Add missing_const_for_fn clippy lint (#8498)

crates/storage/db/src/implementation/mdbx/mod.rs

@@ -52,7 +52,7 @@ pub enum DatabaseEnvKind {
 
 impl DatabaseEnvKind {
     /// Returns `true` if the environment is read-write.
-    pub fn is_rw(&self) -> bool {
+    pub const fn is_rw(&self) -> bool {
         matches!(self, Self::RW)
     }
 }
@@ -91,7 +91,7 @@ pub struct DatabaseArguments {
 
 impl DatabaseArguments {
     /// Create new database arguments with given client version.
-    pub fn new(client_version: ClientVersion) -> Self {
+    pub const fn new(client_version: ClientVersion) -> Self {
         Self {
             client_version,
             log_level: None,
@@ -101,13 +101,13 @@ impl DatabaseArguments {
     }
 
     /// Set the log level.
-    pub fn with_log_level(mut self, log_level: Option<LogLevel>) -> Self {
+    pub const fn with_log_level(mut self, log_level: Option<LogLevel>) -> Self {
         self.log_level = log_level;
         self
     }
 
     /// Set the maximum duration of a read transaction.
-    pub fn with_max_read_transaction_duration(
+    pub const fn with_max_read_transaction_duration(
         mut self,
         max_read_transaction_duration: Option<MaxReadTransactionDuration>,
     ) -> Self {
@@ -116,13 +116,13 @@ impl DatabaseArguments {
     }
 
     /// Set the mdbx exclusive flag.
-    pub fn with_exclusive(mut self, exclusive: Option<bool>) -> Self {
+    pub const fn with_exclusive(mut self, exclusive: Option<bool>) -> Self {
         self.exclusive = exclusive;
         self
     }
 
     /// Returns the client version if any.
-    pub fn client_version(&self) -> &ClientVersion {
+    pub const fn client_version(&self) -> &ClientVersion {
         &self.client_version
     }
 }

crates/storage/db/src/implementation/mdbx/tx.rs

@@ -45,7 +45,7 @@ pub struct Tx<K: TransactionKind> {
 impl<K: TransactionKind> Tx<K> {
     /// Creates new `Tx` object with a `RO` or `RW` transaction.
     #[inline]
-    pub fn new(inner: Transaction<K>) -> Self {
+    pub const fn new(inner: Transaction<K>) -> Self {
         Self::new_inner(inner, None)
     }
 
@@ -68,7 +68,7 @@ impl<K: TransactionKind> Tx<K> {
     }
 
     #[inline]
-    fn new_inner(inner: Transaction<K>, metrics_handler: Option<MetricsHandler<K>>) -> Self {
+    const fn new_inner(inner: Transaction<K>, metrics_handler: Option<MetricsHandler<K>>) -> Self {
         // NOTE: These constants are needed to initialize `OnceCell` at compile-time, as array
         // initialization is not allowed with non-Copy types, and `const { }` blocks are not stable
         // yet.