btrfs-tree: add chunk items: length and type

Signed-off-by: Zygo Blaxell <bees@furryterror.org>

include/crucible/btrfs-tree.h

@@ -33,6 +33,11 @@ namespace crucible {
 		uint64_t block_group_used() const;
 		/// @}
 
+		/// @{ Chunk items
+		uint64_t chunk_length() const;
+		uint64_t chunk_type() const;
+		/// @}
+
 		/// @{ Dev extent items (physical byte ranges)
 		uint64_t dev_extent_chunk_offset() const;
 		uint64_t dev_extent_length() const;

lib/btrfs-tree.cc

@@ -88,6 +88,20 @@ namespace crucible {
 		return btrfs_get_member(&btrfs_block_group_item::used, m_data);
 	}
 
+	uint64_t
+	BtrfsTreeItem::chunk_length() const
+	{
+		THROW_CHECK1(invalid_argument, btrfs_search_type_ntoa(m_type), m_type == BTRFS_CHUNK_ITEM_KEY);
+		return btrfs_get_member(&btrfs_chunk::length, m_data);
+	}
+
+	uint64_t
+	BtrfsTreeItem::chunk_type() const
+	{
+		THROW_CHECK1(invalid_argument, btrfs_search_type_ntoa(m_type), m_type == BTRFS_CHUNK_ITEM_KEY);
+		return btrfs_get_member(&btrfs_chunk::type, m_data);
+	}
+
 	uint64_t
 	BtrfsTreeItem::dev_extent_chunk_offset() const
 	{