Package org.apache.bookkeeper.bookie

Class FileInfoBackingCache.CachedFileInfo

java.lang.Object

org.apache.bookkeeper.common.util.Watchable<LastAddConfirmedUpdateNotification>

org.apache.bookkeeper.bookie.FileInfo

org.apache.bookkeeper.bookie.FileInfoBackingCache.CachedFileInfo

All Implemented Interfaces:

Recyclable

Enclosing class:

FileInfoBackingCache

class FileInfoBackingCache.CachedFileInfo
extends FileInfo

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.bookkeeper.bookie.FileInfo

FileInfo.FileInfoDeletedException

Field Summary

Fields

Modifier and Type	Field	Description
(package private) final long	ledgerId
(package private) final AtomicInteger	refCount

Fields inherited from class org.apache.bookkeeper.bookie.FileInfo

CURRENT_HEADER_VERSION, headerVersion, masterKey, mode, NO_MASTER_KEY, SIGNATURE, START_OF_DATA, STATE_FENCED_BIT, V0, V1

Constructor Summary

Constructors

Constructor	Description
CachedFileInfo(long ledgerId, File lf, byte[] masterKey)

Method Summary

Modifier and Type	Method	Description
(package private) int	getRefCount()
(package private) void	release()
String	toString()
(package private) boolean	tryRetain()	Attempt to retain the file info.

Methods inherited from class org.apache.bookkeeper.bookie.FileInfo

cancelWaitForLastAddConfirmedUpdate, checkOpen, close, delete, flushHeader, getExplicitLac, getLastAddConfirmed, getLf, getMasterKey, getSizeSinceLastWrite, isClosed, isDeleted, isFenced, isSameFile, moveToNewLocation, read, readHeader, setExplicitLac, setFenced, setLastAddConfirmed, size, waitForLastAddConfirmedUpdate, write

Methods inherited from class org.apache.bookkeeper.common.util.Watchable

addWatcher, deleteWatcher, deleteWatchers, notifyWatchers, recycle

Methods inherited from class java.lang.Object

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

Field Details

ledgerId

final long ledgerId

refCount

final AtomicInteger refCount

Constructor Details

CachedFileInfo

CachedFileInfo(long ledgerId,
 File lf,
 byte[] masterKey)
        throws IOException

Throws:

IOException

Method Details

tryRetain

boolean tryRetain()

Attempt to retain the file info. When a client obtains a fileinfo from a container object, but that container object may release the fileinfo before the client has a chance to call retain. In this case, the file info could be released and the destroyed before we ever get a chance to use it.

tryRetain avoids this problem, by doing a compare-and-swap on the reference count. If the refCount is negative, it means that the fileinfo is being cleaned up, and this fileinfo object should not be used. This works in tandem with #markDead, which will only set the refCount to negative if noone currently has it retained (i.e. the refCount is 0).

Returns:

true if we managed to increment the refcount, false otherwise

getRefCount

int getRefCount()

release

void release()

toString

public String toString()

Overrides:

toString in class Object