Package org.elasticsearch.index.seqno

Class SequenceNumbers

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

    • 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 Detail

      • LOCAL_CHECKPOINT_KEY

        public static final java.lang.String LOCAL_CHECKPOINT_KEY
        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 Detail

      • SequenceNumbers

        public SequenceNumbers()

    • Method Detail

      • 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