/*******************************************************************************
* Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.internal.helper;
import java.util.*;
import org.eclipse.persistence.exceptions.ValidationException;
/**
* Special List/Vector subclass that allows concurrent
* population of the contents while the list is in use.
* The list will allow iteration while it is still being populated
* to allow concurrent processing of the contents.
* Other API such as size that require to full contents know will wait until
* the list is notified as being complete.
* This is use to allow the rows and objects of a read-all query to be processed concurrently.
*
* @author James Sutherland
* @since OracleAS 10g TopLink (10.0.3)
*/
public class ThreadCursoredList extends Vector {
/** Store if the list is fully populated. */
protected boolean isComplete;
/** Used to throw exception that occur from the concurrent population thread. */
protected RuntimeException exception;
/**
* Construct an empty list so that its internal data array
* has size <tt>10</tt> and its standard capacity increment is zero.
*/
public ThreadCursoredList() {
this(10);
}
/**
* Construct an empty list with the specified initial capacity and
* with its capacity increment equal to zero.
*/
public ThreadCursoredList(int initialCapacity) {
this(initialCapacity, 0);
}
/**
* Construct an empty list with the specified initial capacity and
* capacity increment.
*/
public ThreadCursoredList(int initialCapacity, int capacityIncrement) {
super(0);
this.isComplete = false;
}
/**
* Add and notify any waiters that there are new elements.
*/
public synchronized void add(int index, Object element) {
super.add(index, element);
this.notifyAll();
}
/**
* Add and notify any waiters that there are new elements.
*/
public synchronized boolean add(Object element) {
boolean result = super.add(element);
notifyAll();
return result;
}
/**
* Add and notify any waiters that there are new elements.
*/
public synchronized boolean addAll(int index, Collection collection) {
boolean result = super.addAll(index, collection);
notifyAll();
return result;
}
/**
* Add and notify any waiters that there are new elements.
*/
public synchronized boolean addAll(Collection collection) {
boolean result = super.addAll(collection);
notifyAll();
return result;
}
/**
* Add and notify any waiters that there are new elements.
*/
public synchronized void addElement(Object object) {
super.addElement(object);
notifyAll();
}
/**
* First wait until complete.
*/
public synchronized void clear() {
waitUntilComplete();
super.clear();
}
/**
* First wait until complete.
*/
public synchronized Object clone() {
waitUntilComplete();
return super.clone();
}
/**
* Return if any exception that was throw from concurrent population thread.
*/
public boolean hasException() {
return exception != null;
}
/**
* Return any exception that was throw from concurrent population thread.
*/
public RuntimeException getException() {
return exception;
}
/**
* Record that the population thread hit an exception,
* that should be thrown to the processing thread on the next access.
* This also records the list and complete.
*/
public synchronized void throwException(RuntimeException exception) {
this.exception = exception;
setIsComplete(true);
}
/**
* Return if the list is complete.
* If an exception was thrown during the concurrent population throw the exception.
*/
public synchronized boolean isComplete() {
if (exception != null) {
// Set the exception to null so it is only thrown once.
RuntimeException thrownException = this.exception;
this.exception = null;
throw thrownException;
}
return isComplete;
}
/**
* Set the list complete and notify any waiters.
*/
public synchronized void setIsComplete(boolean isComplete) {
this.isComplete = isComplete;
notifyAll();
}
/**
* Wait until the list has been fully populated.
*/
public synchronized void waitUntilComplete() {
while (!isComplete()) {
try {
wait();
} catch (InterruptedException ignore) {
}
}
}
/**
* Wait until a new element has been added.
*/
public synchronized void waitUntilAdd() {
try {
wait();
} catch (InterruptedException ignore) {
}
}
/**
* If it does not contain the object must wait until it is complete.
*/
public synchronized boolean contains(Object element) {
boolean result = super.contains(element);
if ((result != true) && (!isComplete())) {
waitUntilComplete();
result = super.contains(element);
}
return result;
}
/**
* If it does not contain the object must wait until it is complete.
*/
public synchronized boolean containsAll(Collection collection) {
boolean result = super.containsAll(collection);
if ((result != true) && (!isComplete())) {
waitUntilComplete();
result = super.containsAll(collection);
}
return result;
}
/**
* First wait until complete.
*/
public synchronized void copyInto(Object[] array) {
waitUntilComplete();
super.copyInto(array);
}
/**
* If the index is beyond the size wait until complete.
*/
public synchronized Object elementAt(int index) {
Object result = super.elementAt(index);
if ((result == null) && (!isComplete())) {
waitUntilComplete();
result = super.elementAt(index);
}
return result;
}
protected int getSize() {
return super.size();
}
/**
* Allow concurrent streaming of the elements.
*/
public Enumeration elements() {
return new Enumeration() {
int count = 0;
public boolean hasMoreElements() {
synchronized (ThreadCursoredList.this) {
boolean result = count < ThreadCursoredList.this.getSize();
while ((!result) && (!isComplete())) {
waitUntilAdd();
result = count < ThreadCursoredList.this.getSize();
}
return result;
}
}
public Object nextElement() {
synchronized (ThreadCursoredList.this) {
boolean result = count < ThreadCursoredList.this.getSize();
while ((!result) && (!isComplete())) {
waitUntilAdd();
result = count < ThreadCursoredList.this.getSize();
}
if (result) {
return get(count++);
}
}
throw new NoSuchElementException("Vector Enumeration");
}
};
}
/**
* First wait until complete.
*/
public synchronized boolean equals(Object object) {
waitUntilComplete();
return super.equals(object);
}
/**
* Wait until has an element or is complete.
*/
public synchronized Object firstElement() {
while ((!isComplete()) && (super.size() < 1)) {
waitUntilAdd();
}
return super.firstElement();
}
/**
* Wait until has the element or is complete.
*/
public synchronized Object get(int index) {
while ((!isComplete()) && (super.size() < index)) {
waitUntilAdd();
}
return super.get(index);
}
/**
* First wait until complete.
*/
public synchronized int hashCode() {
waitUntilComplete();
return super.hashCode();
}
/**
* If does not contain the object wait until complete.
*/
public int indexOf(Object element) {
int result = super.indexOf(element);
if ((result == -1) && (!isComplete())) {
waitUntilComplete();
result = super.indexOf(element);
}
return result;
}
/**
* If does not contain the object wait until complete.
*/
public synchronized int indexOf(Object element, int index) {
int result = super.indexOf(element, index);
if ((result == -1) && (!isComplete())) {
waitUntilComplete();
result = super.indexOf(element, index);
}
return result;
}
/**
* Add the element a notify any waiters that there are new elements.
*/
public synchronized void insertElementAt(Object element, int index) {
super.insertElementAt(element, index);
notify();
}
/**
* If empty wait until an element has been added or is complete.
*/
public boolean isEmpty() {
boolean result = super.isEmpty();
if (result && (!isComplete())) {
waitUntilAdd();
result = super.isEmpty();
}
return result;
}
public Iterator iterator() {
return listIterator(0);
}
/**
* First wait until complete.
*/
public synchronized Object lastElement() {
waitUntilComplete();
return super.lastElement();
}
/**
* First wait until complete.
*/
public int lastIndexOf(Object element) {
waitUntilComplete();
return super.lastIndexOf(element);
}
/**
* First wait until complete.
*/
public synchronized int lastIndexOf(Object element, int index) {
waitUntilComplete();
return super.lastIndexOf(element, index);
}
public ListIterator listIterator() {
return listIterator(0);
}
/**
* Iterate while waiting at end until complete.
*/
public ListIterator listIterator(final int index) {
return new ListIterator() {
int count = index;
public boolean hasNext() {
synchronized (ThreadCursoredList.this) {
boolean result = count < ThreadCursoredList.this.getSize();
while ((!result) && (!isComplete())) {
waitUntilAdd();
result = count < ThreadCursoredList.this.getSize();
}
return result;
}
}
public Object next() {
synchronized (ThreadCursoredList.this) {
boolean result = count < ThreadCursoredList.this.getSize();
while ((!result) && (!isComplete())) {
waitUntilAdd();
result = count < ThreadCursoredList.this.getSize();
}
if (result) {
return get(count++);
}
}
throw new NoSuchElementException("Vector Iterator");
}
public void remove() {
throw ValidationException.operationNotSupported("remove");
}
public void set(Object object) {
throw ValidationException.operationNotSupported("set");
}
public void add(Object object) {
throw ValidationException.operationNotSupported("add");
}
public int previousIndex() {
return count - 1;
}
public int nextIndex() {
return count;
}
public Object previous() {
count--;
return get(count);
}
public boolean hasPrevious() {
return count > 0;
}
};
}
/**
* If index is missing wait until is there.
*/
public synchronized Object remove(int index) {
while ((!isComplete()) && (super.size() < index)) {
waitUntilAdd();
}
return super.remove(index);
}
/**
* If object is missing wait until complete.
*/
public boolean remove(Object element) {
boolean result = super.remove(element);
if ((!result) && (!isComplete())) {
waitUntilAdd();
result = super.remove(element);
}
return result;
}
/**
* First wait until complete.
*/
public synchronized boolean removeAll(Collection collection) {
waitUntilComplete();
return super.removeAll(collection);
}
/**
* First wait until complete.
*/
public synchronized void removeAllElements() {
waitUntilComplete();
super.removeAllElements();
}
/**
* If missing wait until complete.
*/
public synchronized boolean removeElement(Object element) {
boolean result = super.removeElement(element);
if ((!result) && (!isComplete())) {
waitUntilAdd();
result = super.removeElement(element);
}
return result;
}
/**
* If index is missing wait until reasched or complete.
*/
public synchronized void removeElementAt(int index) {
while ((!isComplete()) && (super.size() < index)) {
waitUntilAdd();
}
super.removeElementAt(index);
}
/**
* First wait until complete.
*/
public synchronized boolean retainAll(Collection collection) {
waitUntilComplete();
return super.retainAll(collection);
}
/**
* If index is missing wait until reached or complete.
*/
public synchronized Object set(int index, Object element) {
while ((!isComplete()) && (super.size() < index)) {
waitUntilAdd();
}
return super.set(index, element);
}
/**
* If index is missing wait until reached or complete.
*/
public synchronized void setElementAt(Object element, int index) {
while ((!isComplete()) && (super.size() < index)) {
waitUntilAdd();
}
super.setElementAt(element, index);
}
/**
* First wait until complete.
*/
public int size() {
waitUntilComplete();
return super.size();
}
/**
* If index is missing wait until reached or complete.
*/
public List subList(int fromIndex, int toIndex) {
while ((!isComplete()) && (super.size() < toIndex)) {
waitUntilAdd();
}
return super.subList(fromIndex, toIndex);
}
/**
* First wait until complete.
*/
public synchronized Object[] toArray() {
waitUntilComplete();
return super.toArray();
}
/**
* First wait until complete.
*/
public synchronized Object[] toArray(Object[] array) {
waitUntilComplete();
return super.toArray(array);
}
/**
* First wait until complete.
*/
public synchronized String toString() {
waitUntilComplete();
return super.toString();
}
/**
* First wait until complete.
*/
public synchronized void trimToSize() {
waitUntilComplete();
super.trimToSize();
}
}