alluxio.client.block.stream

Class SharedGrpcDataReader

java.lang.Object

alluxio.client.block.stream.SharedGrpcDataReader

All Implemented Interfaces:

DataReader, java.io.Closeable, java.lang.AutoCloseable

@NotThreadSafe
public class SharedGrpcDataReader
extends java.lang.Object
implements DataReader

A shared gRPC data reader that cache blocks data for multi-thread accessing. It follows GrpcDataReader protocol and takes strong assumption: Parallel read to the same file happens on the same time, so that read request is serialized by kernel

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SharedGrpcDataReader.Factory Factory class to create SharedGrpcDataReaders.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SharedGrpcDataReader(ReadRequest readRequest, BufferCachingGrpcDataReader reader) Creates an instance of SharedGrpcDataReader.

Method Summary

Modifier and Type	Method and Description
void	close()
long	pos()
DataBuffer	readChunk() Reads a chunk.
void	seek(long pos) Seeks to a specific position.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

SharedGrpcDataReader

protected SharedGrpcDataReader(ReadRequest readRequest,
                               BufferCachingGrpcDataReader reader)

Creates an instance of SharedGrpcDataReader.

Parameters:

readRequest - the read request

reader - the cached Grpc data reader for the given block

Method Detail

pos

public long pos()

Specified by:

pos in interface DataReader

Returns:

the current stream position

seek

public void seek(long pos)

Seeks to a specific position.

Parameters:

pos - the position to seek to

readChunk

@Nullable
public DataBuffer readChunk()
                               throws java.io.IOException

Description copied from interface: DataReader

Reads a chunk. The caller needs to release the chunk.

Specified by:

readChunk in interface DataReader

Returns:

the data buffer or null if EOF is reached

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException