Package org.h2.mvstore.tx

Class CommitDecisionMaker<V>

java.lang.Object
org.h2.mvstore.MVMap.DecisionMaker<VersionedValue<V>>
org.h2.mvstore.tx.CommitDecisionMaker<V>
final class CommitDecisionMaker<V> extends MVMap.DecisionMaker<VersionedValue<V>>
Class CommitDecisionMaker makes a decision during post-commit processing about how to transform uncommitted map entry into committed one, based on undo log information.

  • Field Details

    • undoKey

      private long undoKey

    • decision

      private MVMap.Decision decision

  • Constructor Details

    • CommitDecisionMaker

      CommitDecisionMaker()

  • Method Details

    • setUndoKey

      void setUndoKey(long undoKey)

    • decide

      public MVMap.Decision decide(VersionedValue<V> existingValue, VersionedValue<V> providedValue)
      Description copied from class: MVMap.DecisionMaker
      Makes a decision about how to proceed with the update.
      Specified by:
      decide in class MVMap.DecisionMaker<VersionedValue<V>>
      Parameters:
      existingValue - value currently exists in the map
      providedValue - original input value
      Returns:
      PUT if a new value need to replace existing one or a new value to be inserted if there is none REMOVE if existing value should be deleted ABORT if update operation should be aborted or repeated later REPEAT if update operation should be repeated immediately

    • selectValue

      public <T extends VersionedValue<V>> T selectValue(T existingValue, T providedValue)
      Description copied from class: MVMap.DecisionMaker
      Provides revised value for insert/update based on original input value and value currently existing in the map. This method is only invoked after call to decide(), if it returns PUT.
      Overrides:
      selectValue in class MVMap.DecisionMaker<VersionedValue<V>>
      Type Parameters:
      T - value type
      Parameters:
      existingValue - value currently exists in the map
      providedValue - original input value
      Returns:
      value to be used by insert/update

    • reset

      public void reset()
      Description copied from class: MVMap.DecisionMaker
      Resets internal state (if any) of a this DecisionMaker to it's initial state. This method is invoked whenever concurrent update failure is encountered, so we can re-start update process.
      Overrides:
      reset in class MVMap.DecisionMaker<VersionedValue<V>>

    • toString

      public String toString()
      Overrides:
      toString in class Object