bump toolchain

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

mini-lsm/src/block.rs

@@ -27,13 +27,16 @@ impl Block {
     }
 
     pub fn decode(data: &[u8]) -> Self {
+        // get number of elements in the block
         let entry_offsets_len = (&data[data.len() - SIZEOF_U16..]).get_u16() as usize;
         let data_end = data.len() - SIZEOF_U16 - entry_offsets_len * SIZEOF_U16;
         let offsets_raw = &data[data_end..data.len() - SIZEOF_U16];
+        // get offset array
         let offsets = offsets_raw
             .chunks(SIZEOF_U16)
             .map(|mut x| x.get_u16())
             .collect();
+        // retrieve data
         let data = data[0..data_end].to_vec();
         Self { data, offsets }
     }