org.apache.ratis.server.raftlog.memory

Class MemoryRaftLog

java.lang.Object

org.apache.ratis.server.raftlog.RaftLog

org.apache.ratis.server.raftlog.memory.MemoryRaftLog

All Implemented Interfaces:

Closeable, AutoCloseable

public class MemoryRaftLog
extends RaftLog

A simple RaftLog implementation in memory. Used only for testing.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	RaftLogSequentialOps.Runner

Nested classes/interfaces inherited from class org.apache.ratis.server.raftlog.RaftLog

RaftLog.EntryWithData, RaftLog.Metadata

Field Summary

Fields inherited from class org.apache.ratis.server.raftlog.RaftLog

INVALID_LOG_INDEX, LEAST_VALID_LOG_INDEX, LOG, LOG_SYNC

Constructor Summary

Constructors

Constructor and Description
MemoryRaftLog(RaftGroupMemberId memberId, long commitIndex, RaftProperties properties)

Method Summary

Modifier and Type	Method and Description
protected CompletableFuture<Long>	appendEntryImpl(org.apache.ratis.proto.RaftProtos.LogEntryProto entry)
List<CompletableFuture<Long>>	appendImpl(org.apache.ratis.proto.RaftProtos.LogEntryProto... logEntryProtos)
org.apache.ratis.proto.RaftProtos.LogEntryProto	get(long index) Get the log entry of the given index.
TermIndex[]	getEntries(long startIndex, long endIndex)
String	getEntryString()
RaftLog.EntryWithData	getEntryWithData(long index) Get the log entry of the given index along with the state machine data.
long	getFlushIndex()
TermIndex	getLastEntryTermIndex()
long	getStartIndex()
TermIndex	getTermIndex(long index) Get the TermIndex information of the given index.
boolean	isConfigEntry(TermIndex ti)
RaftLog.Metadata	loadMetadata()
protected CompletableFuture<Long>	purgeImpl(long index)
void	syncWithSnapshot(long lastSnapshotIndex)
protected CompletableFuture<Long>	truncateImpl(long index)
void	writeMetadata(long term, RaftPeerId votedFor) Write and flush the metadata (votedFor and term) into the meta file.

Methods inherited from class org.apache.ratis.server.raftlog.RaftLog

append, append, append, appendEntry, appendMetadata, checkLogState, close, contains, getLastCommittedIndex, getName, getNextIndex, getRaftLogMetrics, getSnapshotIndex, hasReadLock, hasWriteLock, isOpened, open, openImpl, purge, readLock, toLogEntryString, toString, truncate, updateLastCommitted, updateSnapshotIndex, validateLogEntry, writeLock

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryRaftLog

public MemoryRaftLog(RaftGroupMemberId memberId,
                     long commitIndex,
                     RaftProperties properties)

Method Detail

get

public org.apache.ratis.proto.RaftProtos.LogEntryProto get(long index)

Description copied from class: RaftLog

Get the log entry of the given index.

Specified by:

get in class RaftLog

Parameters:

index - The given index.

Returns:

The log entry associated with the given index. Null if there is no log entry with the index.

getEntryWithData

public RaftLog.EntryWithData getEntryWithData(long index)

Description copied from class: RaftLog

Get the log entry of the given index along with the state machine data.

Specified by:

getEntryWithData in class RaftLog

Parameters:

index - The given index.

Returns:

The log entry associated with the given index. Null if there is no log entry with the index.

getTermIndex

public TermIndex getTermIndex(long index)

Description copied from class: RaftLog

Get the TermIndex information of the given index.

Specified by:

getTermIndex in class RaftLog

Parameters:

index - The given index.

Returns:

The TermIndex of the log entry associated with the given index. Null if there is no log entry with the index.

getEntries

public TermIndex[] getEntries(long startIndex,
                              long endIndex)

Specified by:

getEntries in class RaftLog

Parameters:

startIndex - the starting log index (inclusive)

endIndex - the ending log index (exclusive)

Returns:

TermIndex of all log entries within the given index range. Null if startIndex is greater than the smallest available index.

truncateImpl

protected CompletableFuture<Long> truncateImpl(long index)

Specified by:

truncateImpl in class RaftLog

purgeImpl

protected CompletableFuture<Long> purgeImpl(long index)

Specified by:

purgeImpl in class RaftLog

getLastEntryTermIndex

public TermIndex getLastEntryTermIndex()

Specified by:

getLastEntryTermIndex in class RaftLog

Returns:

the last log entry's term and index.

appendEntryImpl

protected CompletableFuture<Long> appendEntryImpl(org.apache.ratis.proto.RaftProtos.LogEntryProto entry)

Specified by:

appendEntryImpl in class RaftLog

getStartIndex

public long getStartIndex()

Specified by:

getStartIndex in class RaftLog

appendImpl

public List<CompletableFuture<Long>> appendImpl(org.apache.ratis.proto.RaftProtos.LogEntryProto... logEntryProtos)

Specified by:

appendImpl in class RaftLog

getEntryString

public String getEntryString()

getFlushIndex

public long getFlushIndex()

Specified by:

getFlushIndex in class RaftLog

Returns:

the index of the last entry that has been flushed to the local storage.

writeMetadata

public void writeMetadata(long term,
                          RaftPeerId votedFor)

Description copied from class: RaftLog

Write and flush the metadata (votedFor and term) into the meta file. We need to guarantee that the order of writeMetadata calls is the same with that when we change the in-memory term/votedFor. Otherwise we may persist stale term/votedFor in file. Since the leader change is not frequent, currently we simply put this call in the RaftPeer's lock. Later we can use an IO task queue to enforce the order.

Specified by:

writeMetadata in class RaftLog

loadMetadata

public RaftLog.Metadata loadMetadata()

Specified by:

loadMetadata in class RaftLog

syncWithSnapshot

public void syncWithSnapshot(long lastSnapshotIndex)

Specified by:

syncWithSnapshot in class RaftLog

isConfigEntry

public boolean isConfigEntry(TermIndex ti)

Specified by:

isConfigEntry in class RaftLog