org.apache.flink.connector.base.source.reader.splitreader

接口 SplitReader<E,SplitT extends org.apache.flink.api.connector.source.SourceSplit>

类型参数:

E - the element type.

SplitT - the split type.

@PublicEvolving
public interface SplitReader<E,SplitT extends org.apache.flink.api.connector.source.SourceSplit>

An interface used to read from splits. The implementation could either read from a single split or from multiple splits.

方法概要

限定符和类型	方法和说明
void	close() Close the split reader.
RecordsWithSplitIds<E>	fetch() Fetch elements into the blocking queue for the given splits.
void	handleSplitsChanges(SplitsChange<SplitT> splitsChanges) Handle the split changes.
void	wakeUp() Wake up the split reader in case the fetcher thread is blocking in fetch().

方法详细资料

fetch

RecordsWithSplitIds<E> fetch()
                      throws IOException

Fetch elements into the blocking queue for the given splits. The fetch call could be blocking but it should get unblocked when wakeUp() is invoked. In that case, the implementation may either decide to return without throwing an exception, or it can just throw an interrupted exception. In either case, this method should be reentrant, meaning that the next fetch call should just resume from where the last fetch call was waken up or interrupted.

返回:

the Ids of the finished splits.

抛出:

IOException - when encountered IO errors, such as deserialization failures.

handleSplitsChanges

void handleSplitsChanges(SplitsChange<SplitT> splitsChanges)

Handle the split changes. This call should be non-blocking.

For the consistency of internal state in SourceReaderBase, if an invalid split is added to the reader (for example splits without any records), it should be put back into RecordsWithSplitIds as finished splits so that SourceReaderBase could be able to clean up resources created for it.

参数:

splitsChanges - the split changes that the SplitReader needs to handle.

wakeUp

void wakeUp()

Wake up the split reader in case the fetcher thread is blocking in fetch().

close

void close()
    throws Exception

Close the split reader.

抛出:

Exception - if closing the split reader failed.