Struct tikv::storage::mvcc::MvccTxn

pub struct MvccTxn {
    pub(crate) start_ts: TimeStamp,
    pub(crate) write_size: usize,
    pub(crate) modifies: Vec<Modify>,
    pub(crate) locks_for_1pc: Vec<(Key, Lock, bool)>,
    pub(crate) concurrency_manager: ConcurrencyManager,
    pub(crate) guards: Vec<KeyHandleGuard>,
}

An abstraction of a locally-transactional MVCC key-value store

Fields

start_ts: TimeStamp

write_size: usize

modifies: Vec<Modify>

locks_for_1pc: Vec<(Key, Lock, bool)>

concurrency_manager: ConcurrencyManager

guards: Vec<KeyHandleGuard>

Implementations

impl MvccTxn

pub fn new(
    start_ts: TimeStamp,
    concurrency_manager: ConcurrencyManager
) -> MvccTxn

pub fn into_modifies(self) -> Vec<Modify>

pub fn take_guards(&mut self) -> Vec<KeyHandleGuard>

pub fn write_size(&self) -> usize

pub(crate) fn put_lock(&mut self, key: Key, lock: &Lock)

pub(crate) fn put_locks_for_1pc(
    &mut self,
    key: Key,
    lock: Lock,
    remove_pessimstic_lock: bool
)

pub(crate) fn unlock_key(
    &mut self,
    key: Key,
    pessimistic: bool
) -> Option<ReleasedLock>

pub(crate) fn put_value(&mut self, key: Key, ts: TimeStamp, value: Value)

pub(crate) fn delete_value(&mut self, key: Key, ts: TimeStamp)

pub(crate) fn put_write(&mut self, key: Key, ts: TimeStamp, value: Value)

pub(crate) fn delete_write(&mut self, key: Key, ts: TimeStamp)

pub(crate) fn mark_rollback_on_mismatching_lock(
    &mut self,
    key: &Key,
    lock: Lock,
    is_protected: bool
)

Add the timestamp of the current rollback operation to another transaction’s lock if necessary.

When putting rollback record on a key that’s locked by another transaction, the second transaction may overwrite the current rollback record when it’s committed. Sometimes it may break consistency. To solve the problem, add the timestamp of the current rollback to the lock. So when the lock is committed, it can check if it will overwrite a rollback record by checking the information in the lock.

Trait Implementations

impl Debug for MvccTxn

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

Formats the value using the given formatter.