org.postgresql.replication

Class LogSequenceNumber

java.lang.Object

org.postgresql.replication.LogSequenceNumber

All Implemented Interfaces:

Comparable<LogSequenceNumber>

public final class LogSequenceNumber
extends Object
implements Comparable<LogSequenceNumber>

LSN (Log Sequence Number) data which is a pointer to a location in the XLOG.

Field Summary

Fields

Modifier and Type	Field and Description
static LogSequenceNumber	INVALID_LSN Zero is used indicate an invalid pointer.

Method Summary

Methods

Modifier and Type	Method and Description
long	asLong()
String	asString()
int	compareTo(LogSequenceNumber o)
boolean	equals(Object o)
int	hashCode()
String	toString()
static LogSequenceNumber	valueOf(long value)
static LogSequenceNumber	valueOf(String strValue) Create LSN instance by string represent LSN.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

INVALID_LSN

public static final LogSequenceNumber INVALID_LSN

Zero is used indicate an invalid pointer. Bootstrap skips the first possible WAL segment, initializing the first WAL page at XLOG_SEG_SIZE, so no XLOG record can begin at zero.

Method Detail

valueOf

public static LogSequenceNumber valueOf(long value)

Parameters:

value - numeric represent position in the write-ahead log stream

Returns:

not null LSN instance

valueOf

public static LogSequenceNumber valueOf(String strValue)

Create LSN instance by string represent LSN.

Parameters:

strValue - not null string as two hexadecimal numbers of up to 8 digits each, separated by a slash. For example 16/3002D50, 0/15D68C50

Returns:

not null LSN instance where if specified string represent have not valid form INVALID_LSN

asLong

public long asLong()

Returns:

Long represent position in the write-ahead log stream

asString

public String asString()

Returns:

String represent position in the write-ahead log stream as two hexadecimal numbers of up to 8 digits each, separated by a slash. For example 16/3002D50, 0/15D68C50

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

compareTo

public int compareTo(LogSequenceNumber o)

Specified by:

compareTo in interface Comparable<LogSequenceNumber>