feat(storage): MDBX exclusive mode

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

@@ -63,6 +63,10 @@ pub struct DatabaseArguments {
     log_level: Option<LogLevel>,
     /// Maximum duration of a read transaction. If [None], the default value is used.
     max_read_transaction_duration: Option<MaxReadTransactionDuration>,
+    /// Mdbx exclusive flag. If [None], the default value is used.
+    ///
+    /// See docs at: <https://libmdbx.dqdkfa.ru/group__c__opening.html#gga9138119a904355d245777c4119534061aa516c74e6fed22c9812bb909c8c459ed>
+    exclusive: Option<bool>,
 }
 
 impl DatabaseArguments {
@@ -80,6 +84,12 @@ impl DatabaseArguments {
         self.max_read_transaction_duration = max_read_transaction_duration;
         self
     }
+
+    /// Set the mdbx exclusive flag.
+    pub fn exclusive(mut self, exclusive: Option<bool>) -> Self {
+        self.exclusive = exclusive;
+        self
+    }
 }
 
 /// Wrapper for the libmdbx environment: [Environment]
@@ -247,6 +257,7 @@ impl DatabaseEnv {
             // worsens it for random access (which is our access pattern outside of sync)
             no_rdahead: true,
             coalesce: true,
+            exclusive: inner_env.is_exclusive(),
             ..Default::default()
         });
         // Configure more readers
@@ -308,6 +319,10 @@ impl DatabaseEnv {
             inner_env.set_max_read_transaction_duration(max_read_transaction_duration);
         }
 
+        if let Some(exclusive) = args.exclusive {
+            inner_env.set_exclusive(exclusive);
+        }
+
         let env = DatabaseEnv {
             inner: inner_env.open(path).map_err(|e| DatabaseError::Open(e.into()))?,
             metrics: None,

crates/storage/libmdbx-rs/src/environment.rs

@@ -54,6 +54,7 @@ impl Environment {
             handle_slow_readers: None,
             #[cfg(feature = "read-tx-timeouts")]
             max_read_transaction_duration: None,
+            exclusive: false,
         }
     }
 
@@ -579,6 +580,8 @@ pub struct EnvironmentBuilder {
     /// The maximum duration of a read transaction. If [None], but the `read-tx-timeout` feature is
     /// enabled, the default value of [DEFAULT_MAX_READ_TRANSACTION_DURATION] is used.
     max_read_transaction_duration: Option<read_transactions::MaxReadTransactionDuration>,
+    /// MDBX exclusive flag.
+    exclusive: bool,
 }
 
 impl EnvironmentBuilder {
@@ -722,6 +725,10 @@ impl EnvironmentBuilder {
         Ok(Environment { inner: Arc::new(env) })
     }
 
+    /// Returns true if mdbx exclusive flag is set.
+    pub fn is_exclusive(&self) -> bool {
+        self.exclusive
+    }
     /// Configures how this environment will be opened.
     pub fn set_kind(&mut self, kind: EnvironmentKind) -> &mut Self {
         self.kind = kind;
@@ -860,6 +867,11 @@ pub(crate) mod read_transactions {
             self.max_read_transaction_duration = Some(max_read_transaction_duration);
             self
         }
+        /// Set the mdbx exclusive flag.
+        pub fn set_exclusive(&mut self, exclusive: bool) -> &mut Self {
+            self.exclusive = exclusive;
+            self
+        }
     }
 }