Class SequenceNumbers

java.lang.Object
org.elasticsearch.index.seqno.SequenceNumbers

public class SequenceNumbers
extends java.lang.Object
A utility class for handling sequence numbers.
  • Nested Class Summary

    Nested Classes
    Modifier and Type Class Description
    static class  SequenceNumbers.CommitInfo  
  • Field Summary

    Fields
    Modifier and Type Field Description
    static java.lang.String LOCAL_CHECKPOINT_KEY  
    static java.lang.String MAX_SEQ_NO  
    static long NO_OPS_PERFORMED
    Represents no operations have been performed on the shard.
    static long UNASSIGNED_PRIMARY_TERM
    Represents an unassigned primary term (e.g., when a primary shard was not yet allocated)
    static long UNASSIGNED_SEQ_NO
    Represents an unassigned sequence number (e.g., can be used on primary operations before they are executed).
  • Constructor Summary

    Constructors
    Constructor Description
    SequenceNumbers()  
  • Method Summary

    Modifier and Type Method Description
    static SequenceNumbers.CommitInfo loadSeqNoInfoFromLuceneCommit​(java.lang.Iterable<java.util.Map.Entry<java.lang.String,​java.lang.String>> commitData)
    Reads the sequence number stats from the commit data (maximum sequence number and local checkpoint).
    static long max​(long maxSeqNo, long seqNo)
    Compute the maximum of the given current maximum sequence number and the specified sequence number, accounting for the fact that the current maximum sequence number could be NO_OPS_PERFORMED or UNASSIGNED_SEQ_NO.
    static long min​(long minSeqNo, long seqNo)
    Compute the minimum of the given current minimum sequence number and the specified sequence number, accounting for the fact that the current minimum sequence number could be NO_OPS_PERFORMED or UNASSIGNED_SEQ_NO.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • LOCAL_CHECKPOINT_KEY

      public static final java.lang.String LOCAL_CHECKPOINT_KEY
      See Also:
      Constant Field Values
    • MAX_SEQ_NO

      public static final java.lang.String MAX_SEQ_NO
      See Also:
      Constant Field Values
    • UNASSIGNED_SEQ_NO

      public static final long UNASSIGNED_SEQ_NO
      Represents an unassigned sequence number (e.g., can be used on primary operations before they are executed).
      See Also:
      Constant Field Values
    • NO_OPS_PERFORMED

      public static final long NO_OPS_PERFORMED
      Represents no operations have been performed on the shard. Initial value of a sequence number.
      See Also:
      Constant Field Values
    • UNASSIGNED_PRIMARY_TERM

      public static final long UNASSIGNED_PRIMARY_TERM
      Represents an unassigned primary term (e.g., when a primary shard was not yet allocated)
      See Also:
      Constant Field Values
  • Constructor Details

    • SequenceNumbers

      public SequenceNumbers()
  • Method Details

    • loadSeqNoInfoFromLuceneCommit

      public static SequenceNumbers.CommitInfo loadSeqNoInfoFromLuceneCommit​(java.lang.Iterable<java.util.Map.Entry<java.lang.String,​java.lang.String>> commitData)
      Reads the sequence number stats from the commit data (maximum sequence number and local checkpoint).
      Parameters:
      commitData - the commit data
      Returns:
      the sequence number stats
    • min

      public static long min​(long minSeqNo, long seqNo)
      Compute the minimum of the given current minimum sequence number and the specified sequence number, accounting for the fact that the current minimum sequence number could be NO_OPS_PERFORMED or UNASSIGNED_SEQ_NO. When the current minimum sequence number is not NO_OPS_PERFORMED nor UNASSIGNED_SEQ_NO, the specified sequence number must not be UNASSIGNED_SEQ_NO.
      Parameters:
      minSeqNo - the current minimum sequence number
      seqNo - the specified sequence number
      Returns:
      the new minimum sequence number
    • max

      public static long max​(long maxSeqNo, long seqNo)
      Compute the maximum of the given current maximum sequence number and the specified sequence number, accounting for the fact that the current maximum sequence number could be NO_OPS_PERFORMED or UNASSIGNED_SEQ_NO. When the current maximum sequence number is not NO_OPS_PERFORMED nor UNASSIGNED_SEQ_NO, the specified sequence number must not be UNASSIGNED_SEQ_NO.
      Parameters:
      maxSeqNo - the current maximum sequence number
      seqNo - the specified sequence number
      Returns:
      the new maximum sequence number