/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
* or http://forgerock.org/license/CDDLv1.0.html.
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* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at legal-notices/CDDLv1_0.txt.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
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*
* Copyright 2006-2009 Sun Microsystems, Inc.
* Portions Copyright 2011-2015 ForgeRock AS
*/
package org.opends.server.extensions;
import static org.opends.messages.ExtensionMessages.*;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.forgerock.i18n.LocalizableMessage;
import org.forgerock.i18n.slf4j.LocalizedLogger;
import org.forgerock.opendj.config.server.ConfigException;
import org.forgerock.util.Utils;
import org.opends.server.admin.server.ConfigurationChangeListener;
import org.opends.server.admin.std.server.EntryCacheCfg;
import org.opends.server.admin.std.server.SoftReferenceEntryCacheCfg;
import org.opends.server.api.Backend;
import org.opends.server.api.DirectoryThread;
import org.opends.server.api.EntryCache;
import org.opends.server.core.DirectoryServer;
import org.opends.server.types.Attribute;
import org.opends.server.types.CacheEntry;
import org.forgerock.opendj.config.server.ConfigChangeResult;
import org.opends.server.types.DN;
import org.opends.server.types.Entry;
import org.opends.server.types.InitializationException;
import org.opends.server.types.SearchFilter;
import org.opends.server.util.ServerConstants;
/**
* This class defines a Directory Server entry cache that uses soft references
* to manage objects in a way that will allow them to be freed if the JVM is
* running low on memory.
*/
public class SoftReferenceEntryCache
extends EntryCache <SoftReferenceEntryCacheCfg>
implements
ConfigurationChangeListener<SoftReferenceEntryCacheCfg>,
Runnable
{
private static final LocalizedLogger logger = LocalizedLogger.getLoggerForThisClass();
/** The mapping between entry DNs and their corresponding entries. */
private ConcurrentMap<DN, Reference<CacheEntry>> dnMap;
/** The mapping between backend+ID and their corresponding entries. */
private ConcurrentMap<String, ConcurrentMap<Long, Reference<CacheEntry>>> idMap;
/**
* The reference queue that will be used to notify us whenever a soft
* reference is freed.
*/
private ReferenceQueue<CacheEntry> referenceQueue;
/** Currently registered configuration object. */
private SoftReferenceEntryCacheCfg registeredConfiguration;
private Thread cleanerThread;
private volatile boolean shutdown;
/**
* Creates a new instance of this soft reference entry cache. All
* initialization should be performed in the <CODE>initializeEntryCache</CODE>
* method.
*/
public SoftReferenceEntryCache()
{
super();
dnMap = new ConcurrentHashMap<>();
idMap = new ConcurrentHashMap<>();
setExcludeFilters(new HashSet<SearchFilter>());
setIncludeFilters(new HashSet<SearchFilter>());
referenceQueue = new ReferenceQueue<>();
}
/** {@inheritDoc} */
@Override
public void initializeEntryCache(
SoftReferenceEntryCacheCfg configuration
)
throws ConfigException, InitializationException
{
cleanerThread = new DirectoryThread(this,
"Soft Reference Entry Cache Cleaner");
cleanerThread.setDaemon(true);
cleanerThread.start();
registeredConfiguration = configuration;
configuration.addSoftReferenceChangeListener (this);
dnMap.clear();
idMap.clear();
// Read configuration and apply changes.
boolean applyChanges = true;
List<LocalizableMessage> errorMessages = new ArrayList<>();
EntryCacheCommon.ConfigErrorHandler errorHandler =
EntryCacheCommon.getConfigErrorHandler (
EntryCacheCommon.ConfigPhase.PHASE_INIT, null, errorMessages
);
if (!processEntryCacheConfig(configuration, applyChanges, errorHandler)) {
String buffer = Utils.joinAsString(". ", errorMessages);
throw new ConfigException(ERR_SOFTREFCACHE_CANNOT_INITIALIZE.get(buffer));
}
}
/** {@inheritDoc} */
@Override
public synchronized void finalizeEntryCache()
{
registeredConfiguration.removeSoftReferenceChangeListener (this);
shutdown = true;
dnMap.clear();
idMap.clear();
if (cleanerThread != null) {
for (int i = 0; cleanerThread.isAlive() && i < 5; i++) {
cleanerThread.interrupt();
try {
cleanerThread.join(10);
} catch (InterruptedException e) {
// We'll exit eventually.
}
}
cleanerThread = null;
}
}
/** {@inheritDoc} */
@Override
public boolean containsEntry(DN entryDN)
{
return entryDN != null && dnMap.containsKey(entryDN);
}
/** {@inheritDoc} */
@Override
public Entry getEntry(DN entryDN)
{
Reference<CacheEntry> ref = dnMap.get(entryDN);
if (ref == null)
{
// Indicate cache miss.
cacheMisses.getAndIncrement();
return null;
}
CacheEntry cacheEntry = ref.get();
if (cacheEntry == null)
{
// Indicate cache miss.
cacheMisses.getAndIncrement();
return null;
}
// Indicate cache hit.
cacheHits.getAndIncrement();
return cacheEntry.getEntry();
}
/** {@inheritDoc} */
@Override
public long getEntryID(DN entryDN)
{
Reference<CacheEntry> ref = dnMap.get(entryDN);
if (ref != null)
{
CacheEntry cacheEntry = ref.get();
return cacheEntry != null ? cacheEntry.getEntryID() : -1;
}
return -1;
}
/** {@inheritDoc} */
@Override
public DN getEntryDN(String backendID, long entryID)
{
// Locate specific backend map and return the entry DN by ID.
ConcurrentMap<Long, Reference<CacheEntry>> backendMap = idMap.get(backendID);
if (backendMap != null) {
Reference<CacheEntry> ref = backendMap.get(entryID);
if (ref != null) {
CacheEntry cacheEntry = ref.get();
if (cacheEntry != null) {
return cacheEntry.getDN();
}
}
}
return null;
}
/** {@inheritDoc} */
@Override
public void putEntry(Entry entry, String backendID, long entryID)
{
// Create the cache entry based on the provided information.
CacheEntry cacheEntry = new CacheEntry(entry, backendID, entryID);
Reference<CacheEntry> ref = new SoftReference<>(cacheEntry, referenceQueue);
Reference<CacheEntry> oldRef = dnMap.put(entry.getName(), ref);
if (oldRef != null)
{
oldRef.clear();
}
ConcurrentMap<Long,Reference<CacheEntry>> map = idMap.get(backendID);
if (map == null)
{
map = new ConcurrentHashMap<>();
map.put(entryID, ref);
idMap.put(backendID, map);
}
else
{
oldRef = map.put(entryID, ref);
if (oldRef != null)
{
oldRef.clear();
}
}
}
/** {@inheritDoc} */
@Override
public boolean putEntryIfAbsent(Entry entry, String backendID, long entryID)
{
// See if the entry already exists. If so, then return false.
if (dnMap.containsKey(entry.getName()))
{
return false;
}
// Create the cache entry based on the provided information.
CacheEntry cacheEntry = new CacheEntry(entry, backendID, entryID);
Reference<CacheEntry> ref = new SoftReference<>(cacheEntry, referenceQueue);
dnMap.put(entry.getName(), ref);
ConcurrentMap<Long,Reference<CacheEntry>> map = idMap.get(backendID);
if (map == null)
{
map = new ConcurrentHashMap<>();
map.put(entryID, ref);
idMap.put(backendID, map);
}
else
{
map.put(entryID, ref);
}
return true;
}
/** {@inheritDoc} */
@Override
public void removeEntry(DN entryDN)
{
Reference<CacheEntry> ref = dnMap.remove(entryDN);
if (ref != null)
{
ref.clear();
CacheEntry cacheEntry = ref.get();
if (cacheEntry != null)
{
final String backendID = cacheEntry.getBackendID();
ConcurrentMap<Long, Reference<CacheEntry>> map = idMap.get(backendID);
if (map != null)
{
ref = map.remove(cacheEntry.getEntryID());
if (ref != null)
{
ref.clear();
}
// If this backend becomes empty now remove
// it from the idMap map.
if (map.isEmpty())
{
idMap.remove(backendID);
}
}
}
}
}
/** {@inheritDoc} */
@Override
public void clear()
{
dnMap.clear();
idMap.clear();
}
/** {@inheritDoc} */
@Override
public void clearBackend(String backendID)
{
// FIXME -- Would it be better just to dump everything?
final ConcurrentMap<Long, Reference<CacheEntry>> map = idMap.remove(backendID);
if (map != null)
{
for (Reference<CacheEntry> ref : map.values())
{
final CacheEntry cacheEntry = ref.get();
if (cacheEntry != null)
{
dnMap.remove(cacheEntry.getDN());
}
ref.clear();
}
map.clear();
}
}
/** {@inheritDoc} */
@Override
public void clearSubtree(DN baseDN)
{
// Determine the backend used to hold the specified base DN and clear it.
Backend<?> backend = DirectoryServer.getBackend(baseDN);
if (backend == null)
{
// FIXME -- Should we clear everything just to be safe?
}
else
{
clearBackend(backend.getBackendID());
}
}
/** {@inheritDoc} */
@Override
public void handleLowMemory()
{
// This function should automatically be taken care of by the nature of the
// soft references used in this cache.
// FIXME -- Do we need to do anything at all here?
}
/** {@inheritDoc} */
@Override
public boolean isConfigurationAcceptable(EntryCacheCfg configuration,
List<LocalizableMessage> unacceptableReasons)
{
SoftReferenceEntryCacheCfg config =
(SoftReferenceEntryCacheCfg) configuration;
return isConfigurationChangeAcceptable(config, unacceptableReasons);
}
/** {@inheritDoc} */
@Override
public boolean isConfigurationChangeAcceptable(
SoftReferenceEntryCacheCfg configuration,
List<LocalizableMessage> unacceptableReasons)
{
boolean applyChanges = false;
EntryCacheCommon.ConfigErrorHandler errorHandler =
EntryCacheCommon.getConfigErrorHandler (
EntryCacheCommon.ConfigPhase.PHASE_ACCEPTABLE,
unacceptableReasons,
null
);
processEntryCacheConfig (configuration, applyChanges, errorHandler);
return errorHandler.getIsAcceptable();
}
/** {@inheritDoc} */
@Override
public ConfigChangeResult applyConfigurationChange(SoftReferenceEntryCacheCfg configuration)
{
boolean applyChanges = true;
List<LocalizableMessage> errorMessages = new ArrayList<>();
EntryCacheCommon.ConfigErrorHandler errorHandler =
EntryCacheCommon.getConfigErrorHandler (
EntryCacheCommon.ConfigPhase.PHASE_APPLY, null, errorMessages
);
// Do not apply changes unless this cache is enabled.
if (configuration.isEnabled()) {
processEntryCacheConfig (configuration, applyChanges, errorHandler);
}
final ConfigChangeResult changeResult = new ConfigChangeResult();
changeResult.setResultCode(errorHandler.getResultCode());
changeResult.setAdminActionRequired(errorHandler.getIsAdminActionRequired());
changeResult.getMessages().addAll(errorHandler.getErrorMessages());
return changeResult;
}
/**
* Parses the provided configuration and configure the entry cache.
*
* @param configuration The new configuration containing the changes.
* @param applyChanges If true then take into account the new configuration.
* @param errorHandler An handler used to report errors.
*
* @return <CODE>true</CODE> if configuration is acceptable,
* or <CODE>false</CODE> otherwise.
*/
public boolean processEntryCacheConfig(
SoftReferenceEntryCacheCfg configuration,
boolean applyChanges,
EntryCacheCommon.ConfigErrorHandler errorHandler
)
{
// Local variables to read configuration.
DN newConfigEntryDN;
Set<SearchFilter> newIncludeFilters = null;
Set<SearchFilter> newExcludeFilters = null;
// Read configuration.
newConfigEntryDN = configuration.dn();
// Get include and exclude filters.
switch (errorHandler.getConfigPhase())
{
case PHASE_INIT:
case PHASE_ACCEPTABLE:
case PHASE_APPLY:
newIncludeFilters = EntryCacheCommon.getFilters (
configuration.getIncludeFilter(),
ERR_CACHE_INVALID_INCLUDE_FILTER,
errorHandler,
newConfigEntryDN
);
newExcludeFilters = EntryCacheCommon.getFilters (
configuration.getExcludeFilter(),
ERR_CACHE_INVALID_EXCLUDE_FILTER,
errorHandler,
newConfigEntryDN
);
break;
}
if (applyChanges && errorHandler.getIsAcceptable())
{
setIncludeFilters(newIncludeFilters);
setExcludeFilters(newExcludeFilters);
registeredConfiguration = configuration;
}
return errorHandler.getIsAcceptable();
}
/**
* Operate in a loop, receiving notification of soft references that have been
* freed and removing the corresponding entries from the cache.
*/
@Override
public void run()
{
while (!shutdown)
{
try
{
CacheEntry freedEntry = referenceQueue.remove().get();
if (freedEntry != null)
{
Reference<CacheEntry> ref = dnMap.remove(freedEntry.getDN());
if (ref != null)
{
// Note that the entry is there, but it could be a newer version of
// the entry so we want to make sure it's the same one.
CacheEntry removedEntry = ref.get();
if (removedEntry != freedEntry)
{
dnMap.putIfAbsent(freedEntry.getDN(), ref);
}
else
{
ref.clear();
final String backendID = freedEntry.getBackendID();
final ConcurrentMap<Long, Reference<CacheEntry>> map = idMap.get(backendID);
if (map != null)
{
ref = map.remove(freedEntry.getEntryID());
if (ref != null)
{
ref.clear();
}
// If this backend becomes empty now remove
// it from the idMap map.
if (map.isEmpty()) {
idMap.remove(backendID);
}
}
}
}
}
}
catch (Exception e)
{
logger.traceException(e);
}
}
}
/** {@inheritDoc} */
@Override
public List<Attribute> getMonitorData()
{
try {
return EntryCacheCommon.getGenericMonitorData(
Long.valueOf(cacheHits.longValue()),
// If cache misses is maintained by default cache
// get it from there and if not point to itself.
DirectoryServer.getEntryCache().getCacheMisses(),
null,
null,
Long.valueOf(dnMap.size()),
null
);
} catch (Exception e) {
logger.traceException(e);
return Collections.emptyList();
}
}
/** {@inheritDoc} */
@Override
public Long getCacheCount()
{
return Long.valueOf(dnMap.size());
}
/** {@inheritDoc} */
@Override
public String toVerboseString()
{
StringBuilder sb = new StringBuilder();
// There're no locks in this cache to keep dnMap and idMap in sync.
// Examine dnMap only since its more likely to be up to date than idMap.
// Do not bother with copies either since this
// is SoftReference based implementation.
for(Reference<CacheEntry> ce : dnMap.values()) {
sb.append(ce.get().getDN());
sb.append(":");
sb.append(ce.get().getEntryID());
sb.append(":");
sb.append(ce.get().getBackendID());
sb.append(ServerConstants.EOL);
}
String verboseString = sb.toString();
return verboseString.length() > 0 ? verboseString : null;
}
}