RaftLog (Apache Ratis Server API 3.1.3 API)

所有超级接口:

AutoCloseable, Closeable
```
public interface RaftLog
extends Closeable
```
RaftLog is a transaction log of a raft service.

嵌套类概要

嵌套类
限定符和类型接口和说明

static interface RaftLog.EntryWithData
Log entry with state machine data.

static class RaftLogSequentialOps.Runner

嵌套类
限定符和类型	接口和说明
`static interface`	`RaftLog.EntryWithData` Log entry with state machine data.
`static class`	`RaftLogSequentialOps.Runner`

字段概要

字段
限定符和类型	字段和说明
`static long`	`INVALID_LOG_INDEX` Invalid log index is used to indicate that the log index is missing.
`static long`	`LEAST_VALID_LOG_INDEX` The least valid log index, i.e. the index used when writing to an empty log.
`static org.slf4j.Logger`	`LOG`

方法概要

所有方法实例方法抽象方法默认方法已过时的方法
限定符和类型	方法和说明
`List<CompletableFuture<Long>>`	`append(List<org.apache.ratis.proto.RaftProtos.LogEntryProto> entries)` Append asynchronously all the given log entries.
`long`	`append(long term, RaftConfiguration configuration)` Append asynchronously a log entry for the given term and configuration Used by the leader.
`long`	`append(long term, TransactionContext transaction)` Append asynchronously a log entry for the given term and transaction.
`default List<CompletableFuture<Long>>`	`append(org.apache.ratis.proto.RaftProtos.LogEntryProto... entries)` 已过时。 use `append(List)`
`CompletableFuture<Long>`	`appendEntry(org.apache.ratis.proto.RaftProtos.LogEntryProto entry)` Append asynchronously an entry.
`default CompletableFuture<Long>`	`appendEntry(org.apache.ratis.proto.RaftProtos.LogEntryProto entry, TransactionContext context)` Append asynchronously an entry.
`long`	`appendMetadata(long term, long commitIndex)` Append asynchronously a log entry for the given term and commit index unless the given commit index is an index of a metadata entry Used by the leader.
`default boolean`	`contains(TermIndex ti)` Does this log contains the given `TermIndex`?
`org.apache.ratis.proto.RaftProtos.LogEntryProto`	`get(long index)`
`LogEntryHeader[]`	`getEntries(long startIndex, long endIndex)`
`RaftLog.EntryWithData`	`getEntryWithData(long index)`
`long`	`getFlushIndex()`
`long`	`getLastCommittedIndex()`
`TermIndex`	`getLastEntryTermIndex()`
`default long`	`getNextIndex()`
`RaftLogMetrics`	`getRaftLogMetrics()`
`long`	`getSnapshotIndex()`
`long`	`getStartIndex()`
`TermIndex`	`getTermIndex(long index)`
`RaftStorageMetadata`	`loadMetadata()` Load metadata.
`CompletableFuture<Long>`	`onSnapshotInstalled(long lastSnapshotIndex)` A snapshot is installed so that the indices and other information of this log must be updated.
`void`	`open(long lastIndexInSnapshot, Consumer<org.apache.ratis.proto.RaftProtos.LogEntryProto> consumer)` Open this log for read and write.
`void`	`persistMetadata(RaftStorageMetadata metadata)` Persist the given metadata.
`CompletableFuture<Long>`	`purge(long suggestedIndex)` Purge asynchronously the log transactions.
`CompletableFuture<Long>`	`truncate(long index)` Truncate asynchronously the log entries till the given index (inclusively).
`boolean`	`updateCommitIndex(long majorityIndex, long currentTerm, boolean isLeader)` Update the commit index.
`void`	`updateSnapshotIndex(long newSnapshotIndex)` Update the snapshot index with the given index.

从接口继承的方法 java.io.Closeable
close

- 字段详细资料
  - LOG
```
static final org.slf4j.Logger LOG
```
  - LEAST_VALID_LOG_INDEX
```
static final long LEAST_VALID_LOG_INDEX
```
    The least valid log index, i.e. the index used when writing to an empty log.
    
    另请参阅:
    
    常量字段值
  - INVALID_LOG_INDEX
```
static final long INVALID_LOG_INDEX
```
    Invalid log index is used to indicate that the log index is missing.
    
    另请参阅:
    
    常量字段值
- 方法详细资料
  - contains
```
default boolean contains(TermIndex ti)
```
    Does this log contains the given TermIndex?
  - getTermIndex
```
TermIndex getTermIndex(long index)
```
    返回:
    
    null if the log entry is not found in this log; otherwise, return the TermIndex of the log entry corresponding to the given index.
  - get
```
org.apache.ratis.proto.RaftProtos.LogEntryProto get(long index)
                                             throws RaftLogIOException
```
    返回:
    
    null if the log entry is not found in this log; otherwise, return the log entry corresponding to the given index.
    
    抛出:
    
    RaftLogIOException
  - getEntryWithData
```
RaftLog.EntryWithData getEntryWithData(long index)
                                throws RaftLogIOException
```
    返回:
    
    null if the log entry is not found in this log; otherwise, return the RaftLog.EntryWithData corresponding to the given index.
    
    抛出:
    
    RaftLogIOException
  - getEntries
```
LogEntryHeader[] getEntries(long startIndex,
                            long endIndex)
```
    参数:
    
    startIndex - the starting log index (inclusive)
    
    endIndex - the ending log index (exclusive)
    
    返回:
    
    null if entries are unavailable in this log; otherwise, return the log entry headers within the given index range.
  - getStartIndex
```
long getStartIndex()
```
    返回:
    
    the index of the starting entry of this log.
  - getNextIndex
```
default long getNextIndex()
```
    返回:
    
    the index of the next entry to append.
  - getLastCommittedIndex
```
long getLastCommittedIndex()
```
    返回:
    
    the index of the last entry that has been committed.
  - getSnapshotIndex
```
long getSnapshotIndex()
```
    返回:
    
    the index of the latest snapshot.
  - getFlushIndex
```
long getFlushIndex()
```
    返回:
    
    the index of the last entry that has been flushed to the local storage.
  - getLastEntryTermIndex
```
TermIndex getLastEntryTermIndex()
```
    返回:
    
    the TermIndex of the last log entry.
  - getRaftLogMetrics
```
RaftLogMetrics getRaftLogMetrics()
```
    返回:
    
    the RaftLogMetrics.
  - updateCommitIndex
```
boolean updateCommitIndex(long majorityIndex,
                          long currentTerm,
                          boolean isLeader)
```
    Update the commit index.
    
    参数:
    
    majorityIndex - the index that has achieved majority.
    
    currentTerm - the current term.
    
    isLeader - Is this server the leader?
    
    返回:
    
    true if commit index is changed; otherwise, return false.
  - updateSnapshotIndex
```
void updateSnapshotIndex(long newSnapshotIndex)
```
    Update the snapshot index with the given index. Note that the commit index may also be changed by this update.
  - open
```
void open(long lastIndexInSnapshot,
          Consumer<org.apache.ratis.proto.RaftProtos.LogEntryProto> consumer)
   throws IOException
```
    Open this log for read and write.
    
    抛出:
    
    IOException
  - purge
```
CompletableFuture<Long> purge(long suggestedIndex)
```
    Purge asynchronously the log transactions. The implementation may choose to purge an index other than the suggested index.
    
    参数:
    
    suggestedIndex - the suggested index (inclusive) to be purged.
    
    返回:
    
    the future of the actual purged log index.
  - persistMetadata
```
void persistMetadata(RaftStorageMetadata metadata)
              throws IOException
```
    Persist the given metadata.
    
    抛出:
    
    IOException
  - loadMetadata
```
RaftStorageMetadata loadMetadata()
                          throws IOException
```
    Load metadata.
    
    抛出:
    
    IOException
  - onSnapshotInstalled
```
CompletableFuture<Long> onSnapshotInstalled(long lastSnapshotIndex)
```
    A snapshot is installed so that the indices and other information of this log must be updated. This log may also purge the outdated entries.
    
    返回:
    
    the future of the actual purged log index (inclusive).
  - append
```
long append(long term,
            TransactionContext transaction)
     throws StateMachineException
```
    Append asynchronously a log entry for the given term and transaction. Used by the leader. Note that the underlying I/O operation is submitted but may not be completed when this method returns.
    
    返回:
    
    the index of the new log entry.
    
    抛出:
    
    StateMachineException
  - append
```
long append(long term,
            RaftConfiguration configuration)
```
    Append asynchronously a log entry for the given term and configuration Used by the leader. Note that the underlying I/O operation is submitted but may not be completed when this method returns.
    
    返回:
    
    the index of the new log entry.
  - appendMetadata
```
long appendMetadata(long term,
                    long commitIndex)
```
    Append asynchronously a log entry for the given term and commit index unless the given commit index is an index of a metadata entry Used by the leader. Note that the underlying I/O operation is submitted but may not be completed when this method returns.
    
    返回:
    
    the index of the new log entry if it is appended; otherwise, return INVALID_LOG_INDEX.
  - appendEntry
```
CompletableFuture<Long> appendEntry(org.apache.ratis.proto.RaftProtos.LogEntryProto entry)
```
    Append asynchronously an entry. Used by the leader and the followers.
  - appendEntry
```
default CompletableFuture<Long> appendEntry(org.apache.ratis.proto.RaftProtos.LogEntryProto entry,
                                            TransactionContext context)
```
    Append asynchronously an entry. Used by the leader.
  - append
```
@Deprecated
default List<CompletableFuture<Long>> append(org.apache.ratis.proto.RaftProtos.LogEntryProto... entries)
```
    已过时。 use append(List)
    
    The same as append(Arrays.asList(entries)).
  - append
```
List<CompletableFuture<Long>> append(List<org.apache.ratis.proto.RaftProtos.LogEntryProto> entries)
```
    Append asynchronously all the given log entries. Used by the followers. If an existing entry conflicts with a new one (same index but different terms), delete the existing entry and all entries that follow it (§5.3).
  - truncate
```
CompletableFuture<Long> truncate(long index)
```
    Truncate asynchronously the log entries till the given index (inclusively). Used by the leader and the followers.

接口 RaftLog

嵌套类概要

字段概要

方法概要

从接口继承的方法 java.io.Closeable

字段详细资料

LOG

LEAST_VALID_LOG_INDEX

INVALID_LOG_INDEX

方法详细资料

contains

getTermIndex

get

getEntryWithData

getEntries

getStartIndex

getNextIndex

getLastCommittedIndex

getSnapshotIndex

getFlushIndex

getLastEntryTermIndex

getRaftLogMetrics

updateCommitIndex

updateSnapshotIndex

open

purge

persistMetadata

loadMetadata

onSnapshotInstalled

append

append

appendMetadata

appendEntry

appendEntry

append

append

truncate