diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 859c9707..c30b3316 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -36,7 +36,7 @@ jobs:
         name: Setup Cargo Toolchain 🛎️
         with:
           components: rustfmt, clippy, llvm-tools-preview
-          toolchain: stable
+          toolchain: nightly
           default: true
       - name: Check Code Format 🔧
         run: |
diff --git a/Cargo.toml b/Cargo.toml
index 89e7d1ca..223cd26c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,42 +2,38 @@
 name = "agatedb"
 version = "0.1.0"
 authors = ["Jay Lee <busyjaylee@gmail.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]
-bytes = "1.0"
+bytes = "1.1.0"
 coarsetime = "0.1.22"
-crc = "1.8"
-crc32fast = "1.2"
-crossbeam-channel = "0.5"
-enum_dispatch = "0.3"
-farmhash = "1.1"
+crc = "3.0.0"
+crc32fast = "1.3.2"
+crossbeam-channel = "0.5.5"
+enum_dispatch = "0.3.8"
+farmhash = "1.1.5"
 getset = "0.1.2"
 lazy_static = "1.4.0"
 log = "0.4.17"
-memmap2 = "0.3"
-parking_lot = "0.11"
-prost = "0.8"
+memmap2 = "0.5.4"
+parking_lot = "0.12.1"
+prost = "0.10.4"
 proto = { path = "proto" }
-rand = "0.7"
+rand = "0.8.5"
 skiplist = { path = "skiplist" }
-tempdir = "0.3"
-thiserror = "1.0"
+tempdir = "0.3.7"
+thiserror = "1.0.31"
 yatp = { git = "https://github.com/tikv/yatp.git" }
 
 [dev-dependencies]
-criterion = "0.3"
-tempfile = "3"
+criterion = "0.3.5"
+tempfile = "3.3.0"
 
 [target.'cfg(not(target_env = "msvc"))'.dev-dependencies]
-tikv-jemallocator = "0.4.0"
+tikv-jemallocator = "0.5.0"
 
 [workspace]
-members = [
-    "agate_bench",
-    "proto",
-    "skiplist"
-]
+members = ["agate_bench", "proto", "skiplist"]
 
 [[bench]]
 name = "bench_common"
diff --git a/Makefile b/Makefile
index b0e347a2..292baa5a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,13 +1,16 @@
 
 SANITIZER_FLAGS=-Zsanitizer=address
 
+upgrade:
+	cargo upgrade --workspace
+
 pre-format:
 	@rustup component add rustfmt
-	@cargo install -q cargo-sort 
+	@cargo install -q cargo-sort
 
 format: pre-format
 	@cargo fmt
-	@cargo sort -w ./Cargo.toml ./*/Cargo.toml > /dev/null 
+	@cargo sort -w ./Cargo.toml ./*/Cargo.toml > /dev/null
 
 clippy:
 	cargo clippy --all-targets --all-features --workspace -- -D "warnings"
diff --git a/README.md b/README.md
index b1d03803..f6e833b9 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ optimizations that have been made in [unistore][4].
 
 [1]: https://github.com/tikv/tikv
 [2]: https://github.com/tikv/agatedb/projects/1
-[3]: https://github.com/dgraph-io/badger/tree/45bca18f24ef5cc04701a1e17448ddfce9372da0
+[3]: https://github.com/outcaste-io/badger/tree/45bca18f24ef5cc04701a1e17448ddfce9372da0
 [4]: https://github.com/ngaut/unistore
 
 AgateDB is under active development on [develop](https://github.com/tikv/agatedb/tree/develop)
diff --git a/agate_bench/Cargo.toml b/agate_bench/Cargo.toml
index 4b3faea8..ec40d6df 100644
--- a/agate_bench/Cargo.toml
+++ b/agate_bench/Cargo.toml
@@ -10,13 +10,13 @@ enable-rocksdb = ["rocksdb"]
 
 [dependencies]
 agatedb = { path = "../" }
-bytes = "1.0"
-clap = "2.33"
-indicatif = "0.15"
-rand = "0.7"
-rocksdb = { version = "0.15", optional = true }
-threadpool = "1.8"
+bytes = "1.1.0"
+clap = "3.2.8"
+indicatif = "0.16.2"
+rand = "0.8.5"
+rocksdb = { version = "0.18.0", optional = true }
+threadpool = "1.8.1"
 yatp = { git = "https://github.com/tikv/yatp.git" }
 
 [target.'cfg(not(target_env = "msvc"))'.dependencies]
-tikv-jemallocator = "0.4.0"
+tikv-jemallocator = "0.5.0"
diff --git a/agate_bench/src/main.rs b/agate_bench/src/main.rs
index 7853c576..9c4c8256 100644
--- a/agate_bench/src/main.rs
+++ b/agate_bench/src/main.rs
@@ -1,13 +1,14 @@
+use std::{
+    path::PathBuf,
+    sync::{mpsc::channel, Arc},
+    time::{Duration, UNIX_EPOCH},
+};
+
 use agatedb::{AgateOptions, IteratorOptions};
 use bytes::{Bytes, BytesMut};
 use clap::clap_app;
 use indicatif::{ProgressBar, ProgressStyle};
 use rand::Rng;
-use std::path::PathBuf;
-use std::sync::Arc;
-use std::time::UNIX_EPOCH;
-use std::{sync::mpsc::channel, time::Duration};
-
 #[cfg(not(target_env = "msvc"))]
 use tikv_jemallocator::Jemalloc;
 
@@ -126,14 +127,13 @@ fn main() {
     let pool = threadpool::ThreadPool::new(threads);
     let (tx, rx) = channel();
 
-    match matches.subcommand() {
-        ("populate", Some(sub_matches)) => {
+    match matches.subcommand().unwrap() {
+        ("populate", sub_matches) => {
             let key_nums: u64 = sub_matches.value_of("key_nums").unwrap().parse().unwrap();
             let value_size: usize = sub_matches.value_of("value_size").unwrap().parse().unwrap();
             let chunk_size: u64 = sub_matches.value_of("chunk_size").unwrap().parse().unwrap();
 
             let mut options = AgateOptions {
-                create_if_not_exists: true,
                 dir: directory.clone(),
                 value_dir: directory,
                 managed_txns: true,
@@ -169,7 +169,7 @@ fn main() {
                         let (key, value) = if seq {
                             gen_kv_pair(j, value_size)
                         } else {
-                            gen_kv_pair(rng.gen_range(0, key_nums), value_size)
+                            gen_kv_pair(rng.gen_range(0..key_nums), value_size)
                         };
                         txn.set(key, value).unwrap();
                         write.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
@@ -198,14 +198,13 @@ fn main() {
             }
             pb.finish_with_message("done");
         }
-        ("randread", Some(sub_matches)) => {
+        ("randread", sub_matches) => {
             let key_nums: u64 = sub_matches.value_of("key_nums").unwrap().parse().unwrap();
             let value_size: usize = sub_matches.value_of("value_size").unwrap().parse().unwrap();
             let chunk_size: u64 = sub_matches.value_of("chunk_size").unwrap().parse().unwrap();
             let times: u64 = sub_matches.value_of("times").unwrap().parse().unwrap();
 
             let mut options = AgateOptions {
-                create_if_not_exists: true,
                 sync_writes: true,
                 dir: directory.clone(),
                 value_dir: directory,
@@ -236,7 +235,7 @@ fn main() {
                         let txn = agate.new_transaction_at(unix_time(), false);
                         let mut rng = rand::thread_rng();
                         for _ in range {
-                            let (key, _) = gen_kv_pair(rng.gen_range(0, key_nums), value_size);
+                            let (key, _) = gen_kv_pair(rng.gen_range(0..key_nums), value_size);
                             match txn.get(&key) {
                                 Ok(item) => {
                                     assert_eq!(item.value().len(), value_size);
@@ -276,12 +275,11 @@ fn main() {
             }
             pb.finish_with_message("done");
         }
-        ("iterate", Some(sub_matches)) => {
+        ("iterate", sub_matches) => {
             let times: u64 = sub_matches.value_of("times").unwrap().parse().unwrap();
             let value_size: usize = sub_matches.value_of("value_size").unwrap().parse().unwrap();
 
             let mut options = AgateOptions {
-                create_if_not_exists: true,
                 sync_writes: true,
                 dir: directory.clone(),
                 value_dir: directory,
@@ -327,7 +325,7 @@ fn main() {
             )
         }
         #[cfg(feature = "enable-rocksdb")]
-        ("rocks_populate", Some(sub_matches)) => {
+        ("rocks_populate", sub_matches) => {
             let key_nums: u64 = sub_matches.value_of("key_nums").unwrap().parse().unwrap();
             let value_size: usize = sub_matches.value_of("value_size").unwrap().parse().unwrap();
             let chunk_size: u64 = sub_matches.value_of("chunk_size").unwrap().parse().unwrap();
@@ -369,7 +367,7 @@ fn main() {
                         let (key, value) = if seq {
                             gen_kv_pair(j, value_size)
                         } else {
-                            gen_kv_pair(rng.gen_range(0, key_nums), value_size)
+                            gen_kv_pair(rng.gen_range(0..key_nums), value_size)
                         };
                         batch.put(key, value);
                         write.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
@@ -399,7 +397,7 @@ fn main() {
             pb.finish_with_message("done");
         }
         #[cfg(feature = "enable-rocksdb")]
-        ("rocks_randread", Some(sub_matches)) => {
+        ("rocks_randread", sub_matches) => {
             let key_nums: u64 = sub_matches.value_of("key_nums").unwrap().parse().unwrap();
             let value_size: usize = sub_matches.value_of("value_size").unwrap().parse().unwrap();
             let chunk_size: u64 = sub_matches.value_of("chunk_size").unwrap().parse().unwrap();
@@ -431,7 +429,7 @@ fn main() {
                         let range = (i * chunk_size)..((i + 1) * chunk_size);
                         let mut rng = rand::thread_rng();
                         for _ in range {
-                            let (key, _) = gen_kv_pair(rng.gen_range(0, key_nums), value_size);
+                            let (key, _) = gen_kv_pair(rng.gen_range(0..key_nums), value_size);
                             match db.get(&key) {
                                 Ok(Some(value)) => {
                                     assert_eq!(value.len(), value_size);
@@ -471,7 +469,7 @@ fn main() {
             pb.finish_with_message("done");
         }
         #[cfg(feature = "enable-rocksdb")]
-        ("rocks_iterate", Some(sub_matches)) => {
+        ("rocks_iterate", sub_matches) => {
             let times: u64 = sub_matches.value_of("times").unwrap().parse().unwrap();
             let value_size: usize = sub_matches.value_of("value_size").unwrap().parse().unwrap();
 
diff --git a/benches/bench_iterator.rs b/benches/bench_iterator.rs
index 692c5483..44f07c08 100644
--- a/benches/bench_iterator.rs
+++ b/benches/bench_iterator.rs
@@ -1,12 +1,8 @@
 mod common;
 
-use agatedb::util::unix_time;
-use agatedb::AgateIterator;
-use agatedb::AgateOptions;
-use agatedb::ConcatIterator;
-use agatedb::Iterators;
-use agatedb::MergeIterator;
-
+use agatedb::{
+    util::unix_time, AgateIterator, AgateOptions, ConcatIterator, Iterators, MergeIterator,
+};
 use bytes::Bytes;
 use common::get_table_for_benchmark;
 use criterion::{criterion_group, criterion_main, Criterion};
@@ -58,7 +54,7 @@ fn bench_iterator(c: &mut Criterion) {
 
     c.bench_function("iterate noprefix single key", |b| {
         let txn = db.new_transaction_at(unix_time(), false);
-        let key_id = thread_rng().gen_range(0, N);
+        let key_id = thread_rng().gen_range(0..N);
         let seek_key = key(key_id);
         let it_opts = agatedb::IteratorOptions {
             all_versions: true,
@@ -110,7 +106,7 @@ fn bench_merge_iterator(c: &mut Criterion) {
     c.bench_function("merge iterator random read", |b| {
         b.iter_batched(
             || {
-                let i = rng.gen_range(0, n);
+                let i = rng.gen_range(0..n);
                 (
                     Bytes::from(format!("{:016x}", i)),
                     Bytes::from(i.to_string()),
@@ -149,7 +145,7 @@ fn bench_concat_iterator(c: &mut Criterion) {
     c.bench_function("concat iterator random read", |b| {
         b.iter_batched(
             || {
-                let i = rng.gen_range(0, n);
+                let i = rng.gen_range(0..n);
                 (
                     Bytes::from(format!("{:016x}", i)),
                     Bytes::from(i.to_string()),
diff --git a/benches/bench_table.rs b/benches/bench_table.rs
index 69e66be6..62f09f5e 100644
--- a/benches/bench_table.rs
+++ b/benches/bench_table.rs
@@ -89,7 +89,7 @@ fn bench_table(c: &mut Criterion) {
 
         b.iter_batched(
             || {
-                let i = rng.gen_range(0, n);
+                let i = rng.gen_range(0..n);
                 (
                     Bytes::from(format!("{:016x}", i)),
                     Bytes::from(i.to_string()),
diff --git a/benches/common.rs b/benches/common.rs
index 6742ad2f..af350b82 100644
--- a/benches/common.rs
+++ b/benches/common.rs
@@ -1,17 +1,19 @@
 #![allow(dead_code)]
+use std::ops::{Deref, DerefMut};
+
 use agatedb::{
     opt::build_table_options, AgateOptions, ChecksumVerificationMode::NoVerification, Table,
     TableBuilder, Value,
 };
 use bytes::Bytes;
 use rand::{distributions::Alphanumeric, Rng};
-use std::ops::{Deref, DerefMut};
 use tempdir::TempDir;
 
 pub fn rand_value() -> String {
     rand::thread_rng()
         .sample_iter(&Alphanumeric)
         .take(32)
+        .map(char::from)
         .collect::<String>()
 }
 
diff --git a/proto/Cargo.toml b/proto/Cargo.toml
index 1f55de7e..f0ecd460 100644
--- a/proto/Cargo.toml
+++ b/proto/Cargo.toml
@@ -2,11 +2,11 @@
 name = "proto"
 version = "0.1.0"
 authors = ["Jay Lee <busyjaylee@gmail.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]
-bytes = "1.0"
-prost = "0.8"
+bytes = "1.1.0"
+prost = "0.10.4"
 
 [build-dependencies]
-prost-build = { version = "0.8" }
+prost-build = "0.10.4"
diff --git a/skiplist/Cargo.toml b/skiplist/Cargo.toml
index 3db51e64..4beb97fc 100644
--- a/skiplist/Cargo.toml
+++ b/skiplist/Cargo.toml
@@ -2,18 +2,18 @@
 name = "skiplist"
 version = "0.1.0"
 authors = ["Jay Lee <busyjaylee@gmail.com>"]
-edition = "2018"
+edition = "2021"
 
 [dependencies]
-bytes = "1.0"
-rand = "0.7"
+bytes = "1.1.0"
+rand = "0.8.5"
 
 [dev-dependencies]
-criterion = "0.3"
+criterion = "0.3.5"
 yatp = { git = "https://github.com/tikv/yatp.git" }
 
 [target.'cfg(not(target_env = "msvc"))'.dev-dependencies]
-tikv-jemallocator = "0.4.0"
+tikv-jemallocator = "0.5.0"
 
 [[bench]]
 name = "bench"
diff --git a/skiplist/benches/bench.rs b/skiplist/benches/bench.rs
index affde9dd..374da06a 100644
--- a/skiplist/benches/bench.rs
+++ b/skiplist/benches/bench.rs
@@ -53,13 +53,13 @@ fn bench_read_write_skiplist_frac(b: &mut Bencher<'_>, frac: &usize) {
         let mut rng = rand::thread_rng();
         while !s.load(Ordering::SeqCst) {
             let key = random_key(&mut rng);
-            let case = (key, frac > rng.gen_range(0, 11));
+            let case = (key, frac > rng.gen_range(0..11));
             skiplist_round(&l, &case, &v);
         }
     });
     let mut rng = rand::thread_rng();
     b.iter_batched_ref(
-        || (random_key(&mut rng), frac > rng.gen_range(0, 11)),
+        || (random_key(&mut rng), frac > rng.gen_range(0..11)),
         |case| skiplist_round(&list, case, &value),
         BatchSize::SmallInput,
     );
@@ -104,7 +104,7 @@ fn bench_read_write_map_frac(b: &mut Bencher<'_>, frac: &usize) {
     let h = thread::spawn(move || {
         let mut rng = rand::thread_rng();
         while !s.load(Ordering::SeqCst) {
-            let f = rng.gen_range(0, 11);
+            let f = rng.gen_range(0..11);
             let case = (random_key(&mut rng), f < frac);
             map_round(&m, &case, &v);
         }
@@ -112,7 +112,7 @@ fn bench_read_write_map_frac(b: &mut Bencher<'_>, frac: &usize) {
     let mut rng = rand::thread_rng();
     b.iter_batched_ref(
         || {
-            let f = rng.gen_range(0, 11);
+            let f = rng.gen_range(0..11);
             (random_key(&mut rng), f < frac)
         },
         |case| map_round(&map, case, &value),
diff --git a/src/checksum.rs b/src/checksum.rs
index b6126b82..98768845 100644
--- a/src/checksum.rs
+++ b/src/checksum.rs
@@ -1,6 +1,7 @@
-use crate::{Error, Result};
 use proto::meta::{checksum::Algorithm as ChecksumAlgorithm, Checksum};
 
+use crate::{Error, Result};
+
 pub fn calculate_checksum(data: &[u8], algo: ChecksumAlgorithm) -> u64 {
     match algo {
         ChecksumAlgorithm::Crc32c => {
diff --git a/src/db/opt.rs b/src/db/opt.rs
index c785c3c9..9dad48bb 100644
--- a/src/db/opt.rs
+++ b/src/db/opt.rs
@@ -1,10 +1,10 @@
-use skiplist::MAX_NODE_SIZE;
+use std::cmp;
 
-use super::*;
 use getset::Setters;
+use skiplist::MAX_NODE_SIZE;
 
+use super::*;
 use crate::{entry::Entry, opt};
-use std::cmp;
 
 #[derive(Clone, Setters)]
 pub struct AgateOptions {
@@ -129,12 +129,6 @@ pub struct AgateOptions {
     /// The default value of `managed_txns` is false.
     pub managed_txns: bool,
 
-    /// Create the directory if the provided open path doesn't exists.
-    ///
-    /// The default value of `create_if_not_exists` is false
-    #[getset(set = "pub")]
-    pub create_if_not_exists: bool,
-
     /// Max entries in batch.
     ///
     /// The default value of `max_batch_count` is `max_batch_size` / `MAX_NODE_SIZE`.
@@ -181,8 +175,6 @@ impl Default for AgateOptions {
 
             managed_txns: false,
 
-            create_if_not_exists: false,
-
             max_batch_count: 0,
             max_batch_size: 0,
         }
@@ -245,14 +237,14 @@ mod tests {
     #[test]
     fn test_options_set() {
         let mut opt = AgateOptions::default();
-        opt.set_create_if_not_exists(true)
-            .set_in_memory(true)
+
+        opt.set_in_memory(true)
             .set_value_log_file_size(256)
             .set_num_memtables(3)
             .set_value_log_max_entries(96)
             .set_sync_writes(true)
             .set_mem_table_size(1024);
-        assert!(opt.create_if_not_exists);
+
         assert!(opt.in_memory);
         assert_eq!(opt.value_log_file_size, 256);
         assert_eq!(opt.num_memtables, 3);
diff --git a/src/lib.rs b/src/lib.rs
index 7f01a66e..73f37d74 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -29,8 +29,8 @@ pub use iterator::IteratorOptions;
 pub use iterator_trait::AgateIterator;
 pub use opt::{ChecksumVerificationMode, Options as TableOptions};
 pub use skiplist::Skiplist;
-pub use table::merge_iterator::Iterators;
-pub use table::ConcatIterator;
-pub use table::MergeIterator;
-pub use table::{builder::Builder as TableBuilder, Table};
+pub use table::{
+    builder::Builder as TableBuilder, merge_iterator::Iterators, ConcatIterator, MergeIterator,
+    Table,
+};
 pub use value::Value;
diff --git a/src/managed_db.rs b/src/managed_db.rs
index 8fe4d1ce..b617ba47 100644
--- a/src/managed_db.rs
+++ b/src/managed_db.rs
@@ -1,9 +1,7 @@
-use crate::db::Agate;
-use crate::ops::transaction::Transaction;
-use crate::Result;
-
 use std::sync::Arc;
 
+use crate::{db::Agate, ops::transaction::Transaction, Result};
+
 impl crate::db::Core {
     /// Follows the same logic as `new_transaction`, but uses the provided read timestamp.
     pub fn new_transaction_at(self: &Arc<Self>, read_ts: u64, update: bool) -> Transaction {
diff --git a/src/manifest.rs b/src/manifest.rs
index 347489c1..6943e88a 100644
--- a/src/manifest.rs
+++ b/src/manifest.rs
@@ -7,7 +7,7 @@ use std::{
 };
 
 use bytes::{Buf, BufMut, BytesMut};
-use crc::crc32;
+use crc::{Crc, CRC_32_ISCSI};
 use prost::Message;
 use proto::meta::{
     manifest_change::Operation as ManifestChangeOp, ManifestChange, ManifestChangeSet,
@@ -15,6 +15,8 @@ use proto::meta::{
 
 use crate::{util, AgateOptions, Error, Result};
 
+pub const CRC32_CASTAGNOLI: Crc<u32> = Crc::<u32>::new(&CRC_32_ISCSI);
+
 pub const MANIFEST_FILENAME: &str = "MANIFEST";
 const MANIFEST_REWRITE_FILENAME: &str = "MANIFEST_REWRITE";
 const MANIFEST_DELETION_REWRITE_THRESHOLD: usize = 10000;
@@ -134,7 +136,7 @@ impl Manifest {
 
             offset += length;
 
-            if crc32::checksum_castagnoli(&buf) != (&len_crc_buf[4..]).get_u32() {
+            if CRC32_CASTAGNOLI.checksum(&buf) != (&len_crc_buf[4..]).get_u32() {
                 return Err(Error::CustomError("bad checksum".to_string()));
             }
 
@@ -241,7 +243,7 @@ impl ManifestFile {
 
         let mut len_crc_buf = vec![0; 8];
         (&mut len_crc_buf[..4]).put_u32(change_buf.len() as u32);
-        (&mut len_crc_buf[4..]).put_u32(crc32::checksum_castagnoli(&change_buf));
+        (&mut len_crc_buf[4..]).put_u32(CRC32_CASTAGNOLI.checksum(&change_buf));
 
         buf.extend_from_slice(&len_crc_buf);
         buf.extend_from_slice(&change_buf);
@@ -294,7 +296,7 @@ impl ManifestFile {
         } else {
             let mut len_crc_buf = vec![0; 8];
             (&mut len_crc_buf[..4]).put_u32(buf.len() as u32);
-            (&mut len_crc_buf[4..]).put_u32(crc32::checksum_castagnoli(&buf));
+            (&mut len_crc_buf[4..]).put_u32(CRC32_CASTAGNOLI.checksum(&buf));
             len_crc_buf.extend_from_slice(&buf);
 
             inner.file.as_mut().unwrap().write_all(&len_crc_buf)?;
diff --git a/src/ops/transaction.rs b/src/ops/transaction.rs
index 2fefaa3a..a37b1016 100644
--- a/src/ops/transaction.rs
+++ b/src/ops/transaction.rs
@@ -87,11 +87,7 @@ impl Transaction {
         let mut entries: Vec<_> = self.pending_writes.values().cloned().collect();
         entries.sort_by(|x, y| {
             let cmp = COMPARATOR.compare_key(&x.key, &y.key);
-            if reversed {
-                cmp.reverse()
-            } else {
-                cmp
-            }
+            if reversed { cmp.reverse() } else { cmp }
         });
 
         Some(PendingWritesIterator::new(self.read_ts, reversed, entries))
@@ -458,7 +454,7 @@ impl AgateIterator for PendingWritesIterator {
         let key = user_key(key);
         self.next_idx = crate::util::search(self.entries.len(), |idx| {
             // Should not use COMPARATOR when compare without ts.
-            let cmp = (&self.entries[idx].key[..]).cmp(key);
+            let cmp = self.entries[idx].key[..].cmp(key);
             if !self.reversed {
                 cmp != Less
             } else {
diff --git a/src/ops/transaction_test.rs b/src/ops/transaction_test.rs
index 01869769..5c89edbb 100644
--- a/src/ops/transaction_test.rs
+++ b/src/ops/transaction_test.rs
@@ -1,17 +1,15 @@
-use crate::Error;
-
-use crate::assert_bytes_eq;
+use crate::{assert_bytes_eq, Error};
 
 /// Tests in managed mode.
 mod managed_db {
+    use bytes::{Bytes, BytesMut};
+
+    use super::*;
     use crate::{
         db::tests::{generate_test_agate_options, run_agate_test, with_payload},
         entry::Entry,
         AgateOptions,
     };
-    use bytes::{Bytes, BytesMut};
-
-    use super::*;
 
     fn default_test_managed_opts() -> AgateOptions {
         let mut opts = generate_test_agate_options();
@@ -136,6 +134,12 @@ mod normal_db {
         Arc,
     };
 
+    use bytes::{Bytes, BytesMut};
+    use crossbeam_channel::select;
+    use rand::Rng;
+    use yatp::{task::callback::Handle, Builder};
+
+    use super::*;
     use crate::{
         closer::Closer,
         db::tests::{generate_test_agate_options, run_agate_test},
@@ -146,12 +150,6 @@ mod normal_db {
         value::VALUE_DELETE,
         Agate, AgateOptions,
     };
-    use bytes::{Bytes, BytesMut};
-    use crossbeam_channel::select;
-    use rand::Rng;
-    use yatp::{task::callback::Handle, Builder};
-
-    use super::*;
 
     #[test]
     fn test_txn_simple() {
@@ -259,7 +257,7 @@ mod normal_db {
                 let agate = agatedb.clone();
                 pool.spawn(move |_: &mut Handle<'_>| {
                     let mut txn = agate.new_transaction(true);
-                    let delta = rand::thread_rng().gen_range(0, 100);
+                    let delta = rand::thread_rng().gen_range(0..100);
 
                     for i in 0..3 {
                         txn.set_entry(Entry::new(key(i), Bytes::from((100 - delta).to_string())))
diff --git a/src/table/concat_iterator.rs b/src/table/concat_iterator.rs
index d4743ffd..b736b1a2 100644
--- a/src/table/concat_iterator.rs
+++ b/src/table/concat_iterator.rs
@@ -153,7 +153,7 @@ mod tests {
         let mut rng = thread_rng();
 
         for i in 0..20 {
-            let size = rng.gen_range(100, 200);
+            let size = rng.gen_range(100..200);
             let data: Vec<(Bytes, Bytes)> = (cnt..cnt + size)
                 .map(|x| {
                     (
diff --git a/src/table/merge_iterator.rs b/src/table/merge_iterator.rs
index 612398f4..dd08460d 100644
--- a/src/table/merge_iterator.rs
+++ b/src/table/merge_iterator.rs
@@ -235,8 +235,10 @@ impl AgateIterator for MergeIterator {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::assert_bytes_eq;
-    use crate::format::{key_with_ts, user_key};
+    use crate::{
+        assert_bytes_eq,
+        format::{key_with_ts, user_key},
+    };
 
     pub struct VecIterator {
         vec: Vec<Bytes>,