public void init() throws BabuDBException {
// load persisted snapshots from disk
for (Entry<String, DatabaseInternal> entry :
dbs.getDatabaseManager().getDatabasesInternal().entrySet()) {
final File snapDir = new File(dbs.getConfig().getBaseDir(), entry.getKey() + "/snapshots");
if (snapDir.exists()) {
Map<String, Snapshot> snapMap = new HashMap<String, Snapshot>();
snapshotDBs.put(entry.getKey(), snapMap);
boolean compressed = entry.getValue().getLSMDB().getIndex(0).isCompressed();
boolean mmaped = entry.getValue().getLSMDB().getIndex(0).isMMapEnabled();
String[] snapshots = snapDir.list();
for (String snapName : snapshots) {
BabuDBView view =
new DiskIndexView(
snapDir + "/" + snapName, entry.getValue().getComparators(), compressed, mmaped);
snapMap.put(snapName, new Snapshot(view, dbs));
}
}
}
}
@Override
public void deletePersistentSnapshot(String dbName, String snapshotName) throws BabuDBException {
BabuDBRequestResultImpl<Object> result =
new BabuDBRequestResultImpl<Object>(dbs.getResponseManager());
dbs.getTransactionManager()
.makePersistent(
dbs.getDatabaseManager().createTransaction().deleteSnapshot(dbName, snapshotName),
result);
result.get();
}
/* (non-Javadoc)
* @see org.xtreemfs.babudb.api.SnapshotManager#createPersistentSnapshot(java.lang.String, org.xtreemfs.babudb.snapshots.SnapshotConfig)
*/
@Override
public void createPersistentSnapshot(String dbName, SnapshotConfig snap) throws BabuDBException {
// synchronously executing the request
BabuDBRequestResultImpl<Object> result =
new BabuDBRequestResultImpl<Object>(dbs.getResponseManager());
dbs.getTransactionManager()
.makePersistent(
dbs.getDatabaseManager().createTransaction().createSnapshot(dbName, snap), result);
result.get();
}
/* (non-Javadoc)
* @see org.xtreemfs.babudb.api.dev.SnapshotManagerInternal#getSnapshotDir(java.lang.String,
* java.lang.String)
*/
@Override
public String getSnapshotDir(String dbName, String snapshotName) {
return dbs.getConfig().getBaseDir()
+ dbName
+ "/"
+ SnapshotManagerImpl.SNAP_DIR
+ "/"
+ (snapshotName == null ? "" : snapshotName);
}
/* (non-Javadoc)
* @see org.xtreemfs.babudb.api.dev.SnapshotManagerInternal#snapshotComplete(java.lang.String,
* org.xtreemfs.babudb.snapshots.SnapshotConfig)
*/
@Override
public void snapshotComplete(String dbName, SnapshotConfig snap) throws BabuDBException {
// as soon as the snapshot has been completed, replace the entry in the
// snapshot DB map with a disk index-based BabuDB instance if necessary
synchronized (snapshotDBs) {
DatabaseInternal db = dbs.getDatabaseManager().getDatabase(dbName);
boolean compressed = db.getLSMDB().getIndex(0).isCompressed();
boolean mmaped = db.getLSMDB().getIndex(0).isMMapEnabled();
Snapshot s = snapshotDBs.get(dbName).get(snap.getName());
s.setView(
new DiskIndexView(
getSnapshotDir(dbName, snap.getName()),
dbs.getDatabaseManager().getDatabase(dbName).getComparators(),
compressed,
mmaped));
}
}
/* (non-Javadoc)
* @see org.xtreemfs.babudb.api.dev.SnapshotManagerInternal#deleteAllSnapshots(java.lang.String)
*/
@Override
public void deleteAllSnapshots(String dbName) throws BabuDBException {
final Map<String, Snapshot> snapMap = snapshotDBs.get(dbName);
if (snapMap != null) {
for (Entry<String, Snapshot> snap : snapMap.entrySet()) {
// shut down the view
snap.getValue().shutdown();
// if a snapshot materialization request is currently in the
// checkpointer queue, remove it
dbs.getCheckpointer().removeSnapshotMaterializationRequest(dbName, snap.getKey());
}
// remove the map entry
snapshotDBs.remove(dbName);
}
FSUtils.delTree(new File(getSnapshotDir(dbName, null)));
// no delete log entries for the snapshots are needed here, since the
// method will only be invoked when the database itself is deleted
}
/** Feed the transactionManager with the knowledge on how to handle snapshot related requests. */
private void initializeTransactionManager() {
dbs.getTransactionManager()
.registerInMemoryProcessing(
Operation.TYPE_CREATE_SNAP,
new InMemoryProcessing() {
@Override
public Object[] deserializeRequest(ReusableBuffer serialized) throws BabuDBException {
ObjectInputStream oin = null;
try {
oin = new ObjectInputStream(new ByteArrayInputStream(serialized.array()));
int dbId = oin.readInt();
SnapshotConfig snap = (SnapshotConfig) oin.readObject();
return new Object[] {dbId, snap};
} catch (Exception e) {
throw new BabuDBException(
ErrorCode.IO_ERROR,
"Could not deserialize operation of type "
+ Operation.TYPE_CREATE_SNAP
+ ", because: "
+ e.getMessage(),
e);
} finally {
try {
serialized.flip();
if (oin != null) oin.close();
} catch (IOException ioe) {
/* who cares? */
}
}
}
@Override
public OperationInternal convertToOperation(Object[] args) {
return new BabuDBTransaction.BabuDBOperation(
Operation.TYPE_CREATE_SNAP, (String) null, new Object[] {args[0], args[1]});
}
@Override
public Object process(OperationInternal operation) throws BabuDBException {
Object[] args = operation.getParams();
// parse args
int dbId = (Integer) args[0];
SnapshotConfig snap = (SnapshotConfig) args[1];
// complete arguments
if (dbId == InsertRecordGroup.DB_ID_UNKNOWN
&& operation.getDatabaseName() != null) {
dbId =
dbs.getDatabaseManager()
.getDatabase(operation.getDatabaseName())
.getLSMDB()
.getDatabaseId();
operation.updateParams(new Object[] {dbId, snap});
} else if (operation.getDatabaseName() == null) {
operation.updateDatabaseName(
dbs.getDatabaseManager().getDatabase(dbId).getName());
}
Map<String, Snapshot> snapMap = snapshotDBs.get(operation.getDatabaseName());
if (snapMap == null) {
snapMap = new HashMap<String, Snapshot>();
snapshotDBs.put(operation.getDatabaseName(), snapMap);
}
// if the snapshot already exists ...
if (snapMap.containsKey(snap.getName())) {
throw new BabuDBException(
ErrorCode.SNAP_EXISTS, "snapshot '" + snap.getName() + "' already exists");
}
snapMap.put(snap.getName(), new Snapshot(null, dbs));
// first, create new in-memory snapshots of all indices
int[] snapIds = null;
try {
dbs.getTransactionManager().lockService();
// create the snapshot
snapIds =
dbs.getDatabaseManager()
.getDatabase(dbId)
.getLSMDB()
.createSnapshot(snap.getIndices());
} catch (InterruptedException e) {
throw new BabuDBException(ErrorCode.INTERRUPTED, e.getMessage());
} finally {
dbs.getTransactionManager().unlockService();
}
// then, enqueue a snapshot materialization request in the
// checkpointer's queue
dbs.getCheckpointer()
.addSnapshotMaterializationRequest(operation.getDatabaseName(), snapIds, snap);
// as long as the snapshot has not been persisted yet, add a view on
// the current snapshot in the original database to the snapshot DB map
synchronized (snapshotDBs) {
Snapshot s = snapMap.get(snap.getName());
if (s.getView() == null) {
s.setView(new InMemoryView(dbs, operation.getDatabaseName(), snap, snapIds));
}
}
return null;
}
});
dbs.getTransactionManager()
.registerInMemoryProcessing(
Operation.TYPE_DELETE_SNAP,
new InMemoryProcessing() {
@Override
public Object[] deserializeRequest(ReusableBuffer serialized) throws BabuDBException {
byte[] payload = serialized.array();
int offs = payload[0];
String dbName = new String(payload, 1, offs);
String snapName = new String(payload, offs + 1, payload.length - offs - 1);
serialized.flip();
return new Object[] {dbName, snapName};
}
@Override
public OperationInternal convertToOperation(Object[] args) {
return new BabuDBTransaction.BabuDBOperation(
Operation.TYPE_DELETE_SNAP, (String) args[0], new Object[] {args[1]});
}
@Override
public Object process(OperationInternal operation) throws BabuDBException {
// parse args
String snapshotName = (String) operation.getParams()[0];
final Map<String, Snapshot> snapMap = snapshotDBs.get(operation.getDatabaseName());
if (snapMap == null) {
throw new BabuDBException(
ErrorCode.NO_SUCH_SNAPSHOT, "snapshot '" + snapshotName + "' does not exist");
}
final Snapshot snap = snapMap.get(snapshotName);
// if the snapshot does not exist ...
if (snap == null) {
throw new BabuDBException(
ErrorCode.NO_SUCH_SNAPSHOT, "snapshot '" + snapshotName + "' does not exist");
}
// shut down and remove the view
snap.getView().shutdown();
snapMap.remove(snapshotName);
// if a snapshot materialization request is currently in the
// checkpointer queue, remove it
dbs.getCheckpointer()
.removeSnapshotMaterializationRequest(
operation.getDatabaseName(), snapshotName);
// delete the snapshot subdirectory on disk if available
FSUtils.delTree(
new File(getSnapshotDir(operation.getDatabaseName(), snapshotName)));
return null;
}
});
}