Package 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 Details

    • 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 Details

    • 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(@Nullable 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>