io.pravega.client.batch

Interface BatchClient

@Beta
public interface BatchClient

Please note this is an experimental API. Used to get metadata about and read from an existing streams.

All events written to a stream will be visible to SegmentIterators and reflected in SegmentInfo#getLength().

Events within a segment are strictly ordered, but as this API allows for reading from multiple segments in parallel without adhering to time ordering. This allows for events greater parallelization at the expense of the ordering guarantees provided by EventStreamReader.

Method Summary

Modifier and Type	Method and Description
java.util.Iterator<SegmentInfo>	listSegments(Stream stream) Provides a list of segments and their metadata for a given stream.
<T> SegmentIterator<T>	readSegment(io.pravega.client.segment.impl.Segment segment, Serializer<T> deserializer) Provides a SegmentIterator to read the events in the requested segment starting from the beginning of the segment and ending at the current end of the segment.
<T> SegmentIterator<T>	readSegment(io.pravega.client.segment.impl.Segment segment, Serializer<T> deserializer, long startingOffset, long endingOffset) Provides a SegmentIterator to read the events after the startingOffset but before the endingOffset in the requested segment.

Method Detail

listSegments

java.util.Iterator<SegmentInfo> listSegments(Stream stream)

Provides a list of segments and their metadata for a given stream.

Parameters:

stream - the stream

Returns:

The segments in the requested stream.

readSegment

<T> SegmentIterator<T> readSegment(io.pravega.client.segment.impl.Segment segment,
                                   Serializer<T> deserializer)

Provides a SegmentIterator to read the events in the requested segment starting from the beginning of the segment and ending at the current end of the segment.

Type Parameters:

T - The type of events written to the segment.

Parameters:

segment - The segment to read from

deserializer - A deserializer to be used to parse events

Returns:

A SegmentIterator over the requested segment

readSegment

<T> SegmentIterator<T> readSegment(io.pravega.client.segment.impl.Segment segment,
                                   Serializer<T> deserializer,
                                   long startingOffset,
                                   long endingOffset)

Provides a SegmentIterator to read the events after the startingOffset but before the endingOffset in the requested segment. Offsets can be obtained by calling SegmentIterator.getOffset() or SegmentInfo#getLength()

Type Parameters:

T - The type of events written to the segment.

Parameters:

segment - The segment to read from

deserializer - A deserializer to be used to parse events

startingOffset - The offset to start iterating from.

endingOffset - The offset to stop iterating at.

Returns:

A SegmentIterator over the requested segment at startingOffset