AssertStmtStaleness is used only for test.

CalculateAsOfTsExpr calculates the TsExpr of AsOfClause to get a StartTS.

CalculateTsWithReadStaleness calculates the TsExpr for readStaleness duration.

GetExternalTimestamp returns the external timestamp in cache, or get and store it in cache.

GetSessionSnapshotInfoSchema returns the session's information schema with specified ts.

IsStmtStaleness indicates whether the current statement is staleness or not.

NewStalenessTxnContextProvider creates a new StalenessTxnContextProvider.

NewStaleReadProcessor creates a new stale read processor.

StalenessTxnContextProvider implements sessiontxn.TxnContextProvider.

Processor is an interface used to process stale read.

StalenessTSEvaluator is a function to get staleness ts.