alluxio.master.journal.raft

Class SnapshotDownloader<S,R>

java.lang.Object

alluxio.master.journal.raft.SnapshotDownloader<S,R>

Type Parameters:

S - type of the message to send

R - type of the message to receive

All Implemented Interfaces:

io.grpc.stub.ClientResponseObserver<S,R>, io.grpc.stub.StreamObserver<R>

public class SnapshotDownloader<S,R>
extends Object
implements io.grpc.stub.ClientResponseObserver<S,R>

A stream observer for downloading a snapshot.

Method Summary

Modifier and Type	Method and Description
void	beforeStart(io.grpc.stub.ClientCallStreamObserver<S> requestStream)
static SnapshotDownloader<DownloadSnapshotPRequest,DownloadSnapshotPResponse>	forFollower(org.apache.ratis.statemachine.impl.SimpleStateMachineStorage storage, String source) Builds a stream for follower to download a snapshot.
static SnapshotDownloader<UploadSnapshotPResponse,UploadSnapshotPRequest>	forLeader(org.apache.ratis.statemachine.impl.SimpleStateMachineStorage storage, io.grpc.stub.StreamObserver<UploadSnapshotPResponse> stream, String source) Builds a stream for leader to download a snapshot.
CompletableFuture<org.apache.ratis.server.protocol.TermIndex>	getFuture()
org.apache.ratis.statemachine.SnapshotInfo	getSnapshotToInstall()
void	onCompleted()
void	onError(Throwable t)
void	onNext(R response)

Methods inherited from class java.lang.Object

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

Method Detail

forLeader

public static SnapshotDownloader<UploadSnapshotPResponse,UploadSnapshotPRequest> forLeader(org.apache.ratis.statemachine.impl.SimpleStateMachineStorage storage,
                                                                                           io.grpc.stub.StreamObserver<UploadSnapshotPResponse> stream,
                                                                                           String source)

Builds a stream for leader to download a snapshot.

Parameters:

storage - the snapshot storage

stream - the response stream

source - the source of the snapshot

Returns:

the download stream for leader

forFollower

public static SnapshotDownloader<DownloadSnapshotPRequest,DownloadSnapshotPResponse> forFollower(org.apache.ratis.statemachine.impl.SimpleStateMachineStorage storage,
                                                                                                 String source)

Builds a stream for follower to download a snapshot.

Parameters:

storage - the snapshot storage

source - the source of the snapshot

Returns:

the download stream for follower

onNext

public void onNext(R response)

Specified by:

onNext in interface io.grpc.stub.StreamObserver<R>

onError

public void onError(Throwable t)

Specified by:

onError in interface io.grpc.stub.StreamObserver<R>

onCompleted

public void onCompleted()

Specified by:

onCompleted in interface io.grpc.stub.StreamObserver<R>

beforeStart

public void beforeStart(io.grpc.stub.ClientCallStreamObserver<S> requestStream)

Specified by:

beforeStart in interface io.grpc.stub.ClientResponseObserver<S,R>

getFuture

public CompletableFuture<org.apache.ratis.server.protocol.TermIndex> getFuture()

Returns:

a future that tracks when the stream is completed

getSnapshotToInstall

public org.apache.ratis.statemachine.SnapshotInfo getSnapshotToInstall()

Returns:

the snapshot information if it is downloaded completely, or null otherwise