com.google.cloud.dataflow.sdk.util.common.worker

Interface ShuffleEntryReader

All Known Implementing Classes:

BatchingShuffleEntryReader

@NotThreadSafe
public interface ShuffleEntryReader

ShuffleEntryReader provides an interface for reading key/value entries from a shuffle dataset.

Method Summary

Modifier and Type	Method and Description
Reiterator<ShuffleEntry>	read(ShufflePosition startPosition, ShufflePosition endPosition) Returns an iterator that reads a range of entries from a shuffle dataset.

Method Detail

read

Reiterator<ShuffleEntry> read(@Nullable
                              ShufflePosition startPosition,
                              @Nullable
                              ShufflePosition endPosition)

Returns an iterator that reads a range of entries from a shuffle dataset.

Parameters:

startPosition - encodes the initial key from where to read. This parameter may be null, indicating that the read should start with the first key in the dataset.

endPosition - encodes the key "just past" the end of the range to be read; keys up to endPosition will be returned, but keys equal to or greater than endPosition will not. This parameter may be null, indicating that the read should end just past the last key in the dataset (that is, the last key in the dataset will be included in the read, as long as that key is greater than or equal to startPosition).

Returns:

a Reiterator over the requested range of entries.