block manager: use data paths from layout

src/block/block.rs

@@ -1,3 +1,5 @@
+use std::path::PathBuf;
+
 use bytes::Bytes;
 use serde::{Deserialize, Serialize};
 use zstd::stream::{decode_all as zstd_decode, Encoder};
@@ -19,6 +21,13 @@ pub enum DataBlock {
 	Compressed(Bytes),
 }
 
+pub enum DataBlockPath {
+	/// Uncompressed data fail
+	Plain(PathBuf),
+	/// Compressed data fail
+	Compressed(PathBuf),
+}
+
 impl DataBlock {
 	/// Query whether this block is compressed
 	pub fn is_compressed(&self) -> bool {