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/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you
* may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.internal.cache;
import com.gemstone.gemfire.CancelCriterion;
import com.gemstone.gemfire.i18n.LogWriterI18n;
import com.gemstone.gemfire.internal.i18n.LocalizedStrings;
import com.gemstone.gemfire.internal.size.SingleObjectSizer;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import com.gemstone.gemfire.cache.AttributesFactory;
import com.gemstone.gemfire.cache.AttributesMutator;
import com.gemstone.gemfire.cache.Cache;
import com.gemstone.gemfire.cache.CacheClosedException;
import com.gemstone.gemfire.cache.CacheException;
import com.gemstone.gemfire.cache.CacheListener;
import com.gemstone.gemfire.cache.DataPolicy;
import com.gemstone.gemfire.cache.DiskAccessException;
import com.gemstone.gemfire.cache.DiskStore;
import com.gemstone.gemfire.cache.DiskWriteAttributes;
import com.gemstone.gemfire.cache.DiskWriteAttributesFactory;
import com.gemstone.gemfire.cache.EntryNotFoundException;
import com.gemstone.gemfire.cache.EvictionAction;
import com.gemstone.gemfire.cache.EvictionAttributes;
import com.gemstone.gemfire.cache.Region;
import com.gemstone.gemfire.cache.RegionAttributes;
import com.gemstone.gemfire.cache.RegionDestroyedException;
import com.gemstone.gemfire.cache.Scope;
import com.gemstone.gemfire.cache.util.GatewayQueueAttributes;
import com.gemstone.gemfire.distributed.GatewayCancelledException;
import com.gemstone.gemfire.internal.cache.LocalRegion.Stopper;
import com.gemstone.gemfire.internal.concurrent.AL;
import com.gemstone.gemfire.internal.concurrent.CFactory;
/**
* Class SingleWriteSingleReadRegionQueue is a
* RegionQueue implementation that expects a single thread
* putting entries into it and a single thread taking entries from it.
*
* @author Barry Oglesby
*
* @since 4.2
*/
public class SingleWriteSingleReadRegionQueue implements RegionQueue
{
/**
* The key into the Region used when taking entries from the
* queue. This value is either set when the queue is instantiated or read from
* the Region in the case where this queue takes over where a
* previous one left off.
*/
protected long _headKey = -1;
/**
* The key into the Region used when putting entries onto the
* queue. This value is either set when the queue is instantiated or read from
* the Region in the case where this queue takes over where a
* previous one left off.
*/
protected final AL _tailKey = CFactory.createAL();
protected final LinkedList _peekedIds = new LinkedList();
/**
* The name of the Region backing this queue
*/
private final String _regionName;
/**
* The name of the DiskStore to overflow this queue
*/
private final String _diskStoreName;
/**
* The name of the directory in which to store overflowed queue entries
* @deprecated as of prPersistSprint2
*/
@Deprecated
protected String _overflowDirectory;
/**
* The maximum amount of memory (MB) to allow in the queue before overflowing
* entries to disk
*/
protected int _maximumQueueMemory;
/**
* The maximum number of entries in a batch.
*/
protected int _batchSize;
/**
* Whether conflation is enabled for this queue.
*/
protected boolean _enableConflation;
/**
* Whether persistence is enabled for this queue.
*/
protected boolean _enablePersistence;
/**
* Statistics for this queue. Null if no stats.
*/
protected GatewayStats _stats;
/**
* The Region backing this queue
*/
protected Region _region;
/**
* The Map mapping the regionName->key to the queue key. This
* index allows fast updating of entries in the queue for conflation.
*/
protected Map _indexes;
/**
* The LogWriterI18n used by this queue
*/
protected LogWriterI18n _logger;
/**
* The maximum allowed key before the keys are rolled over
*/
protected static final long MAXIMUM_KEY = Long.MAX_VALUE;
/**
* Whether the Gateway queue should be no-ack instead of ack.
*/
private static final boolean NO_ACK =
Boolean.getBoolean("gemfire.gateway-queue-no-ack");
private static final String HEAD_KEY_57 = "HEAD_KEY";
private static final String TAIL_KEY_57 = "TAIL_KEY";
/**
* Constructor. This constructor forces the queue to be initialized from the
* region.
*
* @param cache
* The GemFire Cache
* @param regionName
* The name of the region on which to create the queue. A region with
* this name will be retrieved if it exists or created if it does
* not.
* @param attributes
* The GatewayQueueAttributes containing queue
* attributes like the name of the directory in which to store
* overflowed queue entries and the maximum amount of memory (MB) to
* allow
* @param listener
* A CacheListener to for the region to use
* @param stats
* a GatewayStats to record this queue's statistics in
*/
public SingleWriteSingleReadRegionQueue(Cache cache, String regionName,
GatewayQueueAttributes attributes, CacheListener listener,
GatewayStats stats) {
// The queue starts out with headKey and tailKey equal to -1 to force
// them to be initialized from the region.
this(cache, regionName, attributes, listener, stats, -1, -1);
}
public Region getRegion()
{
return this._region;
}
/**
* Constructor. This constructor lets the caller initialize the head and tail
* of the queue.
*
* @param cache
* The GemFire Cache
* @param regionName
* The name of the region on which to create the queue. A region with
* this name will be retrieved if it exists or created if it does
* not.
* @param attributes
* The GatewayQueueAttributes containing queue
* attributes like the name of the directory in which to store
* overflowed queue entries and the maximum amount of memory (MB) to
* allow in the queue before overflowing entries to disk
* @param listener
* A CacheListener to for the region to use
* @param stats
* a GatewayStats to record this queue's statistics in
* @param headKey
* The key of the head entry in the Region
* @param tailKey
* The key of the tail entry in the Region
*/
public SingleWriteSingleReadRegionQueue(Cache cache, String regionName,
GatewayQueueAttributes attributes, CacheListener listener,
GatewayStats stats, long headKey, long tailKey) {
this._logger = cache.getLoggerI18n();
this._regionName = regionName;
assert(attributes!=null);
this._diskStoreName = attributes.getDiskStoreName();
if (this._diskStoreName == null) {
this._overflowDirectory = attributes.getOverflowDirectory();
} else {
this._overflowDirectory = null;
}
this._enableConflation = attributes.getBatchConflation();
this._maximumQueueMemory = attributes.getMaximumQueueMemory();
this._batchSize = attributes.getBatchSize();
this._enablePersistence = attributes.getEnablePersistence();
this._stats = stats;
this._headKey = headKey;
this._tailKey.set(tailKey);
this._indexes = new HashMap();
initializeRegion(cache, listener);
if (this._logger.fineEnabled()) {
this._logger.fine(this + ": Contains " + size() + " elements");
}
}
public void destroy() {
getRegion().localDestroyRegion();
}
public synchronized void put(Object object) throws CacheException {
putAndGetKey(object);
}
protected long putAndGetKey(Object object) throws CacheException {
// Get the tail key
Long key = Long.valueOf(getTailKey());
// Put the object into the region at that key
this._region.put(key, object);
// Increment the tail key
//It is important that we increment the tail
//key after putting in the region, this is the
//signal that a new object is available.
incrementTailKey();
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Inserted " + key + "->" + object);
}
if (object instanceof Conflatable) {
removeOldEntry((Conflatable)object, key);
}
return key.longValue();
}
public synchronized Object take() throws CacheException
{
resetLastPeeked();
Object object = peekAhead();
// If it is not null, destroy it and increment the head key
if (object != null) {
Long key = this._peekedIds.getLast();
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Retrieved " + key + "->" + object);
}
// Remove the entry at that key with a callback arg signifying it is
// a WAN queue so that AbstractRegionEntry.destroy can get the value
// even if it has been evicted to disk. In the normal case, the
// AbstractRegionEntry.destroy only gets the value in the VM.
this._region.destroy(key, WAN_QUEUE_TOKEN);
updateHeadKey(key.longValue());
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Destroyed " + key + "->" + object);
}
}
return object;
}
public List take(int batchSize) throws CacheException
{
List batch = new ArrayList(batchSize * 2);
for (int i = 0; i < batchSize; i++) {
Object obj = take();
if (obj != null) {
batch.add(obj);
}
else {
break;
}
}
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Took a batch of " + batch.size()
+ " entries");
}
return batch;
}
/**
* This method removes the last entry. However, it will
* only let the user remove entries that they have peeked.
* If the entry was not peeked, this method will silently
* return.
*/
public synchronized void remove() throws CacheException
{
if(this._peekedIds.isEmpty()) {
return;
}
Long key = this._peekedIds.removeFirst();
try {
removeIndex(key);
// Remove the entry at that key with a callback arg signifying it is
// a WAN queue so that AbstractRegionEntry.destroy can get the value
// even if it has been evicted to disk. In the normal case, the
// AbstractRegionEntry.destroy only gets the value in the VM.
this._region.destroy(key, WAN_QUEUE_TOKEN);
} catch(EntryNotFoundException ok) {
//this is acceptable because the conflation can remove entries
//out from underneath us.
if (this._logger.fineEnabled()) {
this._logger.fine(this + ": Did not destroy entry at " + key
+ " it was not there. It should have been removed by conflation.");
}
}
// Increment the head key
updateHeadKey(key.longValue());
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Destroyed entry at key " + key);
}
}
/**
* This method removes batchSize entries from the queue. It will
* only remove entries that were previously peeked.
* @param batchSize the number of entries to remove
*/
public void remove(int batchSize) throws CacheException
{
for (int i = 0; i < batchSize; i++) {
remove();
}
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Removed a batch of " + batchSize
+ " entries");
}
}
public Object peek() throws CacheException
{
resetLastPeeked();
Object object = peekAhead();
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peeked " + _peekedIds + "->" + object);
}
return object;
}
public List peek(int batchSize) throws CacheException
{
return peek(batchSize, -1);
}
public List peek(int batchSize, int timeToWait) throws CacheException {
return peek(0, batchSize, timeToWait);
}
public List peek(int startIndex, int batchSize, int timeToWait)
throws CacheException {
long start = System.currentTimeMillis();
long end = start + timeToWait;
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peek start time=" + start + " end time="
+ end + " time to wait=" + timeToWait);
}
List batch = new ArrayList(batchSize * 2); // why *2?
resetLastPeeked();
while(batch.size() < batchSize) {
Object object = peekAhead();
// Conflate here
if (object != null) {
batch.add(object);
}
else {
// If time to wait is -1 (don't wait) or time interval has elapsed
long currentTime = System.currentTimeMillis();
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peek current time: " + currentTime);
}
if (timeToWait == -1 || (end <= currentTime)) {
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peek breaking");
}
break;
}
else {
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peek continuing");
}
// Sleep a bit before trying again.
try {
Thread.sleep(getTimeToSleep(timeToWait));
}
catch (InterruptedException e) {
Thread.currentThread().interrupt();
break;
}
continue;
}
}
}
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peeked a batch of " + batch.size()
+ " entries");
}
return batch;
}
private long getTimeToSleep(int timeToWait) {
// Get the minimum of 50 and 5% of the time to wait (which by default is 1000 ms)
long timeToSleep = Math.min(50l, ((long) (timeToWait*0.05)));
// If it is 0, then try 50% of the time to wait
if (timeToSleep == 0) {
timeToSleep = (long) (timeToWait*0.50);
}
// If it is still 0, use the time to wait
if (timeToSleep == 0) {
timeToSleep = timeToWait;
}
return timeToSleep;
}
@Override
public String toString()
{
return "queue " + this._regionName;
}
public int size()
{
int size = ((LocalRegion)this._region).entryCount();
return size;
}
public void addCacheListener(CacheListener listener)
{
AttributesMutator mutator = this._region.getAttributesMutator();
mutator.setCacheListener(listener);
}
public void removeCacheListener()
{
AttributesMutator mutator = this._region.getAttributesMutator();
mutator.setCacheListener(null);
}
// No need to synchronize because it is called from a synchronized method
protected boolean removeOldEntry(Conflatable object, Long tailKey)
throws CacheException
{
boolean keepOldEntry = true;
//_logger.warning("Checking conflation tail key: " + tailKey + " headKey "
// + getHeadKey() + " batch size " + this._batchSize);
// Determine whether conflation is enabled for this queue and object
// Conflation is enabled iff:
// - this queue has conflation enabled
// - the object can be conflated
if (this._enableConflation && object.shouldBeConflated()) {
if (_logger.fineEnabled()) {
_logger.fine(this + ": Conflating " + object + " at queue index="
+ tailKey + " queue size=" + size() + " head=" + this._headKey
+ " tail=" + tailKey);
}
// Determine whether this region / key combination is already indexed.
// If so, it is already in the queue. Update the value in the queue and
// set the shouldAddToQueue flag accordingly.
String regionName = object.getRegionToConflate();
Object key = object.getKeyToConflate();
Map latestIndexesForRegion = (Map)this._indexes.get(regionName);
if (latestIndexesForRegion == null) {
latestIndexesForRegion = new HashMap();
this._indexes.put(regionName, latestIndexesForRegion);
}
Long previousIndex = (Long) latestIndexesForRegion.put(key, tailKey);
this._stats.incConflationIndexesMapSize();
if (_logger.fineEnabled()) {
_logger.fine(this + ": Adding index key=" + key + "->index="
+ tailKey + " for " + object + " head=" + this._headKey
+ " tail=" + tailKey);
}
// Test if the key is contained in the latest indexes map. If the key is
// not contained in the latest indexes map, then it should be added to
// the queue.
//
// It no longer matters if we remove an entry that is going out in the current
// batch, because we already put the latest value on the tail of the queue, and
// peekedIds list prevents us from removing an entry that was not peeked.
if (previousIndex != null) {
if (_logger.fineEnabled()) {
_logger
.fine(this
+ ": Indexes contains index="
+ previousIndex
+ " for key="
+ key
+ " head="
+ this._headKey
+ " tail="
+ tailKey
+ " and it can be used.");
}
keepOldEntry = false;
}
else {
if (_logger.fineEnabled()) {
_logger
.fine(this
+ ": No old entry for key="
+ key
+ " head="
+ this._headKey
+ " tail="
+ tailKey
+ " not removing old entry.");
}
keepOldEntry = true;
}
// Replace the object's value into the queue if necessary
if (!keepOldEntry) {
Conflatable previous = (Conflatable)this._region.remove(previousIndex);
if (_logger.fineEnabled()) {
_logger
.fine(this + ": Previous conflatable at key=" + previousIndex
+ " head=" + this._headKey + " tail=" + tailKey + ": "
+ previous);
_logger.fine(this + ": Current conflatable at key=" + tailKey
+ " head=" + this._headKey + " tail=" + tailKey + ": " + object);
if(previous != null) {
_logger.fine(this + ": Removed "
+ deserialize(previous.getValueToConflate()) + " and added "
+ deserialize(object.getValueToConflate()) + " for key=" + key
+ " head=" + this._headKey + " tail=" + tailKey
+ " in queue for region=" + regionName + " old event " + previous);
}
}
}
}
else {
if (_logger.fineEnabled()) {
_logger.fine(this + ": Not conflating " + object + " queue size: "
+ size() + " head=" + this._headKey + " tail=" + tailKey);
}
}
return keepOldEntry;
}
/**
* Does a get that attempts to not fault values in from disk
* or make the entry the most recent in the LRU.
*/
private Object optimalGet(Long k) {
// Get the object at that key (to remove the index).
LocalRegion lr = (LocalRegion)this._region;
Object o = null;
try {
o = lr.getValueInVM(k); // OFFHEAP deserialize
if (o == null) {
// must be on disk
// fault it in w/o putting it back in the region
o = lr.getValueOnDiskOrBuffer(k);
if (o == null) {
// try memory one more time in case it was already faulted back in
o = lr.getValueInVM(k); // OFFHEAP deserialize
if (o == null) {
// if we get this far give up and just do a get
o = lr.get(k);
} else {
if (o instanceof CachedDeserializable) {
o = ((CachedDeserializable)o).getDeserializedValue(lr, lr.getRegionEntry(k));
}
}
}
} else {
if (o instanceof CachedDeserializable) {
o = ((CachedDeserializable)o).getDeserializedValue(lr, lr.getRegionEntry(k));
}
}
} catch(EntryNotFoundException ok) {
// just return null;
}
// bug #46023 do not return a destroyed entry marker
if (o == Token.TOMBSTONE) {
o = null;
}
return o;
}
// No need to synchronize because it is called from a synchronized method
private void removeIndex(Long qkey) {
// Determine whether conflation is enabled for this queue and object
if (this._enableConflation) {
// only call get after checking enableConflation for bug 40508
Object o = optimalGet(qkey);
if (o instanceof Conflatable) {
Conflatable object = (Conflatable)o;
if (object.shouldBeConflated()) {
// Otherwise, remove the index from the indexes map.
String regionName = object.getRegionToConflate();
Object key = object.getKeyToConflate();
Map latestIndexesForRegion = (Map)this._indexes.get(regionName);
if (latestIndexesForRegion != null) {
// Remove the index.
Long index = (Long)latestIndexesForRegion.remove(key);
this._stats.decConflationIndexesMapSize();
if (_logger.fineEnabled()) {
if (index != null) {
_logger.fine(this + ": Removed index " + index + " for " + object);
}
}
}
}
}
}
}
protected Object deserialize(Object serializedBytes)
{
Object deserializedObject = serializedBytes;
if (serializedBytes instanceof byte[]) {
byte[] serializedBytesCast = (byte[])serializedBytes;
// This is a debugging method so ignore all exceptions like
// ClassNotFoundException
try {
deserializedObject = EntryEventImpl.deserialize(serializedBytesCast);
}
catch (Exception e) {
}
}
return deserializedObject;
}
/**
* returns true if key a is before key b. This
* test handles keys that have wrapped around
* @param a
* @param b
*/
private boolean before(long a, long b) {
// a is before b if a < b or a>b and a MAXIMUM_KEY/2 larger than b
// (indicating we have wrapped)
return a < b ^ a - b > (MAXIMUM_KEY / 2);
}
/**
* returns true if key a is before key b. This
* test handles keys that have wrapped around
* @param a
* @param b
*/
private boolean beforeOrEquals(long a, long b) {
return a <= b && b - a < (MAXIMUM_KEY / 2);
}
private long inc(long value) {
value++;
value = value == MAXIMUM_KEY ? 0 : value;
return value;
}
/**
* Clear the list of peeked keys. The next peek will start
* again at the head key.
*
*/
protected void resetLastPeeked() {
this._peekedIds.clear();
}
/**
* Finds the next object after the last key peeked
*
* @throws CacheException
*/
protected Object peekAhead() throws CacheException
{
Object object = null;
long currentKey = this._peekedIds.isEmpty() ? getHeadKey()
: (this._peekedIds.getLast().longValue() + 1);
//It's important here that we check where the current key
//is in relation to the tail key before we check to see if the
//object exists. The reason is that the tail key is basically
//the synchronization between this thread and the putter thread.
//The tail key will not be incremented until the object is put in the region
//If we check for the object, and then check the tail key, we could
//skip objects.
// @todo don't do a get which updates the lru, instead just get the value
// w/o modifying the LRU.
// Note: getting the serialized form here (if it has overflowed to disk)
// does not save anything since GatewayBatchOp needs to GatewayEventImpl
// in object form.
while(before(currentKey, getTailKey())
// use optimalGet here to fix bug 40654
&& (object = optimalGet(Long.valueOf(currentKey))) == null ) {
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Trying head key + offset: "
+ currentKey);
}
currentKey= inc(currentKey);
if (this._stats != null) {
this._stats.incEventsNotQueuedConflated();
}
}
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peeked " + currentKey + "->" + object);
}
if(object != null) {
this._peekedIds.addLast(Long.valueOf(currentKey));
}
return object;
}
// !!ezoerner:20090325
// Added this method for benefit of subclass SqlDDLRegionQueue,
// to get the key as well as the value
protected Object[] peekAheadGetKeyAndValue() throws CacheException {
Object object = null;
long currentKey = this._peekedIds.isEmpty() ? getHeadKey()
: (this._peekedIds.getLast().longValue() + 1);
// It's important here that we check where the current key
// is in relation to the tail key before we check to see if the
// object exists. The reason is that the tail key is basically
// the synchronization between this thread and the putter thread.
// The tail key will not be incremented until the object is put in the
// region. If we check for the object, and then check the tail key,
// we could skip objects.
while (before(currentKey, getTailKey())
&& (object = this._region.get(Long.valueOf(currentKey))) == null) {
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Trying head key + offset: " + currentKey);
}
currentKey = inc(currentKey);
if (this._stats != null) {
this._stats.incEventsNotQueuedConflated();
}
}
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Peeked " + currentKey + "->" + object);
}
if (object != null) {
this._peekedIds.addLast(Long.valueOf(currentKey));
}
return object != null ? new Object[] { currentKey, object } : null;
}
/**
* Returns the value of the tail key. The tail key points to an empty where
* the next queue entry will be stored.
*
* @return the value of the tail key
* @throws CacheException
*/
protected long getTailKey() throws CacheException
{
long tailKey;
// Test whether _tailKey = -1. If so, the queue has just been created.
// Go into the region to get the value of TAIL_KEY. If it is null, then
// this is the first attempt to access this queue. Set the _tailKey and
// tailKey appropriately (to 0). If there is a value in the region, then
// this queue has been accessed before and this instance is taking up where
// a previous one left off. Set the _tailKey to the value in the region.
// From now on, this queue will use the value of _tailKey in the VM to
// determine the tailKey. If the _tailKey != -1, set the tailKey
// to the value of the _tailKey.
initializeKeys();
tailKey = this._tailKey.get();
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Determined tail key: " + tailKey);
}
return tailKey;
}
/**
* Increments the value of the tail key by one.
*
* @throws CacheException
*/
protected void incrementTailKey() throws CacheException
{
this._tailKey.set(inc(this._tailKey.get()));
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Incremented TAIL_KEY for region "
+ this._region.getName() + " to " + this._tailKey);
}
}
/**
* If the keys are not yet initialized, initialize them from the region .
*
* TODO - We could initialize the _indexes maps at the time time
* here. However, that would require iterating over the values of the
* region rather than the keys, which could be much more expensive
* if the region has overflowed to disk.
*
* We do iterate over the values of the region in GatewayImpl at the time
* of failover. see GatewayImpl.handleFailover. So there's a possibility we
* can consolidate that code with this method and iterate over the
* region once.
*
* @throws CacheException
*/
protected void initializeKeys() throws CacheException
{
if(_tailKey.get() != -1) {
return;
}
synchronized(this) {
long largestKey = -1;
long largestKeyLessThanHalfMax = -1;
long smallestKey = -1;
long smallestKeyGreaterThanHalfMax = -1;
remove57Keys();
Set keySet = this._region.keySet();
for(Iterator itr = keySet.iterator(); itr.hasNext(); ) {
long key = ((Long) itr.next()).longValue();
if(key > largestKey) {
largestKey = key;
}
if(key > largestKeyLessThanHalfMax && key < MAXIMUM_KEY/2) {
largestKeyLessThanHalfMax = key;
}
if(key < smallestKey || smallestKey == -1) {
smallestKey = key;
}
if((key < smallestKeyGreaterThanHalfMax || smallestKeyGreaterThanHalfMax == -1) && key > MAXIMUM_KEY/2) {
smallestKeyGreaterThanHalfMax= key;
}
}
//Test to see if the current set of keys has keys that are
//both before and after we wrapped around the MAXIMUM_KEY
//If we do have keys that wrapped, the
//head key should be something close to MAXIMUM_KEY
//and the tail key should be something close to 0.
//Here, I'm guessing that the head key should be greater than MAXIMUM_KEY/2
// and the head key - tail key > MAXIMUM/2.
if (smallestKeyGreaterThanHalfMax != -1 && largestKeyLessThanHalfMax != -1
&& (smallestKeyGreaterThanHalfMax - largestKeyLessThanHalfMax) > MAXIMUM_KEY / 2) {
this._headKey = smallestKeyGreaterThanHalfMax;
this._tailKey.set(inc(largestKeyLessThanHalfMax));
if(this._logger.infoEnabled()) {
this._logger.info(LocalizedStrings.SingleWriteSingleReadRegionQueue_0_DURING_FAILOVER_DETECTED_THAT_KEYS_HAVE_WRAPPED, new Object[] {this
, this._tailKey, Long.valueOf(this._headKey)});
}
} else {
this._headKey = smallestKey == -1 ? 0 : smallestKey;
this._tailKey.set(inc(largestKey));
}
if (this._logger.fineEnabled()) {
this._logger.fine(this + " Initialized tail key to: " +
this._tailKey + ", head key to: " + this._headKey);
}
}
}
/**
* For backwards compatability, we will check for and remove the HEAD_KEY and TAIL_KEY entries
* that 57 used to keep track of the position in the queue.
*/
private void remove57Keys() {
boolean was57File = false;;
if(this._region.containsKey(HEAD_KEY_57)) {
this._region.destroy(HEAD_KEY_57);
was57File = true;
}
if(this._region.containsKey(TAIL_KEY_57)) {
this._region.destroy(TAIL_KEY_57);
was57File = true;
}
if(was57File) {
this._logger.info(LocalizedStrings.SingleWriteSingleReadRegionQueue_57_QUEUE_UPGRADED, this._regionName);
}
}
/**
* Returns the value of the head key. The head key points to the next entry to
* be removed from the queue.
*
* @return the value of the head key
* @throws CacheException
*/
protected long getHeadKey() throws CacheException
{
long headKey;
// Test whether _headKey = -1. If so, the queue has just been created.
// Go into the region to get the value of HEAD_KEY. If it is null, then
// this is the first attempt to access this queue. Set the _headKey and
// headKey appropriately (to 0). If there is a value in the region, then
// this queue has been accessed before and this instance is taking up where
// a previous one left off. Set the _headKey to the value in the region.
// From now on, this queue will use the value of _headKey in the VM to
// determine the headKey. If the _headKey != -1, set the headKey
// to the value of the _headKey.
initializeKeys();
headKey = this._headKey;
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Determined head key: " + headKey);
}
return headKey;
}
/**
* Increments the value of the head key by one.
*
* @throws CacheException
*/
protected void updateHeadKey(long destroyedKey) throws CacheException
{
this._headKey = inc(destroyedKey);
if (this._logger.finerEnabled()) {
this._logger.finer(this + ": Incremented HEAD_KEY for region "
+ this._region.getName() + " to " + this._headKey);
}
}
protected boolean isPersistent() {
return this._enablePersistence;
}
/**
* Initializes the Region backing this queue. The
* Region's scope is DISTRIBUTED_NO_ACK and mirror type is
* KEYS_VALUES and is set to overflow to disk based on the
* GatewayQueueAttributes.
*
* @param cache
* The GemFire Cache
* @param listener
* The GemFire CacheListener. The
* CacheListener can be null.
* @see com.gemstone.gemfire.cache.util.GatewayQueueAttributes
*/
protected void initializeRegion(Cache cache, CacheListener listener)
{
final GemFireCacheImpl gemCache = (GemFireCacheImpl)cache;
this._region = cache.getRegion(this._regionName);
if (this._region == null) {
AttributesFactory factory = new AttributesFactory();
// Set scope
factory.setScope(NO_ACK ? Scope.DISTRIBUTED_NO_ACK: Scope.DISTRIBUTED_ACK);
// Set persistence & replication
if (this._enablePersistence) {
factory.setDataPolicy(DataPolicy.PERSISTENT_REPLICATE);
}
else {
factory.setDataPolicy(DataPolicy.REPLICATE);
}
// Set listener if it is not null. The listener will be non-null
// when the user of this queue is a secondary VM.
if (listener != null) {
factory.setCacheListener(listener);
}
// allow for no overflow directory
// Set capacity controller to overflow to disk every
// maximumMemoryInQueue MB using the default sizer (Sizeof)
// to compute the size
EvictionAttributes ea = EvictionAttributes.createLRUMemoryAttributes(
this._maximumQueueMemory, null /* sizer */,
EvictionAction.OVERFLOW_TO_DISK);
factory.setEvictionAttributes(ea);
if (this._overflowDirectory != null && !this._overflowDirectory.equals(GatewayQueueAttributes.DEFAULT_OVERFLOW_DIRECTORY)) {
// Set disk write attributes for backward compatibility
// we might follow BSI's getAttribFactoryForClientMessagesRegion()
// to create a diskstore here
/*
* @todo: barry/greg: You might need to set time-interval and
* byte-threshold for best performance with oplogs. They default
* to 1 sec and 0 bytes.
*/
DiskWriteAttributesFactory dwaf = new DiskWriteAttributesFactory();
dwaf.setSynchronous(true); // fix for bug 37458 and 37509
dwaf.setMaxOplogSizeInBytes(GatewayImpl.QUEUE_OPLOG_SIZE);
dwaf.setRollOplogs(false); // fix for bug 40493
DiskWriteAttributes dwa = dwaf.create();
factory.setDiskWriteAttributes(dwa);
// Set overflow disk directories
File[] diskDirs = new File[1];
diskDirs[0] = new File(this._overflowDirectory);
if (!diskDirs[0].mkdirs() && !diskDirs[0].isDirectory()) {
throw new DiskAccessException("Could not create directory "
+ diskDirs[0].getAbsolutePath(), this._region);
}
// fix for bug 40731
factory.setDiskDirsAndSizes(diskDirs, new int[]{Integer.MAX_VALUE});
}
else {
factory.setDiskStoreName(this._diskStoreName);
// if persistence, we write to disk sync, if overflow, then use async
// see feature request #41479
factory.setDiskSynchronous(true/*this._enablePersistence*/);
}
// Create the region
if (this._logger.fineEnabled()) {
this._logger.fine(this + ": Attempting to create queue region: "
+ this._regionName);
}
final RegionAttributes ra = factory.createRegionAttributes();
try {
SingleReadWriteMetaRegion meta = new SingleReadWriteMetaRegion(
this._regionName, ra, null, gemCache);
try {
this._region = gemCache.createVMRegion(this._regionName, ra,
new InternalRegionArguments().setInternalMetaRegion(meta)
.setDestroyLockFlag(true).setSnapshotInputStream(null)
.setImageTarget(null));
((LocalRegion)this._region).destroyFilterProfile();
}
catch (IOException veryUnLikely) {
this._logger.severe(
LocalizedStrings.SingleWriteSingleReadRegionQueue_UNEXPECTED_EXCEPTION_DURING_INIT_OF_0,
this.getClass(), veryUnLikely);
}
catch (ClassNotFoundException alsoUnlikely) {
this._logger.severe(
LocalizedStrings.SingleWriteSingleReadRegionQueue_UNEXPECTED_EXCEPTION_DURING_INIT_OF_0,
this.getClass(), alsoUnlikely);
}
if (this._logger.fineEnabled()) {
this._logger.fine(this + ": Created queue region: " + this._region);
}
}
catch (CacheException e) {
this._logger.severe(
LocalizedStrings.SingleWriteSingleReadRegionQueue_0_THE_QUEUE_REGION_NAMED_1_COULD_NOT_BE_CREATED,
new Object[] {this, this._regionName}, e);
}
}
else {
if (this._logger.fineEnabled()) {
this._logger.fine(this + ": Retrieved queue region: " + this._region);
}
}
}
public void destroyPersistentFiles(Cache cache) {
DiskStoreImpl diskStore = (DiskStoreImpl) cache.findDiskStore(this._diskStoreName);
String region = "/" + this._regionName;
if(diskStore.getDiskInitFile().getDiskRegionByName(region) != null) {
diskStore.destroyRegion(region, true);
}
}
@Override
public void close() {
Region r = getRegion();
if (r != null && !r.isDestroyed()) {
try {
r.close();
} catch (RegionDestroyedException e) {
}
}
}
/**
* A secret meta region used whose contents
*
* @author Mitch Thomas
* @since 4.3
*/
static private class SingleReadWriteMetaRegion extends DistributedRegion
{
protected class Stopper extends CancelCriterion {
@Override
public String cancelInProgress() {
checkFailure();
GemFireCacheImpl gfc = SingleReadWriteMetaRegion.this.getCache();
assert gfc!=null;
if (gfc.closingGatewayHubsByShutdownAll) {
return "Gateway hubs are being closed by shutdownall."; // this + ": closed";
}
return gfc.getCancelCriterion().cancelInProgress();
}
/* (non-Javadoc)
* @see com.gemstone.gemfire.CancelCriterion#generateCancelledException(java.lang.Throwable)
*/
@Override
public RuntimeException generateCancelledException(Throwable e) {
String result = cancelInProgress();
return new GatewayCancelledException(result, e);
}
}
@Override
protected CancelCriterion createStopper() {
return new Stopper();
}
protected SingleReadWriteMetaRegion(String regionName,
RegionAttributes attrs, LocalRegion parentRegion, GemFireCacheImpl cache) {
super(regionName, attrs, parentRegion, cache,
new InternalRegionArguments().setDestroyLockFlag(true)
.setRecreateFlag(false).setSnapshotInputStream(null)
.setImageTarget(null));
}
@Override
protected boolean isCopyOnRead() {
return false;
}
// Prevent this region from participating in a TX, bug 38709
@Override
final public boolean isSecret() {
return true;
}
@Override
public boolean deferRecovery() {
return true;
}
//@override event tracker not needed for this type of region
@Override
public void createEventTracker() {
}
@Override
final protected boolean shouldNotifyBridgeClients()
{
return false;
}
@Override
final public boolean generateEventID()
{
return false;
}
}
@Override
public long estimateMemoryFootprint(SingleObjectSizer sizer) {
return sizer.sizeof(this) + sizer.sizeof(_peekedIds);
}
@Override
public void release() {
}
}