Package fr.gouv.vitam.storage.offers.tape.cas

Class ArchiveCacheStorage

java.lang.Object

fr.gouv.vitam.storage.offers.tape.cas.ArchiveCacheStorage

@ThreadSafe
public class ArchiveCacheStorage
extends Object

Cache for archive storage on disk with Least Recently Used (LRU) eviction policy. Archives are stored as files on a cache directory in the following topology {cacheDirectory}/{fileBucketId}/{tarId}. Cache is configured with storage capacity thresholds : - Max storage space : max capacity that cannot be exceeded by archive cache. - An eviction storage space threshold : triggers background delete of old unused archive files. - Safe storage capacity threshold : causes background delete process to stop when enough disk space is available. Typical use would be : - reserveArchiveStorageSpace() to ensure enough disk space is available - Write data to temporary archive in a dedicated folder (different from cache directory which is managed by the cache), but on same file system partition (to ensure atomic file move is available) - moveArchiveToCache() to move atomically temporary archive to cache directory and add it to cache OR cancelReservedArchive() on failure - At any time, try read an archive from disk using the tryReadFile() method. When initialized, the cache loads all existing archive files from storage directory. This class is Thread-Safe.

Constructor Summary

Constructors

Constructor	Description
ArchiveCacheStorage(String cacheDirectory, BucketTopologyHelper bucketTopologyHelper, ArchiveCacheEvictionController archiveCacheEvictionController, long maxStorageSpace, long evictionStorageSpaceThreshold, long safeStorageSpaceThreshold)

Method Summary

Modifier and Type	Method	Description
void	cancelReservedArchive(String fileBucketId, String tarId)
boolean	containsArchive(String fileBucketId, String tarId)
long	getCurrentStorageSpaceUsage()
long	getEvictionStorageSpaceThreshold()
long	getMaxStorageSpace()
long	getSafeStorageSpaceThreshold()
boolean	isArchiveReserved(String fileBucketId, String tarId)
boolean	isCacheEvictionRunning()
void	moveArchiveToCache(Path initialFilePath, String fileBucketId, String tarId)
void	reserveArchiveStorageSpace(String fileBucketId, String tarId, long fileSize)
Optional<FileInputStream>	tryReadArchive(String fileBucketId, String tarId)

Methods inherited from class java.lang.Object

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

Constructor Details

ArchiveCacheStorage

public ArchiveCacheStorage(String cacheDirectory,
 BucketTopologyHelper bucketTopologyHelper,
 ArchiveCacheEvictionController archiveCacheEvictionController,
 long maxStorageSpace,
 long evictionStorageSpaceThreshold,
 long safeStorageSpaceThreshold)
                    throws IllegalPathException,
IOException

Parameters:

cacheDirectory - the cache storage directory

bucketTopologyHelper - bucket topology helper

archiveCacheEvictionController - controller of archive cache eviction.

maxStorageSpace - max capacity (in bytes) that cannot be exceeded by archive cache.

evictionStorageSpaceThreshold - : storage space capacity (in bytes) that triggers background delete of old unused archive files

safeStorageSpaceThreshold - safe storage space capacity level (in bytes). When enough storage space is available, background cache delete process ends.

Throws:

IllegalPathException - if provided cache directory contains unsafe or illegal archive names.

IOException - if an I/O error is thrown when accessing disk.

Method Details

reserveArchiveStorageSpace

public void reserveArchiveStorageSpace(String fileBucketId,
 String tarId,
 long fileSize)
                                throws IllegalPathException

Throws:

IllegalPathException

moveArchiveToCache

public void moveArchiveToCache(Path initialFilePath,
 String fileBucketId,
 String tarId)
                        throws IllegalPathException,
IOException

Throws:

IllegalPathException

IOException

cancelReservedArchive

public void cancelReservedArchive(String fileBucketId,
 String tarId)

tryReadArchive

public Optional<FileInputStream> tryReadArchive(String fileBucketId,
 String tarId)
                                         throws IllegalPathException

Throws:

IllegalPathException

containsArchive

public boolean containsArchive(String fileBucketId,
 String tarId)

isArchiveReserved

public boolean isArchiveReserved(String fileBucketId,
 String tarId)

getMaxStorageSpace

public long getMaxStorageSpace()

getEvictionStorageSpaceThreshold

public long getEvictionStorageSpaceThreshold()

getSafeStorageSpaceThreshold

public long getSafeStorageSpaceThreshold()

getCurrentStorageSpaceUsage

public long getCurrentStorageSpaceUsage()

isCacheEvictionRunning

public boolean isCacheEvictionRunning()