protected synchronized void flushToDisk() {
if (!memoryList.isEmpty() && store != null) {
long start = 0;
if (LOG.isTraceEnabled()) {
start = System.currentTimeMillis();
LOG.trace(
"{}, flushToDisk() mem list size: {} {}",
new Object[] {
name, memoryList.size(), (systemUsage != null ? systemUsage.getMemoryUsage() : "")
});
}
for (Iterator<MessageReference> iterator = memoryList.iterator(); iterator.hasNext(); ) {
MessageReference node = iterator.next();
node.decrementReferenceCount();
ByteSequence bs;
try {
bs = getByteSequence(node.getMessage());
getDiskList().addLast(node.getMessageId().toString(), bs);
} catch (IOException e) {
LOG.error("Failed to write to disk list", e);
throw new RuntimeException(e);
}
}
memoryList.clear();
setCacheEnabled(false);
LOG.trace(
"{}, flushToDisk() done - {} ms {}",
new Object[] {
name,
(System.currentTimeMillis() - start),
(systemUsage != null ? systemUsage.getMemoryUsage() : "")
});
}
}
@Override
public synchronized void destroy() throws Exception {
stop();
for (Iterator<MessageReference> i = memoryList.iterator(); i.hasNext(); ) {
MessageReference node = i.next();
node.decrementReferenceCount();
}
memoryList.clear();
destroyDiskList();
}
protected synchronized void expireOldMessages() {
if (!memoryList.isEmpty()) {
for (Iterator<MessageReference> iterator = memoryList.iterator(); iterator.hasNext(); ) {
MessageReference node = iterator.next();
if (node.isExpired()) {
node.decrementReferenceCount();
discardExpiredMessage(node);
iterator.remove();
}
}
}
}
/** @return true if there are no pending messages */
@Override
public synchronized boolean isEmpty() {
if (memoryList.isEmpty() && isDiskListEmpty()) {
return true;
}
for (Iterator<MessageReference> iterator = memoryList.iterator(); iterator.hasNext(); ) {
MessageReference node = iterator.next();
if (node == QueueMessageReference.NULL_MESSAGE) {
continue;
}
if (!node.isDropped()) {
return false;
}
// We can remove dropped references.
iterator.remove();
}
return isDiskListEmpty();
}
@Override
public synchronized boolean tryAddMessageLast(MessageReference node, long maxWaitTime)
throws Exception {
if (!node.isExpired()) {
try {
regionDestination = (Destination) node.getMessage().getRegionDestination();
if (isDiskListEmpty()) {
if (hasSpace() || this.store == null) {
memoryList.addMessageLast(node);
node.incrementReferenceCount();
setCacheEnabled(true);
return true;
}
}
if (!hasSpace()) {
if (isDiskListEmpty()) {
expireOldMessages();
if (hasSpace()) {
memoryList.addMessageLast(node);
node.incrementReferenceCount();
return true;
} else {
flushToDisk();
}
}
}
if (systemUsage.getTempUsage().waitForSpace(maxWaitTime)) {
ByteSequence bs = getByteSequence(node.getMessage());
getDiskList().addLast(node.getMessageId().toString(), bs);
return true;
}
return false;
} catch (Exception e) {
LOG.error(
"Caught an Exception adding a message: {} first to FilePendingMessageCursor ", node, e);
throw new RuntimeException(e);
}
} else {
discardExpiredMessage(node);
}
// message expired
return true;
}
/** clear all pending messages */
@Override
public synchronized void clear() {
memoryList.clear();
if (!isDiskListEmpty()) {
try {
getDiskList().destroy();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
last = null;
}
/**
* add message to await dispatch
*
* @param node
*/
@Override
public synchronized void addMessageFirst(MessageReference node) {
if (!node.isExpired()) {
try {
regionDestination = (Destination) node.getMessage().getRegionDestination();
if (isDiskListEmpty()) {
if (hasSpace()) {
memoryList.addMessageFirst(node);
node.incrementReferenceCount();
setCacheEnabled(true);
return;
}
}
if (!hasSpace()) {
if (isDiskListEmpty()) {
expireOldMessages();
if (hasSpace()) {
memoryList.addMessageFirst(node);
node.incrementReferenceCount();
return;
} else {
flushToDisk();
}
}
}
systemUsage.getTempUsage().waitForSpace();
node.decrementReferenceCount();
ByteSequence bs = getByteSequence(node.getMessage());
Object locator = getDiskList().addFirst(node.getMessageId().toString(), bs);
node.getMessageId().setPlistLocator(locator);
} catch (Exception e) {
LOG.error(
"Caught an Exception adding a message: {} first to FilePendingMessageCursor ", node, e);
throw new RuntimeException(e);
}
} else {
discardExpiredMessage(node);
}
}
/**
* @param node
* @see
* org.apache.activemq.broker.region.cursors.AbstractPendingMessageCursor#remove(org.apache.activemq.broker.region.MessageReference)
*/
@Override
public synchronized void remove(MessageReference node) {
if (memoryList.remove(node) != null) {
node.decrementReferenceCount();
}
if (!isDiskListEmpty()) {
try {
getDiskList().remove(node.getMessageId().getPlistLocator());
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
@Override
public synchronized LinkedList<MessageReference> pageInList(int maxItems) {
LinkedList<MessageReference> result = new LinkedList<MessageReference>();
int count = 0;
for (Iterator<MessageReference> i = memoryList.iterator(); i.hasNext() && count < maxItems; ) {
MessageReference ref = i.next();
ref.incrementReferenceCount();
result.add(ref);
count++;
}
if (count < maxItems && !isDiskListEmpty()) {
for (Iterator<MessageReference> i = new DiskIterator(); i.hasNext() && count < maxItems; ) {
Message message = (Message) i.next();
message.setRegionDestination(regionDestination);
message.setMemoryUsage(this.getSystemUsage().getMemoryUsage());
message.incrementReferenceCount();
result.add(message);
count++;
}
}
return result;
}
/** @return the number of pending messages */
@Override
public synchronized int size() {
return memoryList.size() + (isDiskListEmpty() ? 0 : (int) getDiskList().size());
}