Java PriorEventViewFactory类代码示例

import com.espertech.esper.view.internal.PriorEventViewFactory; //导入依赖的package包/类
private static boolean inspectViewFactoriesForPrevious(List<ViewFactory> viewFactories) {
    // We allow the capability only if
    //  - 1 view
    //  - 2 views and the first view is a group-by (for window-per-group access)
    if (viewFactories.size() == 1) {
        return true;
    }
    if (viewFactories.size() == 2) {
        if (viewFactories.get(0) instanceof GroupByViewFactory) {
            return true;
        }
        if (viewFactories.get(1) instanceof PriorEventViewFactory) {
            return true;
        }
        return false;
    }
    return true;
}
 

import com.espertech.esper.view.internal.PriorEventViewFactory; //导入依赖的package包/类
private static boolean inspectViewFactoriesForPrevious(List<ViewFactory> viewFactories)
{
    // We allow the capability only if
    //  - 1 view
    //  - 2 views and the first view is a group-by (for window-per-group access)
    if (viewFactories.size() == 1)
    {
        return true;
    }
    if (viewFactories.size() == 2)
    {
        if (viewFactories.get(0) instanceof GroupByViewFactory)
        {
            return true;
        }
        if (viewFactories.get(1) instanceof PriorEventViewFactory) {
            return true;
        }
        return false;
    }
    return true;
}
 

import com.espertech.esper.view.internal.PriorEventViewFactory; //导入依赖的package包/类
public static AgentInstanceViewFactoryChainContext create(List<ViewFactory> viewFactoryChain, AgentInstanceContext agentInstanceContext, ViewResourceDelegateVerifiedStream viewResourceDelegate) {

        Object previousNodeGetter = null;
        if (viewResourceDelegate.getPreviousRequests() != null && !viewResourceDelegate.getPreviousRequests().isEmpty()) {
            DataWindowViewWithPrevious factoryFound = EPStatementStartMethodHelperPrevious.findPreviousViewFactory(viewFactoryChain);
            previousNodeGetter = factoryFound.makePreviousGetter();
        }

        ViewUpdatedCollection priorViewUpdatedCollection = null;
        if (viewResourceDelegate.getPriorRequests() != null && !viewResourceDelegate.getPriorRequests().isEmpty()) {
            PriorEventViewFactory priorEventViewFactory = EPStatementStartMethodHelperPrior.findPriorViewFactory(viewFactoryChain);
            SortedMap<Integer, List<ExprPriorNode>> callbacksPerIndex = viewResourceDelegate.getPriorRequests();
            priorViewUpdatedCollection = priorEventViewFactory.makeViewUpdatedCollection(callbacksPerIndex, agentInstanceContext.getAgentInstanceId());
        }

        boolean removedStream = false;
        if (viewFactoryChain.size() > 1) {
            int countDataWindow = 0;
            for (ViewFactory viewFactory : viewFactoryChain) {
                if (viewFactory instanceof DataWindowViewFactory) {
                    countDataWindow++;
                }
            }
            removedStream = countDataWindow > 1;
        }

        return new AgentInstanceViewFactoryChainContext(agentInstanceContext, removedStream, previousNodeGetter, priorViewUpdatedCollection);
    }
 

import com.espertech.esper.view.internal.PriorEventViewFactory; //导入依赖的package包/类
public static PriorEventViewFactory findPriorViewFactory(List<ViewFactory> factories) {
    ViewFactory factoryFound = null;
    for (ViewFactory factory : factories) {
        if (factory instanceof PriorEventViewFactory) {
            factoryFound = factory;
            break;
        }
    }
    if (factoryFound == null) {
        throw new RuntimeException("Failed to find 'prior'-handling view factory");  // was verified earlier, should not occur
    }
    return (PriorEventViewFactory) factoryFound;
}
 

import com.espertech.esper.view.internal.PriorEventViewFactory; //导入依赖的package包/类
public SubSelectStrategyRealization instantiate(final EPServicesContext services,
                                             Viewable viewableRoot,
                                             final AgentInstanceContext agentInstanceContext,
                                             List<StopCallback> stopCallbackList) {

    List<ViewFactory> viewFactoryChain = subSelectHolder.getViewFactoryChain().getViewFactoryChain();

    // add "prior" view factory
    boolean hasPrior = viewResourceDelegate.getPerStream()[0].getPriorRequests() != null && !viewResourceDelegate.getPerStream()[0].getPriorRequests().isEmpty();
    if (hasPrior) {
        PriorEventViewFactory priorEventViewFactory = EPStatementStartMethodHelperPrior.getPriorEventViewFactory(agentInstanceContext.getStatementContext(), 1024 + subqueryNumber, viewFactoryChain.size() + 1, viewFactoryChain.isEmpty());
        viewFactoryChain = new ArrayList<ViewFactory>(viewFactoryChain);
        viewFactoryChain.add(priorEventViewFactory);
    }

    // create factory chain context to hold callbacks specific to "prior" and "prev"
    AgentInstanceViewFactoryChainContext viewFactoryChainContext = AgentInstanceViewFactoryChainContext.create(viewFactoryChain, agentInstanceContext, viewResourceDelegate.getPerStream()[0]);

    ViewServiceCreateResult createResult = services.getViewService().createViews(viewableRoot, viewFactoryChain, viewFactoryChainContext, false);
    final Viewable subselectView = createResult.getFinalViewable();

    // create index/holder table
    final EventTable index = pair.getFirst().makeEventTable();
    stopCallbackList.add(new SubqueryStopCallback(index));

    // create strategy
    SubordTableLookupStrategy strategy = pair.getSecond().makeStrategy(index);
    SubselectAggregationPreprocessor subselectAggregationPreprocessor = null;

    // handle "prior" nodes and their strategies
    Map<ExprPriorNode, ExprPriorEvalStrategy> priorNodeStrategies = EPStatementStartMethodHelperPrior.compilePriorNodeStrategies(viewResourceDelegate, new AgentInstanceViewFactoryChainContext[]{viewFactoryChainContext});

    // handle "previous" nodes and their strategies
    Map<ExprPreviousNode, ExprPreviousEvalStrategy> previousNodeStrategies = EPStatementStartMethodHelperPrevious.compilePreviousNodeStrategies(viewResourceDelegate, new AgentInstanceViewFactoryChainContext[]{viewFactoryChainContext});

    AggregationService aggregationService = null;
    if (aggregationServiceFactory != null) {
        aggregationService = aggregationServiceFactory.getAggregationServiceFactory().makeService(agentInstanceContext, agentInstanceContext.getStatementContext().getMethodResolutionService());

        if (!correlatedSubquery) {
            SubselectAggregatorView aggregatorView = new SubselectAggregatorView(aggregationService, filterExprEval, agentInstanceContext);
            subselectView.addView(aggregatorView);

            preload(services, null, aggregatorView, agentInstanceContext);

            return new SubSelectStrategyRealization(NULL_ROW_STRATEGY, null, aggregationService, priorNodeStrategies, previousNodeStrategies, subselectView, null);
        }
        else {
            subselectAggregationPreprocessor = new SubselectAggregationPreprocessor(aggregationService, filterExprEval);
        }
    }

    // preload
    preload(services, index, subselectView, agentInstanceContext);
    StatementAgentInstancePostLoad postLoad = new StatementAgentInstancePostLoad() {
        public void executePostLoad() {
            preload(services, index, subselectView, agentInstanceContext);
        }
    };

    BufferView bufferView = new BufferView(subSelectHolder.getStreamNumber());
    bufferView.setObserver(new SubselectBufferObserver(index));
    subselectView.addView(bufferView);

    return new SubSelectStrategyRealization(strategy, subselectAggregationPreprocessor, aggregationService, priorNodeStrategies, previousNodeStrategies, subselectView, postLoad);
}