/*
* 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
* trunk/opends/resource/legal-notices/OpenDS.LICENSE
* or https://OpenDS.dev.java.net/OpenDS.LICENSE.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at
* trunk/opends/resource/legal-notices/OpenDS.LICENSE. If applicable,
* add the following below this CDDL HEADER, with the fields enclosed
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*
*
* Copyright 2006-2009 Sun Microsystems, Inc.
* Portions Copyright 2011-2013 ForgeRock AS
*/
package org.opends.server.extensions;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import org.opends.messages.Message;
import org.opends.messages.MessageBuilder;
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.EntryCache;
import org.opends.server.api.DirectoryThread;
import org.opends.server.config.ConfigException;
import org.opends.server.core.DirectoryServer;
import org.opends.server.loggers.debug.DebugTracer;
import org.opends.server.types.Attribute;
import org.opends.server.types.CacheEntry;
import org.opends.server.types.ConfigChangeResult;
import org.opends.server.types.DebugLogLevel;
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;
import static org.opends.server.loggers.debug.DebugLogger.*;
import static org.opends.messages.ExtensionMessages.*;
/**
* 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
{
/**
* The tracer object for the debug logger.
*/
private static final DebugTracer TRACER = getTracer();
// The mapping between entry DNs and their corresponding entries.
private ConcurrentHashMap<DN,SoftReference<CacheEntry>> dnMap;
// The mapping between backend+ID and their corresponding entries.
private ConcurrentHashMap<Backend,
ConcurrentHashMap<Long,SoftReference<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 = false;
/**
* 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<DN,SoftReference<CacheEntry>>();
idMap = new ConcurrentHashMap<Backend,
ConcurrentHashMap<Long,SoftReference<CacheEntry>>>();
setExcludeFilters(new HashSet<SearchFilter>());
setIncludeFilters(new HashSet<SearchFilter>());
referenceQueue = new ReferenceQueue<CacheEntry>();
}
/**
* {@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;
ArrayList<Message> errorMessages = new ArrayList<Message>();
EntryCacheCommon.ConfigErrorHandler errorHandler =
EntryCacheCommon.getConfigErrorHandler (
EntryCacheCommon.ConfigPhase.PHASE_INIT, null, errorMessages
);
if (!processEntryCacheConfig(configuration, applyChanges, errorHandler)) {
MessageBuilder buffer = new MessageBuilder();
if (!errorMessages.isEmpty()) {
Iterator<Message> iterator = errorMessages.iterator();
buffer.append(iterator.next());
while (iterator.hasNext()) {
buffer.append(". ");
buffer.append(iterator.next());
}
}
Message message = ERR_SOFTREFCACHE_CANNOT_INITIALIZE.get(
buffer.toString());
throw new ConfigException(message);
}
}
/**
* {@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)
{
if (entryDN == null) {
return false;
}
// Indicate whether the DN map contains the specified DN.
return dnMap.containsKey(entryDN);
}
/**
* {@inheritDoc}
*/
@Override
public Entry getEntry(DN entryDN)
{
SoftReference<CacheEntry> ref = dnMap.get(entryDN);
if (ref == null)
{
// Indicate cache miss.
cacheMisses.getAndIncrement();
return null;
}
else
{
CacheEntry cacheEntry = ref.get();
if (cacheEntry == null)
{
// Indicate cache miss.
cacheMisses.getAndIncrement();
return null;
}
else
{
// Indicate cache hit.
cacheHits.getAndIncrement();
return cacheEntry.getEntry();
}
}
}
/**
* {@inheritDoc}
*/
@Override
public long getEntryID(DN entryDN)
{
SoftReference<CacheEntry> ref = dnMap.get(entryDN);
if (ref == null)
{
return -1;
}
else
{
CacheEntry cacheEntry = ref.get();
if (cacheEntry == null)
{
return -1;
}
else
{
return cacheEntry.getEntryID();
}
}
}
/**
* {@inheritDoc}
*/
@Override
public DN getEntryDN(Backend backend, long entryID)
{
// Locate specific backend map and return the entry DN by ID.
ConcurrentHashMap<Long,SoftReference<CacheEntry>>
backendMap = idMap.get(backend);
if (backendMap != null) {
SoftReference<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, Backend backend, long entryID)
{
// Create the cache entry based on the provided information.
CacheEntry cacheEntry = new CacheEntry(entry, backend, entryID);
SoftReference<CacheEntry> ref =
new SoftReference<CacheEntry>(cacheEntry, referenceQueue);
SoftReference<CacheEntry> oldRef = dnMap.put(entry.getDN(), ref);
if (oldRef != null)
{
oldRef.clear();
}
ConcurrentHashMap<Long,SoftReference<CacheEntry>> map = idMap.get(backend);
if (map == null)
{
map = new ConcurrentHashMap<Long,SoftReference<CacheEntry>>();
map.put(entryID, ref);
idMap.put(backend, map);
}
else
{
oldRef = map.put(entryID, ref);
if (oldRef != null)
{
oldRef.clear();
}
}
}
/**
* {@inheritDoc}
*/
@Override
public boolean putEntryIfAbsent(Entry entry, Backend backend,
long entryID)
{
// See if the entry already exists. If so, then return false.
if (dnMap.containsKey(entry.getDN()))
{
return false;
}
// Create the cache entry based on the provided information.
CacheEntry cacheEntry = new CacheEntry(entry, backend, entryID);
SoftReference<CacheEntry> ref =
new SoftReference<CacheEntry>(cacheEntry, referenceQueue);
dnMap.put(entry.getDN(), ref);
ConcurrentHashMap<Long,SoftReference<CacheEntry>> map = idMap.get(backend);
if (map == null)
{
map = new ConcurrentHashMap<Long,SoftReference<CacheEntry>>();
map.put(entryID, ref);
idMap.put(backend, map);
}
else
{
map.put(entryID, ref);
}
return true;
}
/**
* {@inheritDoc}
*/
@Override
public void removeEntry(DN entryDN)
{
SoftReference<CacheEntry> ref = dnMap.remove(entryDN);
if (ref != null)
{
ref.clear();
CacheEntry cacheEntry = ref.get();
if (cacheEntry != null)
{
Backend backend = cacheEntry.getBackend();
ConcurrentHashMap<Long,SoftReference<CacheEntry>> map =
idMap.get(backend);
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(backend);
}
}
}
}
}
/**
* {@inheritDoc}
*/
@Override
public void clear()
{
dnMap.clear();
idMap.clear();
}
/**
* {@inheritDoc}
*/
@Override
public void clearBackend(Backend backend)
{
// FIXME -- Would it be better just to dump everything?
ConcurrentHashMap<Long,SoftReference<CacheEntry>> map =
idMap.remove(backend);
if (map != null)
{
for (SoftReference<CacheEntry> ref : map.values())
{
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);
}
}
/**
* {@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<Message> unacceptableReasons)
{
SoftReferenceEntryCacheCfg config =
(SoftReferenceEntryCacheCfg) configuration;
return isConfigurationChangeAcceptable(config, unacceptableReasons);
}
/**
* {@inheritDoc}
*/
@Override
public boolean isConfigurationChangeAcceptable(
SoftReferenceEntryCacheCfg configuration,
List<Message> 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;
ArrayList<Message> errorMessages = new ArrayList<Message>();
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);
}
boolean adminActionRequired = errorHandler.getIsAdminActionRequired();
ConfigChangeResult changeResult = new ConfigChangeResult(
errorHandler.getResultCode(),
adminActionRequired,
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;
HashSet<SearchFilter> newIncludeFilters = null;
HashSet<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)
{
SoftReference<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();
Backend backend = freedEntry.getBackend();
ConcurrentHashMap<Long,SoftReference<CacheEntry>> map =
idMap.get(backend);
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(backend);
}
}
}
}
}
}
catch (Exception e)
{
if (debugEnabled())
{
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
}
}
}
/**
* {@inheritDoc}
*/
@Override
public ArrayList<Attribute> getMonitorData()
{
ArrayList<Attribute> attrs = new ArrayList<Attribute>();
try {
attrs = EntryCacheCommon.getGenericMonitorData(
new Long(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,
new Long(dnMap.size()),
null
);
} catch (Exception e) {
if (debugEnabled()) {
TRACER.debugCaught(DebugLogLevel.ERROR, e);
}
}
return attrs;
}
/**
* {@inheritDoc}
*/
@Override
public Long getCacheCount()
{
return new Long(dnMap.size());
}
/**
* {@inheritDoc}
*/
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. Dont bother with copies either since this
// is SoftReference based implementation.
for(SoftReference<CacheEntry> ce : dnMap.values()) {
sb.append(ce.get().getDN().toString());
sb.append(":");
sb.append(Long.toString(ce.get().getEntryID()));
sb.append(":");
sb.append(ce.get().getBackend().getBackendID());
sb.append(ServerConstants.EOL);
}
String verboseString = sb.toString();
return (verboseString.length() > 0 ? verboseString : null);
}
}