com.espertech.esper.epl.enummethod.eval.EnumToMapEventsForgeEval Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of esper Show documentation
Complex event processing and event series analysis component
The newest version!
/*
 ***************************************************************************************
 *  Copyright (C) 2006 EsperTech, Inc. All rights reserved.                            *
 *  http://www.espertech.com/esper                                                     *
 *  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.epl.enummethod.eval;

import com.espertech.esper.client.EventBean;
import com.espertech.esper.codegen.base.CodegenBlock;
import com.espertech.esper.codegen.base.CodegenClassScope;
import com.espertech.esper.codegen.base.CodegenMethodScope;
import com.espertech.esper.codegen.model.expression.CodegenExpression;
import com.espertech.esper.epl.enummethod.codegen.EnumForgeCodegenParams;
import com.espertech.esper.epl.enummethod.codegen.EnumForgeCodegenNames;
import com.espertech.esper.epl.expression.codegen.ExprForgeCodegenSymbol;
import com.espertech.esper.codegen.base.CodegenMethodNode;
import com.espertech.esper.epl.expression.core.ExprEvaluator;
import com.espertech.esper.epl.expression.core.ExprEvaluatorContext;

import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import static com.espertech.esper.codegen.model.expression.CodegenExpressionBuilder.*;

public class EnumToMapEventsForgeEval implements EnumEval {

    private final EnumToMapEventsForge forge;
    private final ExprEvaluator innerExpression;
    private final ExprEvaluator secondExpression;

    public EnumToMapEventsForgeEval(EnumToMapEventsForge forge, ExprEvaluator innerExpression, ExprEvaluator secondExpression) {
        this.forge = forge;
        this.innerExpression = innerExpression;
        this.secondExpression = secondExpression;
    }

    public Object evaluateEnumMethod(EventBean[] eventsLambda, Collection enumcoll, boolean isNewData, ExprEvaluatorContext context) {
        if (enumcoll.isEmpty()) {
            return Collections.emptyMap();
        }

        Map map = new HashMap();

        Collection beans = (Collection) enumcoll;
        for (EventBean next : beans) {
            eventsLambda[forge.streamNumLambda] = next;

            Object key = innerExpression.evaluate(eventsLambda, isNewData, context);
            Object value = secondExpression.evaluate(eventsLambda, isNewData, context);
            map.put(key, value);
        }

        return map;
    }

    public static CodegenExpression codegen(EnumToMapEventsForge forge, EnumForgeCodegenParams args, CodegenMethodScope codegenMethodScope, CodegenClassScope codegenClassScope) {
        ExprForgeCodegenSymbol scope = new ExprForgeCodegenSymbol(false, null);
        CodegenMethodNode methodNode = codegenMethodScope.makeChildWithScope(Map.class, EnumToMapEventsForgeEval.class, scope, codegenClassScope).addParam(EnumForgeCodegenNames.PARAMS);

        CodegenBlock block = methodNode.getBlock()
                .ifCondition(exprDotMethod(EnumForgeCodegenNames.REF_ENUMCOLL, "isEmpty"))
                .blockReturn(staticMethod(Collections.class, "emptyMap"));
        block.declareVar(Map.class, "map", newInstance(HashMap.class));
        block.forEach(EventBean.class, "next", EnumForgeCodegenNames.REF_ENUMCOLL)
                .assignArrayElement(EnumForgeCodegenNames.REF_EPS, constant(forge.streamNumLambda), ref("next"))
                .declareVar(Object.class, "key", forge.innerExpression.evaluateCodegen(Object.class, methodNode, scope, codegenClassScope))
                .declareVar(Object.class, "value", forge.secondExpression.evaluateCodegen(Object.class, methodNode, scope, codegenClassScope))
                .expression(exprDotMethod(ref("map"), "put", ref("key"), ref("value")));
        block.methodReturn(ref("map"));
        return localMethod(methodNode, args.getEps(), args.getEnumcoll(), args.getIsNewData(), args.getExprCtx());
    }
}