+ LogicalCachedExtent &nextent) = 0;
+
+ virtual alloc_extent_ret clone_extent(
+ Transaction &t,
+ laddr_t hint,
+ extent_len_t len,
+ laddr_t intermediate_key,
+ paddr_t actual_addr,
+ laddr_t intermediate_base) = 0;
+
+ virtual alloc_extent_ret reserve_region(
+ Transaction &t,
+ laddr_t hint,
+ extent_len_t len) = 0;