org.neo4j.kernel.impl.api.KernelTransactionImplementation Maven / Gradle / Ivy
/*
* Copyright (c) 2018-2020 "Graph Foundation,"
* Graph Foundation, Inc. [https://graphfoundation.org]
*
* This file is part of ONgDB.
*
* ONgDB 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 pool;
private final Supplier explicitIndexTxStateSupplier;
// For committing
private final TransactionHeaderInformationFactory headerInformationFactory;
private final TransactionCommitProcess commitProcess;
private final TransactionMonitor transactionMonitor;
private final PageCursorTracerSupplier cursorTracerSupplier;
private final VersionContextSupplier versionContextSupplier;
private final StoreReadLayer storeLayer;
private final ClockContext clocks;
private final AccessCapability accessCapability;
// State that needs to be reset between uses. Most of these should be cleared or released in #release(),
// whereas others, such as timestamp or txId when transaction starts, even locks, needs to be set in #initialize().
private TxState txState;
private ExplicitIndexTransactionState explicitIndexTransactionState;
private TransactionWriteState writeState;
private TransactionHooks.TransactionHooksState hooksState;
private final KernelStatement currentStatement;
private final StorageStatement storageStatement;
private final List closeListeners = new ArrayList<>( 2 );
private SecurityContext securityContext;
private volatile StatementLocks statementLocks;
private volatile long userTransactionId;
private boolean beforeHookInvoked;
private volatile boolean closing;
private volatile boolean closed;
private boolean failure;
private boolean success;
private volatile Status terminationReason;
private long startTimeMillis;
private long startTimeNanos;
private long timeoutMillis;
private long lastTransactionIdWhenStarted;
private volatile long lastTransactionTimestampWhenStarted;
private final Statistics statistics;
private TransactionEvent transactionEvent;
private Type type;
private long transactionId;
private long commitTime;
private volatile int reuseCount;
private volatile Map userMetaData;
private final Operations operations;
/**
* Lock prevents transaction {@link #markForTermination(Status)} transaction termination} from interfering with
* {@link #close() transaction commit} and specifically with {@link #release()}.
* Termination can run concurrently with commit and we need to make sure that it terminates the right lock client
* and the right transaction (with the right {@link #reuseCount}) because {@link KernelTransactionImplementation}
* instances are pooled.
*/
private final Lock terminationReleaseLock = new ReentrantLock();
public KernelTransactionImplementation( StatementOperationParts statementOperations, SchemaWriteGuard schemaWriteGuard, TransactionHooks hooks,
ConstraintIndexCreator constraintIndexCreator, Procedures procedures, TransactionHeaderInformationFactory headerInformationFactory,
TransactionCommitProcess commitProcess, TransactionMonitor transactionMonitor, Supplier explicitIndexTxStateSupplier,
Pool pool, SystemNanoClock clock, AtomicReference cpuClockRef,
AtomicReference heapAllocationRef, TransactionTracer transactionTracer, LockTracer lockTracer,
PageCursorTracerSupplier cursorTracerSupplier, StorageEngine storageEngine, AccessCapability accessCapability, DefaultCursors cursors,
AutoIndexing autoIndexing, ExplicitIndexStore explicitIndexStore, VersionContextSupplier versionContextSupplier,
CollectionsFactorySupplier collectionsFactorySupplier, ConstraintSemantics constraintSemantics, SchemaState schemaState,
IndexingService indexingService, IndexProviderMap indexProviderMap )
{
this.schemaWriteGuard = schemaWriteGuard;
this.hooks = hooks;
this.constraintIndexCreator = constraintIndexCreator;
this.headerInformationFactory = headerInformationFactory;
this.commitProcess = commitProcess;
this.transactionMonitor = transactionMonitor;
this.storeLayer = storageEngine.storeReadLayer();
this.storageEngine = storageEngine;
this.explicitIndexTxStateSupplier = explicitIndexTxStateSupplier;
this.pool = pool;
this.clocks = new ClockContext( clock );
this.transactionTracer = transactionTracer;
this.cursorTracerSupplier = cursorTracerSupplier;
this.versionContextSupplier = versionContextSupplier;
this.storageStatement = storeLayer.newStatement();
this.currentStatement = new KernelStatement( this, this, storageStatement,
lockTracer, statementOperations, this.clocks,
versionContextSupplier );
this.accessCapability = accessCapability;
this.statistics = new Statistics( this, cpuClockRef, heapAllocationRef );
this.userMetaData = new HashMap<>();
AllStoreHolder allStoreHolder =
new AllStoreHolder( storageEngine, storageStatement, this, cursors, explicitIndexStore,
procedures, schemaState );
this.operations =
new Operations(
allStoreHolder,
new IndexTxStateUpdater( storageEngine.storeReadLayer(), allStoreHolder, indexingService ),
storageStatement,
this, new KernelToken( storeLayer, this ), cursors, autoIndexing, constraintIndexCreator,
constraintSemantics,
indexProviderMap );
this.collectionsFactory = collectionsFactorySupplier.create();
}
/**
* Reset this transaction to a vanilla state, turning it into a logically new transaction.
*/
public KernelTransactionImplementation initialize( long lastCommittedTx, long lastTimeStamp, StatementLocks statementLocks, Type type,
SecurityContext frozenSecurityContext, long transactionTimeout, long userTransactionId )
{
this.type = type;
this.statementLocks = statementLocks;
this.userTransactionId = userTransactionId;
this.terminationReason = null;
this.closing = false;
this. closed = false;
this.beforeHookInvoked = false;
this.failure = false;
this.success = false;
this.writeState = TransactionWriteState.NONE;
this.startTimeMillis = clocks.systemClock().millis();
this.startTimeNanos = clocks.systemClock().nanos();
this.timeoutMillis = transactionTimeout;
this.lastTransactionIdWhenStarted = lastCommittedTx;
this.lastTransactionTimestampWhenStarted = lastTimeStamp;
this.transactionEvent = transactionTracer.beginTransaction();
assert transactionEvent != null : "transactionEvent was null!";
this.securityContext = frozenSecurityContext;
this.transactionId = NOT_COMMITTED_TRANSACTION_ID;
this.commitTime = NOT_COMMITTED_TRANSACTION_COMMIT_TIME;
PageCursorTracer pageCursorTracer = cursorTracerSupplier.get();
this.statistics.init( Thread.currentThread().getId(), pageCursorTracer );
this.currentStatement.initialize( statementLocks, pageCursorTracer );
this.operations.initialize();
return this;
}
int getReuseCount()
{
return reuseCount;
}
@Override
public long startTime()
{
return startTimeMillis;
}
@Override
public long startTimeNanos()
{
return startTimeNanos;
}
@Override
public long timeout()
{
return timeoutMillis;
}
@Override
public long lastTransactionIdWhenStarted()
{
return lastTransactionIdWhenStarted;
}
@Override
public void success()
{
this.success = true;
}
boolean isSuccess()
{
return success;
}
@Override
public void failure()
{
failure = true;
}
@Override
public Optional getReasonIfTerminated()
{
return Optional.ofNullable( terminationReason );
}
boolean markForTermination( long expectedReuseCount, Status reason )
{
terminationReleaseLock.lock();
try
{
return expectedReuseCount == reuseCount && markForTerminationIfPossible( reason );
}
finally
{
terminationReleaseLock.unlock();
}
}
/**
* {@inheritDoc}
*
* This method is guarded by {@link #terminationReleaseLock} to coordinate concurrent
* {@link #close()} and {@link #release()} calls.
*/
@Override
public void markForTermination( Status reason )
{
terminationReleaseLock.lock();
try
{
markForTerminationIfPossible( reason );
}
finally
{
terminationReleaseLock.unlock();
}
}
private boolean markForTerminationIfPossible( Status reason )
{
if ( canBeTerminated() )
{
failure = true;
terminationReason = reason;
if ( statementLocks != null )
{
statementLocks.stop();
}
transactionMonitor.transactionTerminated( hasTxStateWithChanges() );
return true;
}
return false;
}
@Override
public boolean isOpen()
{
return !closed && !closing;
}
@Override
public SecurityContext securityContext()
{
if ( securityContext == null )
{
throw new NotInTransactionException();
}
return securityContext;
}
public AuthSubject subjectOrAnonymous()
{
SecurityContext context = this.securityContext;
return context == null ? AuthSubject.ANONYMOUS : context.subject();
}
public void setMetaData( Map data )
{
this.userMetaData = data;
}
public Map getMetaData()
{
return userMetaData;
}
@Override
public KernelStatement acquireStatement()
{
assertTransactionOpen();
currentStatement.acquire();
return currentStatement;
}
@Override
public long pageHits()
{
return cursorTracerSupplier.get().hits();
}
@Override
public long pageFaults()
{
return cursorTracerSupplier.get().faults();
}
ExecutingQueryList executingQueries()
{
return currentStatement.executingQueryList();
}
void upgradeToDataWrites() throws InvalidTransactionTypeKernelException
{
writeState = writeState.upgradeToDataWrites();
}
void upgradeToSchemaWrites() throws InvalidTransactionTypeKernelException
{
schemaWriteGuard.assertSchemaWritesAllowed();
writeState = writeState.upgradeToSchemaWrites();
}
private void dropCreatedConstraintIndexes() throws TransactionFailureException
{
if ( hasTxStateWithChanges() )
{
for ( SchemaIndexDescriptor createdConstraintIndex : txState().constraintIndexesCreatedInTx() )
{
// TODO logically, which statement should this operation be performed on?
constraintIndexCreator.dropUniquenessConstraintIndex( createdConstraintIndex );
}
}
}
@Override
public TransactionState txState()
{
if ( txState == null )
{
transactionMonitor.upgradeToWriteTransaction();
txState = new TxState( collectionsFactory );
}
return txState;
}
@Override
public ExplicitIndexTransactionState explicitIndexTxState()
{
return explicitIndexTransactionState != null ? explicitIndexTransactionState :
(explicitIndexTransactionState = explicitIndexTxStateSupplier.get());
}
@Override
public boolean hasTxStateWithChanges()
{
return txState != null && txState.hasChanges();
}
private void markAsClosed( long txId )
{
assertTransactionOpen();
closed = true;
notifyListeners( txId );
closeCurrentStatementIfAny();
}
private void notifyListeners( long txId )
{
for ( CloseListener closeListener : closeListeners )
{
closeListener.notify( txId );
}
}
private void closeCurrentStatementIfAny()
{
currentStatement.forceClose();
}
private void assertTransactionNotClosing()
{
if ( closing )
{
throw new IllegalStateException( "This transaction is already being closed." );
}
}
private void assertTransactionOpen()
{
if ( closed )
{
throw new IllegalStateException( "This transaction has already been completed." );
}
}
@Override
public void assertOpen()
{
Status reason = this.terminationReason;
if ( reason != null )
{
throw new TransactionTerminatedException( reason );
}
if ( closed )
{
throw new NotInTransactionException( "The transaction has been closed." );
}
}
private boolean hasChanges()
{
return hasTxStateWithChanges() || hasExplicitIndexChanges();
}
private boolean hasExplicitIndexChanges()
{
return explicitIndexTransactionState != null && explicitIndexTransactionState.hasChanges();
}
private boolean hasDataChanges()
{
return hasTxStateWithChanges() && txState.hasDataChanges();
}
@Override
public long closeTransaction() throws TransactionFailureException
{
assertTransactionOpen();
assertTransactionNotClosing();
closing = true;
try
{
if ( failure || !success || isTerminated() )
{
rollback();
failOnNonExplicitRollbackIfNeeded();
return ROLLBACK;
}
else
{
return commit();
}
}
finally
{
try
{
closed = true;
closing = false;
transactionEvent.setSuccess( success );
transactionEvent.setFailure( failure );
transactionEvent.setTransactionWriteState( writeState.name() );
transactionEvent.setReadOnly( txState == null || !txState.hasChanges() );
transactionEvent.close();
}
finally
{
release();
}
}
}
public boolean isClosing()
{
return closing;
}
/**
* Throws exception if this transaction was marked as successful but failure flag has also been set to true.
*
* This could happen when:
*
* - caller explicitly calls both {@link #success()} and {@link #failure()}
* - caller explicitly calls {@link #success()} but transaction execution fails
* - caller explicitly calls {@link #success()} but transaction is terminated
*
*
*
* @throws TransactionFailureException when execution failed
* @throws TransactionTerminatedException when transaction was terminated
*/
private void failOnNonExplicitRollbackIfNeeded() throws TransactionFailureException
{
if ( success && isTerminated() )
{
throw new TransactionTerminatedException( terminationReason );
}
if ( success )
{
// Success was called, but also failure which means that the client code using this
// transaction passed through a happy path, but the transaction was still marked as
// failed for one or more reasons. Tell the user that although it looked happy it
// wasn't committed, but was instead rolled back.
throw new TransactionFailureException( Status.Transaction.TransactionMarkedAsFailed,
"Transaction rolled back even if marked as successful" );
}
}
private long commit() throws TransactionFailureException
{
boolean success = false;
long txId = READ_ONLY;
try ( CommitEvent commitEvent = transactionEvent.beginCommitEvent() )
{
// Trigger transaction "before" hooks.
if ( hasDataChanges() )
{
try
{
hooksState = hooks.beforeCommit( txState, this, storageEngine.storeReadLayer(), storageStatement );
if ( hooksState != null && hooksState.failed() )
{
Throwable cause = hooksState.failure();
throw new TransactionFailureException( Status.Transaction.TransactionHookFailed, cause, "" );
}
}
finally
{
beforeHookInvoked = true;
}
}
// Convert changes into commands and commit
if ( hasChanges() )
{
// grab all optimistic locks now, locks can't be deferred any further
statementLocks.prepareForCommit( currentStatement.lockTracer() );
// use pessimistic locks for the rest of the commit process, locks can't be deferred any further
Locks.Client commitLocks = statementLocks.pessimistic();
// Gather up commands from the various sources
Collection extractedCommands = new ArrayList<>();
storageEngine.createCommands(
extractedCommands,
txState,
storageStatement,
commitLocks,
lastTransactionIdWhenStarted );
if ( hasExplicitIndexChanges() )
{
explicitIndexTransactionState.extractCommands( extractedCommands );
}
/* Here's the deal: we track a quick-to-access hasChanges in transaction state which is true
* if there are any changes imposed by this transaction. Some changes made inside a transaction undo
* previously made changes in that same transaction, and so at some point a transaction may have
* changes and at another point, after more changes seemingly,
* the transaction may not have any changes.
* However, to track that "undoing" of the changes is a bit tedious, intrusive and hard to maintain
* and get right.... So to really make sure the transaction has changes we re-check by looking if we
* have produced any commands to add to the logical log.
*/
if ( !extractedCommands.isEmpty() )
{
// Finish up the whole transaction representation
PhysicalTransactionRepresentation transactionRepresentation =
new PhysicalTransactionRepresentation( extractedCommands );
TransactionHeaderInformation headerInformation = headerInformationFactory.create();
long timeCommitted = clocks.systemClock().millis();
transactionRepresentation.setHeader( headerInformation.getAdditionalHeader(),
headerInformation.getMasterId(),
headerInformation.getAuthorId(),
startTimeMillis, lastTransactionIdWhenStarted, timeCommitted,
commitLocks.getLockSessionId() );
// Commit the transaction
success = true;
TransactionToApply batch = new TransactionToApply( transactionRepresentation,
versionContextSupplier.getVersionContext() );
txId = transactionId = commitProcess.commit( batch, commitEvent, INTERNAL );
commitTime = timeCommitted;
}
}
success = true;
return txId;
}
catch ( ConstraintValidationException | CreateConstraintFailureException e )
{
throw new ConstraintViolationTransactionFailureException(
e.getUserMessage( new SilentTokenNameLookup( tokenRead() ) ), e );
}
finally
{
if ( !success )
{
rollback();
}
else
{
afterCommit( txId );
}
}
}
private void rollback() throws TransactionFailureException
{
try
{
try
{
dropCreatedConstraintIndexes();
}
catch ( IllegalStateException | SecurityException e )
{
throw new TransactionFailureException( Status.Transaction.TransactionRollbackFailed, e,
"Could not drop created constraint indexes" );
}
// Free any acquired id's
if ( txState != null )
{
try
{
txState.accept( new TxStateVisitor.Adapter()
{
@Override
public void visitCreatedNode( long id )
{
storeLayer.releaseNode( id );
}
@Override
public void visitCreatedRelationship( long id, int type, long startNode, long endNode )
{
storeLayer.releaseRelationship( id );
}
} );
}
catch ( ConstraintValidationException | CreateConstraintFailureException e )
{
throw new IllegalStateException(
"Releasing locks during rollback should perform no constraints checking.", e );
}
}
}
finally
{
afterRollback();
}
}
@Override
public Read dataRead()
{
assertAllows( AccessMode::allowsReads, "Read" );
return operations.dataRead();
}
@Override
public Read stableDataRead()
{
assertAllows( AccessMode::allowsReads, "Read" );
return operations.dataRead();
}
@Override
public void markAsStable()
{
// ignored until 2-layer tx-state is supported
}
@Override
public Write dataWrite() throws InvalidTransactionTypeKernelException
{
accessCapability.assertCanWrite();
assertAllows( AccessMode::allowsWrites, "Write" );
upgradeToDataWrites();
return operations;
}
@Override
public TokenWrite tokenWrite()
{
accessCapability.assertCanWrite();
return operations.token();
}
@Override
public Token token()
{
accessCapability.assertCanWrite();
return operations.token();
}
@Override
public TokenRead tokenRead()
{
assertAllows( AccessMode::allowsReads, "Read" );
return operations.token();
}
@Override
public ExplicitIndexRead indexRead()
{
assertAllows( AccessMode::allowsReads, "Read" );
return operations.indexRead();
}
@Override
public ExplicitIndexWrite indexWrite() throws InvalidTransactionTypeKernelException
{
accessCapability.assertCanWrite();
assertAllows( AccessMode::allowsWrites, "Write" );
upgradeToDataWrites();
return operations;
}
@Override
public SchemaRead schemaRead()
{
assertAllows( AccessMode::allowsReads, "Read" );
return operations.schemaRead();
}
@Override
public SchemaWrite schemaWrite() throws InvalidTransactionTypeKernelException
{
accessCapability.assertCanWrite();
assertAllows( AccessMode::allowsSchemaWrites, "Schema" );
upgradeToSchemaWrites();
return operations;
}
@Override
public org.neo4j.internal.kernel.api.Locks locks()
{
return operations.locks();
}
public StatementLocks statementLocks()
{
assertOpen();
return statementLocks;
}
@Override
public CursorFactory cursors()
{
return operations.cursors();
}
@Override
public org.neo4j.internal.kernel.api.Procedures procedures()
{
return operations.procedures();
}
@Override
public ExecutionStatistics executionStatistics()
{
return this;
}
public LockTracer lockTracer()
{
return currentStatement.lockTracer();
}
public void assertAllows( Function allows, String mode )
{
AccessMode accessMode = securityContext().mode();
if ( !allows.apply( accessMode ) )
{
throw accessMode.onViolation(
format( "%s operations are not allowed for %s.", mode,
securityContext().description() ) );
}
}
private void afterCommit( long txId )
{
try
{
markAsClosed( txId );
if ( beforeHookInvoked )
{
hooks.afterCommit( txState, this, hooksState );
}
}
finally
{
transactionMonitor.transactionFinished( true, hasTxStateWithChanges() );
}
}
private void afterRollback()
{
try
{
markAsClosed( ROLLBACK );
if ( beforeHookInvoked )
{
hooks.afterRollback( txState, this, hooksState );
}
}
finally
{
transactionMonitor.transactionFinished( false, hasTxStateWithChanges() );
}
}
/**
* Release resources held up by this transaction & return it to the transaction pool.
* This method is guarded by {@link #terminationReleaseLock} to coordinate concurrent
* {@link #markForTermination(Status)} calls.
*/
private void release()
{
terminationReleaseLock.lock();
try
{
statementLocks.close();
statementLocks = null;
terminationReason = null;
type = null;
securityContext = null;
transactionEvent = null;
explicitIndexTransactionState = null;
if ( txState != null )
{
txState.release();
txState = null;
}
hooksState = null;
closeListeners.clear();
reuseCount++;
userMetaData = Collections.emptyMap();
userTransactionId = 0;
statistics.reset();
operations.release();
pool.release( this );
}
finally
{
terminationReleaseLock.unlock();
}
}
/**
* Transaction can be terminated only when it is not closed and not already terminated.
* Otherwise termination does not make sense.
*/
private boolean canBeTerminated()
{
return !closed && !isTerminated();
}
@Override
public boolean isTerminated()
{
return terminationReason != null;
}
@Override
public long lastTransactionTimestampWhenStarted()
{
return lastTransactionTimestampWhenStarted;
}
@Override
public void registerCloseListener( CloseListener listener )
{
assert listener != null;
closeListeners.add( listener );
}
@Override
public Type transactionType()
{
return type;
}
@Override
public long getTransactionId()
{
if ( transactionId == NOT_COMMITTED_TRANSACTION_ID )
{
throw new IllegalStateException( "Transaction id is not assigned yet. " +
"It will be assigned during transaction commit." );
}
return transactionId;
}
@Override
public long getCommitTime()
{
if ( commitTime == NOT_COMMITTED_TRANSACTION_COMMIT_TIME )
{
throw new IllegalStateException( "Transaction commit time is not assigned yet. " +
"It will be assigned during transaction commit." );
}
return commitTime;
}
@Override
public Revertable overrideWith( SecurityContext context )
{
SecurityContext oldContext = this.securityContext;
this.securityContext = context;
return () -> this.securityContext = oldContext;
}
@Override
public String toString()
{
String lockSessionId = statementLocks == null
? "statementLocks == null"
: String.valueOf( statementLocks.pessimistic().getLockSessionId() );
return "KernelTransaction[" + lockSessionId + "]";
}
public void dispose()
{
storageStatement.close();
}
/**
* This method will be invoked by concurrent threads for inspecting the locks held by this transaction.
*
* The fact that {@link #statementLocks} is a volatile fields, grants us enough of a read barrier to get a good
* enough snapshot of the lock state (as long as the underlying methods give us such guarantees).
*
* @return the locks held by this transaction.
*/
public Stream activeLocks()
{
StatementLocks locks = this.statementLocks;
return locks == null ? Stream.empty() : locks.activeLocks();
}
long userTransactionId()
{
return userTransactionId;
}
public Statistics getStatistics()
{
return statistics;
}
public static class Statistics
{
private volatile long cpuTimeNanosWhenQueryStarted;
private volatile long heapAllocatedBytesWhenQueryStarted;
private volatile long waitingTimeNanos;
private volatile long transactionThreadId;
private volatile PageCursorTracer pageCursorTracer = PageCursorTracer.NULL;
private final KernelTransactionImplementation transaction;
private final AtomicReference cpuClockRef;
private final AtomicReference heapAllocationRef;
private CpuClock cpuClock;
private HeapAllocation heapAllocation;
public Statistics( KernelTransactionImplementation transaction, AtomicReference cpuClockRef,
AtomicReference heapAllocationRef )
{
this.transaction = transaction;
this.cpuClockRef = cpuClockRef;
this.heapAllocationRef = heapAllocationRef;
}
protected void init( long threadId, PageCursorTracer pageCursorTracer )
{
this.cpuClock = cpuClockRef.get();
this.heapAllocation = heapAllocationRef.get();
this.transactionThreadId = threadId;
this.pageCursorTracer = pageCursorTracer;
this.cpuTimeNanosWhenQueryStarted = cpuClock.cpuTimeNanos( transactionThreadId );
this.heapAllocatedBytesWhenQueryStarted = heapAllocation.allocatedBytes( transactionThreadId );
}
/**
* Returns number of allocated bytes by current transaction.
* @return number of allocated bytes by the thread.
*/
long heapAllocatedBytes()
{
return heapAllocation.allocatedBytes( transactionThreadId ) - heapAllocatedBytesWhenQueryStarted;
}
/**
* Returns amount of direct memory allocated by current transaction.
*
* @return amount of direct memory allocated by the thread in bytes.
*/
long directAllocatedBytes()
{
return transaction.collectionsFactory.getMemoryTracker().usedDirectMemory();
}
/**
* Return CPU time used by current transaction in milliseconds
* @return the current CPU time used by the transaction, in milliseconds.
*/
public long cpuTimeMillis()
{
long cpuTimeNanos = cpuClock.cpuTimeNanos( transactionThreadId ) - cpuTimeNanosWhenQueryStarted;
return NANOSECONDS.toMillis( cpuTimeNanos );
}
/**
* Return total number of page cache hits that current transaction performed
* @return total page cache hits
*/
long totalTransactionPageCacheHits()
{
return pageCursorTracer.accumulatedHits();
}
/**
* Return total number of page cache faults that current transaction performed
* @return total page cache faults
*/
long totalTransactionPageCacheFaults()
{
return pageCursorTracer.accumulatedFaults();
}
/**
* Report how long any particular query was waiting during it's execution
* @param waitTimeNanos query waiting time in nanoseconds
*/
@SuppressWarnings( "NonAtomicOperationOnVolatileField" )
void addWaitingTime( long waitTimeNanos )
{
waitingTimeNanos += waitTimeNanos;
}
/**
* Accumulated transaction waiting time that includes waiting time of all already executed queries
* plus waiting time of currently executed query.
* @return accumulated transaction waiting time
* @param nowNanos current moment in nanoseconds
*/
long getWaitingTimeNanos( long nowNanos )
{
ExecutingQueryList queryList = transaction.executingQueries();
long waitingTime = waitingTimeNanos;
if ( queryList != null )
{
Long latestQueryWaitingNanos = queryList.top( executingQuery ->
executingQuery.totalWaitingTimeNanos( nowNanos ) );
waitingTime = latestQueryWaitingNanos != null ? waitingTime + latestQueryWaitingNanos : waitingTime;
}
return waitingTime;
}
void reset()
{
pageCursorTracer = PageCursorTracer.NULL;
cpuTimeNanosWhenQueryStarted = 0;
heapAllocatedBytesWhenQueryStarted = 0;
waitingTimeNanos = 0;
transactionThreadId = -1;
}
}
@Override
public ClockContext clocks()
{
return clocks;
}
@Override
public NodeCursor ambientNodeCursor()
{
return operations.nodeCursor();
}
@Override
public RelationshipScanCursor ambientRelationshipCursor()
{
return operations.relationshipCursor();
}
@Override
public PropertyCursor ambientPropertyCursor()
{
return operations.propertyCursor();
}
/**
* It is not allowed for the same transaction to perform database writes as well as schema writes.
* This enum tracks the current write transactionStatus of the transaction, allowing it to transition from
* no writes (NONE) to data writes (DATA) or schema writes (SCHEMA), but it cannot transition between
* DATA and SCHEMA without throwing an InvalidTransactionTypeKernelException. Note that this behavior
* is orthogonal to the SecurityContext which manages what the transaction or statement is allowed to do
* based on authorization.
*/
private enum TransactionWriteState
{
NONE,
DATA
{
@Override
TransactionWriteState upgradeToSchemaWrites() throws InvalidTransactionTypeKernelException
{
throw new InvalidTransactionTypeKernelException(
"Cannot perform schema updates in a transaction that has performed data updates." );
}
},
SCHEMA
{
@Override
TransactionWriteState upgradeToDataWrites() throws InvalidTransactionTypeKernelException
{
throw new InvalidTransactionTypeKernelException(
"Cannot perform data updates in a transaction that has performed schema updates." );
}
};
TransactionWriteState upgradeToDataWrites() throws InvalidTransactionTypeKernelException
{
return DATA;
}
TransactionWriteState upgradeToSchemaWrites() throws InvalidTransactionTypeKernelException
{
return SCHEMA;
}
}
}