Examples with VersionContext org.neo4j.io.pagecache.context.VersionContext used on opensource projects

Example 1 with VersionContext

use of org.neo4j.io.pagecache.context.VersionContext in project neo4j by neo4j.

the class SnapshotExecutionEngine method executeWithRetries.

protected MaterialisedResult executeWithRetries(String query, TransactionalContext context, QueryExecutor executor) throws QueryExecutionKernelException {
    VersionContext versionContext = getCursorContext(context);
    MaterialisedResult materialisedResult;
    int attempt = 0;
    boolean dirtySnapshot;
    do {
        if (attempt == maxQueryExecutionAttempts) {
            throw new QueryExecutionKernelException(new UnstableSnapshotException("Unable to get clean data snapshot for query '%s' after %d attempts.", query, attempt));
        }
        if (attempt > 0) {
            context.executingQuery().onRetryAttempted();
        }
        attempt++;
        versionContext.initRead();
        materialisedResult = new MaterialisedResult();
        QueryExecution queryExecution = executor.execute(materialisedResult);
        materialisedResult.consumeAll(queryExecution);
        // objects is guaranteed by schema and not by execution engine
        if (context.transaction().kernelTransaction().isSchemaTransaction()) {
            return materialisedResult;
        }
        dirtySnapshot = versionContext.isDirty();
        if (isUnstableSnapshot(materialisedResult, dirtySnapshot)) {
            throw new QueryExecutionKernelException(new UnstableSnapshotException("Unable to get clean data snapshot for query '%s' that performs updates.", query, attempt));
        }
    } while (dirtySnapshot);
    return materialisedResult;
}

Example 2 with VersionContext

use of org.neo4j.io.pagecache.context.VersionContext in project neo4j by neo4j.

the class SnapshotExecutionEngineTest method setUp.

@BeforeEach
void setUp() throws Exception {
    transactionalContext = mock(TransactionalContext.class, RETURNS_DEEP_STUBS);
    KernelStatement kernelStatement = mock(KernelStatement.class);
    executor = mock(SnapshotExecutionEngine.QueryExecutor.class);
    versionContext = mock(VersionContext.class);
    statistics = mock(QueryStatistics.class);
    executionEngine = new SnapshotExecutionEngine(new GraphDatabaseCypherService(db), config, TestExecutorCaffeineCacheFactory$.MODULE$, NullLogProvider.getInstance(), mock(CompilerFactory.class));
    when(transactionalContext.kernelTransaction().cursorContext()).thenReturn(new CursorContext(NULL, versionContext));
    when(transactionalContext.statement()).thenReturn(kernelStatement);
    var innerExecution = mock(QueryExecution.class);
    when(executor.execute(any())).thenAnswer((Answer<QueryExecution>) invocationOnMock -> {
        MaterialisedResult materialisedResult = invocationOnMock.getArgument(0);
        materialisedResult.onResultCompleted(statistics);
        return innerExecution;
    });
}