fix: clippy warnings for mysql and final sqlite modules

- Fix unnecessary_cast in sqlite/statement/virtual.rs
- Add is_empty() method to MySqlArguments to fix len_without_is_empty
- Fix explicit_auto_deref in mysql/column.rs and mysql/options/parse.rs
- Fix needless_borrows_for_generic_args in mysql/connection/auth.rs
- Fix borrow_deref_ref in mysql/connection/auth.rs
- Fix needless_borrow in mysql/connection/auth.rs and executor.rs
- Remove unused lifetime in mysql/connection/executor.rs
- Fix get_first by using first() instead of get(0)

Author: cursoragent

sqlx-core/src/mysql/arguments.rs

@@ -31,6 +31,11 @@ impl MySqlArguments {
     pub fn len(&self) -> usize {
         self.types.len()
     }
+
+    #[doc(hidden)]
+    pub fn is_empty(&self) -> bool {
+        self.types.is_empty()
+    }
 }
 
 impl<'q> Arguments<'q> for MySqlArguments {

sqlx-core/src/mysql/column.rs

@@ -24,7 +24,7 @@ impl Column for MySqlColumn {
     }
 
     fn name(&self) -> &str {
-        &*self.name
+        &self.name
     }
 
     fn type_info(&self) -> &MySqlTypeInfo {

sqlx-core/src/mysql/connection/auth.rs

@@ -76,7 +76,7 @@ fn scramble_sha1(password: &str, nonce: &Chain<Bytes, Bytes>) -> Vec<u8> {
 
     let mut pw_hash = ctx.finalize_reset();
 
-    ctx.update(&pw_hash);
+    ctx.update(pw_hash);
 
     let pw_hash_hash = ctx.finalize_reset();
 
@@ -100,7 +100,7 @@ fn scramble_sha256(password: &str, nonce: &Chain<Bytes, Bytes>) -> Vec<u8> {
 
     let mut pw_hash = ctx.finalize_reset();
 
-    ctx.update(&pw_hash);
+    ctx.update(pw_hash);
 
     let pw_hash_hash = ctx.finalize_reset();
 
@@ -141,10 +141,10 @@ async fn encrypt_rsa<'s>(
 
     let (a, b) = (nonce.first_ref(), nonce.last_ref());
     let mut nonce = Vec::with_capacity(a.len() + b.len());
-    nonce.extend_from_slice(&*a);
-    nonce.extend_from_slice(&*b);
+    nonce.extend_from_slice(a);
+    nonce.extend_from_slice(b);
 
-    xor_eq(&mut pass, &*nonce);
+    xor_eq(&mut pass, &nonce);
 
     // client sends an RSA encrypted password
     let pkey = parse_rsa_pub_key(rsa_pub_key)?;
@@ -179,5 +179,5 @@ fn parse_rsa_pub_key(key: &[u8]) -> Result<RsaPublicKey, Error> {
     // we are receiving a PKCS#8 RSA Public Key at all
     // times from MySQL
 
-    RsaPublicKey::from_public_key_pem(&pem).map_err(Error::protocol)
+    RsaPublicKey::from_public_key_pem(pem).map_err(Error::protocol)
 }

sqlx-core/src/mysql/connection/executor.rs

@@ -25,7 +25,7 @@ use futures_util::{pin_mut, TryStreamExt};
 use std::{borrow::Cow, sync::Arc};
 
 impl MySqlConnection {
-    async fn get_or_prepare<'c>(
+    async fn get_or_prepare(
         &mut self,
         sql: &str,
         persistent: bool,
@@ -289,7 +289,7 @@ impl<'c> Executor<'c> for &'c mut MySqlConnection {
 
             let (_, metadata) = self.get_or_prepare(sql, false).await?;
 
-            let columns = (&*metadata.columns).clone();
+            let columns = (*metadata.columns).clone();
 
             let nullable = columns
                 .iter()
@@ -335,7 +335,7 @@ fn recv_next_result_column(def: &ColumnDefinition, ordinal: usize) -> Result<MyS
         (name, _) => UStr::new(name),
     };
 
-    let type_info = MySqlTypeInfo::from_column(&def);
+    let type_info = MySqlTypeInfo::from_column(def);
 
     Ok(MySqlColumn {
         name,

sqlx-core/src/mysql/connection/stream.rs

@@ -149,7 +149,7 @@ impl MySqlStream {
         // TODO: packet joining
 
         if payload
-            .get(0)
+            .first()
             .ok_or(err_protocol!("Packet empty"))?
             .eq(&0xff)
         {

sqlx-core/src/mysql/options/parse.rs

@@ -22,7 +22,7 @@ impl FromStr for MySqlConnectOptions {
         let username = url.username();
         if !username.is_empty() {
             options = options.username(
-                &*percent_decode_str(username)
+                &percent_decode_str(username)
                     .decode_utf8()
                     .map_err(Error::config)?,
             );

sqlx-core/src/sqlite/statement/virtual.rs

@@ -191,7 +191,7 @@ fn prepare(
                 conn,
                 query_ptr,
                 query_len,
-                flags as u32,
+                flags,
                 &mut statement_handle,
                 &mut tail,
             )