org.hibernate.LockOptions Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2009-2012, Red Hat Inc. or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Inc.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate;
import java.io.Serializable;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
/**
* Contains locking details (LockMode, Timeout and Scope).
*
* @author Scott Marlow
*/
public class LockOptions implements Serializable {
/**
* NONE represents LockMode.NONE (timeout + scope do not apply)
*/
public static final LockOptions NONE = new LockOptions(LockMode.NONE);
/**
* READ represents LockMode.READ (timeout + scope do not apply)
*/
public static final LockOptions READ = new LockOptions(LockMode.READ);
/**
* UPGRADE represents LockMode.UPGRADE (will wait forever for lock and
* scope of false meaning only entity is locked)
*/
@SuppressWarnings("deprecation")
public static final LockOptions UPGRADE = new LockOptions(LockMode.UPGRADE);
/**
* Indicates that the database should not wait at all to acquire the pessimistic lock.
* @see #getTimeOut
*/
public static final int NO_WAIT = 0;
/**
* Indicates that there is no timeout for the acquisition.
* @see #getTimeOut
*/
public static final int WAIT_FOREVER = -1;
private LockMode lockMode = LockMode.NONE;
private int timeout = WAIT_FOREVER;
//initialize lazily as LockOptions is frequently created without needing this
private Map aliasSpecificLockModes = null;
public LockOptions() {
}
public LockOptions( LockMode lockMode) {
this.lockMode = lockMode;
}
/**
* Retrieve the overall lock mode in effect for this set of options.
*
* In certain contexts (hql and criteria), lock-modes can be defined in an
* even more granular {@link #setAliasSpecificLockMode(String, LockMode) per-alias} fashion
*
* @return The overall lock mode.
*/
public LockMode getLockMode() {
return lockMode;
}
/**
* Set the overall {@link LockMode} to be used. The default is
* {@link LockMode#NONE}
*
* @param lockMode The new overall lock mode to use.
*
* @return this (for method chaining).
*/
public LockOptions setLockMode(LockMode lockMode) {
this.lockMode = lockMode;
return this;
}
/**
* Specify the {@link LockMode} to be used for a specific query alias.
*
* @param alias used to reference the LockMode.
* @param lockMode The lock mode to apply to the given alias
* @return this LockRequest instance for operation chaining.
*
* @see Query#setLockMode(String, LockMode)
* @see Criteria#setLockMode(LockMode)
* @see Criteria#setLockMode(String, LockMode)
*/
public LockOptions setAliasSpecificLockMode(String alias, LockMode lockMode) {
if ( aliasSpecificLockModes == null ) {
aliasSpecificLockModes = new HashMap();
}
aliasSpecificLockModes.put( alias, lockMode );
return this;
}
/**
* Get the {@link LockMode} explicitly specified for the given alias via
* {@link #setAliasSpecificLockMode}
*
* Differs from {@link #getEffectiveLockMode} in that here we only return
* explicitly specified alias-specific lock modes.
*
* @param alias The alias for which to locate the explicit lock mode.
*
* @return The explicit lock mode for that alias.
*/
public LockMode getAliasSpecificLockMode(String alias) {
if ( aliasSpecificLockModes == null ) {
return null;
}
return aliasSpecificLockModes.get( alias );
}
/**
* Determine the {@link LockMode} to apply to the given alias. If no
* mode was explicitly {@link #setAliasSpecificLockMode set}, the
* {@link #getLockMode overall mode} is returned. If the overall lock mode is
* null as well, {@link LockMode#NONE} is returned.
*
* Differs from {@link #getAliasSpecificLockMode} in that here we fallback to we only return
* the overall lock mode.
*
* @param alias The alias for which to locate the effective lock mode.
*
* @return The effective lock mode.
*/
public LockMode getEffectiveLockMode(String alias) {
LockMode lockMode = getAliasSpecificLockMode( alias );
if ( lockMode == null ) {
lockMode = this.lockMode;
}
return lockMode == null ? LockMode.NONE : lockMode;
}
public boolean hasAliasSpecificLockModes() {
return aliasSpecificLockModes != null
&& ! aliasSpecificLockModes.isEmpty();
}
/**
* Get the number of aliases that have specific lock modes defined.
*
* @return the number of explicitly defined alias lock modes.
*/
public int getAliasLockCount() {
if ( aliasSpecificLockModes == null ) {
return 0;
}
return aliasSpecificLockModes.size();
}
/**
* Iterator for accessing Alias (key) and LockMode (value) as Map.Entry
*
* @return Iterator for accessing the Map.Entry's
*/
public Iterator getAliasLockIterator() {
if ( aliasSpecificLockModes == null ) {
return Collections.emptyList().iterator();
}
return aliasSpecificLockModes.entrySet().iterator();
}
/**
* Currently needed for follow-on locking
*
* @return The greatest of all requested lock modes.
*/
public LockMode findGreatestLockMode() {
LockMode lockModeToUse = getLockMode();
if ( lockModeToUse == null ) {
lockModeToUse = LockMode.NONE;
}
if ( aliasSpecificLockModes == null ) {
return lockModeToUse;
}
for ( LockMode lockMode : aliasSpecificLockModes.values() ) {
if ( lockMode.greaterThan( lockModeToUse ) ) {
lockModeToUse = lockMode;
}
}
return lockModeToUse;
}
/**
* Retrieve the current timeout setting.
*
* The timeout is the amount of time, in milliseconds, we should instruct the database
* to wait for any requested pessimistic lock acquisition.
*
* {@link #NO_WAIT} and {@link #WAIT_FOREVER} represent 2 "magic" values.
*
* @return timeout in milliseconds, or {@link #NO_WAIT} or {@link #WAIT_FOREVER}
*/
public int getTimeOut() {
return timeout;
}
/**
* Set the timeout setting.
*
* See {@link #getTimeOut} for a discussion of meaning.
*
* @param timeout The new timeout setting.
*
* @return this (for method chaining).
*
* @see #getTimeOut
*/
public LockOptions setTimeOut(int timeout) {
this.timeout = timeout;
return this;
}
private boolean scope=false;
/**
* Retrieve the current lock scope setting.
*
* "scope" is a JPA defined term. It is basically a cascading of the lock to associations.
*
* @return true if locking will be extended to owned associations
*/
public boolean getScope() {
return scope;
}
/**
* Set the cope.
*
* @param scope The new scope setting
*
* @return this (for method chaining).
*/
public LockOptions setScope(boolean scope) {
this.scope = scope;
return this;
}
/**
* Perform a shallow copy
*
* @param source Source for the copy (copied from)
* @param destination Destination for the copy (copied to)
*
* @return destination
*/
public static LockOptions copy(LockOptions source, LockOptions destination) {
destination.setLockMode( source.getLockMode() );
destination.setScope( source.getScope() );
destination.setTimeOut( source.getTimeOut() );
if ( source.aliasSpecificLockModes != null ) {
destination.aliasSpecificLockModes = new HashMap( source.aliasSpecificLockModes );
}
return destination;
}
public LockOptions makeCopy() {
LockOptions copy = new LockOptions();
copy( this, copy );
return copy;
}
}