This functor use seek operations to perform fast folds over block devices.
val mapped_s :
f:('a -> int64 -> Cstruct.t -> 'a Lwt.t) ->
'a ->
A.t ->
('a, A.error) Result.result Lwt.tFolds f across data blocks read sequentially from a block device. In contrast to fold_s, Fold.mapped_s will use knowledge about the underlying disk structure and will skip blocks which it knows contain only zeroes. Note it may still read blocks containing zeroes. The function f receives an accumulator, the sector number and a data buffer.
val unmapped_s :
f:('a -> int64 -> int64 -> 'a Lwt.t) ->
'a ->
A.t ->
('a, A.error) Result.result Lwt.tFolds f acc ofs len across offsets of unmapped data blocks read sequentially from the block device. Fold.unmapped_s will use knowledge about the underlying disk structure and will only fold across those blocks which are guaranteed to be zero i.e. those which are unmapped somehow.