Struct tikv::storage::txn::commands::resolve_lock::ResolveLock

pub struct ResolveLock {
    pub ctx: Context,
    pub txn_status: HashMap<TimeStamp, TimeStamp>,
    pub scan_key: Option<Key>,
    pub key_locks: Vec<(Key, Lock)>,
}

Resolve locks according to txn_status.

During the GC operation, this should be called to clean up stale locks whose timestamp is before safe point. This should follow after a ResolveLockReadPhase.

Fields

ctx: Context

txn_status: HashMap<TimeStamp, TimeStamp>

Maps lock_ts to commit_ts. If a transaction was rolled back, it is mapped to 0.

For example, let txn_status be { 100: 101, 102: 0 }, then it means that the transaction whose start_ts is 100 was committed with commit_ts 101, and the transaction whose start_ts is 102 was rolled back. If there are these keys in the db:

• “k1”, lock_ts = 100
• “k2”, lock_ts = 102
• “k3”, lock_ts = 104
• “k4”, no lock

Here "k1", "k2" and "k3" each has a not-yet-committed version, because they have locks. After calling resolve_lock, "k1" will be committed with commit_ts = 101 and "k2" will be rolled back. "k3" will not be affected, because its lock_ts is not contained in txn_status. "k4" will not be affected either, because it doesn’t have a non-committed version.

scan_key: Option<Key>

key_locks: Vec<(Key, Lock)>

Implementations

impl ResolveLock

pub fn new(
    txn_status: HashMap<TimeStamp, TimeStamp>,
    scan_key: Option<Key>,
    key_locks: Vec<(Key, Lock)>,
    ctx: Context
) -> TypedCommand<()>

Return a TypedCommand that encapsulates the result of executing this command.

Trait Implementations

impl CommandExt for ResolveLock

fn get_ctx(&self) -> &Context

fn get_ctx_mut(&mut self) -> &mut Context

fn tag(&self) -> CommandKind

fn incr_cmd_metric(&self)

fn readonly(&self) -> bool

fn is_sys_cmd(&self) -> bool

fn write_bytes(&self) -> usize

fn gen_lock(&self) -> Lock

fn ts(&self) -> TimeStamp

fn can_be_pipelined(&self) -> bool

impl Debug for ResolveLock

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

Formats the value using the given formatter.

impl Display for ResolveLock

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

Formats the value using the given formatter.

impl<S: Snapshot, L: LockManager> WriteCommand<S, L> for ResolveLock

fn process_write(
    self,
    snapshot: S,
    context: WriteContext<'_, L>
) -> Result<WriteResult>