@Override
public <L extends AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>>
ListenerRegistration<L> registerChangeListener(
final YangInstanceIdentifier path, final L listener, final DataChangeScope scope) {
/*
* Make sure commit is not occurring right now. Listener has to be
* registered and its state capture enqueued at a consistent point.
*
* FIXME: improve this to read-write lock, such that multiple listener
* registrations can occur simultaneously
*/
final DataChangeListenerRegistration<L> reg;
synchronized (this) {
LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
reg = listenerTree.registerDataChangeListener(path, listener, scope);
Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
if (currentState.isPresent()) {
final NormalizedNode<?, ?> data = currentState.get();
final DOMImmutableDataChangeEvent event =
DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
.setAfter(data) //
.addCreated(path, data) //
.build();
executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
}
}
return new AbstractListenerRegistration<L>(listener) {
@Override
protected void removeRegistration() {
synchronized (InMemoryDOMDataStore.this) {
reg.close();
}
}
};
}
/**
* In-memory DOM Data Store
*
* <p>Implementation of {@link DOMStore} which uses {@link DataTree} and other classes such as
* {@link SnapshotBackedWriteTransaction}. {@link SnapshotBackedReadTransaction} and {@link
* ResolveDataChangeEventsTask} to implement {@link DOMStore} contract.
*/
public class InMemoryDOMDataStore
implements DOMStore,
Identifiable<String>,
SchemaContextListener,
TransactionReadyPrototype,
AutoCloseable {
private static final Logger LOG = LoggerFactory.getLogger(InMemoryDOMDataStore.class);
private final DataTree dataTree = InMemoryDataTreeFactory.getInstance().create();
private final ListenerTree listenerTree = ListenerTree.create();
private final AtomicLong txCounter = new AtomicLong(0);
private final ListeningExecutorService executor;
private final String name;
public InMemoryDOMDataStore(final String name, final ListeningExecutorService executor) {
this.name = Preconditions.checkNotNull(name);
this.executor = Preconditions.checkNotNull(executor);
}
@Override
public final String getIdentifier() {
return name;
}
@Override
public DOMStoreReadTransaction newReadOnlyTransaction() {
return new SnapshotBackedReadTransaction(nextIdentifier(), dataTree.takeSnapshot());
}
@Override
public DOMStoreReadWriteTransaction newReadWriteTransaction() {
return new SnapshotBackedReadWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
}
@Override
public DOMStoreWriteTransaction newWriteOnlyTransaction() {
return new SnapshotBackedWriteTransaction(nextIdentifier(), dataTree.takeSnapshot(), this);
}
@Override
public DOMStoreTransactionChain createTransactionChain() {
return new DOMStoreTransactionChainImpl();
}
@Override
public synchronized void onGlobalContextUpdated(final SchemaContext ctx) {
dataTree.setSchemaContext(ctx);
}
@Override
public void close() {
executor.shutdownNow();
}
@Override
public <L extends AsyncDataChangeListener<YangInstanceIdentifier, NormalizedNode<?, ?>>>
ListenerRegistration<L> registerChangeListener(
final YangInstanceIdentifier path, final L listener, final DataChangeScope scope) {
/*
* Make sure commit is not occurring right now. Listener has to be
* registered and its state capture enqueued at a consistent point.
*
* FIXME: improve this to read-write lock, such that multiple listener
* registrations can occur simultaneously
*/
final DataChangeListenerRegistration<L> reg;
synchronized (this) {
LOG.debug("{}: Registering data change listener {} for {}", name, listener, path);
reg = listenerTree.registerDataChangeListener(path, listener, scope);
Optional<NormalizedNode<?, ?>> currentState = dataTree.takeSnapshot().readNode(path);
if (currentState.isPresent()) {
final NormalizedNode<?, ?> data = currentState.get();
final DOMImmutableDataChangeEvent event =
DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE) //
.setAfter(data) //
.addCreated(path, data) //
.build();
executor.submit(new ChangeListenerNotifyTask(Collections.singletonList(reg), event));
}
}
return new AbstractListenerRegistration<L>(listener) {
@Override
protected void removeRegistration() {
synchronized (InMemoryDOMDataStore.this) {
reg.close();
}
}
};
}
@Override
public synchronized DOMStoreThreePhaseCommitCohort ready(
final SnapshotBackedWriteTransaction writeTx) {
LOG.debug(
"Tx: {} is submitted. Modifications: {}",
writeTx.getIdentifier(),
writeTx.getMutatedView());
return new ThreePhaseCommitImpl(writeTx);
}
private Object nextIdentifier() {
return name + "-" + txCounter.getAndIncrement();
}
private class DOMStoreTransactionChainImpl
implements DOMStoreTransactionChain, TransactionReadyPrototype {
@GuardedBy("this")
private SnapshotBackedWriteTransaction latestOutstandingTx;
private boolean chainFailed = false;
private void checkFailed() {
Preconditions.checkState(!chainFailed, "Transaction chain is failed.");
}
@Override
public synchronized DOMStoreReadTransaction newReadOnlyTransaction() {
final DataTreeSnapshot snapshot;
checkFailed();
if (latestOutstandingTx != null) {
checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
snapshot = latestOutstandingTx.getMutatedView();
} else {
snapshot = dataTree.takeSnapshot();
}
return new SnapshotBackedReadTransaction(nextIdentifier(), snapshot);
}
@Override
public synchronized DOMStoreReadWriteTransaction newReadWriteTransaction() {
final DataTreeSnapshot snapshot;
checkFailed();
if (latestOutstandingTx != null) {
checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
snapshot = latestOutstandingTx.getMutatedView();
} else {
snapshot = dataTree.takeSnapshot();
}
final SnapshotBackedReadWriteTransaction ret =
new SnapshotBackedReadWriteTransaction(nextIdentifier(), snapshot, this);
latestOutstandingTx = ret;
return ret;
}
@Override
public synchronized DOMStoreWriteTransaction newWriteOnlyTransaction() {
final DataTreeSnapshot snapshot;
checkFailed();
if (latestOutstandingTx != null) {
checkState(latestOutstandingTx.isReady(), "Previous transaction in chain must be ready.");
snapshot = latestOutstandingTx.getMutatedView();
} else {
snapshot = dataTree.takeSnapshot();
}
final SnapshotBackedWriteTransaction ret =
new SnapshotBackedWriteTransaction(nextIdentifier(), snapshot, this);
latestOutstandingTx = ret;
return ret;
}
@Override
public DOMStoreThreePhaseCommitCohort ready(final SnapshotBackedWriteTransaction tx) {
DOMStoreThreePhaseCommitCohort storeCohort = InMemoryDOMDataStore.this.ready(tx);
return new ChainedTransactionCommitImpl(tx, storeCohort, this);
}
@Override
public void close() {
executor.shutdownNow();
}
protected synchronized void onTransactionFailed(
final SnapshotBackedWriteTransaction transaction, final Throwable t) {
chainFailed = true;
}
public synchronized void onTransactionCommited(
final SnapshotBackedWriteTransaction transaction) {
// If commited transaction is latestOutstandingTx we clear
// latestOutstandingTx
// field in order to base new transactions on Datastore Data Tree
// directly.
if (transaction.equals(latestOutstandingTx)) {
latestOutstandingTx = null;
}
}
}
private static class ChainedTransactionCommitImpl implements DOMStoreThreePhaseCommitCohort {
private final SnapshotBackedWriteTransaction transaction;
private final DOMStoreThreePhaseCommitCohort delegate;
private final DOMStoreTransactionChainImpl txChain;
protected ChainedTransactionCommitImpl(
final SnapshotBackedWriteTransaction transaction,
final DOMStoreThreePhaseCommitCohort delegate,
final DOMStoreTransactionChainImpl txChain) {
super();
this.transaction = transaction;
this.delegate = delegate;
this.txChain = txChain;
}
@Override
public ListenableFuture<Boolean> canCommit() {
return delegate.canCommit();
}
@Override
public ListenableFuture<Void> preCommit() {
return delegate.preCommit();
}
@Override
public ListenableFuture<Void> abort() {
return delegate.abort();
}
@Override
public ListenableFuture<Void> commit() {
ListenableFuture<Void> commitFuture = delegate.commit();
Futures.addCallback(
commitFuture,
new FutureCallback<Void>() {
@Override
public void onFailure(final Throwable t) {
txChain.onTransactionFailed(transaction, t);
}
@Override
public void onSuccess(final Void result) {
txChain.onTransactionCommited(transaction);
}
});
return commitFuture;
}
}
private class ThreePhaseCommitImpl implements DOMStoreThreePhaseCommitCohort {
private final SnapshotBackedWriteTransaction transaction;
private final DataTreeModification modification;
private ResolveDataChangeEventsTask listenerResolver;
private DataTreeCandidate candidate;
public ThreePhaseCommitImpl(final SnapshotBackedWriteTransaction writeTransaction) {
this.transaction = writeTransaction;
this.modification = transaction.getMutatedView();
}
@Override
public ListenableFuture<Boolean> canCommit() {
return executor.submit(
new Callable<Boolean>() {
@Override
public Boolean call() throws TransactionCommitFailedException {
try {
dataTree.validate(modification);
LOG.debug("Store Transaction: {} can be committed", transaction.getIdentifier());
return true;
} catch (ConflictingModificationAppliedException e) {
LOG.warn(
"Store Tx: {} Conflicting modification for {}.",
transaction.getIdentifier(),
e.getPath());
throw new OptimisticLockFailedException("Optimistic lock failed.", e);
} catch (DataValidationFailedException e) {
LOG.warn(
"Store Tx: {} Data Precondition failed for {}.",
transaction.getIdentifier(),
e.getPath(),
e);
throw new TransactionCommitFailedException("Data did not pass validation.", e);
}
}
});
}
@Override
public ListenableFuture<Void> preCommit() {
return executor.submit(
new Callable<Void>() {
@Override
public Void call() {
candidate = dataTree.prepare(modification);
listenerResolver = ResolveDataChangeEventsTask.create(candidate, listenerTree);
return null;
}
});
}
@Override
public ListenableFuture<Void> abort() {
candidate = null;
return Futures.immediateFuture(null);
}
@Override
public ListenableFuture<Void> commit() {
checkState(candidate != null, "Proposed subtree must be computed");
/*
* The commit has to occur atomically with regard to listener
* registrations.
*/
synchronized (this) {
dataTree.commit(candidate);
for (ChangeListenerNotifyTask task : listenerResolver.call()) {
LOG.trace("Scheduling invocation of listeners: {}", task);
executor.submit(task);
}
}
return Futures.immediateFuture(null);
}
}
}
