org.apache.hudi.common.table.timeline

Interface TimeGenerator

All Known Implementing Classes:

TimeGeneratorBase, WaitBasedTimeGenerator

public interface TimeGenerator

Time generator for global monotonically increasing time generation.

Basically there are two ways to make the time generation monotonically increasing: i). lock provider to guard the time generation with mutex, along with a max allowed clock skew on distributed hosts; ii). TrueTime API that behaves like Google Spanner Time Service, the service itself can ensure the monotonicity. Currently only AWS supplies an SDK for the TrueTime generation.

Method Summary

Modifier and Type	Method and Description
void	consumeTimestamp(boolean skipLocking, Consumer<Long> func) Passes an auto generated timestamp to the given function func.
long	currentTimeMillis(boolean skipLocking) Generates a globally monotonically increasing timestamp.

Method Detail

currentTimeMillis

long currentTimeMillis(boolean skipLocking)

Generates a globally monotonically increasing timestamp. The implementation must ensure that a new generated timestamp T is guaranteed to be greater than any timestamp generated by the preceding calls.

Parameters:

skipLocking - If this is triggered by another parent transaction, locking can be skipped.

Returns:

Current true time as milliseconds.

consumeTimestamp

void consumeTimestamp(boolean skipLocking,
                      Consumer<Long> func)

Passes an auto generated timestamp to the given function func. The implementations need to ensure timestamp generation and executing func are atomic.

Parameters:

skipLocking - If this is triggered by another parent transaction, locking can be skipped.

func - A consumer that takes a monotonically increasing timestamp.