com.alipay.sofa.jraft.storage.log

类 SegmentFile

java.lang.Object

com.alipay.sofa.jraft.storage.log.SegmentFile

所有已实现的接口:

Lifecycle<SegmentFile.SegmentFileOptions>

public class SegmentFile
extends Object
implements Lifecycle<SegmentFile.SegmentFileOptions>

A fixed size file. The content format is:

   magic bytes       first log index    reserved
   [0x20 0x20]      [... 8 bytes...]   [8 bytes]

   [record, record, ...]
 

 Every record format is:
 
   Magic bytes     data length   data
   [0x57, 0x8A]    [4 bytes]     [bytes]

从以下版本开始:

1.2.6

作者:

boyan(boyan@antfin.com)

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	SegmentFile.SegmentFileOptions Segment file options.
static class	SegmentFile.SegmentHeader Segment file header.

字段概要

字段

限定符和类型	字段和说明
static int	HEADER_SIZE
static byte[]	RECORD_MAGIC_BYTES Magic bytes for data buffer.
static int	RECORD_MAGIC_BYTES_SIZE

构造器概要

构造器

构造器和说明
SegmentFile(int size, String path, ThreadPoolExecutor writeExecutor)

方法概要

限定符和类型	方法和说明
void	clear(int startPos, boolean sync) Clear data in [startPos, startPos+64).
boolean	contains(long logIndex) Returns true when the segment file contains the log index.
void	destroy() Destroy the file.
int	getWrotePos()
void	hintLoad()
void	hintUnload()
boolean	init(SegmentFile.SegmentFileOptions opts) Initialize the service.
boolean	isFull()
boolean	isSwappedOut()
boolean	reachesFileEndBy(long waitToWroteBytes)
byte[]	read(long logIndex, int pos) Read data from the position.
void	setLastLogIndex(long lastLogIndex)
void	shutdown() Dispose the resources for service.
void	swapOut()
void	sync(boolean sync) Forces any changes made to this segment file's content to be written to the storage device containing the mapped file.
String	toString()
void	truncateSuffix(int wrotePos, long logIndex, boolean sync) Truncate data from wrotePos(inclusive) to the file end and set lastLogIndex=logIndex.
int	write(long logIndex, byte[] data, RocksDBLogStorage.WriteContext ctx) Write the data and return it's wrote position.

从类继承的方法 java.lang.Object

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

字段详细资料

HEADER_SIZE

public static final int HEADER_SIZE

另请参阅:

常量字段值

RECORD_MAGIC_BYTES

public static final byte[] RECORD_MAGIC_BYTES

Magic bytes for data buffer.

RECORD_MAGIC_BYTES_SIZE

public static final int RECORD_MAGIC_BYTES_SIZE

构造器详细资料

SegmentFile

public SegmentFile(int size,
                   String path,
                   ThreadPoolExecutor writeExecutor)

方法详细资料

getWrotePos

@OnlyForTest
public int getWrotePos()

isSwappedOut

public boolean isSwappedOut()

setLastLogIndex

public void setLastLogIndex(long lastLogIndex)

hintLoad

public void hintLoad()

hintUnload

public void hintUnload()

swapOut

public void swapOut()

truncateSuffix

public void truncateSuffix(int wrotePos,
                           long logIndex,
                           boolean sync)

Truncate data from wrotePos(inclusive) to the file end and set lastLogIndex=logIndex.

参数:

wrotePos - the wrote position(inclusive)

logIndex - the log index

sync - whether to call fsync

contains

public boolean contains(long logIndex)

Returns true when the segment file contains the log index.

参数:

logIndex - the log index

返回:

true if the segment file contains the log index, otherwise return false

clear

public void clear(int startPos,
                  boolean sync)

Clear data in [startPos, startPos+64).

参数:

startPos - the start position(inclusive)

init

public boolean init(SegmentFile.SegmentFileOptions opts)

从接口复制的说明: Lifecycle

Initialize the service.

指定者:

init 在接口中 Lifecycle<SegmentFile.SegmentFileOptions>

返回:

true when successes.

reachesFileEndBy

public boolean reachesFileEndBy(long waitToWroteBytes)

isFull

public boolean isFull()

write

public int write(long logIndex,
                 byte[] data,
                 RocksDBLogStorage.WriteContext ctx)

Write the data and return it's wrote position.

参数:

logIndex - the log index

data - data to write

返回:

the wrote position

read

public byte[] read(long logIndex,
                   int pos)
            throws IOException

Read data from the position.

参数:

logIndex - the log index

pos - the position to read

返回:

read data

抛出:

IOException

sync

public void sync(boolean sync)
          throws IOException

Forces any changes made to this segment file's content to be written to the storage device containing the mapped file.

抛出:

IOException

destroy

public void destroy()

Destroy the file.

shutdown

public void shutdown()

从接口复制的说明: Lifecycle

Dispose the resources for service.

指定者:

shutdown 在接口中 Lifecycle<SegmentFile.SegmentFileOptions>

toString

public String toString()

覆盖:

toString 在类中 Object