Struct txn_lock::TxnLock

pub struct TxnLock<TxnId, T> { /* private fields */ }

A futures-aware read-write lock which supports transaction-specific versioning

Implementations

impl<TxnId: Ord, T> TxnLock<TxnId, T>

pub fn new<Name: Display>(name: Name, txn_id: TxnId, value: T) -> Self

Create a new transactional lock.

impl<TxnId: Display + Debug + Ord + Copy, T: Clone> TxnLock<TxnId, T>

pub async fn read(&self, txn_id: TxnId) -> Result<TxnLockReadGuard<T>, Error>

Lock this value for reading at the given txn_id.

pub fn try_read(&self, txn_id: TxnId) -> Result<TxnLockReadGuard<T>, Error>

Synchronously Lock this value for reading at the given txn_id, if possible.

pub async fn read_exclusive(
    &self,
    txn_id: TxnId
) -> Result<TxnLockReadGuardExclusive<T>, Error>

Lock this value for exclusive reading at the given txn_id.

pub fn try_read_exclusive(
    &self,
    txn_id: TxnId
) -> Result<TxnLockReadGuardExclusive<T>, Error>

Synchronously lock this value for exclusive reading at the given txn_id, if possible.

pub async fn write(&self, txn_id: TxnId) -> Result<TxnLockWriteGuard<T>, Error>

Lock this value for writing at the given txn_id.

pub fn try_write(&self, txn_id: TxnId) -> Result<TxnLockWriteGuard<T>, Error>

Synchronously lock this value for writing at the given txn_id, if possible.

impl<TxnId: Debug + Display + Copy + Ord, T: Clone> TxnLock<TxnId, T>

pub async fn commit(&self, txn_id: TxnId) -> Option<TxnLockCommit<TxnId, T>>

Commit the value of this TxnLock at the given txn_id. This will wait until any earlier write locks have been committed or rolled back.

Panics:

• when called with a txn_id which has already been finalized.
• when attempting to commit a version at a txn_id less than the last committed version

pub async fn rollback(&self, txn_id: &TxnId) -> Option<TxnLockRollback<T>>

Roll back the value of this TxnLock at the given txn_id.

Returns the version that was rolled back, if any lock was acquired at txn_id.

Panics:

• if the initial version is rolled back
• if a committed version is rolled back

pub async fn finalize(&self, txn_id: &TxnId) -> Option<TxnLockFinalize<T>>

Drop all values of this TxnLock as old as than the given txn_id up to the last commit.

Returns Some(Arc<T>) with the finalized version, if any lock was acquired at txn_id.

Panics:

• if the initial version is finalized before being committed
• if the last commit is finalized

Trait Implementations

impl<TxnId, T> Clone for TxnLock<TxnId, T>

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<TxnId, T> Debug for TxnLock<TxnId, T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.