com.espertech.esper.epl.parse.ASTCreateSchemaHelper 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.parse;

import com.espertech.esper.client.EPException;
import com.espertech.esper.epl.generated.EsperEPL2GrammarParser;
import com.espertech.esper.epl.spec.ColumnDesc;
import com.espertech.esper.epl.spec.CreateSchemaDesc;
import org.antlr.v4.runtime.Token;

import java.util.*;

public class ASTCreateSchemaHelper {

    public static CreateSchemaDesc walkCreateSchema(EsperEPL2GrammarParser.CreateSchemaExprContext ctx) throws EPException {
        CreateSchemaDesc.AssignedType assignedType = CreateSchemaDesc.AssignedType.NONE;
        if (ctx.keyword != null) {
            assignedType = CreateSchemaDesc.AssignedType.parseKeyword(ctx.keyword.getText());
        }
        return getSchemaDesc(ctx.createSchemaDef(), assignedType);
    }

    private static CreateSchemaDesc getSchemaDesc(EsperEPL2GrammarParser.CreateSchemaDefContext ctx, CreateSchemaDesc.AssignedType assignedType) throws EPException {
        String schemaName = ctx.name.getText();
        List columnTypes = getColTypeList(ctx.createColumnList());

        // get model-after types (could be multiple for variants)
        Set typeNames = new LinkedHashSet();
        if (ctx.variantList() != null) {
            List variantCtxs = ctx.variantList().variantListElement();
            for (EsperEPL2GrammarParser.VariantListElementContext variantCtx : variantCtxs) {
                typeNames.add(variantCtx.getText());
            }
        }

        // get inherited and start timestamp and end timestamps
        String startTimestamp = null;
        String endTimestamp = null;
        Set inherited = new LinkedHashSet();
        Set copyFrom = new LinkedHashSet();
        if (ctx.createSchemaQual() != null) {
            List qualCtxs = ctx.createSchemaQual();
            for (EsperEPL2GrammarParser.CreateSchemaQualContext qualCtx : qualCtxs) {
                String qualName = qualCtx.i.getText().toLowerCase(Locale.ENGLISH);
                List cols = ASTUtil.getIdentList(qualCtx.columnList());
                if (qualName.toLowerCase(Locale.ENGLISH).equals("inherits")) {
                    inherited.addAll(cols);
                    continue;
                } else if (qualName.toLowerCase(Locale.ENGLISH).equals("starttimestamp")) {
                    startTimestamp = cols.get(0);
                    continue;
                } else if (qualName.toLowerCase(Locale.ENGLISH).equals("endtimestamp")) {
                    endTimestamp = cols.get(0);
                    continue;
                } else if (qualName.toLowerCase(Locale.ENGLISH).equals("copyfrom")) {
                    copyFrom.addAll(cols);
                    continue;
                }
                throw new EPException("Expected 'inherits', 'starttimestamp', 'endtimestamp' or 'copyfrom' keyword after create-schema clause but encountered '" + qualName + "'");
            }
        }

        return new CreateSchemaDesc(schemaName, typeNames, columnTypes, inherited, assignedType, startTimestamp, endTimestamp, copyFrom);
    }

    public static List getColTypeList(EsperEPL2GrammarParser.CreateColumnListContext ctx) {
        if (ctx == null) {
            return Collections.emptyList();
        }
        List result = new ArrayList(ctx.createColumnListElement().size());
        for (EsperEPL2GrammarParser.CreateColumnListElementContext colctx : ctx.createColumnListElement()) {
            List idents = colctx.classIdentifier();
            String name = ASTUtil.unescapeClassIdent(idents.get(0));
            String type;
            if (colctx.VALUE_NULL() != null) {
                type = null;
            } else {
                type = ASTUtil.unescapeClassIdent(idents.get(1));
            }
            boolean array = colctx.b != null;
            boolean primitiveArray = validateIsPrimitiveArray(colctx.p);
            result.add(new ColumnDesc(name, type, array, primitiveArray));
        }
        return result;
    }

    protected static boolean validateIsPrimitiveArray(Token p) {
        if (p != null) {
            if (!p.getText().toLowerCase(Locale.ENGLISH).equals("primitive")) {
                throw ASTWalkException.from("Column type keyword '" + p.getText() + "' not recognized, expecting '[primitive]'");
            }
            return true;
        }
        return false;
    }
}