com.arjuna.ats.internal.arjuna.objectstore

Class HashedStore

java.lang.Object

com.arjuna.ats.arjuna.objectstore.ObjectStore

com.arjuna.ats.internal.arjuna.objectstore.FileSystemStore

com.arjuna.ats.internal.arjuna.objectstore.ShadowingStore

com.arjuna.ats.internal.arjuna.objectstore.ShadowNoFileLockStore

com.arjuna.ats.internal.arjuna.objectstore.HashedStore

All Implemented Interfaces:

BaseStore, ObjectStoreAPI, ParticipantStore, RecoveryStore, TxLog

Direct Known Subclasses:

CacheStore, HashedActionStore

public class HashedStore
extends ShadowNoFileLockStore

The basic shadowing store implementations store the object states in a separate file within the same directory in the object store, determined by the object's type. However, as the number of file entries within the directory increases, so does the search time for finding a specific file. The HashStore implementation hashes object states over many different sub-directories to attempt to keep the number of files in a given directory low, thus improving performance as the number of object states grows.

Since:

JTS 2.0.

Version:

$Id: HashedStore.java 2342 2006-03-30 13:06:17Z $

Author:

Mark Little (mark@arjuna.com)

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_NUMBER_DIRECTORIES
static char	SHADOWCHAR

Fields inherited from class com.arjuna.ats.internal.arjuna.objectstore.ShadowingStore

HIDDINGCHAR

Fields inherited from class com.arjuna.ats.internal.arjuna.objectstore.FileSystemStore

doSync, scanZeroLengthFiles, syncWrites

Fields inherited from class com.arjuna.ats.arjuna.objectstore.ObjectStore

_objectStoreRoot, shareStatus

Constructor Summary

Constructors

Constructor and Description
HashedStore(ObjectStoreEnvironmentBean objectStoreEnvironmentBean)

Method Summary

Modifier and Type	Method and Description
boolean	allObjUids(String tName, InputObjectState state, int match) Given a type name initialise state to contains all of the Uids of objects of that type
protected String	genPathName(Uid objUid, String tName, int otype)
protected String	truncate(String value)

Methods inherited from class com.arjuna.ats.internal.arjuna.objectstore.ShadowNoFileLockStore

lock, unlock

Methods inherited from class com.arjuna.ats.internal.arjuna.objectstore.ShadowingStore

commit_state, currentState, hide_state, read_state, remove_state, reveal_state, revealedId, write_state

Methods inherited from class com.arjuna.ats.internal.arjuna.objectstore.FileSystemStore

addToCache, allTypes, allTypes, closeAndUnlock, createHierarchy, exists, getStoreName, openAndLock, read_committed, read_uncommitted, remove_committed, remove_uncommitted, removeFromCache, removeFromCache, renameFromTo, supressEntry, synchronousWrites, write_committed, write_uncommitted

Methods inherited from class com.arjuna.ats.arjuna.objectstore.ObjectStore

allObjUids, fullCommitNeeded, initialise, isType, locateStore, shareState, start, stop, storeDir, storeRoot, sync

Methods inherited from class java.lang.Object

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

Field Detail

SHADOWCHAR

public static final char SHADOWCHAR

See Also:

Constant Field Values

DEFAULT_NUMBER_DIRECTORIES

public static final int DEFAULT_NUMBER_DIRECTORIES

See Also:

Constant Field Values

Constructor Detail

HashedStore

public HashedStore(ObjectStoreEnvironmentBean objectStoreEnvironmentBean)
            throws ObjectStoreException

Throws:

ObjectStoreException

Method Detail

allObjUids

public boolean allObjUids(String tName,
                          InputObjectState state,
                          int match)
                   throws ObjectStoreException

Given a type name initialise state to contains all of the Uids of objects of that type

Specified by:

allObjUids in interface RecoveryStore

Overrides:

allObjUids in class FileSystemStore

Parameters:

tName - The type to scan for.

state - The object state in which to store the Uids

match - The file type to look for (e.g., committed, shadowed). [StateStatus]

Returns:

true if no errors occurred, false otherwise.

Throws:

ObjectStoreException

truncate

protected String truncate(String value)

Overrides:

truncate in class FileSystemStore

genPathName

protected String genPathName(Uid objUid,
                             String tName,
                             int otype)
                      throws ObjectStoreException

Overrides:

genPathName in class ShadowingStore

Returns:

the file name for the state of the object identified by the Uid and TypeName.

Throws:

ObjectStoreException