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

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
StreamSegmentsIterator	getSegments(Stream stream, StreamCut fromStreamCut, StreamCut toStreamCut) Provide a list of segments for a given stream between fromStreamCut and toStreamCut.
java.util.concurrent.CompletableFuture<StreamInfo>	getStreamInfo(Stream stream) Get information about a given Stream, StreamInfo.
<T> SegmentIterator<T>	readSegment(SegmentRange 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.

Method Detail

getStreamInfo

java.util.concurrent.CompletableFuture<StreamInfo> getStreamInfo(Stream stream)

Get information about a given Stream, StreamInfo.

Parameters:

stream - the stream.

Returns:

stream information.

getSegments

StreamSegmentsIterator getSegments(Stream stream,
                                   StreamCut fromStreamCut,
                                   StreamCut toStreamCut)

Provide a list of segments for a given stream between fromStreamCut and toStreamCut. Passing StreamCut.UNBOUNDED or null to fromStreamCut and toStreamCut will result in using the current start of stream and the current end of stream respectively.

Note: In case of stream truncation:

- Passing a null to fromStreamCut will result in using the current start of the Stream post truncation.

- Passing a fromStreamCut which points to the truncated stream will result in a NoSuchSegmentException while iterating over SegmentRange iterator obtained via StreamSegmentsIterator.getIterator()

Parameters:

stream - the stream.

fromStreamCut - starting stream cut.

toStreamCut - end stream cut.

Returns:

Segment information between the two stream cuts.

readSegment

<T> SegmentIterator<T> readSegment(SegmentRange 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