Module dk.cloudcreate.essentials.components.foundation
Package dk.cloudcreate.essentials.components.foundation.fencedlock

Interface FencedLockStorage<UOW extends UnitOfWork,LOCK extends DBFencedLock>

public interface FencedLockStorage<UOW extends UnitOfWork,LOCK extends DBFencedLock>

  • Method Details

    • initializeLockStorage

      void initializeLockStorage(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow)
      Initialize the database storage (e.g. create table, collection, etc.)
      Parameters:
      lockManager - the lock manager
      uow - the active unit of work

    • confirmLockInDB

      boolean confirmLockInDB(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow, LOCK fencedLock, OffsetDateTime confirmedTimestamp)
      Update the database status for the lock as being confirmed by this lock manager instance
      Parameters:
      lockManager - the lock manager
      uow - the active unit of work
      fencedLock - the fenced lock instance that is being confirmed
      confirmedTimestamp - the new confirmed timestamp
      Returns:
      true if the update in the DB was successful or false if we couldn't confirm the lock (e.g. because another lock manager instance had acquired the lock and updated the FencedLock.getCurrentToken() value in the DB

    • releaseLockInDB

      boolean releaseLockInDB(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow, LOCK fencedLock)
      Update the database status for the lock as being released
      Parameters:
      lockManager - the lock manager
      uow - the active unit of work
      fencedLock - the fenced lock instance that is being released
      Returns:
      true if the update in the DB was successful or false if we couldn't release the lock (e.g. because another lock manager instance had acquired the lock and updated the FencedLock.getCurrentToken() value in the DB

    • lookupLockInDB

      Optional<LOCK> lookupLockInDB(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow, LockName lockName)
      Lookup a Lock in the underlying database
      Parameters:
      lockManager - the lock manager
      uow - the active unit of work
      lockName - the name of the lock to find in the DB
      Returns:
      the result of the search

    • createUninitializedLock

      LOCK createUninitializedLock(DBFencedLockManager<UOW,LOCK> lockManager, LockName lockName)
      Create an un-initialized lock (with a default DB specific un-initialized value for the DBFencedLock.getCurrentToken())
      Parameters:
      lockManager - the lock manager
      lockName - the name of the lock
      Returns:
      the concrete DB specific DBFencedLock subclass

    • createInitializedLock

      LOCK createInitializedLock(DBFencedLockManager<UOW,LOCK> lockManager, LockName name, long currentToken, String lockedByLockManagerInstanceId, OffsetDateTime lockAcquiredTimestamp, OffsetDateTime lockLastConfirmedTimestamp)
      Create an initialized lock
      Parameters:
      lockManager - the lock manager
      name - the name of the lock
      currentToken - the current token value
      lockedByLockManagerInstanceId - the id (if any) of the local managed that has acquired the lock
      lockAcquiredTimestamp - the lock Acquired Timestamp
      lockLastConfirmedTimestamp - the lock Last Confirmed Timestamp
      Returns:
      the concrete DB specific DBFencedLock subclass

    • getUninitializedTokenValue

      Long getUninitializedTokenValue()
      Return the DB specific uninitialized value for a FencedLock.getCurrentToken() that has yet to be persisted for the very first time
      Returns:
      the DB specific uninitialized value for a FencedLock.getCurrentToken() that has yet to be persisted for the very first time

    • getInitialTokenValue

      long getInitialTokenValue()
      Return the DB specific value for a FencedLock.getCurrentToken() that is being persisted the very first time
      Returns:
      the DB specific value for a FencedLock.getCurrentToken() that is being persisted the very first time

    • insertLockIntoDB

      boolean insertLockIntoDB(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow, LOCK initialLock, OffsetDateTime lockAcquiredAndLastConfirmedTimestamp)
      Insert the local into the DB for the very first time
      Parameters:
      lockManager - the lock manager
      uow - the unit of work
      initialLock - the initial and no yet persisted lock (with no FencedLock.getCurrentToken() value set yet)
      lockAcquiredAndLastConfirmedTimestamp - the timestamp of when the lock is being acquired and last confirmed
      Returns:

    • updateLockInDB

      boolean updateLockInDB(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow, LOCK timedOutLock, LOCK newLockReadyToBeAcquiredLocally)
      Update the lock in the DB.
      Parameters:
      lockManager - the lock manager
      uow - the unit of work
      timedOutLock - the lock that has timed out
      newLockReadyToBeAcquiredLocally - the lock that was acquired by this lock manager instance
      Returns:
      true if the update in the DB was successful or false if we couldn't confirm the lock (e.g. because another lock manager instance had acquired the lock)

    • deleteLockInDB

      void deleteLockInDB(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow, LockName nameOfLockToDelete)
      Delete a lock in the DB. Should be used with caution (i.e. when you're sure that the lock is no longer used by any nodes
      Parameters:
      lockManager - the lock manager
      uow - the unit of work
      nameOfLockToDelete - the name of the lock to delete

    • deleteAllLocksInDB

      void deleteAllLocksInDB(DBFencedLockManager<UOW,LOCK> lockManager, UOW uow)
      Delete all locks in the DB. Should be used with caution and typically only for testing purposes
      Parameters:
      lockManager - the lock manager
      uow - the unit of work