Java tutorial
/************************************************************************************** * Copyright (C) 2008 EsperTech, Inc. All rights reserved. * * http://esper.codehaus.org * * http://www.espertech.com * * ---------------------------------------------------------------------------------- * * The software in this package is published under the terms of the GPL license * * a copy of which has been included with this distribution in the license.txt file. * **************************************************************************************/ package com.espertech.esper.core.start; import com.espertech.esper.client.EPException; import com.espertech.esper.client.EventBean; import com.espertech.esper.client.EventType; import com.espertech.esper.client.context.ContextPartitionSelector; import com.espertech.esper.collection.Pair; import com.espertech.esper.core.service.EPPreparedQueryResult; import com.espertech.esper.core.service.EPServicesContext; import com.espertech.esper.core.service.StatementContext; import com.espertech.esper.epl.core.StreamTypeServiceImpl; import com.espertech.esper.epl.expression.ExprValidationException; import com.espertech.esper.epl.named.NamedWindowProcessor; import com.espertech.esper.epl.named.NamedWindowProcessorInstance; import com.espertech.esper.epl.spec.NamedWindowConsumerStreamSpec; import com.espertech.esper.epl.spec.StatementSpecCompiled; import com.espertech.esper.epl.spec.StreamSpecCompiled; import com.espertech.esper.filter.FilterSpecCompiled; import com.espertech.esper.filter.FilterSpecCompiler; import com.espertech.esper.util.AuditPath; import com.espertech.esper.util.CollectionUtil; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.util.*; /** * Starts and provides the stop method for EPL statements. */ public abstract class EPPreparedExecuteSingleStream implements EPPreparedExecuteMethod { private static final Log queryPlanLog = LogFactory.getLog(AuditPath.QUERYPLAN_LOG); private static final Log log = LogFactory.getLog(EPPreparedExecuteSingleStream.class); protected final StatementSpecCompiled statementSpec; protected final NamedWindowProcessor processor; protected final EPServicesContext services; protected final EPPreparedExecuteSingleStreamExec executor; protected final StatementContext statementContext; public abstract EPPreparedExecuteSingleStreamExec getExecutor(FilterSpecCompiled filter, String aliasName) throws ExprValidationException; /** * Ctor. * @param statementSpec is a container for the definition of all statement constructs that * may have been used in the statement, i.e. if defines the select clauses, insert into, outer joins etc. * @param services is the service instances for dependency injection * @param statementContext is statement-level information and statement services * @throws com.espertech.esper.epl.expression.ExprValidationException if the preparation failed */ public EPPreparedExecuteSingleStream(StatementSpecCompiled statementSpec, EPServicesContext services, StatementContext statementContext) throws ExprValidationException { boolean queryPlanLogging = services.getConfigSnapshot().getEngineDefaults().getLogging() .isEnableQueryPlan(); if (queryPlanLogging) { queryPlanLog.info("Query plans for Fire-and-forget query '" + statementContext.getExpression() + "'"); } this.statementSpec = statementSpec; this.services = services; this.statementContext = statementContext; EPPreparedExecuteMethodHelper.validateFAFQuery(statementSpec); // resolve named window processor final StreamSpecCompiled streamSpec = statementSpec.getStreamSpecs()[0]; NamedWindowConsumerStreamSpec namedSpec = (NamedWindowConsumerStreamSpec) streamSpec; String aliasName = namedSpec.getWindowName(); if (namedSpec.getOptionalStreamName() != null) { aliasName = namedSpec.getOptionalStreamName(); } processor = services.getNamedWindowService().getProcessor(namedSpec.getWindowName()); if (processor == null) { throw new ExprValidationException( "A named window by name '" + namedSpec.getWindowName() + "' does not exist"); } EventType eventType = processor.getTailView().getEventType(); // compile filter to optimize access to named window StreamTypeServiceImpl typeService = new StreamTypeServiceImpl(new EventType[] { eventType }, new String[] { aliasName }, new boolean[] { true }, services.getEngineURI(), true); FilterSpecCompiled filter; if (statementSpec.getFilterRootNode() != null) { LinkedHashMap<String, Pair<EventType, String>> tagged = new LinkedHashMap<String, Pair<EventType, String>>(); FilterSpecCompiled filterCompiled; try { filterCompiled = FilterSpecCompiler.makeFilterSpec(eventType, aliasName, Collections.singletonList(statementSpec.getFilterRootNode()), null, tagged, tagged, typeService, null, statementContext, Collections.singleton(0)); } catch (Exception ex) { log.warn("Unexpected exception analyzing filter paths: " + ex.getMessage(), ex); filterCompiled = null; } filter = filterCompiled; } else { filter = null; } // validate expressions EPStatementStartMethodHelperValidate.validateNodes(statementSpec, statementContext, typeService, null); // get executor executor = getExecutor(filter, aliasName); } /** * Returns the event type of the prepared statement. * @return event type */ public EventType getEventType() { return processor.getNamedWindowType(); } /** * Executes the prepared query. * @return query results */ public EPPreparedQueryResult execute(ContextPartitionSelector[] contextPartitionSelectors) { if (contextPartitionSelectors != null && contextPartitionSelectors.length != 1) { throw new IllegalArgumentException("Number of context partition selectors must be one"); } ContextPartitionSelector optionalSingleSelector = contextPartitionSelectors != null && contextPartitionSelectors.length > 0 ? contextPartitionSelectors[0] : null; // validate context if (processor.getContextName() != null && statementSpec.getOptionalContextName() != null && !processor.getContextName().equals(statementSpec.getOptionalContextName())) { throw new EPException("Context for named window is '" + processor.getContextName() + "' and query specifies context '" + statementSpec.getOptionalContextName() + "'"); } // handle non-specified context if (statementSpec.getOptionalContextName() == null) { NamedWindowProcessorInstance processorInstance = processor.getProcessorInstanceNoContext(); if (processorInstance != null) { EventBean[] rows = executor.execute(processorInstance); if (rows.length > 0) { dispatch(); } return new EPPreparedQueryResult(processor.getNamedWindowType(), rows); } } // context partition runtime query Collection<Integer> agentInstanceIds = EPPreparedExecuteMethodHelper.getAgentInstanceIds(processor, optionalSingleSelector, services.getContextManagementService(), processor.getContextName()); // collect events and agent instances if (agentInstanceIds.isEmpty()) { return new EPPreparedQueryResult(processor.getNamedWindowType(), CollectionUtil.EVENT_PER_STREAM_EMPTY); } if (agentInstanceIds.size() == 1) { int agentInstanceId = agentInstanceIds.iterator().next(); NamedWindowProcessorInstance processorInstance = processor.getProcessorInstance(agentInstanceId); EventBean[] rows = executor.execute(processorInstance); if (rows.length > 0) { dispatch(); } return new EPPreparedQueryResult(processor.getNamedWindowType(), rows); } ArrayDeque<EventBean> allRows = new ArrayDeque<EventBean>(); for (int agentInstanceId : agentInstanceIds) { NamedWindowProcessorInstance processorInstance = processor.getProcessorInstance(agentInstanceId); if (processorInstance != null) { EventBean[] rows = executor.execute(processorInstance); allRows.addAll(Arrays.asList(rows)); } } if (allRows.size() > 0) { dispatch(); } return new EPPreparedQueryResult(processor.getNamedWindowType(), allRows.toArray(new EventBean[allRows.size()])); } protected void dispatch() { services.getInternalEventEngineRouteDest().processThreadWorkQueue(); } }