Struct tikv::storage::mvcc::reader::reader::SnapshotReader

pub struct SnapshotReader<S: EngineSnapshot> {
    pub reader: MvccReader<S>,
    pub start_ts: TimeStamp,
}

Read from an MVCC snapshot, i.e., a logical view of the database at a specific timestamp (the start_ts).

This represents the view of the database from a single transaction.

Confusingly, there are two meanings of the word ‘snapshot’ here. In the name of the struct, ‘snapshot’ means an mvcc snapshot. In the type parameter bound (of S), ‘snapshot’ means a view of the underlying storage engine at a given point in time. This latter snapshot will include values for keys at multiple timestamps.

Fields

reader: MvccReader<S>

start_ts: TimeStamp

Implementations

impl<S: EngineSnapshot> SnapshotReader<S>

pub fn new(start_ts: TimeStamp, snapshot: S, fill_cache: bool) -> Self

pub fn get_txn_commit_record(&mut self, key: &Key) -> Result<TxnCommitRecord>

pub fn load_lock(&mut self, key: &Key) -> Result<Option<Lock>>

pub fn key_exist(&mut self, key: &Key, ts: TimeStamp) -> Result<bool>

pub fn get(&mut self, key: &Key, ts: TimeStamp) -> Result<Option<Value>>

pub fn get_write(&mut self, key: &Key, ts: TimeStamp) -> Result<Option<Write>>

pub fn seek_write(
    &mut self,
    key: &Key,
    ts: TimeStamp
) -> Result<Option<(TimeStamp, Write)>>

pub fn load_data(&mut self, key: &Key, write: Write) -> Result<Value>

pub fn get_old_value(
    &mut self,
    key: &Key,
    ts: TimeStamp,
    prev_write_loaded: bool,
    prev_write: Option<Write>
) -> Result<OldValue>

pub fn take_statistics(&mut self) -> Statistics