decoder/flac: move class FLACMetadataIterator to separate source

src/lib/xiph/FlacMetadataIterator.hxx

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2003-2018 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_FLAC_METADATA_ITERATOR_HXX
+#define MPD_FLAC_METADATA_ITERATOR_HXX
+
+#include "Compiler.h"
+
+#include <FLAC/metadata.h>
+
+class FLACMetadataIterator {
+	FLAC__Metadata_Iterator *iterator;
+
+public:
+	FLACMetadataIterator():iterator(::FLAC__metadata_iterator_new()) {}
+
+	FLACMetadataIterator(FLAC__Metadata_Chain *chain)
+		:iterator(::FLAC__metadata_iterator_new()) {
+		::FLAC__metadata_iterator_init(iterator, chain);
+	}
+
+	~FLACMetadataIterator() {
+		::FLAC__metadata_iterator_delete(iterator);
+	}
+
+	bool Next() noexcept {
+		return ::FLAC__metadata_iterator_next(iterator);
+	}
+
+	gcc_pure
+	FLAC__StreamMetadata *GetBlock() noexcept {
+		return ::FLAC__metadata_iterator_get_block(iterator);
+	}
+};
+
+#endif