Added clippy to CI and fixed all clippy warnings (#613)

* Fixed all clippy warnings.

* Added `clippy` to CI.

* Reverted an unwanted change + Applied `cargo fmt`.

* Fixed the idiom version.

* Revert "Fixed the idiom version."

This reverts commit 6f78be0d42.

* Fixed clippy issues on CI.

* Revert "Fixed clippy issues on CI."

This reverts commit a9fa6ba189.

* Revert "Reverted an unwanted change + Applied `cargo fmt`."

This reverts commit 6bd37b6479.

* Revert "Fixed all clippy warnings."

This reverts commit d1f3b847e3.

* Removed Clippy

* Removed Lint

* `admin.rs` clippy fixes.

* Applied more clippy changes.

* Even more clippy changes.

* `client.rs` clippy fixes.

* `server.rs` clippy fixes.

* Revert "Removed Lint"

This reverts commit cb5042b144.

* Revert "Removed Clippy"

This reverts commit 6dec8bffb1.

* Applied lint.

* Revert "Revert "Fixed clippy issues on CI.""

This reverts commit 49164a733c.

.circleci/config.yml

@@ -63,6 +63,9 @@ jobs:
       - run:
           name: "Lint"
           command: "cargo fmt --check"
+      - run:
+          name: "Clippy"
+          command: "cargo clippy --all --all-targets -- -Dwarnings"
       - run:
           name: "Tests"
           command: "cargo clean && cargo build && cargo test && bash .circleci/run_tests.sh && .circleci/generate_coverage.sh"

CONTRIBUTING.md

@@ -2,7 +2,7 @@
 
 Thank you for contributing! Just a few tips here:
 
-1. `cargo fmt` your code before opening up a PR
+1. `cargo fmt` and `cargo clippy` your code before opening up a PR
 2. Run the test suite (e.g. `pgbench`) to make sure everything still works. The tests are in `.circleci/run_tests.sh`.
 3. Performance is important, make sure there are no regressions in your branch vs. `main`.
 

src/admin.rs

@@ -283,7 +283,7 @@ where
 {
     let mut res = BytesMut::new();
 
-    let detail_msg = vec![
+    let detail_msg = [
         "",
         "SHOW HELP|CONFIG|DATABASES|POOLS|CLIENTS|SERVERS|USERS|VERSION",
         // "SHOW PEERS|PEER_POOLS", // missing PEERS|PEER_POOLS
@@ -301,7 +301,6 @@ where
         // "KILL <db>",
         // "SUSPEND",
         "SHUTDOWN",
-        // "WAIT_CLOSE [<db>]", // missing
     ];
 
     res.put(notify("Console usage", detail_msg.join("\n\t")));
@@ -802,7 +801,7 @@ where
     T: tokio::io::AsyncWrite + std::marker::Unpin,
 {
     let parts: Vec<&str> = match tokens.len() == 2 {
-        true => tokens[1].split(",").map(|part| part.trim()).collect(),
+        true => tokens[1].split(',').map(|part| part.trim()).collect(),
         false => Vec::new(),
     };
 
@@ -865,7 +864,7 @@ where
     T: tokio::io::AsyncWrite + std::marker::Unpin,
 {
     let parts: Vec<&str> = match tokens.len() == 2 {
-        true => tokens[1].split(",").map(|part| part.trim()).collect(),
+        true => tokens[1].split(',').map(|part| part.trim()).collect(),
         false => Vec::new(),
     };
 

src/client.rs

@@ -131,7 +131,7 @@ pub async fn client_entrypoint(
         // Client requested a TLS connection.
         Ok((ClientConnectionType::Tls, _)) => {
             // TLS settings are configured, will setup TLS now.
-            if tls_certificate != None {
+            if tls_certificate.is_some() {
                 debug!("Accepting TLS request");
 
                 let mut yes = BytesMut::new();
@@ -448,7 +448,7 @@ where
             None => "pgcat",
         };
 
-        let client_identifier = ClientIdentifier::new(&application_name, &username, &pool_name);
+        let client_identifier = ClientIdentifier::new(application_name, username, pool_name);
 
         let admin = ["pgcat", "pgbouncer"]
             .iter()
@@ -795,7 +795,7 @@ where
         let mut will_prepare = false;
 
         let client_identifier = ClientIdentifier::new(
-            &self.server_parameters.get_application_name(),
+            self.server_parameters.get_application_name(),
             &self.username,
             &self.pool_name,
         );
@@ -982,15 +982,11 @@ where
             }
 
             // Check on plugin results.
-            match plugin_output {
+            if let Some(PluginOutput::Deny(error)) = plugin_output {
-                Some(PluginOutput::Deny(error)) => {
+                self.buffer.clear();
-                    self.buffer.clear();
+                error_response(&mut self.write, &error).await?;
-                    error_response(&mut self.write, &error).await?;
+                plugin_output = None;
-                    plugin_output = None;
+                continue;
-                    continue;
-                }
-
-                _ => (),
             };
 
             // Check if the pool is paused and wait until it's resumed.
@@ -1267,7 +1263,7 @@ where
 
                 // Safe to unwrap because we know this message has a certain length and has the code
                 // This reads the first byte without advancing the internal pointer and mutating the bytes
-                let code = *message.get(0).unwrap() as char;
+                let code = *message.first().unwrap() as char;
 
                 trace!("Message: {}", code);
 
@@ -1325,7 +1321,7 @@ where
                             self.stats.transaction();
                             server
                                 .stats()
-                                .transaction(&self.server_parameters.get_application_name());
+                                .transaction(self.server_parameters.get_application_name());
 
                             // Release server back to the pool if we are in transaction mode.
                             // If we are in session mode, we keep the server until the client disconnects.
@@ -1400,13 +1396,10 @@ where
                             let close: Close = (&message).try_into()?;
 
                             if close.is_prepared_statement() && !close.anonymous() {
-                                match self.prepared_statements.get(&close.name) {
+                                if let Some(parse) = self.prepared_statements.get(&close.name) {
-                                    Some(parse) => {
+                                    server.will_close(&parse.generated_name);
-                                        server.will_close(&parse.generated_name);
+                                } else {
-                                    }
-
                                     // A prepared statement slipped through? Not impossible, since we don't support PREPARE yet.
-                                    None => (),
                                 };
                             }
                         }
@@ -1445,7 +1438,7 @@ where
 
                         self.buffer.put(&message[..]);
 
-                        let first_message_code = (*self.buffer.get(0).unwrap_or(&0)) as char;
+                        let first_message_code = (*self.buffer.first().unwrap_or(&0)) as char;
 
                         // Almost certainly true
                         if first_message_code == 'P' && !prepared_statements_enabled {
@@ -1477,7 +1470,7 @@ where
                             self.stats.transaction();
                             server
                                 .stats()
-                                .transaction(&self.server_parameters.get_application_name());
+                                .transaction(self.server_parameters.get_application_name());
 
                             // Release server back to the pool if we are in transaction mode.
                             // If we are in session mode, we keep the server until the client disconnects.
@@ -1739,7 +1732,7 @@ where
         client_stats.query();
         server.stats().query(
             Instant::now().duration_since(query_start).as_millis() as u64,
-            &self.server_parameters.get_application_name(),
+            self.server_parameters.get_application_name(),
         );
 
         Ok(())

src/cmd_args.rs

@@ -25,7 +25,7 @@ pub struct Args {
 }
 
 pub fn parse() -> Args {
-    return Args::parse();
+    Args::parse()
 }
 
 #[derive(ValueEnum, Clone, Debug)]

src/config.rs

@@ -236,18 +236,14 @@ impl Default for User {
 
 impl User {
     fn validate(&self) -> Result<(), Error> {
-        match self.min_pool_size {
+        if let Some(min_pool_size) = self.min_pool_size {
-            Some(min_pool_size) => {
+            if min_pool_size > self.pool_size {
-                if min_pool_size > self.pool_size {
+                error!(
-                    error!(
+                    "min_pool_size of {} cannot be larger than pool_size of {}",
-                        "min_pool_size of {} cannot be larger than pool_size of {}",
+                    min_pool_size, self.pool_size
-                        min_pool_size, self.pool_size
+                );
-                    );
+                return Err(Error::BadConfig);
-                    return Err(Error::BadConfig);
-                }
             }
-
-            None => (),
         };
 
         Ok(())
@@ -677,9 +673,9 @@ impl Pool {
             Some(key) => {
                 // No quotes in the key so we don't have to compare quoted
                 // to unquoted idents.
-                let key = key.replace("\"", "");
+                let key = key.replace('\"', "");
 
-                if key.split(".").count() != 2 {
+                if key.split('.').count() != 2 {
                     error!(
                         "automatic_sharding_key '{}' must be fully qualified, e.g. t.{}`",
                         key, key
@@ -692,17 +688,14 @@ impl Pool {
             None => None,
         };
 
-        match self.default_shard {
+        if let DefaultShard::Shard(shard_number) = self.default_shard {
-            DefaultShard::Shard(shard_number) => {
+            if shard_number >= self.shards.len() {
-                if shard_number >= self.shards.len() {
+                error!("Invalid shard {:?}", shard_number);
-                    error!("Invalid shard {:?}", shard_number);
+                return Err(Error::BadConfig);
-                    return Err(Error::BadConfig);
-                }
             }
-            _ => (),
         }
 
-        for (_, user) in &self.users {
+        for user in self.users.values() {
             user.validate()?;
         }
 
@@ -777,8 +770,8 @@ impl<'de> serde::Deserialize<'de> for DefaultShard {
         D: Deserializer<'de>,
     {
         let s = String::deserialize(deserializer)?;
-        if s.starts_with("shard_") {
+        if let Some(s) = s.strip_prefix("shard_") {
-            let shard = s[6..].parse::<usize>().map_err(serde::de::Error::custom)?;
+            let shard = s.parse::<usize>().map_err(serde::de::Error::custom)?;
             return Ok(DefaultShard::Shard(shard));
         }
 
@@ -874,7 +867,7 @@ pub trait Plugin {
 impl std::fmt::Display for Plugins {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         fn is_enabled<T: Plugin>(arg: Option<&T>) -> bool {
-            if let Some(ref arg) = arg {
+            if let Some(arg) = arg {
                 arg.is_enabled()
             } else {
                 false
@@ -955,6 +948,7 @@ pub struct Query {
 }
 
 impl Query {
+    #[allow(clippy::needless_range_loop)]
     pub fn substitute(&mut self, db: &str, user: &str) {
         for col in self.result.iter_mut() {
             for i in 0..col.len() {
@@ -1079,8 +1073,8 @@ impl From<&Config> for std::collections::HashMap<String, String> {
                     (
                         format!("pools.{:?}.users", pool_name),
                         pool.users
-                            .iter()
+                            .values()
-                            .map(|(_username, user)| &user.username)
+                            .map(|user| &user.username)
                             .cloned()
                             .collect::<Vec<String>>()
                             .join(", "),
@@ -1165,13 +1159,9 @@ impl Config {
             Some(tls_certificate) => {
                 info!("TLS certificate: {}", tls_certificate);
 
-                match self.general.tls_private_key.clone() {
+                if let Some(tls_private_key) = self.general.tls_private_key.clone() {
-                    Some(tls_private_key) => {
+                    info!("TLS private key: {}", tls_private_key);
-                        info!("TLS private key: {}", tls_private_key);
+                    info!("TLS support is enabled");
-                        info!("TLS support is enabled");
-                    }
-
-                    None => (),
                 }
             }
 
@@ -1206,8 +1196,8 @@ impl Config {
                 pool_name,
                 pool_config
                     .users
-                    .iter()
+                    .values()
-                    .map(|(_, user_cfg)| user_cfg.pool_size)
+                    .map(|user_cfg| user_cfg.pool_size)
                     .sum::<u32>()
                     .to_string()
             );
@@ -1377,34 +1367,31 @@ impl Config {
         }
 
         // Validate TLS!
-        match self.general.tls_certificate.clone() {
+        if let Some(tls_certificate) = self.general.tls_certificate.clone() {
-            Some(tls_certificate) => {
+            match load_certs(Path::new(&tls_certificate)) {
-                match load_certs(Path::new(&tls_certificate)) {
+                Ok(_) => {
-                    Ok(_) => {
+                    // Cert is okay, but what about the private key?
-                        // Cert is okay, but what about the private key?
+                    match self.general.tls_private_key.clone() {
-                        match self.general.tls_private_key.clone() {
+                        Some(tls_private_key) => match load_keys(Path::new(&tls_private_key)) {
-                            Some(tls_private_key) => match load_keys(Path::new(&tls_private_key)) {
+                            Ok(_) => (),
-                                Ok(_) => (),
+                            Err(err) => {
-                                Err(err) => {
+                                error!("tls_private_key is incorrectly configured: {:?}", err);
-                                    error!("tls_private_key is incorrectly configured: {:?}", err);
-                                    return Err(Error::BadConfig);
-                                }
-                            },
-
-                            None => {
-                                error!("tls_certificate is set, but the tls_private_key is not");
                                 return Err(Error::BadConfig);
                             }
-                        };
+                        },
-                    }
 
-                    Err(err) => {
+                        None => {
-                        error!("tls_certificate is incorrectly configured: {:?}", err);
+                            error!("tls_certificate is set, but the tls_private_key is not");
-                        return Err(Error::BadConfig);
+                            return Err(Error::BadConfig);
-                    }
+                        }
+                    };
+                }
+
+                Err(err) => {
+                    error!("tls_certificate is incorrectly configured: {:?}", err);
+                    return Err(Error::BadConfig);
                 }
             }
-            None => (),
         };
 
         for pool in self.pools.values_mut() {

src/messages.rs

@@ -163,12 +163,10 @@ where
 
     match stream.write_all(&startup).await {
         Ok(_) => Ok(()),
-        Err(err) => {
+        Err(err) => Err(Error::SocketError(format!(
-            return Err(Error::SocketError(format!(
+            "Error writing startup to server socket - Error: {:?}",
-                "Error writing startup to server socket - Error: {:?}",
+            err
-                err
+        ))),
-            )))
-        }
     }
 }
 
@@ -244,8 +242,8 @@ pub fn md5_hash_password(user: &str, password: &str, salt: &[u8]) -> Vec<u8> {
     let mut md5 = Md5::new();
 
     // First pass
-    md5.update(&password.as_bytes());
+    md5.update(password.as_bytes());
-    md5.update(&user.as_bytes());
+    md5.update(user.as_bytes());
 
     let output = md5.finalize_reset();
 
@@ -281,7 +279,7 @@ where
 {
     let password = md5_hash_password(user, password, salt);
 
-    let mut message = BytesMut::with_capacity(password.len() as usize + 5);
+    let mut message = BytesMut::with_capacity(password.len() + 5);
 
     message.put_u8(b'p');
     message.put_i32(password.len() as i32 + 4);
@@ -295,7 +293,7 @@ where
     S: tokio::io::AsyncWrite + std::marker::Unpin,
 {
     let password = md5_hash_second_pass(hash, salt);
-    let mut message = BytesMut::with_capacity(password.len() as usize + 5);
+    let mut message = BytesMut::with_capacity(password.len() + 5);
 
     message.put_u8(b'p');
     message.put_i32(password.len() as i32 + 4);
@@ -516,7 +514,7 @@ pub fn data_row_nullable(row: &Vec<Option<String>>) -> BytesMut {
             data_row.put_i32(column.len() as i32);
             data_row.put_slice(column);
         } else {
-            data_row.put_i32(-1 as i32);
+            data_row.put_i32(-1_i32);
         }
     }
 
@@ -571,12 +569,10 @@ where
 {
     match stream.write_all(&buf).await {
         Ok(_) => Ok(()),
-        Err(err) => {
+        Err(err) => Err(Error::SocketError(format!(
-            return Err(Error::SocketError(format!(
+            "Error writing to socket - Error: {:?}",
-                "Error writing to socket - Error: {:?}",
+            err
-                err
+        ))),
-            )))
-        }
     }
 }
 
@@ -587,12 +583,10 @@ where
 {
     match stream.write_all(buf).await {
         Ok(_) => Ok(()),
-        Err(err) => {
+        Err(err) => Err(Error::SocketError(format!(
-            return Err(Error::SocketError(format!(
+            "Error writing to socket - Error: {:?}",
-                "Error writing to socket - Error: {:?}",
+            err
-                err
+        ))),
-            )))
-        }
     }
 }
 
@@ -603,19 +597,15 @@ where
     match stream.write_all(buf).await {
         Ok(_) => match stream.flush().await {
             Ok(_) => Ok(()),
-            Err(err) => {
+            Err(err) => Err(Error::SocketError(format!(
-                return Err(Error::SocketError(format!(
+                "Error flushing socket - Error: {:?}",
-                    "Error flushing socket - Error: {:?}",
-                    err
-                )))
-            }
-        },
-        Err(err) => {
-            return Err(Error::SocketError(format!(
-                "Error writing to socket - Error: {:?}",
                 err
-            )))
+            ))),
-        }
+        },
+        Err(err) => Err(Error::SocketError(format!(
+            "Error writing to socket - Error: {:?}",
+            err
+        ))),
     }
 }
 
@@ -730,7 +720,7 @@ impl BytesMutReader for Cursor<&BytesMut> {
         let mut buf = vec![];
         match self.read_until(b'\0', &mut buf) {
             Ok(_) => Ok(String::from_utf8_lossy(&buf[..buf.len() - 1]).to_string()),
-            Err(err) => return Err(Error::ParseBytesError(err.to_string())),
+            Err(err) => Err(Error::ParseBytesError(err.to_string())),
         }
     }
 }
@@ -746,7 +736,7 @@ impl BytesMutReader for BytesMut {
                 let string_bytes = self.split_to(index + 1);
                 Ok(String::from_utf8_lossy(&string_bytes[..string_bytes.len() - 1]).to_string())
             }
-            None => return Err(Error::ParseBytesError("Could not read string".to_string())),
+            None => Err(Error::ParseBytesError("Could not read string".to_string())),
         }
     }
 }
@@ -1311,38 +1301,38 @@ mod tests {
     fn parse_fields() {
         let mut complete_msg = vec![];
         let severity = "FATAL";
-        complete_msg.extend(field('S', &severity));
+        complete_msg.extend(field('S', severity));
-        complete_msg.extend(field('V', &severity));
+        complete_msg.extend(field('V', severity));
 
         let error_code = "29P02";
-        complete_msg.extend(field('C', &error_code));
+        complete_msg.extend(field('C', error_code));
         let message = "password authentication failed for user \"wrong_user\"";
-        complete_msg.extend(field('M', &message));
+        complete_msg.extend(field('M', message));
         let detail_msg = "super detailed message";
-        complete_msg.extend(field('D', &detail_msg));
+        complete_msg.extend(field('D', detail_msg));
         let hint_msg = "hint detail here";
-        complete_msg.extend(field('H', &hint_msg));
+        complete_msg.extend(field('H', hint_msg));
         complete_msg.extend(field('P', "123"));
         complete_msg.extend(field('p', "234"));
         let internal_query = "SELECT * from foo;";
-        complete_msg.extend(field('q', &internal_query));
+        complete_msg.extend(field('q', internal_query));
         let where_msg = "where goes here";
-        complete_msg.extend(field('W', &where_msg));
+        complete_msg.extend(field('W', where_msg));
         let schema_msg = "schema_name";
-        complete_msg.extend(field('s', &schema_msg));
+        complete_msg.extend(field('s', schema_msg));
         let table_msg = "table_name";
-        complete_msg.extend(field('t', &table_msg));
+        complete_msg.extend(field('t', table_msg));
         let column_msg = "column_name";
-        complete_msg.extend(field('c', &column_msg));
+        complete_msg.extend(field('c', column_msg));
         let data_type_msg = "type_name";
-        complete_msg.extend(field('d', &data_type_msg));
+        complete_msg.extend(field('d', data_type_msg));
         let constraint_msg = "constraint_name";
-        complete_msg.extend(field('n', &constraint_msg));
+        complete_msg.extend(field('n', constraint_msg));
         let file_msg = "pgcat.c";
-        complete_msg.extend(field('F', &file_msg));
+        complete_msg.extend(field('F', file_msg));
         complete_msg.extend(field('L', "335"));
         let routine_msg = "my_failing_routine";
-        complete_msg.extend(field('R', &routine_msg));
+        complete_msg.extend(field('R', routine_msg));
 
         tracing_subscriber::fmt()
             .with_max_level(tracing::Level::INFO)
@@ -1378,11 +1368,11 @@ mod tests {
         );
 
         let mut only_mandatory_msg = vec![];
-        only_mandatory_msg.extend(field('S', &severity));
+        only_mandatory_msg.extend(field('S', severity));
-        only_mandatory_msg.extend(field('V', &severity));
+        only_mandatory_msg.extend(field('V', severity));
-        only_mandatory_msg.extend(field('C', &error_code));
+        only_mandatory_msg.extend(field('C', error_code));
-        only_mandatory_msg.extend(field('M', &message));
+        only_mandatory_msg.extend(field('M', message));
-        only_mandatory_msg.extend(field('D', &detail_msg));
+        only_mandatory_msg.extend(field('D', detail_msg));
 
         let err_fields = PgErrorMsg::parse(only_mandatory_msg.clone()).unwrap();
         info!("only mandatory fields: {}", &err_fields);

src/mirrors.rs

@@ -137,18 +137,18 @@ impl MirroringManager {
                 bytes_rx,
                 disconnect_rx: exit_rx,
             };
-            exit_senders.push(exit_tx.clone());
+            exit_senders.push(exit_tx);
-            byte_senders.push(bytes_tx.clone());
+            byte_senders.push(bytes_tx);
             client.start();
         });
 
         Self {
-            byte_senders: byte_senders,
+            byte_senders,
             disconnect_senders: exit_senders,
         }
     }
 
-    pub fn send(self: &mut Self, bytes: &BytesMut) {
+    pub fn send(&mut self, bytes: &BytesMut) {
         // We want to avoid performing an allocation if we won't be able to send the message
         // There is a possibility of a race here where we check the capacity and then the channel is
         // closed or the capacity is reduced to 0, but mirroring is best effort anyway
@@ -170,7 +170,7 @@ impl MirroringManager {
         });
     }
 
-    pub fn disconnect(self: &mut Self) {
+    pub fn disconnect(&mut self) {
         self.disconnect_senders
             .iter_mut()
             .for_each(|sender| match sender.try_send(()) {

src/plugins/intercept.rs

@@ -92,7 +92,7 @@ impl<'a> Plugin for Intercept<'a> {
                             .map(|s| {
                                 let s = s.as_str().to_string();
 
-                                if s == "" {
+                                if s.is_empty() {
                                     None
                                 } else {
                                     Some(s)

src/plugins/mod.rs

@@ -33,6 +33,7 @@ pub enum PluginOutput {
 #[async_trait]
 pub trait Plugin {
     // Run before the query is sent to the server.
+    #[allow(clippy::ptr_arg)]
     async fn run(
         &mut self,
         query_router: &QueryRouter,

src/plugins/prewarmer.rs

@@ -20,7 +20,7 @@ impl<'a> Prewarmer<'a> {
                 self.server.address(),
                 query
             );
-            self.server.query(&query).await?;
+            self.server.query(query).await?;
         }
 
         Ok(())

src/plugins/table_access.rs

@@ -34,7 +34,7 @@ impl<'a> Plugin for TableAccess<'a> {
 
         visit_relations(ast, |relation| {
             let relation = relation.to_string();
-            let parts = relation.split(".").collect::<Vec<&str>>();
+            let parts = relation.split('.').collect::<Vec<&str>>();
             let table_name = parts.last().unwrap();
 
             if self.tables.contains(&table_name.to_string()) {

src/pool.rs

@@ -241,20 +241,17 @@ impl ConnectionPool {
                 let old_pool_ref = get_pool(pool_name, &user.username);
                 let identifier = PoolIdentifier::new(pool_name, &user.username);
 
-                match old_pool_ref {
+                if let Some(pool) = old_pool_ref {
-                    Some(pool) => {
+                    // If the pool hasn't changed, get existing reference and insert it into the new_pools.
-                        // If the pool hasn't changed, get existing reference and insert it into the new_pools.
+                    // We replace all pools at the end, but if the reference is kept, the pool won't get re-created (bb8).
-                        // We replace all pools at the end, but if the reference is kept, the pool won't get re-created (bb8).
+                    if pool.config_hash == new_pool_hash_value {
-                        if pool.config_hash == new_pool_hash_value {
+                        info!(
-                            info!(
+                            "[pool: {}][user: {}] has not changed",
-                                "[pool: {}][user: {}] has not changed",
+                            pool_name, user.username
-                                pool_name, user.username
+                        );
-                            );
+                        new_pools.insert(identifier.clone(), pool.clone());
-                            new_pools.insert(identifier.clone(), pool.clone());
+                        continue;
-                            continue;
-                        }
                     }
-                    None => (),
                 }
 
                 info!(
@@ -399,7 +396,7 @@ impl ConnectionPool {
                             },
                         };
 
-                        let reaper_rate = *vec![idle_timeout, server_lifetime, POOL_REAPER_RATE]
+                        let reaper_rate = *[idle_timeout, server_lifetime, POOL_REAPER_RATE]
                             .iter()
                             .min()
                             .unwrap();
@@ -489,7 +486,7 @@ impl ConnectionPool {
                             .clone()
                             .map(|regex| Regex::new(regex.as_str()).unwrap()),
                         regex_search_limit: pool_config.regex_search_limit.unwrap_or(1000),
-                        default_shard: pool_config.default_shard.clone(),
+                        default_shard: pool_config.default_shard,
                         auth_query: pool_config.auth_query.clone(),
                         auth_query_user: pool_config.auth_query_user.clone(),
                         auth_query_password: pool_config.auth_query_password.clone(),
@@ -678,7 +675,7 @@ impl ConnectionPool {
             let mut force_healthcheck = false;
 
             if self.is_banned(address) {
-                if self.try_unban(&address).await {
+                if self.try_unban(address).await {
                     force_healthcheck = true;
                 } else {
                     debug!("Address {:?} is banned", address);
@@ -806,8 +803,8 @@ impl ConnectionPool {
         // Don't leave a bad connection in the pool.
         server.mark_bad();
 
-        self.ban(&address, BanReason::FailedHealthCheck, Some(client_info));
+        self.ban(address, BanReason::FailedHealthCheck, Some(client_info));
-        return false;
+        false
     }
 
     /// Ban an address (i.e. replica). It no longer will serve
@@ -931,10 +928,10 @@ impl ConnectionPool {
         let guard = self.banlist.read();
         for banlist in guard.iter() {
             for (address, (reason, timestamp)) in banlist.iter() {
-                bans.push((address.clone(), (reason.clone(), timestamp.clone())));
+                bans.push((address.clone(), (reason.clone(), *timestamp)));
             }
         }
-        return bans;
+        bans
     }
 
     /// Get the address from the host url
@@ -992,7 +989,7 @@ impl ConnectionPool {
         }
         let busy = provisioned - idle;
         debug!("{:?} has {:?} busy connections", address, busy);
-        return busy;
+        busy
     }
 
     fn valid_shard_id(&self, shard: Option<usize>) -> bool {
@@ -1031,6 +1028,7 @@ pub struct ServerPool {
 }
 
 impl ServerPool {
+    #[allow(clippy::too_many_arguments)]
     pub fn new(
         address: Address,
         user: User,
@@ -1043,7 +1041,7 @@ impl ServerPool {
     ) -> ServerPool {
         ServerPool {
             address,
-            user: user.clone(),
+            user,
             database: database.to_string(),
             client_server_map,
             auth_hash,

src/query_router.rs

@@ -91,7 +91,7 @@ impl QueryRouter {
     /// One-time initialization of regexes
     /// that parse our custom SQL protocol.
     pub fn setup() -> bool {
-        let set = match RegexSet::new(&CUSTOM_SQL_REGEXES) {
+        let set = match RegexSet::new(CUSTOM_SQL_REGEXES) {
             Ok(rgx) => rgx,
             Err(err) => {
                 error!("QueryRouter::setup Could not compile regex set: {:?}", err);
@@ -132,7 +132,7 @@ impl QueryRouter {
         self.pool_settings = pool_settings;
     }
 
-    pub fn pool_settings<'a>(&'a self) -> &'a PoolSettings {
+    pub fn pool_settings(&self) -> &PoolSettings {
         &self.pool_settings
     }
 
@@ -148,7 +148,7 @@ impl QueryRouter {
 
         // Check for any sharding regex matches in any queries
         if comment_shard_routing_enabled {
-            match code as char {
+            match code {
                 // For Parse and Query messages peek to see if they specify a shard_id as a comment early in the statement
                 'P' | 'Q' => {
                     // Check only the first block of bytes configured by the pool settings
@@ -344,16 +344,13 @@ impl QueryRouter {
         let code = message_cursor.get_u8() as char;
         let len = message_cursor.get_i32() as usize;
 
-        match self.pool_settings.query_parser_max_length {
+        if let Some(max_length) = self.pool_settings.query_parser_max_length {
-            Some(max_length) => {
+            if len > max_length {
-                if len > max_length {
+                return Err(Error::QueryRouterParserError(format!(
-                    return Err(Error::QueryRouterParserError(format!(
+                    "Query too long for parser: {} > {}",
-                        "Query too long for parser: {} > {}",
+                    len, max_length
-                        len, max_length
+                )));
-                    )));
-                }
             }
-            None => (),
         };
 
         let query = match code {
@@ -467,22 +464,18 @@ impl QueryRouter {
         inferred_shard: Option<usize>,
         prev_inferred_shard: &mut Option<usize>,
     ) -> Result<(), Error> {
-        match inferred_shard {
+        if let Some(shard) = inferred_shard {
-            Some(shard) => {
+            if let Some(prev_shard) = *prev_inferred_shard {
-                if let Some(prev_shard) = *prev_inferred_shard {
+                if prev_shard != shard {
-                    if prev_shard != shard {
+                    debug!("Found more than one shard in the query, not supported yet");
-                        debug!("Found more than one shard in the query, not supported yet");
+                    return Err(Error::QueryRouterParserError(
-                        return Err(Error::QueryRouterParserError(
+                        "multiple shards in query".into(),
-                            "multiple shards in query".into(),
+                    ));
-                        ));
-                    }
                 }
-                *prev_inferred_shard = Some(shard);
-                self.active_shard = Some(shard);
-                debug!("Automatically using shard: {:?}", self.active_shard);
             }
-
+            *prev_inferred_shard = Some(shard);
-            None => (),
+            self.active_shard = Some(shard);
+            debug!("Automatically using shard: {:?}", self.active_shard);
         };
         Ok(())
     }
@@ -513,7 +506,7 @@ impl QueryRouter {
                 assert!(after_columns.is_empty());
 
                 Self::process_table(table_name, &mut table_names);
-                Self::process_query(&*source, &mut exprs, &mut table_names, &Some(columns));
+                Self::process_query(source, &mut exprs, &mut table_names, &Some(columns));
             }
             Delete {
                 tables,
@@ -529,7 +522,7 @@ impl QueryRouter {
                 // Multi tables delete are not supported in postgres.
                 assert!(tables.is_empty());
 
-                Self::process_tables_with_join(&from, &mut exprs, &mut table_names);
+                Self::process_tables_with_join(from, &mut exprs, &mut table_names);
                 if let Some(using_tbl_with_join) = using {
                     Self::process_tables_with_join(
                         using_tbl_with_join,
@@ -569,7 +562,7 @@ impl QueryRouter {
     ) {
         match &*query.body {
             SetExpr::Query(query) => {
-                Self::process_query(&*query, exprs, table_names, columns);
+                Self::process_query(query, exprs, table_names, columns);
             }
 
             // SELECT * FROM ...
@@ -611,7 +604,7 @@ impl QueryRouter {
     }
 
     fn process_tables_with_join(
-        tables: &Vec<TableWithJoins>,
+        tables: &[TableWithJoins],
         exprs: &mut Vec<Expr>,
         table_names: &mut Vec<Vec<Ident>>,
     ) {
@@ -625,37 +618,21 @@ impl QueryRouter {
         exprs: &mut Vec<Expr>,
         table_names: &mut Vec<Vec<Ident>>,
     ) {
-        match &table.relation {
+        if let TableFactor::Table { name, .. } = &table.relation {
-            TableFactor::Table { name, .. } => {
+            Self::process_table(name, table_names);
-                Self::process_table(name, table_names);
-            }
-
-            _ => (),
         };
 
         // Get table names from all the joins.
         for join in table.joins.iter() {
-            match &join.relation {
+            if let TableFactor::Table { name, .. } = &join.relation {
-                TableFactor::Table { name, .. } => {
+                Self::process_table(name, table_names);
-                    Self::process_table(name, table_names);
-                }
-
-                _ => (),
             };
 
             // We can filter results based on join conditions, e.g.
             // SELECT * FROM t INNER JOIN B ON B.sharding_key = 5;
-            match &join.join_operator {
+            if let JoinOperator::Inner(JoinConstraint::On(expr)) = &join.join_operator {
-                JoinOperator::Inner(inner_join) => match &inner_join {
+                // Parse the selection criteria later.
-                    JoinConstraint::On(expr) => {
+                exprs.push(expr.clone());
-                        // Parse the selection criteria later.
-                        exprs.push(expr.clone());
-                    }
-
-                    _ => (),
-                },
-
-                _ => (),
             };
         }
     }
@@ -814,7 +791,7 @@ impl QueryRouter {
             .automatic_sharding_key
             .as_ref()
             .unwrap()
-            .split(".")
+            .split('.')
             .map(|ident| Ident::new(ident.to_lowercase()))
             .collect::<Vec<Ident>>();
 
@@ -822,12 +799,12 @@ impl QueryRouter {
         assert_eq!(sharding_key.len(), 2);
 
         for a in assignments {
-            if sharding_key[0].value == "*" {
+            if sharding_key[0].value == "*"
-                if sharding_key[1].value == a.id.last().unwrap().value.to_lowercase() {
+                && sharding_key[1].value == a.id.last().unwrap().value.to_lowercase()
-                    return Err(Error::QueryRouterParserError(
+            {
-                        "Sharding key cannot be updated.".into(),
+                return Err(Error::QueryRouterParserError(
-                    ));
+                    "Sharding key cannot be updated.".into(),
-                }
+                ));
             }
         }
         Ok(())
@@ -844,7 +821,7 @@ impl QueryRouter {
             .automatic_sharding_key
             .as_ref()
             .unwrap()
-            .split(".")
+            .split('.')
             .map(|ident| Ident::new(ident.to_lowercase()))
             .collect::<Vec<Ident>>();
 
@@ -861,7 +838,7 @@ impl QueryRouter {
                 Expr::Identifier(ident) => {
                     // Only if we're dealing with only one table
                     // and there is no ambiguity
-                    if &ident.value.to_lowercase() == &sharding_key[1].value {
+                    if ident.value.to_lowercase() == sharding_key[1].value {
                         // Sharding key is unique enough, don't worry about
                         // table names.
                         if &sharding_key[0].value == "*" {
@@ -874,13 +851,13 @@ impl QueryRouter {
                                 //      SELECT * FROM t WHERE sharding_key = 5
                                 // Make sure the table name from the sharding key matches
                                 // the table name from the query.
-                                found = &sharding_key[0].value == &table[0].value.to_lowercase();
+                                found = sharding_key[0].value == table[0].value.to_lowercase();
                             } else if table.len() == 2 {
                                 // Table name is fully qualified with the schema: e.g.
                                 //      SELECT * FROM public.t WHERE sharding_key = 5
                                 // Ignore the schema (TODO: at some point, we want schema support)
                                 // and use the table name only.
-                                found = &sharding_key[0].value == &table[1].value.to_lowercase();
+                                found = sharding_key[0].value == table[1].value.to_lowercase();
                             } else {
                                 debug!("Got table name with more than two idents, which is not possible");
                             }
@@ -893,8 +870,8 @@ impl QueryRouter {
                     // it will exist or Postgres will throw an error.
                     if idents.len() == 2 {
                         found = (&sharding_key[0].value == "*"
-                            || &sharding_key[0].value == &idents[0].value.to_lowercase())
+                            || sharding_key[0].value == idents[0].value.to_lowercase())
-                            && &sharding_key[1].value == &idents[1].value.to_lowercase();
+                            && sharding_key[1].value == idents[1].value.to_lowercase();
                     }
                     // TODO: key can have schema as well, e.g. public.data.id (len == 3)
                 }
@@ -926,7 +903,7 @@ impl QueryRouter {
                 }
 
                 Expr::Value(Value::Placeholder(placeholder)) => {
-                    match placeholder.replace("$", "").parse::<i16>() {
+                    match placeholder.replace('$', "").parse::<i16>() {
                         Ok(placeholder) => result.push(ShardingKey::Placeholder(placeholder)),
                         Err(_) => {
                             debug!(
@@ -1020,16 +997,16 @@ impl QueryRouter {
                 db: &self.pool_settings.db,
             };
 
-            let _ = query_logger.run(&self, ast).await;
+            let _ = query_logger.run(self, ast).await;
         }
 
         if let Some(ref intercept) = plugins.intercept {
             let mut intercept = Intercept {
                 enabled: intercept.enabled,
-                config: &intercept,
+                config: intercept,
             };
 
-            let result = intercept.run(&self, ast).await;
+            let result = intercept.run(self, ast).await;
 
             if let Ok(PluginOutput::Intercept(output)) = result {
                 return Ok(PluginOutput::Intercept(output));
@@ -1042,7 +1019,7 @@ impl QueryRouter {
                 tables: &table_access.tables,
             };
 
-            let result = table_access.run(&self, ast).await;
+            let result = table_access.run(self, ast).await;
 
             if let Ok(PluginOutput::Deny(error)) = result {
                 return Ok(PluginOutput::Deny(error));
@@ -1078,7 +1055,7 @@ impl QueryRouter {
 
     /// Should we attempt to parse queries?
     pub fn query_parser_enabled(&self) -> bool {
-        let enabled = match self.query_parser_enabled {
+        match self.query_parser_enabled {
             None => {
                 debug!(
                     "Using pool settings, query_parser_enabled: {}",
@@ -1094,9 +1071,7 @@ impl QueryRouter {
                 );
                 value
             }
-        };
+        }
-
-        enabled
     }
 
     pub fn primary_reads_enabled(&self) -> bool {
@@ -1107,6 +1082,12 @@ impl QueryRouter {
     }
 }
 
+impl Default for QueryRouter {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -1128,10 +1109,14 @@ mod test {
         QueryRouter::setup();
         let mut qr = QueryRouter::new();
         qr.pool_settings.query_parser_read_write_splitting = true;
-        assert!(qr.try_execute_command(&simple_query("SET SERVER ROLE TO 'auto'")) != None);
+        assert!(qr
+            .try_execute_command(&simple_query("SET SERVER ROLE TO 'auto'"))
+            .is_some());
         assert!(qr.query_parser_enabled());
 
-        assert!(qr.try_execute_command(&simple_query("SET PRIMARY READS TO off")) != None);
+        assert!(qr
+            .try_execute_command(&simple_query("SET PRIMARY READS TO off"))
+            .is_some());
 
         let queries = vec![
             simple_query("SELECT * FROM items WHERE id = 5"),
@@ -1173,7 +1158,9 @@ mod test {
         QueryRouter::setup();
         let mut qr = QueryRouter::new();
         let query = simple_query("SELECT * FROM items WHERE id = 5");
-        assert!(qr.try_execute_command(&simple_query("SET PRIMARY READS TO on")) != None);
+        assert!(qr
+            .try_execute_command(&simple_query("SET PRIMARY READS TO on"))
+            .is_some());
 
         assert!(qr.infer(&qr.parse(&query).unwrap()).is_ok());
         assert_eq!(qr.role(), None);
@@ -1186,7 +1173,9 @@ mod test {
         qr.pool_settings.query_parser_read_write_splitting = true;
 
         qr.try_execute_command(&simple_query("SET SERVER ROLE TO 'auto'"));
-        assert!(qr.try_execute_command(&simple_query("SET PRIMARY READS TO off")) != None);
+        assert!(qr
+            .try_execute_command(&simple_query("SET PRIMARY READS TO off"))
+            .is_some());
 
         let prepared_stmt = BytesMut::from(
             &b"WITH t AS (SELECT * FROM items WHERE name = $1) SELECT * FROM t WHERE id = $2\0"[..],
@@ -1356,9 +1345,11 @@ mod test {
         qr.pool_settings.query_parser_read_write_splitting = true;
 
         let query = simple_query("SET SERVER ROLE TO 'auto'");
-        assert!(qr.try_execute_command(&simple_query("SET PRIMARY READS TO off")) != None);
+        assert!(qr
+            .try_execute_command(&simple_query("SET PRIMARY READS TO off"))
+            .is_some());
 
-        assert!(qr.try_execute_command(&query) != None);
+        assert!(qr.try_execute_command(&query).is_some());
         assert!(qr.query_parser_enabled());
         assert_eq!(qr.role(), None);
 
@@ -1372,7 +1363,7 @@ mod test {
 
         assert!(qr.query_parser_enabled());
         let query = simple_query("SET SERVER ROLE TO 'default'");
-        assert!(qr.try_execute_command(&query) != None);
+        assert!(qr.try_execute_command(&query).is_some());
         assert!(!qr.query_parser_enabled());
     }
 
@@ -1420,11 +1411,11 @@ mod test {
         assert!(!qr.primary_reads_enabled());
 
         let q1 = simple_query("SET SERVER ROLE TO 'primary'");
-        assert!(qr.try_execute_command(&q1) != None);
+        assert!(qr.try_execute_command(&q1).is_some());
         assert_eq!(qr.active_role.unwrap(), Role::Primary);
 
         let q2 = simple_query("SET SERVER ROLE TO 'default'");
-        assert!(qr.try_execute_command(&q2) != None);
+        assert!(qr.try_execute_command(&q2).is_some());
         assert_eq!(qr.active_role.unwrap(), pool_settings.default_role);
     }
 
@@ -1485,29 +1476,29 @@ mod test {
         };
 
         let mut qr = QueryRouter::new();
-        qr.update_pool_settings(pool_settings.clone());
+        qr.update_pool_settings(pool_settings);
 
         // Shard should start out unset
         assert_eq!(qr.active_shard, None);
 
         // Don't panic when short query eg. ; is sent
         let q0 = simple_query(";");
-        assert!(qr.try_execute_command(&q0) == None);
+        assert!(qr.try_execute_command(&q0).is_none());
         assert_eq!(qr.active_shard, None);
 
         // Make sure setting it works
         let q1 = simple_query("/* shard_id: 1 */ select 1 from foo;");
-        assert!(qr.try_execute_command(&q1) == None);
+        assert!(qr.try_execute_command(&q1).is_none());
         assert_eq!(qr.active_shard, Some(1));
 
         // And make sure changing it works
         let q2 = simple_query("/* shard_id: 0 */ select 1 from foo;");
-        assert!(qr.try_execute_command(&q2) == None);
+        assert!(qr.try_execute_command(&q2).is_none());
         assert_eq!(qr.active_shard, Some(0));
 
         // Validate setting by shard with expected shard copied from sharding.rs tests
         let q2 = simple_query("/* sharding_key: 6 */ select 1 from foo;");
-        assert!(qr.try_execute_command(&q2) == None);
+        assert!(qr.try_execute_command(&q2).is_none());
         assert_eq!(qr.active_shard, Some(2));
     }
 
@@ -1863,10 +1854,11 @@ mod test {
         };
 
         QueryRouter::setup();
-        let mut pool_settings = PoolSettings::default();
+        let pool_settings = PoolSettings {
-        pool_settings.query_parser_enabled = true;
+            query_parser_enabled: true,
-        pool_settings.plugins = Some(plugins);
+            plugins: Some(plugins),
-
+            ..Default::default()
+        };
         let mut qr = QueryRouter::new();
         qr.update_pool_settings(pool_settings);
 

src/scram.rs

@@ -79,12 +79,12 @@ impl ScramSha256 {
         let server_message = Message::parse(message)?;
 
         if !server_message.nonce.starts_with(&self.nonce) {
-            return Err(Error::ProtocolSyncError(format!("SCRAM")));
+            return Err(Error::ProtocolSyncError("SCRAM".to_string()));
         }
 
         let salt = match general_purpose::STANDARD.decode(&server_message.salt) {
             Ok(salt) => salt,
-            Err(_) => return Err(Error::ProtocolSyncError(format!("SCRAM"))),
+            Err(_) => return Err(Error::ProtocolSyncError("SCRAM".to_string())),
         };
 
         let salted_password = Self::hi(
@@ -166,9 +166,9 @@ impl ScramSha256 {
     pub fn finish(&mut self, message: &BytesMut) -> Result<(), Error> {
         let final_message = FinalMessage::parse(message)?;
 
-        let verifier = match general_purpose::STANDARD.decode(&final_message.value) {
+        let verifier = match general_purpose::STANDARD.decode(final_message.value) {
             Ok(verifier) => verifier,
-            Err(_) => return Err(Error::ProtocolSyncError(format!("SCRAM"))),
+            Err(_) => return Err(Error::ProtocolSyncError("SCRAM".to_string())),
         };
 
         let mut hmac = match Hmac::<Sha256>::new_from_slice(&self.salted_password) {
@@ -230,14 +230,14 @@ impl Message {
             .collect::<Vec<String>>();
 
         if parts.len() != 3 {
-            return Err(Error::ProtocolSyncError(format!("SCRAM")));
+            return Err(Error::ProtocolSyncError("SCRAM".to_string()));
         }
 
         let nonce = str::replace(&parts[0], "r=", "");
         let salt = str::replace(&parts[1], "s=", "");
         let iterations = match str::replace(&parts[2], "i=", "").parse::<u32>() {
             Ok(iterations) => iterations,
-            Err(_) => return Err(Error::ProtocolSyncError(format!("SCRAM"))),
+            Err(_) => return Err(Error::ProtocolSyncError("SCRAM".to_string())),
         };
 
         Ok(Message {
@@ -257,7 +257,7 @@ impl FinalMessage {
     /// Parse the server final validation message.
     pub fn parse(message: &BytesMut) -> Result<FinalMessage, Error> {
         if !message.starts_with(b"v=") || message.len() < 4 {
-            return Err(Error::ProtocolSyncError(format!("SCRAM")));
+            return Err(Error::ProtocolSyncError("SCRAM".to_string()));
         }
 
         Ok(FinalMessage {

src/server.rs

@@ -197,12 +197,8 @@ impl ServerParameters {
             key = "DateStyle".to_string();
         };
 
-        if TRACKED_PARAMETERS.contains(&key) {
+        if TRACKED_PARAMETERS.contains(&key) || startup {
             self.parameters.insert(key, value);
-        } else {
-            if startup {
-                self.parameters.insert(key, value);
-            }
         }
     }
 
@@ -332,6 +328,7 @@ pub struct Server {
 impl Server {
     /// Pretend to be the Postgres client and connect to the server given host, port and credentials.
     /// Perform the authentication and return the server in a ready for query state.
+    #[allow(clippy::too_many_arguments)]
     pub async fn startup(
         address: &Address,
         user: &User,
@@ -440,10 +437,7 @@ impl Server {
 
                 // Something else?
                 m => {
-                    return Err(Error::SocketError(format!(
+                    return Err(Error::SocketError(format!("Unknown message: {}", { m })));
-                        "Unknown message: {}",
-                        m as char
-                    )));
                 }
             }
         } else {
@@ -461,6 +455,8 @@ impl Server {
             None => &user.username,
         };
 
+        #[allow(clippy::match_as_ref)]
+        #[allow(clippy::manual_map)]
         let password = match user.server_password {
             Some(ref server_password) => Some(server_password),
             None => match user.password {
@@ -473,14 +469,11 @@ impl Server {
 
         let mut process_id: i32 = 0;
         let mut secret_key: i32 = 0;
-        let server_identifier = ServerIdentifier::new(username, &database);
+        let server_identifier = ServerIdentifier::new(username, database);
 
         // We'll be handling multiple packets, but they will all be structured the same.
         // We'll loop here until this exchange is complete.
-        let mut scram: Option<ScramSha256> = match password {
+        let mut scram: Option<ScramSha256> = password.map(|password| ScramSha256::new(password));
-            Some(password) => Some(ScramSha256::new(password)),
-            None => None,
-        };
 
         let mut server_parameters = ServerParameters::new();
 
@@ -882,7 +875,7 @@ impl Server {
         self.mirror_send(messages);
         self.stats().data_sent(messages.len());
 
-        match write_all_flush(&mut self.stream, &messages).await {
+        match write_all_flush(&mut self.stream, messages).await {
             Ok(_) => {
                 // Successfully sent to server
                 self.last_activity = SystemTime::now();
@@ -1359,16 +1352,14 @@ impl Server {
     }
 
     pub fn mirror_send(&mut self, bytes: &BytesMut) {
-        match self.mirror_manager.as_mut() {
+        if let Some(manager) = self.mirror_manager.as_mut() {
-            Some(manager) => manager.send(bytes),
+            manager.send(bytes)
-            None => (),
         }
     }
 
     pub fn mirror_disconnect(&mut self) {
-        match self.mirror_manager.as_mut() {
+        if let Some(manager) = self.mirror_manager.as_mut() {
-            Some(manager) => manager.disconnect(),
+            manager.disconnect()
-            None => (),
         }
     }
 
@@ -1397,7 +1388,7 @@ impl Server {
         server.send(&simple_query(query)).await?;
         let mut message = server.recv(None).await?;
 
-        Ok(parse_query_message(&mut message).await?)
+        parse_query_message(&mut message).await
     }
 }
 

src/sharding.rs

@@ -64,7 +64,7 @@ impl Sharder {
     fn sha1(&self, key: i64) -> usize {
         let mut hasher = Sha1::new();
 
-        hasher.update(&key.to_string().as_bytes());
+        hasher.update(key.to_string().as_bytes());
 
         let result = hasher.finalize();
 
@@ -202,10 +202,10 @@ mod test {
     #[test]
     fn test_sha1_hash() {
         let sharder = Sharder::new(12, ShardingFunction::Sha1);
-        let ids = vec![
+        let ids = [
             0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
         ];
-        let shards = vec![
+        let shards = [
             4, 7, 8, 3, 6, 0, 0, 10, 3, 11, 1, 7, 4, 4, 11, 2, 5, 0, 8, 3,
         ];
 

src/stats/pool.rs

@@ -86,11 +86,11 @@ impl PoolStats {
             }
         }
 
-        return map;
+        map
     }
 
     pub fn generate_header() -> Vec<(&'static str, DataType)> {
-        return vec![
+        vec![
             ("database", DataType::Text),
             ("user", DataType::Text),
             ("pool_mode", DataType::Text),
@@ -105,11 +105,11 @@ impl PoolStats {
             ("sv_login", DataType::Numeric),
             ("maxwait", DataType::Numeric),
             ("maxwait_us", DataType::Numeric),
-        ];
+        ]
     }
 
     pub fn generate_row(&self) -> Vec<String> {
-        return vec![
+        vec![
             self.identifier.db.clone(),
             self.identifier.user.clone(),
             self.mode.to_string(),
@@ -124,7 +124,7 @@ impl PoolStats {
             self.sv_login.to_string(),
             (self.maxwait / 1_000_000).to_string(),
             (self.maxwait % 1_000_000).to_string(),
-        ];
+        ]
     }
 }