com.tangosol.persistence.AbstractPersistenceEnvironment Maven / Gradle / Ivy
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/*
* Copyright (c) 2000, 2021, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.persistence;
import com.oracle.coherence.common.base.Continuation;
import com.oracle.coherence.persistence.PersistenceException;
import com.oracle.coherence.persistence.PersistenceManager;
import com.oracle.coherence.persistence.PersistentStore;
import com.oracle.datagrid.persistence.PersistenceEnvironment;
import com.tangosol.internal.util.DaemonPool;
import com.tangosol.io.FileHelper;
import com.tangosol.io.ReadBuffer;
import com.tangosol.net.CacheFactory;
import com.tangosol.util.Base;
import com.tangosol.util.ClassHelper;
import java.io.File;
import java.io.IOException;
import java.nio.channels.FileLock;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardCopyOption;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
/**
* Abstract implementation of a ReadBuffer-based PersistentEnvironment.
*
* @author jh 2013.05.21
*/
public abstract class AbstractPersistenceEnvironment
extends Base
implements PersistenceEnvironment, PersistenceEnvironmentInfo
{
// ----- constructors ---------------------------------------------------
/**
* Create a new AbstractPersistenceEnvironment that manages a singleton
* AbstractPersistenceManager with the specified data directory and that
* creates, opens, and deletes snapshots under the specified snapshot
* directory.
*
* @param fileActive the data directory of the singleton active
* manager or null if an active manager shouldn't
* be maintained by this environment
* @param fileSnapshot the snapshot directory
* @param fileTrash an optional trash directory used for "safe"
* deletes
*
* @throws IOException if the data directory could not be created
*
* @throws IllegalArgumentException if the data, snapshot, and trash
* directories are not unique
*/
public AbstractPersistenceEnvironment(File fileActive, File fileSnapshot, File fileTrash)
throws IOException
{
if (fileActive != null && !fileActive.exists())
{
CacheFactory.log("Creating persistence active directory \""
+ fileActive.getAbsolutePath() + '"', CacheFactory.LOG_INFO);
}
f_fileActive = fileActive == null ? null : FileHelper.ensureDir(fileActive);
f_fileSnapshot = fileSnapshot;
f_fileTrash = fileTrash;
// validate that the active and snapshot directories are not the same
if (f_fileActive != null && f_fileActive.equals(f_fileSnapshot))
{
throw new IllegalArgumentException("active directory \""
+ f_fileActive
+ " \"cannot be the same as the snapshot directory");
}
// validate that the trash directory is unique as well
if (f_fileTrash != null && (f_fileTrash.equals(f_fileActive) ||
f_fileTrash.equals(f_fileSnapshot)))
{
throw new IllegalArgumentException("trash directory \""
+ f_fileTrash
+ " \"cannot be the same as the active or snapshot directory");
}
}
// ----- PersistenceEnvironment interface -------------------------------
/**
* {@inheritDoc}
*/
@Override
public synchronized PersistenceManager openActive()
{
if (f_fileActive == null)
{
return null;
}
AbstractPersistenceManager manager = m_managerActive;
if (manager == null)
{
m_managerActive = manager = openActiveInternal();
manager.setPersistenceEnvironment(this);
}
return manager;
}
/**
* {@inheritDoc}
*/
@Override
public synchronized PersistenceManager openSnapshot(String sSnapshot)
{
File fileSnapshot = new File(f_fileSnapshot, FileHelper.toFilename(sSnapshot));
if (!fileSnapshot.isDirectory())
{
return null; // unrecognized snapshot
}
AbstractPersistenceManager manager = f_mapSnapshots.get(sSnapshot);
if (manager == null)
{
manager = openSnapshotInternal(fileSnapshot, sSnapshot);
manager.setPersistenceEnvironment(this);
manager.setDaemonPool(null);
f_mapSnapshots.put(sSnapshot, manager);
}
return manager;
}
/**
* {@inheritDoc}
*/
@Override
public synchronized PersistenceManager createSnapshot(String sSnapshot,
PersistenceManager manager)
{
if (f_mapSnapshots.containsKey(sSnapshot))
{
throw new IllegalArgumentException("duplicate snapshot: " + sSnapshot);
}
// validate the snapshot name
String sFilename = FileHelper.toFilename(sSnapshot);
if (sFilename.startsWith(DELETED_PREFIX))
{
throw new IllegalArgumentException("snapshot starts with a reserved character: "
+ sSnapshot);
}
// create the snapshot directory
if (!f_fileSnapshot.exists())
{
CacheFactory.log("Creating persistence snapshot directory \""
+ f_fileSnapshot.getAbsolutePath() + '"', CacheFactory.LOG_INFO);
}
File fileSnapshot;
try
{
fileSnapshot = FileHelper.ensureDir(new File(f_fileSnapshot,
sFilename));
}
catch (IOException e)
{
throw ensurePersistenceException(e);
}
AbstractPersistenceManager snapshot = createSnapshotInternal(
fileSnapshot, sSnapshot, manager);
snapshot.setPersistenceEnvironment(this);
snapshot.setDaemonPool(null);
f_mapSnapshots.put(sSnapshot, snapshot);
return snapshot;
}
/**
* {@inheritDoc}
*/
@Override
public synchronized boolean removeSnapshot(String sSnapshot)
{
AbstractPersistenceManager manager = f_mapSnapshots.get(sSnapshot);
if (manager != null)
{
manager.release();
}
File fileSnapshot = new File(f_fileSnapshot, FileHelper.toFilename(sSnapshot));
return fileSnapshot.isDirectory() && removeSnapshotInternal(fileSnapshot, sSnapshot);
}
/**
* {@inheritDoc}
*/
@Override
public String[] listSnapshots()
{
File[] aFiles = f_fileSnapshot.listFiles(file ->
file.isDirectory() && !file.getName().startsWith(DELETED_PREFIX));
int cNames = aFiles == null ? 0 : aFiles.length;
String[] asNames = cNames == 0 ? NO_STRINGS : new String[cNames];
for (int i = 0; i < cNames; ++i)
{
asNames[i] = aFiles[i].getName();
}
return asNames;
}
/**
* {@inheritDoc}
*/
@Override
public synchronized void release()
{
AbstractPersistenceManager managerActive = m_managerActive;
if (managerActive != null)
{
managerActive.release();
}
AbstractPersistenceManager[] aSnapshots = new AbstractPersistenceManager[f_mapSnapshots.size()];
aSnapshots = f_mapSnapshots.values().toArray(aSnapshots);
for (int i = 0, c = aSnapshots.length; i < c; ++i)
{
aSnapshots[i].release();
}
}
// ----- PersistenceEnvironmentInfo interface ---------------------------
/**
* {@inheritDoc}
*/
@Override
public File getPersistenceActiveDirectory()
{
return f_fileActive;
}
/**
* {@inheritDoc}
*/
@Override
public File getPersistenceSnapshotDirectory()
{
return f_fileSnapshot;
}
/**
* {@inheritDoc}
*/
@Override
public File getPersistenceTrashDirectory()
{
return f_fileTrash;
}
/**
* {@inheritDoc}
*/
@Override
public long getPersistenceActiveSpaceUsed()
{
long cBytes = 0L;
if (m_managerActive != null && f_fileActive != null)
{
// go through each directory owned by the active manager and
// sum up the bytes used by the files in the directory
for (String sId : m_managerActive.f_mapStores.keySet())
{
File fileDir = new File(f_fileActive, sId);
cBytes += FileHelper.sizeDir(fileDir);
}
}
return cBytes;
}
// ----- helper methods -------------------------------------------------
/**
* Return a PersistenceException with the given cause. The returned
* exception is also initialized with this environment.
*
* @param eCause an optional cause
*
* @return a PersistenceException with the given cause
*/
protected PersistenceException ensurePersistenceException(Throwable eCause)
{
return ensurePersistenceException(eCause, null /*sMessage*/);
}
/**
* Return a PersistenceException with the given cause and detail message.
* The returned exception is also initialized with this environment.
*
* @param eCause an optional cause
* @param sMessage an optional detail message
*
* @return a PersistenceException with the given cause and detail message
*/
protected PersistenceException ensurePersistenceException(Throwable eCause, String sMessage)
{
PersistenceException e = CachePersistenceHelper.ensurePersistenceException(
eCause, sMessage);
e.initPersistenceEnvironment(this);
return e;
}
/**
* Called by the specified manager when it has been released.
*
* @param manager the manager that was released
*/
protected synchronized void onReleased(AbstractPersistenceManager manager)
{
if (manager == m_managerActive)
{
m_managerActive = null;
}
else
{
f_mapSnapshots.remove(manager.getName());
}
manager.setPersistenceEnvironment(null /*env*/);
}
/**
* Open the active manager.
*
* Note: this method is guaranteed to only be called by a thread that
* holds a monitor on this environment.
*
* @return the active manager
*
* @throws PersistenceException if a general persistence error occurs
*/
protected abstract AbstractPersistenceManager openActiveInternal();
/**
* Open the snapshot with the specified identifier.
*
* Note: this method is guaranteed to only be called by a thread that
* holds a monitor on this environment.
*
* @param fileSnapshot the directory of the snapshot
* @param sSnapshot the snapshot identifier
*
* @return the snapshot
*
* @throws PersistenceException if a general persistence error occurs
*/
protected abstract AbstractPersistenceManager openSnapshotInternal(File fileSnapshot,
String sSnapshot);
/**
* Create a snapshot with the specified identifier.
*
* Note: this method is guaranteed to only be called by a thread that
* holds a monitor on this environment.
*
* @param fileSnapshot the directory of the snapshot
* @param sSnapshot the snapshot identifier
* @param manager the optional manager to create a snapshot of; if
* null, an empty snapshot will be created
*
* @return the snapshot
*
* @throws PersistenceException if a general persistence error occurs
*
* @throws IllegalArgumentException if the specified manager is
* incompatible with this environment
*/
protected abstract AbstractPersistenceManager createSnapshotInternal(File fileSnapshot,
String sSnapshot, PersistenceManager manager);
/**
* Remove the snapshot with the specified identifier.
*
* Note: this method is guaranteed to only be called by a thread that
* holds a monitor on this environment.
*
* @param fileSnapshot the directory of the snapshot
* @param sSnapshot the snapshot identifier
*
* @return true if the snapshot was successfully deleted, false otherwise
*
* @throws PersistenceException if a general persistence error occurs
*/
protected boolean removeSnapshotInternal(File fileSnapshot, String sSnapshot)
{
File fileLock = new File(fileSnapshot.getParentFile(), fileSnapshot.getName() + ".lck");
FileLock lock = null;
if (fileSnapshot.exists())
{
// acquire process level lock
lock = FileHelper.lockFile(fileLock);
}
if (lock == null)
{
return false;
}
File fileDest = null;
try
{
Path pathSnapshot = fileSnapshot.toPath();
Path pathDest = null;
int nAttempt = 128;
IOException error = null;
// generate a hidden directory (hidden from snapshot listings) to move
// the snapshot to, immediately attempting to delete the directory
// Note: upon failure a destination path is occasionally re-generated
// in a *hope* to avoid some OS error, but is not necessary as
// only one process will attempt to remove a unique snapshot name
// for each shared volume thus there should be no contention
do
{
if ((nAttempt & (nAttempt - 1)) == 0) // nAttempt is a power of 2
{
pathDest = createHiddenSnapshotDirectory(fileSnapshot.getName());
fileDest = pathDest.toFile();
}
try
{
// windoze has been known to give false-negatives in windows function
// MoveFileEx, hence the compensation in the while condition
Files.move(pathSnapshot, pathDest,
StandardCopyOption.REPLACE_EXISTING);
}
catch (IOException e)
{
error = e;
}
}
while (--nAttempt > 0 &&
(!fileDest.exists() || !fileDest.isDirectory() || fileSnapshot.exists()));
if (nAttempt > 0)
{
FileHelper.deleteDir(fileDest);
}
else
{
// the move failed; last ditch attempt to remove the snapshot
FileHelper.deleteDir(fileSnapshot);
if (fileSnapshot.exists())
{
fileDest = fileSnapshot; // for logging
throw error;
}
}
}
catch (IOException e)
{
String sMsg = "Unable to remove snapshot directory " + FileHelper.getPath(fileDest) +
"; subsequent snapshot creations will not succeed with the name: " + sSnapshot + '\n' +
e + '\n' + Base.getStackTrace(e);
CacheFactory.log(sMsg, CacheFactory.LOG_ERR);
throw CachePersistenceHelper.ensurePersistenceException(e, sMsg);
}
finally
{
fileLock.delete();
FileHelper.unlockFile(lock);
}
return false;
}
/**
* Return a Path to a hidden directory within the snapshot directory that
* does not exist.
*
* @param sPrefix a prefix for the directory name
*
* @return a Path to a hidden directory within the snapshot directory that
* does not exist
*/
protected Path createHiddenSnapshotDirectory(String sPrefix)
{
Path path;
do
{
path = f_fileSnapshot.toPath().resolve(DELETED_PREFIX +
sPrefix + '-' + f_atomicRemovesCounter.incrementAndGet());
}
while (path.toFile().exists());
return path;
}
// ----- Object methods -------------------------------------------------
/**
* Return a human readable description of this AbstractPersistenceManager.
*
* @return a human readable description
*/
@Override
public String toString()
{
return ClassHelper.getSimpleName(getClass())
+ "(ActiveDirectory=" + f_fileActive
+ ", SnapshotDirectory=" + f_fileSnapshot
+ ')';
}
// ----- accessors ------------------------------------------------------
/**
* Return the optional DaemonPool used to execute tasks.
*
* @return the DaemonPool or null if one hasn't been configured
*/
public DaemonPool getDaemonPool()
{
return m_pool;
}
/**
* Configure the DaemonPool used to execute tasks.
*
* @param pool the DaemonPool
*/
public void setDaemonPool(DaemonPool pool)
{
m_pool = pool;
}
// ----- inner class ----------------------------------------------------
/**
* Continuation implementation that accepts a Throwable and throws a
* PersistenceException. If the provided Throwable is a
* PersistenceException, it is thrown as is; otherwise, a wrapper
* PersistenceException is thrown.
*/
public static class DefaultFailureContinuation
implements Continuation
{
/**
* Create a new DefaultFailureContinuation for the given exception
* source.
*
* @param oSource the object that threw the exception
*/
public DefaultFailureContinuation(Object oSource)
{
f_oSource = oSource;
}
/**
* {@inheritDoc}
*/
@Override
public void proceed(Throwable e)
{
// rethrow PersistenceException as-is
if (e instanceof PersistenceException)
{
throw(PersistenceException) e;
}
// handle abstract extensions
if (f_oSource instanceof AbstractPersistenceEnvironment)
{
throw((AbstractPersistenceEnvironment) f_oSource).ensurePersistenceException(e);
}
if (f_oSource instanceof AbstractPersistenceManager)
{
throw((AbstractPersistenceManager) f_oSource).ensurePersistenceException(e);
}
if (f_oSource instanceof AbstractPersistenceManager.AbstractPersistentStore)
{
throw((AbstractPersistenceManager.AbstractPersistentStore) f_oSource).ensurePersistenceException(e);
}
// handle custom implementations
PersistenceException ee = new PersistenceException(e);
if (f_oSource instanceof PersistenceEnvironment)
{
ee.initPersistenceEnvironment((PersistenceEnvironment) f_oSource);
}
else if (f_oSource instanceof PersistenceManager)
{
ee.initPersistenceManager((PersistenceManager) f_oSource);
}
else if (f_oSource instanceof PersistentStore)
{
ee.initPersistentStore((PersistentStore) f_oSource);
}
throw ee;
}
// ----- data members -----------------------------------------------
/**
* The exception source.
*/
private final Object f_oSource;
}
// ----- constants ------------------------------------------------------
/**
* An empty String array (by definition immutable).
*/
protected static final String[] NO_STRINGS = new String[0];
/**
* A filename prefix for deleted snapshots used to handle concurrent
* deletions.
*/
protected static final String DELETED_PREFIX = ".";
// ----- data members ---------------------------------------------------
/**
* An atomic counter counter used during {@link #removeSnapshot(String)
* snapshot removal}.
*/
protected final AtomicInteger f_atomicRemovesCounter = new AtomicInteger();
/**
* The data directory of the active persistence manager.
*/
protected final File f_fileActive;
/**
* The snapshot directory.
*/
protected final File f_fileSnapshot;
/**
* An optional trash directory.
*/
protected final File f_fileTrash;
/**
* This singleton active manager.
*/
protected AbstractPersistenceManager m_managerActive;
/**
* The map of snapshots, keyed by snapshot name.
*/
protected final Map f_mapSnapshots
= new HashMap<>();
/**
* An optional DaemonPool used to execute tasks.
*/
protected DaemonPool m_pool;
}