Package dk.netarkivet.archive.arcrepository.bitpreservation

Class DatabasePreservationState

  • All Implemented Interfaces:
    PreservationState
    public class DatabasePreservationState
extends Object
implements PreservationState
    This class contains the preservation data based on the database data of a given filename. Contains the ReplicaFileInfos corresponding to the file.

    • Constructor Detail

      • DatabasePreservationState

        public DatabasePreservationState​(String fileName,
                                 List<ReplicaFileInfo> rfis)
                          throws ArgumentNotValid
        Constructor.
        Parameters:
        fileName - The name of the file.
        rfis - A list of the ReplicaFileInfo entries in the database for the given file.
        Throws:
        ArgumentNotValid - If the filename is null or the empty string, or if the list of ReplicaFileInfos are null or empty.

    • Method Detail

      • getReplicaChecksum

        public List<String> getReplicaChecksum​(Replica replica)
                                throws ArgumentNotValid
        Get the checksum of this file in a specific replica.
        Specified by:
        getReplicaChecksum in interface PreservationState
        Parameters:
        replica - The replica to get the checksum from.
        Returns:
        A list of the checksums for the file within the replica (only more than one if there is duplicates in a bitarchive replica). An empty list is returned if no file is present or if an error occurred.
        Throws:
        ArgumentNotValid - If the replica is null.

      • getAdminChecksum

        public String getAdminChecksum()
        Get the MD5 checksum stored in the admin data. Inherited dummy function. No admin data for database instance, thus no admin data checksum.
        Specified by:
        getAdminChecksum in interface PreservationState
        Returns:
        Checksum value as found in the admin data given at creation.

      • getAdminReplicaState

        public String getAdminReplicaState​(Replica replica)
                            throws ArgumentNotValid
        Get the status of the file in a replica, according to the admin data. This returns the status as a string for presentation purposes only.
        Specified by:
        getAdminReplicaState in interface PreservationState
        Parameters:
        replica - The replica to get status for
        Returns:
        Status that the admin data knows for this file in the replica.
        Throws:
        ArgumentNotValid - If the replica is null.

      • isAdminDataOk

        public boolean isAdminDataOk()
        INHERITED DUMMY FUNCTION!
        Specified by:
        isAdminDataOk in interface PreservationState
        Returns:
        true, since a non-existing admin.data is OK for the database instance.

      • getReferenceBitarchive

        public Replica getReferenceBitarchive()
        Returns a reference to a replica that contains a version of the file with the correct checksum.

        The correct checksum is defined as the checksum that the majority of the replica and admin data agree upon.

        If no replica exists with a correct version of the file null is returned.

        Specified by:
        getReferenceBitarchive in interface PreservationState
        Returns:
        the name of the reference replica or null if no reference exists.

      • getUniqueChecksum

        public String getUniqueChecksum​(Replica replica)
                         throws ArgumentNotValid
        Get a checksum that the whole replica agrees upon, or else "".
        Specified by:
        getUniqueChecksum in interface PreservationState
        Parameters:
        replica - A replica to get checksum for this file from
        Returns:
        The checksum for this file in the replica, if all machines that have that file agree, otherwise "". If no checksums are found, also returns "".
        Throws:
        ArgumentNotValid - If the replica is null.

      • fileIsMissing

        public boolean fileIsMissing​(Replica replica)
                      throws ArgumentNotValid
        Check if the file is missing from a replica.
        Specified by:
        fileIsMissing in interface PreservationState
        Parameters:
        replica - the replica to check
        Returns:
        true if the file is missing from the replica
        Throws:
        ArgumentNotValid - If the replica is null.

      • getReferenceCheckSum

        public String getReferenceCheckSum()
        THIS IS VOTING! Retrieve checksum that the majority of checksum references replicas agree upon.

        TODO Voting is already done by the DatabasedActiveBitPreservation. Thus replace with finding an entry with checksum-status = OK.

        Specified by:
        getReferenceCheckSum in interface PreservationState
        Returns:
        the reference checksum or "" if no majority exists

      • isAdminCheckSumOk

        public boolean isAdminCheckSumOk()
        Returns true if the checksum reported by admin data is equal to the majority checksum. If no majority checksum exists true is also returned. When this method returns false it is possible to correct the admin checksum using the majority checksum - when true is returned no better checksum exists for admin data.
        Specified by:
        isAdminCheckSumOk in interface PreservationState
        Returns:
        true, if the checksum reported by admin data is equal to the majority checksum

      • toString

        public String toString()
        Returns a human-readable representation of this object. Do not depend on this format for anything automated, as it may change at any time.
        Specified by:
        toString in interface PreservationState
        Overrides:
        toString in class Object
        Returns:
        Description of this object.

      • getFilename

        public String getFilename()
        Get the filename, this FilePreservationState is about. Needed to get at the filename given to constructor, and allow for a better datastructure.
        Specified by:
        getFilename in interface PreservationState
        Returns:
        the filename