dk.netarkivet.archive.arcrepository.bitpreservation
Class FilePreservationState

java.lang.Object
  dk.netarkivet.archive.arcrepository.bitpreservation.FilePreservationState

All Implemented Interfaces:

PreservationState

public class FilePreservationState
extends java.lang.Object
implements PreservationState

This class collects the available bit preservation information for a file.
This information is the following:
1) admin information for the file for each replica and

2) the actual upload status

Constructor Summary

FilePreservationState(java.lang.String filename, ArcRepositoryEntry admindata, java.util.Map<Replica,java.util.List<java.lang.String>> checksumMap)
Create new instance of the preservation status for a file.

Method Summary

boolean	fileIsMissing(Replica replica) Check if the file is missing from a replica.
java.lang.String	getAdminChecksum() Get the MD5 checksum stored in the admin data.
java.lang.String	getAdminReplicaState(Replica replica) Get the status of the file in a replica, according to the admin data.
java.lang.String	getFilename() Get the filename, this FilePreservationState is about.
Replica	getReferenceBitarchive() Returns a reference to a bitarchive replica that contains a version of the file with the correct checksum.
java.lang.String	getReferenceCheckSum() Retrieve checksum that the majority of checksum references (replicas+admin) agree upon.
java.util.List<java.lang.String>	getReplicaChecksum(Replica replica) Get the checksum of this file in a specific replica.
java.lang.String	getUniqueChecksum(Replica r) Get a checksum that the whole replica agrees upon, or else "".
boolean	isAdminCheckSumOk() Returns true if the checksum reported by admin data is equal to the majority checksum.
boolean	isAdminDataOk() Check if the admin data reflect the actual status of the archive.
java.lang.String	toString() Returns a human-readable representation of this object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FilePreservationState

FilePreservationState(java.lang.String filename,
                      ArcRepositoryEntry admindata,
                      java.util.Map<Replica,java.util.List<java.lang.String>> checksumMap)
                throws ArgumentNotValid

Create new instance of the preservation status for a file.

Parameters:

filename - The filename to get status for

admindata - The admin data for the file

checksumMap - The map with the checksums for this file in all replicas

Throws:

ArgumentNotValid - if filename is null or empty string, or if admindata is null.

Method Detail

getReplicaChecksum

public java.util.List<java.lang.String> getReplicaChecksum(Replica replica)

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:

The file's checksum, if it is present in the replica, or "" if it either is absent or an error occurred.

getAdminChecksum

public java.lang.String getAdminChecksum()

Get the MD5 checksum stored in the admin data.

Specified by:

getAdminChecksum in interface PreservationState

Returns:

Checksum value as found in the admin data given at creation.

getAdminReplicaState

public java.lang.String getAdminReplicaState(Replica replica)

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.

isAdminDataOk

public boolean isAdminDataOk()

Check if the admin data reflect the actual status of the archive. Admin State checking: For each replica the admin state is compared to the checksum received from the replica. If no checksum is received from the replica the valid admin states are UPLOAD_STARTED and UPLOAD_FAILED. If a checksum is received from the replica the valid admin state is UPLOAD_COMPLETED Admin checksum checking: The admin checksum must match the majority of reported checksums. Notice that a valid Admin data record does NOT imply that everything is ok. Specifically a file may be missing from a replica, or the checksum of a file in a replica may be wrong.

Specified by:

isAdminDataOk in interface PreservationState

Returns:

true, if admin data match the state of the replicas, false otherwise

fileIsMissing

public boolean fileIsMissing(Replica replica)

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.

getReferenceBitarchive

public Replica getReferenceBitarchive()

Returns a reference to a bitarchive 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 replicas and admin data agree upon. If no bitarchive 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 java.lang.String getUniqueChecksum(Replica r)

Get a checksum that the whole replica agrees upon, or else "".

Specified by:

getUniqueChecksum in interface PreservationState

Parameters:

r - 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 "".

getReferenceCheckSum

public java.lang.String getReferenceCheckSum()

Retrieve checksum that the majority of checksum references (replicas+admin) agree upon.

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 java.lang.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 java.lang.Object

Returns:

Description of this object.

getFilename

public java.lang.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