org.apache.paimon.reader

Interface RecordReader<T>

All Superinterfaces:

AutoCloseable, Closeable

All Known Subinterfaces:

FileRecordReader<T>, SortMergeReader<T>

All Known Implementing Classes:

ApplyBitmapIndexRecordReader, ApplyDeletionVectorReader, AsyncRecordReader, ConcatRecordReader, DataFileRecordReader, DropDeleteReader, EmptyFileRecordReader, EmptyRecordReader, IteratorRecordReader, KeyValueDataFileRecordReader, PackChangelogReader, ReverseReader, SortMergeReaderWithLoserTree, SortMergeReaderWithMinHeap

@Public
public interface RecordReader<T>
extends Closeable

The reader that reads the batches of records.

Since:

0.4.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	RecordReader.RecordIterator<T> An internal iterator interface which presents a more restrictive API than Iterator.

Method Summary

Modifier and Type	Method and Description
void	close() Closes the reader and should release all resources.
default RecordReader<T>	filter(Filter<T> filter) Filters a RecordReader.
default void	forEachRemaining(java.util.function.Consumer<? super T> action) Performs the given action for each remaining element in RecordReader until all elements have been processed or the action throws an exception.
default void	forEachRemainingWithPosition(java.util.function.BiConsumer<Long,? super T> action) Performs the given action for each remaining element with row position in RecordReader until all elements have been processed or the action throws an exception.
RecordReader.RecordIterator<T>	readBatch() Reads one batch.
default CloseableIterator<T>	toCloseableIterator() Convert this reader to a CloseableIterator.
default <R> RecordReader<R>	transform(java.util.function.Function<T,R> function) Returns a RecordReader that applies function to each element.

Method Detail

readBatch

@Nullable
RecordReader.RecordIterator<T> readBatch()
                                            throws IOException

Reads one batch. The method should return null when reaching the end of the input.

The returned iterator object and any contained objects may be held onto by the source for some time, so it should not be immediately reused by the reader.

Throws:

IOException

close

void close()
    throws IOException

Closes the reader and should release all resources.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

forEachRemaining

default void forEachRemaining(java.util.function.Consumer<? super T> action)
                       throws IOException

Performs the given action for each remaining element in RecordReader until all elements have been processed or the action throws an exception.

Throws:

IOException

forEachRemainingWithPosition

default void forEachRemainingWithPosition(java.util.function.BiConsumer<Long,? super T> action)
                                   throws IOException

Performs the given action for each remaining element with row position in RecordReader until all elements have been processed or the action throws an exception.

Throws:

IOException

transform

default <R> RecordReader<R> transform(java.util.function.Function<T,R> function)

Returns a RecordReader that applies function to each element.

filter

default RecordReader<T> filter(Filter<T> filter)

Filters a RecordReader.

toCloseableIterator

default CloseableIterator<T> toCloseableIterator()

Convert this reader to a CloseableIterator.