? plugin->tag_dup(path_fs)
+		: NULL;
+}
+
+/**
+ * Read the tag of a stream.
+ */
+static inline struct tag *
+decoder_plugin_stream_tag(const struct decoder_plugin *plugin,
+			  struct input_stream *is)
+{
+	return plugin->stream_tag != NULL
+		? plugin->stream_tag(is)
+		: NULL;
 }
 
 /**