diff --git a/src/bin/logging/mod.rs b/src/bin/logging/mod.rs
index f91315e1..4005b146 100644
--- a/src/bin/logging/mod.rs
+++ b/src/bin/logging/mod.rs
@@ -1,5 +1,7 @@
-use std::env;
-use std::io::{self, Write};
+use std::{
+    env,
+    io::{self, Write},
+};
 
 use env_logger::{fmt::Formatter, Builder};
 use log::{LevelFilter, Record};
diff --git a/src/bin/monitor/windows.rs b/src/bin/monitor/windows.rs
index d36e2e0d..d0a064da 100644
--- a/src/bin/monitor/windows.rs
+++ b/src/bin/monitor/windows.rs
@@ -1,5 +1,7 @@
-use futures::future::{self, Either, FutureExt};
-use futures::StreamExt;
+use futures::{
+    future::{self, Either, FutureExt},
+    StreamExt,
+};
 use log::info;
 use std::io;
 use tokio::signal::{ctrl_c, windows::ctrl_break};
diff --git a/src/bin/tunnel.rs b/src/bin/tunnel.rs
index a0733744..0984b35e 100644
--- a/src/bin/tunnel.rs
+++ b/src/bin/tunnel.rs
@@ -13,9 +13,16 @@ use log::{debug, error, info};
 use std::net::SocketAddr;
 use tokio;
 
-use shadowsocks::plugin::PluginConfig;
-use shadowsocks::relay::socks5::Address;
-use shadowsocks::{run_local, Config, ConfigType, Mode, ServerAddr, ServerConfig};
+use shadowsocks::{
+    plugin::PluginConfig,
+    relay::socks5::Address,
+    run_local,
+    Config,
+    ConfigType,
+    Mode,
+    ServerAddr,
+    ServerConfig,
+};
 
 mod logging;
 mod monitor;
diff --git a/src/config.rs b/src/config.rs
index f78cdaa9..c6312049 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -41,19 +41,21 @@
 //!
 //! These defined server will be used with a load balancing algorithm.
 
-use std::collections::HashSet;
-use std::convert::From;
-use std::default::Default;
-use std::error;
-use std::fmt::{self, Debug, Display, Formatter};
-use std::fs::OpenOptions;
-use std::io::Read;
-use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
-use std::option::Option;
-use std::path::Path;
-use std::str::FromStr;
-use std::string::ToString;
-use std::time::Duration;
+use std::{
+    collections::HashSet,
+    convert::From,
+    default::Default,
+    error,
+    fmt::{self, Debug, Display, Formatter},
+    fs::OpenOptions,
+    io::Read,
+    net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6},
+    option::Option,
+    path::Path,
+    str::FromStr,
+    string::ToString,
+    time::Duration,
+};
 
 use base64::{decode_config, encode_config, URL_SAFE_NO_PAD};
 use bytes::Bytes;
@@ -65,9 +67,7 @@ use serde_urlencoded;
 use trust_dns_resolver::config::{NameServerConfigGroup, ResolverConfig};
 use url::{self, Url};
 
-use crate::crypto::cipher::CipherType;
-use crate::plugin::PluginConfig;
-use crate::relay::socks5::Address;
+use crate::{crypto::cipher::CipherType, plugin::PluginConfig, relay::socks5::Address};
 
 #[derive(Serialize, Deserialize, Debug, Default)]
 struct SSConfig {
diff --git a/src/context.rs b/src/context.rs
index 69c6f6d9..29f3c31d 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -1,7 +1,9 @@
 //! Shadowsocks Server Context
 
-use std::sync::atomic::{AtomicBool, Ordering};
-use std::sync::Arc;
+use std::sync::{
+    atomic::{AtomicBool, Ordering},
+    Arc,
+};
 
 #[cfg(futures = "trust-dns")]
 use trust_dns_resolver::AsyncResolver;
diff --git a/src/crypto/cipher.rs b/src/crypto/cipher.rs
index 78c448e6..bd6bb732 100644
--- a/src/crypto/cipher.rs
+++ b/src/crypto/cipher.rs
@@ -3,7 +3,8 @@
 use std::{
     convert::From,
     fmt::{self, Debug, Display},
-    io, mem,
+    io,
+    mem,
     str::{self, FromStr},
 };
 
diff --git a/src/crypto/rc4_md5.rs b/src/crypto/rc4_md5.rs
index b5833cef..e2b8a94a 100644
--- a/src/crypto/rc4_md5.rs
+++ b/src/crypto/rc4_md5.rs
@@ -3,7 +3,10 @@
 use crate::crypto::{
     digest::{self, Digest, DigestType},
     openssl::OpenSSLCrypto,
-    CipherResult, CipherType, CryptoMode, StreamCipher,
+    CipherResult,
+    CipherType,
+    CryptoMode,
+    StreamCipher,
 };
 
 use bytes::{BufMut, BytesMut};
diff --git a/src/crypto/ring.rs b/src/crypto/ring.rs
index a3671b28..a8b96bc5 100644
--- a/src/crypto/ring.rs
+++ b/src/crypto/ring.rs
@@ -2,8 +2,17 @@
 
 use ring::{
     aead::{
-        Aad, Algorithm, Nonce, NonceSequence, OpeningKey, SealingKey, UnboundKey, AES_128_GCM, AES_256_GCM,
-        CHACHA20_POLY1305, NONCE_LEN,
+        Aad,
+        Algorithm,
+        Nonce,
+        NonceSequence,
+        OpeningKey,
+        SealingKey,
+        UnboundKey,
+        AES_128_GCM,
+        AES_256_GCM,
+        CHACHA20_POLY1305,
+        NONCE_LEN,
     },
     error::Unspecified,
 };
@@ -11,7 +20,10 @@ use ring::{
 use crate::crypto::{
     aead::{increase_nonce, make_skey},
     cipher::Error,
-    AeadDecryptor, AeadEncryptor, CipherResult, CipherType,
+    AeadDecryptor,
+    AeadEncryptor,
+    CipherResult,
+    CipherType,
 };
 
 use byte_string::ByteStr;
diff --git a/src/crypto/siv.rs b/src/crypto/siv.rs
index 1e93b6a8..f644176e 100644
--- a/src/crypto/siv.rs
+++ b/src/crypto/siv.rs
@@ -7,7 +7,10 @@ use miscreant::aead::{Aead, Aes128PmacSivAead, Aes256PmacSivAead};
 use crate::crypto::{
     aead::{increase_nonce, make_skey},
     cipher::Error,
-    AeadDecryptor, AeadEncryptor, CipherResult, CipherType,
+    AeadDecryptor,
+    AeadEncryptor,
+    CipherResult,
+    CipherType,
 };
 
 use byte_string::ByteStr;
diff --git a/src/crypto/sodium.rs b/src/crypto/sodium.rs
index 2f32e8af..9fba6c16 100644
--- a/src/crypto/sodium.rs
+++ b/src/crypto/sodium.rs
@@ -6,15 +6,23 @@ use bytes::{BufMut, Bytes, BytesMut};
 
 use libc::c_ulonglong;
 use libsodium_ffi::{
-    crypto_aead_xchacha20poly1305_ietf_decrypt, crypto_aead_xchacha20poly1305_ietf_encrypt,
-    crypto_stream_chacha20_ietf_xor_ic, crypto_stream_chacha20_xor_ic, crypto_stream_salsa20_xor_ic,
-    crypto_stream_xsalsa20_xor_ic, sodium_init,
+    crypto_aead_xchacha20poly1305_ietf_decrypt,
+    crypto_aead_xchacha20poly1305_ietf_encrypt,
+    crypto_stream_chacha20_ietf_xor_ic,
+    crypto_stream_chacha20_xor_ic,
+    crypto_stream_salsa20_xor_ic,
+    crypto_stream_xsalsa20_xor_ic,
+    sodium_init,
 };
 
 use crate::crypto::{
     aead::{increase_nonce, make_skey},
     cipher::Error,
-    AeadDecryptor, AeadEncryptor, CipherResult, CipherType, StreamCipher,
+    AeadDecryptor,
+    AeadEncryptor,
+    CipherResult,
+    CipherType,
+    StreamCipher,
 };
 
 static SODIUM_INIT_FLAG: Once = Once::new();
diff --git a/src/crypto/stream.rs b/src/crypto/stream.rs
index 2ef979bb..15a09ad9 100644
--- a/src/crypto/stream.rs
+++ b/src/crypto/stream.rs
@@ -8,7 +8,9 @@ use crate::crypto::rc4_md5;
 use crate::crypto::sodium;
 use crate::crypto::{
     cipher::{CipherCategory, CipherResult, CipherType},
-    dummy, table, CryptoMode,
+    dummy,
+    table,
+    CryptoMode,
 };
 
 use bytes::BufMut;
diff --git a/src/crypto/table.rs b/src/crypto/table.rs
index ff182eab..814401a5 100644
--- a/src/crypto/table.rs
+++ b/src/crypto/table.rs
@@ -4,7 +4,9 @@ use std::io::Cursor;
 
 use crate::crypto::{
     digest::{self, Digest, DigestType},
-    CipherResult, CryptoMode, StreamCipher,
+    CipherResult,
+    CryptoMode,
+    StreamCipher,
 };
 
 use byteorder::{LittleEndian, ReadBytesExt};
diff --git a/src/relay/dns_resolver/mod.rs b/src/relay/dns_resolver/mod.rs
index cd57e76a..5b08a7f5 100644
--- a/src/relay/dns_resolver/mod.rs
+++ b/src/relay/dns_resolver/mod.rs
@@ -2,5 +2,4 @@
 
 mod trust_dns_resolver;
 
-pub use self::trust_dns_resolver::create_resolver;
-pub use self::trust_dns_resolver::resolve;
+pub use self::trust_dns_resolver::{create_resolver, resolve};
diff --git a/src/relay/loadbalancing/server/ping.rs b/src/relay/loadbalancing/server/ping.rs
index 507c0ea7..4652d67e 100644
--- a/src/relay/loadbalancing/server/ping.rs
+++ b/src/relay/loadbalancing/server/ping.rs
@@ -1,19 +1,26 @@
-use std::collections::VecDeque;
-use std::fmt;
-use std::io;
-use std::sync::atomic::{AtomicU64, AtomicUsize, Ordering};
-use std::sync::{Arc, Mutex};
+use std::{
+    collections::VecDeque,
+    fmt,
+    io,
+    sync::{
+        atomic::{AtomicU64, AtomicUsize, Ordering},
+        Arc,
+        Mutex,
+    },
+};
 
-use crate::config::ServerConfig;
-use crate::context::SharedContext;
-use crate::relay::loadbalancing::server::LoadBalancer;
-use crate::relay::socks5::Address;
-use crate::relay::tcprelay::client::ServerClient;
+use crate::{
+    config::ServerConfig,
+    context::SharedContext,
+    relay::{loadbalancing::server::LoadBalancer, socks5::Address, tcprelay::client::ServerClient},
+};
 
 use log::{debug, info};
-use tokio;
-use tokio::io::{AsyncReadExt, AsyncWriteExt};
-use tokio::time::{self, Duration, Instant};
+use tokio::{
+    self,
+    io::{AsyncReadExt, AsyncWriteExt},
+    time::{self, Duration, Instant},
+};
 
 struct Server {
     config: Arc<ServerConfig>,
diff --git a/src/relay/socks5.rs b/src/relay/socks5.rs
index 590e623d..724592b0 100644
--- a/src/relay/socks5.rs
+++ b/src/relay/socks5.rs
@@ -2,22 +2,26 @@
 //!
 //! Implements [SOCKS Protocol Version 5](https://www.ietf.org/rfc/rfc1928.txt) proxy protocol
 
-use std::convert::From;
-use std::error;
-use std::fmt::{self, Debug, Formatter};
-use std::io::{self, Cursor};
-use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6, ToSocketAddrs};
-use std::str::FromStr;
-use std::u8;
-use std::vec;
+use std::{
+    convert::From,
+    error,
+    fmt::{self, Debug, Formatter},
+    io::{self, Cursor},
+    net::{Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6, ToSocketAddrs},
+    str::FromStr,
+    u8,
+    vec,
+};
 
-use bytes::buf::BufExt;
-use bytes::{Buf, BufMut, BytesMut};
+use bytes::{buf::BufExt, Buf, BufMut, BytesMut};
 use log::error;
 use tokio::prelude::*;
 
 pub use self::consts::{
-    SOCKS5_AUTH_METHOD_GSSAPI, SOCKS5_AUTH_METHOD_NONE, SOCKS5_AUTH_METHOD_NOT_ACCEPTABLE, SOCKS5_AUTH_METHOD_PASSWORD,
+    SOCKS5_AUTH_METHOD_GSSAPI,
+    SOCKS5_AUTH_METHOD_NONE,
+    SOCKS5_AUTH_METHOD_NOT_ACCEPTABLE,
+    SOCKS5_AUTH_METHOD_PASSWORD,
 };
 
 #[rustfmt::skip]
diff --git a/src/relay/tcprelay/aead.rs b/src/relay/tcprelay/aead.rs
index 3105b2ff..3b9df435 100644
--- a/src/relay/tcprelay/aead.rs
+++ b/src/relay/tcprelay/aead.rs
@@ -33,7 +33,8 @@
 //! ```
 
 use std::{
-    cmp, io,
+    cmp,
+    io,
     marker::Unpin,
     pin::Pin,
     slice,
diff --git a/src/relay/tcprelay/client.rs b/src/relay/tcprelay/client.rs
index ab421e56..15d53acb 100644
--- a/src/relay/tcprelay/client.rs
+++ b/src/relay/tcprelay/client.rs
@@ -12,7 +12,14 @@ use log::trace;
 use tokio::{net::TcpStream, prelude::*};
 
 use crate::relay::socks5::{
-    self, Address, Command, HandshakeRequest, HandshakeResponse, Reply, TcpRequestHeader, TcpResponseHeader,
+    self,
+    Address,
+    Command,
+    HandshakeRequest,
+    HandshakeResponse,
+    Reply,
+    TcpRequestHeader,
+    TcpResponseHeader,
 };
 
 use super::{CryptoStream, STcpStream};
diff --git a/src/relay/tcprelay/mod.rs b/src/relay/tcprelay/mod.rs
index 8f80959b..b75d3984 100644
--- a/src/relay/tcprelay/mod.rs
+++ b/src/relay/tcprelay/mod.rs
@@ -4,27 +4,31 @@
 // Maybe removed in the future
 #![allow(clippy::unnecessary_mut_passed)]
 
-use std::io;
-use std::marker::Unpin;
-use std::ops::{Deref, DerefMut};
-use std::pin::Pin;
-use std::sync::Arc;
-use std::task::{Context, Poll};
-use std::time::Duration;
+use std::{
+    io,
+    marker::Unpin,
+    ops::{Deref, DerefMut},
+    pin::Pin,
+    sync::Arc,
+    task::{Context, Poll},
+    time::Duration,
+};
 
-use crate::config::{ConfigType, ServerAddr, ServerConfig};
-use crate::context::SharedContext;
-use crate::relay::socks5::Address;
-use crate::relay::utils::try_timeout;
+use crate::{
+    config::{ConfigType, ServerAddr, ServerConfig},
+    context::SharedContext,
+    relay::{socks5::Address, utils::try_timeout},
+};
 
 use bytes::BytesMut;
-use futures::future::FusedFuture;
-use futures::{ready, select, Future};
+use futures::{future::FusedFuture, ready, select, Future};
 use log::trace;
-use tokio::io::{BufReader, ReadHalf, WriteHalf};
-use tokio::net::TcpStream;
-use tokio::prelude::*;
-use tokio::time::{self, Delay};
+use tokio::{
+    io::{BufReader, ReadHalf, WriteHalf},
+    net::TcpStream,
+    prelude::*,
+    time::{self, Delay},
+};
 
 mod aead;
 pub mod client;
diff --git a/src/relay/tcprelay/server.rs b/src/relay/tcprelay/server.rs
index 743c6af5..293a858d 100644
--- a/src/relay/tcprelay/server.rs
+++ b/src/relay/tcprelay/server.rs
@@ -1,21 +1,25 @@
 //! Relay for TCP server that running on the server side
 
-use std::io;
-use std::net::SocketAddr;
-use std::sync::Arc;
+use std::{io, net::SocketAddr, sync::Arc};
 
-use futures::future::{self, Either};
-use futures::stream::{FuturesUnordered, StreamExt};
+use futures::{
+    future::{self, Either},
+    stream::{FuturesUnordered, StreamExt},
+};
 use log::{debug, error, info, trace};
-use tokio;
-use tokio::net::{TcpListener, TcpStream};
+use tokio::{
+    self,
+    net::{TcpListener, TcpStream},
+};
 
-use crate::context::SharedContext;
-use crate::relay::socks5::Address;
+use crate::{context::SharedContext, relay::socks5::Address};
 
-use super::context::{SharedTcpServerContext, TcpServerContext};
-use super::monitor::TcpMonStream;
-use super::{CryptoStream, STcpStream};
+use super::{
+    context::{SharedTcpServerContext, TcpServerContext},
+    monitor::TcpMonStream,
+    CryptoStream,
+    STcpStream,
+};
 
 #[allow(clippy::cognitive_complexity)]
 async fn handle_client(
diff --git a/src/relay/tcprelay/socks5_local.rs b/src/relay/tcprelay/socks5_local.rs
index 7600a64b..707e5a9b 100644
--- a/src/relay/tcprelay/socks5_local.rs
+++ b/src/relay/tcprelay/socks5_local.rs
@@ -8,7 +8,8 @@ use tokio::{
     self,
     net::{
         tcp::{ReadHalf, WriteHalf},
-        TcpListener, TcpStream,
+        TcpListener,
+        TcpStream,
     },
     prelude::*,
 };
diff --git a/src/relay/tcprelay/stream.rs b/src/relay/tcprelay/stream.rs
index ac35fa59..debef19e 100644
--- a/src/relay/tcprelay/stream.rs
+++ b/src/relay/tcprelay/stream.rs
@@ -1,7 +1,8 @@
 //! Stream protocol implementation
 
 use std::{
-    cmp, io,
+    cmp,
+    io,
     marker::Unpin,
     pin::Pin,
     task::{Context, Poll},
diff --git a/src/relay/tcprelay/tunnel_local.rs b/src/relay/tcprelay/tunnel_local.rs
index 9c3b2b54..ab0264e9 100644
--- a/src/relay/tcprelay/tunnel_local.rs
+++ b/src/relay/tcprelay/tunnel_local.rs
@@ -1,17 +1,19 @@
 //! Local server that establish a TCP tunnel with server
 
-use std::io;
-use std::net::SocketAddr;
-use std::sync::Arc;
+use std::{io, net::SocketAddr, sync::Arc};
 
 use futures::future::{self, Either};
 use log::{debug, error, info, trace};
 use tokio::net::{TcpListener, TcpStream};
 
-use crate::config::ServerConfig;
-use crate::context::SharedContext;
-use crate::relay::loadbalancing::server::{LoadBalancer, PingBalancer};
-use crate::relay::socks5::Address;
+use crate::{
+    config::ServerConfig,
+    context::SharedContext,
+    relay::{
+        loadbalancing::server::{LoadBalancer, PingBalancer},
+        socks5::Address,
+    },
+};
 
 /// Established Client Tunnel
 ///
diff --git a/src/relay/udprelay/crypto_io.rs b/src/relay/udprelay/crypto_io.rs
index 97007f6f..018001f4 100644
--- a/src/relay/udprelay/crypto_io.rs
+++ b/src/relay/udprelay/crypto_io.rs
@@ -20,8 +20,7 @@
 //! +--------+-----------+-----------+
 //! ```
 
-use std::io;
-use std::slice;
+use std::{io, slice};
 
 use byte_string::ByteStr;
 use bytes::{BufMut, BytesMut};
diff --git a/src/relay/udprelay/server.rs b/src/relay/udprelay/server.rs
index 089456ad..3152f5c2 100644
--- a/src/relay/udprelay/server.rs
+++ b/src/relay/udprelay/server.rs
@@ -1,26 +1,35 @@
 //! UDP relay proxy server
 
-use std::io::{self, Cursor};
-use std::net::{IpAddr, Ipv4Addr, SocketAddr};
-use std::sync::Arc;
-use std::time::Duration;
+use std::{
+    io::{self, Cursor},
+    net::{IpAddr, Ipv4Addr, SocketAddr},
+    sync::Arc,
+    time::Duration,
+};
 
 use bytes::BytesMut;
-use futures::stream::FuturesUnordered;
-use futures::{self, StreamExt};
+use futures::{self, stream::FuturesUnordered, StreamExt};
 use log::{debug, error, info, trace};
 use lru_time_cache::{Entry, LruCache};
-use tokio;
-use tokio::net::udp::{RecvHalf, SendHalf};
-use tokio::net::UdpSocket;
-use tokio::sync::mpsc;
+use tokio::{
+    self,
+    net::{
+        udp::{RecvHalf, SendHalf},
+        UdpSocket,
+    },
+    sync::mpsc,
+};
 
-use crate::config::ServerConfig;
-use crate::context::SharedContext;
-use crate::relay::{socks5::Address, utils::try_timeout};
+use crate::{
+    config::ServerConfig,
+    context::SharedContext,
+    relay::{socks5::Address, utils::try_timeout},
+};
 
-use super::crypto_io::{decrypt_payload, encrypt_payload};
-use super::MAXIMUM_UDP_PAYLOAD_SIZE;
+use super::{
+    crypto_io::{decrypt_payload, encrypt_payload},
+    MAXIMUM_UDP_PAYLOAD_SIZE,
+};
 
 const DEFAULT_TIMEOUT: Duration = Duration::from_secs(5);
 
diff --git a/src/relay/udprelay/socks5_local.rs b/src/relay/udprelay/socks5_local.rs
index 0f8a76b4..1e807e4f 100644
--- a/src/relay/udprelay/socks5_local.rs
+++ b/src/relay/udprelay/socks5_local.rs
@@ -1,26 +1,38 @@
 //! UDP relay local server
 
-use std::io::{self, Cursor, ErrorKind, Read};
-use std::net::{IpAddr, Ipv4Addr, SocketAddr};
-use std::sync::Arc;
-use std::time::Duration;
+use std::{
+    io::{self, Cursor, ErrorKind, Read},
+    net::{IpAddr, Ipv4Addr, SocketAddr},
+    sync::Arc,
+    time::Duration,
+};
 
 use bytes::BytesMut;
 use log::{debug, error, info, trace};
 use lru_time_cache::{Entry, LruCache};
-use tokio;
-use tokio::net::udp::{RecvHalf, SendHalf};
-use tokio::net::UdpSocket;
-use tokio::sync::mpsc;
+use tokio::{
+    self,
+    net::{
+        udp::{RecvHalf, SendHalf},
+        UdpSocket,
+    },
+    sync::mpsc,
+};
 
-use crate::config::{ServerAddr, ServerConfig};
-use crate::context::SharedContext;
-use crate::relay::loadbalancing::server::{LoadBalancer, RoundRobin};
-use crate::relay::socks5::{Address, UdpAssociateHeader};
-use crate::relay::utils::try_timeout;
+use crate::{
+    config::{ServerAddr, ServerConfig},
+    context::SharedContext,
+    relay::{
+        loadbalancing::server::{LoadBalancer, RoundRobin},
+        socks5::{Address, UdpAssociateHeader},
+        utils::try_timeout,
+    },
+};
 
-use super::crypto_io::{decrypt_payload, encrypt_payload};
-use super::MAXIMUM_UDP_PAYLOAD_SIZE;
+use super::{
+    crypto_io::{decrypt_payload, encrypt_payload},
+    MAXIMUM_UDP_PAYLOAD_SIZE,
+};
 
 const DEFAULT_TIMEOUT: Duration = Duration::from_secs(5);
 
diff --git a/src/relay/udprelay/tunnel_local.rs b/src/relay/udprelay/tunnel_local.rs
index 265a2997..01fd6365 100644
--- a/src/relay/udprelay/tunnel_local.rs
+++ b/src/relay/udprelay/tunnel_local.rs
@@ -1,26 +1,38 @@
 //! UDP relay local server
 
-use std::io::{self, Cursor, Read};
-use std::net::{IpAddr, Ipv4Addr, SocketAddr};
-use std::sync::Arc;
-use std::time::Duration;
+use std::{
+    io::{self, Cursor, Read},
+    net::{IpAddr, Ipv4Addr, SocketAddr},
+    sync::Arc,
+    time::Duration,
+};
 
 use bytes::BytesMut;
 use log::{debug, error, info, trace};
 use lru_time_cache::{Entry, LruCache};
-use tokio;
-use tokio::net::udp::{RecvHalf, SendHalf};
-use tokio::net::UdpSocket;
-use tokio::sync::mpsc;
+use tokio::{
+    self,
+    net::{
+        udp::{RecvHalf, SendHalf},
+        UdpSocket,
+    },
+    sync::mpsc,
+};
 
-use crate::config::{ServerAddr, ServerConfig};
-use crate::context::{Context, SharedContext};
-use crate::relay::loadbalancing::server::{LoadBalancer, RoundRobin};
-use crate::relay::socks5::Address;
-use crate::relay::utils::try_timeout;
+use crate::{
+    config::{ServerAddr, ServerConfig},
+    context::{Context, SharedContext},
+    relay::{
+        loadbalancing::server::{LoadBalancer, RoundRobin},
+        socks5::Address,
+        utils::try_timeout,
+    },
+};
 
-use super::crypto_io::{decrypt_payload, encrypt_payload};
-use super::MAXIMUM_UDP_PAYLOAD_SIZE;
+use super::{
+    crypto_io::{decrypt_payload, encrypt_payload},
+    MAXIMUM_UDP_PAYLOAD_SIZE,
+};
 
 const DEFAULT_TIMEOUT: Duration = Duration::from_secs(5);
 
diff --git a/src/relay/utils.rs b/src/relay/utils.rs
index 61782773..4894af36 100644
--- a/src/relay/utils.rs
+++ b/src/relay/utils.rs
@@ -1,5 +1,4 @@
-use std::future::Future;
-use std::{io, time::Duration};
+use std::{future::Future, io, time::Duration};
 
 use tokio::time;
 
diff --git a/tests/socks5.rs b/tests/socks5.rs
index fb566797..4dfeefd3 100644
--- a/tests/socks5.rs
+++ b/tests/socks5.rs
@@ -1,13 +1,16 @@
 use std::net::{SocketAddr, ToSocketAddrs};
 
-use tokio::prelude::*;
-use tokio::time::{self, Duration};
+use tokio::{
+    prelude::*,
+    time::{self, Duration},
+};
 
 use shadowsocks::{
     config::{Config, ConfigType, Mode, ServerConfig},
     crypto::CipherType,
     relay::{socks5::Address, tcprelay::client::Socks5Client},
-    run_local, run_server,
+    run_local,
+    run_server,
 };
 
 pub struct Socks5TestServer {
diff --git a/tests/tunnel.rs b/tests/tunnel.rs
index b65436da..6015cc11 100644
--- a/tests/tunnel.rs
+++ b/tests/tunnel.rs
@@ -1,12 +1,17 @@
 use env_logger;
-use tokio;
-use tokio::net::{TcpStream, UdpSocket};
-use tokio::prelude::*;
-use tokio::time::{self, Duration};
+use tokio::{
+    self,
+    net::{TcpStream, UdpSocket},
+    prelude::*,
+    time::{self, Duration},
+};
 
-use shadowsocks::config::{Config, ConfigType};
-use shadowsocks::relay::socks5::Address;
-use shadowsocks::{run_local, run_server};
+use shadowsocks::{
+    config::{Config, ConfigType},
+    relay::socks5::Address,
+    run_local,
+    run_server,
+};
 
 #[tokio::test]
 async fn tcp_tunnel() {
diff --git a/tests/udp.rs b/tests/udp.rs
index 7b026bf8..f9f6398a 100644
--- a/tests/udp.rs
+++ b/tests/udp.rs
@@ -7,8 +7,10 @@ use std::{
 
 use bytes::{BufMut, BytesMut};
 use log::debug;
-use tokio::prelude::*;
-use tokio::time::{self, Duration};
+use tokio::{
+    prelude::*,
+    time::{self, Duration},
+};
 
 use shadowsocks::{
     config::{Config, ConfigType, Mode, ServerConfig},
@@ -17,7 +19,8 @@ use shadowsocks::{
         socks5::{Address, UdpAssociateHeader},
         tcprelay::client::Socks5Client,
     },
-    run_local, run_server,
+    run_local,
+    run_server,
 };
 
 const SERVER_ADDR: &str = "127.0.0.1:8093";