package org.opendaylight.controller.cluster.datastore;
import akka.actor.ActorSelection;
-import akka.dispatch.Futures;
+import com.google.common.base.Preconditions;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
import org.opendaylight.controller.cluster.datastore.messages.CloseTransactionChain;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
+import org.opendaylight.controller.md.sal.common.api.data.TransactionChainClosedException;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransactionChain;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
-import scala.concurrent.Await;
import scala.concurrent.Future;
-import java.util.Collections;
-import java.util.List;
-
/**
* TransactionChainProxy acts as a proxy for a DOMStoreTransactionChain created on a remote shard
*/
-public class TransactionChainProxy implements DOMStoreTransactionChain{
+public class TransactionChainProxy implements DOMStoreTransactionChain {
+
+ private interface State {
+ boolean isReady();
+
+ List<Future<ActorSelection>> getPreviousReadyFutures();
+ }
+
+ private static class Allocated implements State {
+ private final ChainedTransactionProxy transaction;
+
+ Allocated(ChainedTransactionProxy transaction) {
+ this.transaction = transaction;
+ }
+
+ @Override
+ public boolean isReady() {
+ return transaction.isReady();
+ }
+
+ @Override
+ public List<Future<ActorSelection>> getPreviousReadyFutures() {
+ return transaction.getReadyFutures();
+ }
+ }
+
+ private static abstract class AbstractDefaultState implements State {
+ @Override
+ public List<Future<ActorSelection>> getPreviousReadyFutures() {
+ return Collections.emptyList();
+ }
+ }
+
+ private static final State IDLE_STATE = new AbstractDefaultState() {
+ @Override
+ public boolean isReady() {
+ return true;
+ }
+ };
+
+ private static final State CLOSED_STATE = new AbstractDefaultState() {
+ @Override
+ public boolean isReady() {
+ throw new TransactionChainClosedException("Transaction chain has been closed");
+ }
+ };
+
+ private static final AtomicInteger counter = new AtomicInteger(0);
+
private final ActorContext actorContext;
private final String transactionChainId;
- private volatile List<Future<ActorSelection>> cohortFutures = Collections.emptyList();
+ private volatile State currentState = IDLE_STATE;
public TransactionChainProxy(ActorContext actorContext) {
this.actorContext = actorContext;
- transactionChainId = actorContext.getCurrentMemberName() + "-" + System.currentTimeMillis();
+ transactionChainId = actorContext.getCurrentMemberName() + "-txn-chain-" + counter.incrementAndGet();
+ }
+
+ public String getTransactionChainId() {
+ return transactionChainId;
}
@Override
public DOMStoreReadTransaction newReadOnlyTransaction() {
- return new TransactionProxy(actorContext,
- TransactionProxy.TransactionType.READ_ONLY, this);
+ State localState = currentState;
+ checkReadyState(localState);
+
+ return new ChainedTransactionProxy(actorContext, TransactionProxy.TransactionType.READ_ONLY,
+ transactionChainId, localState.getPreviousReadyFutures());
}
@Override
public DOMStoreReadWriteTransaction newReadWriteTransaction() {
- return new TransactionProxy(actorContext,
- TransactionProxy.TransactionType.READ_WRITE, this);
+ actorContext.acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionProxy.TransactionType.READ_WRITE);
}
@Override
public DOMStoreWriteTransaction newWriteOnlyTransaction() {
- return new TransactionProxy(actorContext,
- TransactionProxy.TransactionType.WRITE_ONLY, this);
+ actorContext.acquireTxCreationPermit();
+ return allocateWriteTransaction(TransactionProxy.TransactionType.WRITE_ONLY);
}
@Override
public void close() {
+ currentState = CLOSED_STATE;
+
// Send a close transaction chain request to each and every shard
actorContext.broadcast(new CloseTransactionChain(transactionChainId));
}
- public String getTransactionChainId() {
- return transactionChainId;
- }
+ private ChainedTransactionProxy allocateWriteTransaction(TransactionProxy.TransactionType type) {
+ State localState = currentState;
- public void onTransactionReady(List<Future<ActorSelection>> cohortFutures){
- this.cohortFutures = cohortFutures;
+ checkReadyState(localState);
+
+ // Pass the ready Futures from the previous Tx.
+ ChainedTransactionProxy txProxy = new ChainedTransactionProxy(actorContext, type,
+ transactionChainId, localState.getPreviousReadyFutures());
+
+ currentState = new Allocated(txProxy);
+
+ return txProxy;
}
- public void waitTillCurrentTransactionReady(){
- try {
- Await.result(Futures
- .sequence(this.cohortFutures, actorContext.getActorSystem().dispatcher()),
- actorContext.getOperationDuration());
- } catch (Exception e) {
- throw new IllegalStateException("Failed when waiting for transaction on a chain to become ready", e);
- }
+ private void checkReadyState(State state) {
+ Preconditions.checkState(state.isReady(), "Previous transaction is not ready yet");
}
}