import com.google.common.base.Preconditions;
import com.google.common.collect.Iterables;
import com.google.common.util.concurrent.CheckedFuture;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
+import java.util.Collection;
+import javax.annotation.Nonnull;
import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
-import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
-import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
-import org.opendaylight.yangtools.concepts.Identifiable;
+import org.opendaylight.mdsal.common.api.ReadFailedException;
+import org.opendaylight.mdsal.dom.api.DOMDataTreeCursor;
+import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteCursor;
+import org.opendaylight.mdsal.dom.spi.store.DOMStoreThreePhaseCommitCohort;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
/**
- * Client-side view of a free-standing transaction.
+ * Client-side view of a transaction.
*
+ * <p>
* This interface is used by the world outside of the actor system and in the actor system it is manifested via
* its client actor. That requires some state transfer with {@link DistributedDataStoreClientBehavior}. In order to
* reduce request latency, all messages are carbon-copied (and enqueued first) to the client actor.
*
+ * <p>
* It is internally composed of multiple {@link RemoteProxyTransaction}s, each responsible for a component shard.
*
+ * <p>
* Implementation is quite a bit complex, and involves cooperation with {@link AbstractClientHistory} for tracking
* gaps in transaction identifiers seen by backends.
*
+ * <p>
* These gaps need to be accounted for in the transaction setup message sent to a particular backend, so it can verify
* that the requested transaction is in-sequence. This is critical in ensuring that transactions (which are independent
* entities from message queueing perspective) do not get reodered -- thus allowing multiple in-flight transactions.
*
+ * <p>
* Alternative would be to force visibility by sending an abort request to all potential backends, but that would mean
* that even empty transactions increase load on all shards -- which would be a scalability issue.
*
+ * <p>
* Yet another alternative would be to introduce inter-transaction dependencies to the queueing layer in client actor,
* but that would require additional indirection and complexity.
*
* @author Robert Varga
*/
@Beta
-public final class ClientTransaction extends LocalAbortable implements Identifiable<TransactionIdentifier> {
- private static final Logger LOG = LoggerFactory.getLogger(ClientTransaction.class);
- private static final AtomicIntegerFieldUpdater<ClientTransaction> STATE_UPDATER =
- AtomicIntegerFieldUpdater.newUpdater(ClientTransaction.class, "state");
- private static final int OPEN_STATE = 0;
- private static final int CLOSED_STATE = 1;
-
- private final Map<Long, AbstractProxyTransaction> proxies = new HashMap<>();
- private final TransactionIdentifier transactionId;
- private final AbstractClientHistory parent;
-
- private volatile int state = OPEN_STATE;
-
- ClientTransaction(final DistributedDataStoreClientBehavior client, final AbstractClientHistory parent,
- final TransactionIdentifier transactionId) {
- this.transactionId = Preconditions.checkNotNull(transactionId);
- this.parent = Preconditions.checkNotNull(parent);
- }
+public class ClientTransaction extends AbstractClientHandle<AbstractProxyTransaction> {
+
+ private ClientTransactionCursor cursor;
- private void checkNotClosed() {
- Preconditions.checkState(state == OPEN_STATE, "Transaction %s is closed", transactionId);
+ ClientTransaction(final AbstractClientHistory parent, final TransactionIdentifier transactionId) {
+ super(parent, transactionId);
}
private AbstractProxyTransaction createProxy(final Long shard) {
- return parent.createTransactionProxy(transactionId, shard);
+ return parent().createTransactionProxy(getIdentifier(), shard);
}
- private AbstractProxyTransaction ensureProxy(final YangInstanceIdentifier path) {
- checkNotClosed();
-
- final ModuleShardBackendResolver resolver = parent.getClient().resolver();
- final Long shard = resolver.resolveShardForPath(path);
- return proxies.computeIfAbsent(shard, this::createProxy);
+ private AbstractProxyTransaction ensureTransactionProxy(final YangInstanceIdentifier path) {
+ return ensureProxy(path, this::createProxy);
}
- @Override
- public TransactionIdentifier getIdentifier() {
- return transactionId;
+ public DOMDataTreeWriteCursor openCursor() {
+ Preconditions.checkState(cursor == null, "Transaction %s has open cursor", getIdentifier());
+ cursor = new ClientTransactionCursor(this);
+ return cursor;
}
public CheckedFuture<Boolean, ReadFailedException> exists(final YangInstanceIdentifier path) {
- return ensureProxy(path).exists(path);
+ return ensureTransactionProxy(path).exists(path);
}
- public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(final YangInstanceIdentifier path) {
- return ensureProxy(path).read(path);
+ public CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> read(
+ final YangInstanceIdentifier path) {
+ return ensureTransactionProxy(path).read(path);
}
public void delete(final YangInstanceIdentifier path) {
- ensureProxy(path).delete(path);
+ ensureTransactionProxy(path).delete(path);
}
public void merge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
- ensureProxy(path).merge(path, data);
+ ensureTransactionProxy(path).merge(path, data);
}
public void write(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
- ensureProxy(path).write(path, data);
- }
-
- private boolean ensureClosed() {
- final int local = state;
- if (local != CLOSED_STATE) {
- final boolean success = STATE_UPDATER.compareAndSet(this, OPEN_STATE, CLOSED_STATE);
- Preconditions.checkState(success, "Transaction %s raced during close", this);
- return true;
- } else {
- return false;
- }
+ ensureTransactionProxy(path).write(path, data);
}
public DOMStoreThreePhaseCommitCohort ready() {
- Preconditions.checkState(ensureClosed(), "Attempted to submit a closed transaction %s", this);
+ final Collection<AbstractProxyTransaction> toReady = ensureClosed();
+ Preconditions.checkState(toReady != null, "Attempted to submit a closed transaction %s", this);
- for (AbstractProxyTransaction p : proxies.values()) {
- p.seal();
- }
- parent.onTransactionReady(this);
-
- switch (proxies.size()) {
+ toReady.forEach(AbstractProxyTransaction::seal);
+ final AbstractTransactionCommitCohort cohort;
+ switch (toReady.size()) {
case 0:
- return EmptyTransactionCommitCohort.INSTANCE;
+ cohort = new EmptyTransactionCommitCohort(parent(), getIdentifier());
+ break;
case 1:
- return new DirectTransactionCommitCohort(Iterables.getOnlyElement(proxies.values()));
+ cohort = new DirectTransactionCommitCohort(parent(), getIdentifier(),
+ Iterables.getOnlyElement(toReady));
+ break;
default:
- return new ClientTransactionCommitCohort(proxies.values());
+ cohort = new ClientTransactionCommitCohort(parent(), getIdentifier(), toReady);
+ break;
}
- }
- /**
- * Release all state associated with this transaction.
- */
- public void abort() {
- if (ensureClosed()) {
- for (AbstractProxyTransaction proxy : proxies.values()) {
- proxy.abort();
- }
- proxies.clear();
- }
+ return parent().onTransactionReady(this, cohort);
}
- @Override
- void localAbort(final Throwable cause) {
- LOG.debug("Aborting transaction {}", getIdentifier(), cause);
- abort();
+ void closeCursor(@Nonnull final DOMDataTreeCursor cursor) {
+ if (cursor.equals(this.cursor)) {
+ this.cursor = null;
+ }
}
}