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/*
* Copyright (c) "Neo4j"
* Neo4j Sweden AB [https://neo4j.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*/
package org.neo4j.fabric.executor;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.TimeUnit;
import org.neo4j.cypher.internal.FullyParsedQuery;
import org.neo4j.cypher.internal.javacompat.ExecutionEngine;
import org.neo4j.fabric.FabricDatabaseManager;
import org.neo4j.fabric.bookmark.LocalBookmark;
import org.neo4j.fabric.bookmark.LocalGraphTransactionIdTracker;
import org.neo4j.fabric.bookmark.TransactionBookmarkManager;
import org.neo4j.fabric.config.FabricConfig;
import org.neo4j.fabric.executor.QueryStatementLifecycles.StatementLifecycle;
import org.neo4j.fabric.stream.Record;
import org.neo4j.fabric.stream.StatementResult;
import org.neo4j.fabric.transaction.FabricTransactionInfo;
import org.neo4j.fabric.transaction.TransactionMode;
import org.neo4j.fabric.transaction.parent.CompoundTransaction;
import org.neo4j.graphdb.TransactionFailureException;
import org.neo4j.kernel.api.KernelTransaction;
import org.neo4j.kernel.api.exceptions.Status;
import org.neo4j.kernel.availability.UnavailableException;
import org.neo4j.kernel.impl.coreapi.InternalTransaction;
import org.neo4j.kernel.impl.query.TransactionalContextFactory;
import org.neo4j.kernel.internal.GraphDatabaseAPI;
import org.neo4j.values.virtual.MapValue;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
public class FabricLocalExecutor {
private final FabricConfig config;
private final FabricDatabaseManager dbms;
private final LocalGraphTransactionIdTracker transactionIdTracker;
public FabricLocalExecutor(
FabricConfig config, FabricDatabaseManager dbms, LocalGraphTransactionIdTracker transactionIdTracker) {
this.config = config;
this.dbms = dbms;
this.transactionIdTracker = transactionIdTracker;
}
public LocalTransactionContext startTransactionContext(
CompoundTransaction parentTransaction,
FabricTransactionInfo transactionInfo,
TransactionBookmarkManager bookmarkManager) {
return new LocalTransactionContext(parentTransaction, transactionInfo, bookmarkManager);
}
public class LocalTransactionContext implements AutoCloseable {
private final Map kernelTransactions = new ConcurrentHashMap<>();
private final Set internalTransactions = ConcurrentHashMap.newKeySet();
private final CompoundTransaction parentTransaction;
private final FabricTransactionInfo transactionInfo;
private final TransactionBookmarkManager bookmarkManager;
private LocalTransactionContext(
CompoundTransaction parentTransaction,
FabricTransactionInfo transactionInfo,
TransactionBookmarkManager bookmarkManager) {
this.parentTransaction = parentTransaction;
this.transactionInfo = transactionInfo;
this.bookmarkManager = bookmarkManager;
}
public StatementResult run(
Location.Local location,
TransactionMode transactionMode,
StatementLifecycle parentLifecycle,
FullyParsedQuery query,
MapValue params,
Flux input,
ExecutionOptions executionOptions,
Boolean targetsComposite) {
var kernelTransaction = getOrCreateTx(location, transactionMode, targetsComposite);
return kernelTransaction.run(query, params, input, parentLifecycle, executionOptions);
}
public StatementResult runInAutocommitTransaction(
Location.Local location,
StatementLifecycle parentLifecycle,
FullyParsedQuery query,
MapValue params,
Flux input,
ExecutionOptions executionOptions) {
var databaseFacade = getDatabaseFacade(location);
bookmarkManager
.getBookmarkForLocal(location)
.ifPresent(bookmark -> transactionIdTracker.awaitGraphUpToDate(location, bookmark.transactionId()));
var kernelTransaction = beginKernelTx(databaseFacade);
var driverResult = kernelTransaction.run(query, params, input, parentLifecycle, executionOptions);
var result = new AutocommitLocalStatementResult(
driverResult, kernelTransaction, bookmarkManager, transactionIdTracker, location);
parentTransaction.registerAutocommitQuery(result);
return result;
}
@Override
public void close() {}
public Set getInternalTransactions() {
return internalTransactions;
}
public FabricKernelTransaction getOrCreateTx(
Location.Local location, TransactionMode transactionMode, Boolean targetsComposite) {
var existingTx = kernelTransactions.get(location.getUuid());
if (!targetsComposite && existingTx != null) {
maybeUpgradeToWritingTransaction(existingTx, transactionMode);
return existingTx.fabricKernelTransaction;
}
// it is important to try to get the facade before handling bookmarks
// Unlike the bookmark logic, this will fail gracefully if the database is not available
var databaseFacade = getDatabaseFacade(location);
bookmarkManager
.getBookmarkForLocal(location)
.ifPresent(bookmark -> transactionIdTracker.awaitGraphUpToDate(location, bookmark.transactionId()));
return kernelTransactions.computeIfAbsent(
location.getUuid(),
dbUuid -> parentTransaction.registerNewChildTransaction(location, transactionMode, () -> {
var tx = beginKernelTx(databaseFacade);
return new KernelTxWrapper(tx, bookmarkManager, location);
}))
.fabricKernelTransaction;
}
private void maybeUpgradeToWritingTransaction(KernelTxWrapper tx, TransactionMode transactionMode) {
if (transactionMode == TransactionMode.DEFINITELY_WRITE) {
parentTransaction.upgradeToWritingTransaction(tx);
}
}
private FabricKernelTransaction beginKernelTx(GraphDatabaseAPI databaseFacade) {
var dependencyResolver = databaseFacade.getDependencyResolver();
var executionEngine = dependencyResolver.resolveDependency(ExecutionEngine.class);
var internalTransaction = beginInternalTransaction(databaseFacade, transactionInfo);
var transactionalContextFactory = dependencyResolver.resolveDependency(TransactionalContextFactory.class);
return new FabricKernelTransaction(
executionEngine, transactionalContextFactory, internalTransaction, config, transactionInfo);
}
private GraphDatabaseAPI getDatabaseFacade(Location.Local location) {
try {
var facade = dbms.getDatabaseFacade(location.getDatabaseName());
if (!Objects.equals(facade.databaseId().databaseId().uuid(), location.getUuid())) {
throw new FabricException(
Status.Transaction.Outdated,
"The locations associated with the graph name %s have "
+ "changed whilst the transaction was running.",
location.getDatabaseName());
}
return facade;
} catch (UnavailableException e) {
throw new FabricException(Status.General.DatabaseUnavailable, e);
}
}
private InternalTransaction beginInternalTransaction(
GraphDatabaseAPI databaseAPI, FabricTransactionInfo transactionInfo) {
KernelTransaction.Type kernelTransactionType = getKernelTransactionType(transactionInfo);
InternalTransaction internalTransaction = databaseAPI.beginTransaction(
kernelTransactionType,
transactionInfo.getLoginContext(),
transactionInfo.getClientConnectionInfo(),
transactionInfo.getTxTimeout().toMillis(),
TimeUnit.MILLISECONDS,
parentTransaction::childTransactionTerminated,
this::transformTerminalOperationError);
if (transactionInfo.getTxMetadata() != null) {
internalTransaction.setMetaData(transactionInfo.getTxMetadata());
}
internalTransactions.add(internalTransaction);
return internalTransaction;
}
private KernelTransaction.Type getKernelTransactionType(FabricTransactionInfo fabricTransactionInfo) {
if (fabricTransactionInfo.isImplicitTransaction()) {
return KernelTransaction.Type.IMPLICIT;
}
return KernelTransaction.Type.EXPLICIT;
}
private RuntimeException transformTerminalOperationError(Exception e) {
// The main purpose of this is mapping of checked exceptions
// while preserving status codes
if (e instanceof Status.HasStatus) {
if (e instanceof RuntimeException) {
return (RuntimeException) e;
}
return new FabricException(((Status.HasStatus) e).status(), e.getMessage(), e);
}
// We don't know what operation is being executed,
// so it is not possible to come up with a reasonable status code here.
// The error is wrapped into a generic one
// and a proper status code will be added later.
throw new TransactionFailureException("Unable to complete transaction.", e, Status.General.UnknownError);
}
}
private class KernelTxWrapper implements SingleDbTransaction {
private final FabricKernelTransaction fabricKernelTransaction;
private final TransactionBookmarkManager bookmarkManager;
private final Location.Local location;
KernelTxWrapper(
FabricKernelTransaction fabricKernelTransaction,
TransactionBookmarkManager bookmarkManager,
Location.Local location) {
this.fabricKernelTransaction = fabricKernelTransaction;
this.bookmarkManager = bookmarkManager;
this.location = location;
}
@Override
public Mono commit() {
return Mono.fromRunnable(this::doCommit);
}
@Override
public Mono rollback() {
return Mono.fromRunnable(this::doRollback);
}
private void doCommit() {
fabricKernelTransaction.commit();
long transactionId = transactionIdTracker.getTransactionId(location);
bookmarkManager.localTransactionCommitted(location, new LocalBookmark(transactionId));
}
private void doRollback() {
fabricKernelTransaction.rollback();
}
@Override
public Mono terminate(Status reason) {
return Mono.fromRunnable(() -> fabricKernelTransaction.terminate(reason));
}
@Override
public Location location() {
return location;
}
}
}
