finish week 1 day 7

Signed-off-by: Alex Chi <iskyzh@gmail.com>

Cargo.lock

@@ -274,6 +274,12 @@ dependencies = [
  "version_check",
 ]
 
+[[package]]
+name = "farmhash"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f35ce9c8fb9891c75ceadbc330752951a4e369b50af10775955aeb9af3eee34b"
+
 [[package]]
 name = "fastrand"
 version = "1.8.0"
@@ -434,6 +440,7 @@ dependencies = [
  "crossbeam-channel",
  "crossbeam-epoch",
  "crossbeam-skiplist",
+ "farmhash",
  "moka",
  "ouroboros 0.18.2",
  "parking_lot",