SongUpdate: move code to handle_lsinfo()

Don't create a temporary Song object in handle_lsinfo().  Instead,
print all tags while parsing the remote file.

src/Song.hxx

@@ -130,7 +130,6 @@ struct Song {
 
 	bool UpdateFile();
 	bool UpdateFileInArchive();
-	bool UpdateStream();
 
 	/**
 	 * Returns the URI of the song in UTF-8 encoding, including its

src/SongUpdate.cxx

@@ -132,17 +132,3 @@ Song::UpdateFileInArchive()
 	tag = tag_builder.CommitNew();
 	return true;
 }
-
-bool
-Song::UpdateStream()
-{
-	assert(!IsFile());
-
-	TagBuilder tag_builder;
-	if (!tag_stream_scan(uri, full_tag_handler, &tag_builder))
-		return false;
-
-	delete tag;
-	tag = tag_builder.CommitNew();
-	return true;
-}

src/TagPrint.cxx

@@ -35,6 +35,12 @@ void tag_print_types(Client &client)
 	}
 }
 
+void
+tag_print(Client &client, TagType type, const char *value)
+{
+	client_printf(client, "%s: %s\n", tag_item_names[type], value);
+}
+
 void tag_print(Client &client, const Tag &tag)
 {
 	if (tag.time >= 0)

src/TagPrint.hxx

@@ -20,11 +20,18 @@
 #ifndef MPD_TAG_PRINT_HXX
 #define MPD_TAG_PRINT_HXX
 
+#include <stdint.h>
+
+enum TagType : uint8_t;
+
 struct Tag;
 class Client;
 
 void tag_print_types(Client &client);
 
+void
+tag_print(Client &client, TagType type, const char *value);
+
 void
 tag_print(Client &client, const Tag &tag);
 

src/command/OtherCommands.cxx

@@ -26,6 +26,8 @@
 #include "Song.hxx"
 #include "SongPrint.hxx"
 #include "TagPrint.hxx"
+#include "TagStream.hxx"
+#include "tag/TagHandler.hxx"
 #include "TimePrint.hxx"
 #include "Mapper.hxx"
 #include "DecoderPrint.hxx"
@@ -98,6 +100,20 @@ handle_close(gcc_unused Client &client,
 	return CommandResult::FINISH;
 }
 
+static void
+print_tag(TagType type, const char *value, void *ctx)
+{
+	Client &client = *(Client *)ctx;
+
+	tag_print(client, type, value);
+}
+
+static constexpr tag_handler print_tag_handler = {
+	nullptr,
+	print_tag,
+	nullptr,
+};
+
 CommandResult
 handle_lsinfo(Client &client, int argc, char *argv[])
 {
@@ -143,16 +159,12 @@ handle_lsinfo(Client &client, int argc, char *argv[])
 			return CommandResult::ERROR;
 		}
 
-		Song *song = Song::NewRemote(uri);
-		if (!song->UpdateStream()) {
-			song->Free();
+		if (!tag_stream_scan(uri, print_tag_handler, &client)) {
 			command_error(client, ACK_ERROR_NO_EXIST,
 				      "No such file");
 			return CommandResult::ERROR;
 		}
 
-		song_print_info(client, *song);
-		song->Free();
 		return CommandResult::OK;
 	}