io.druid.sql.calcite.expression.TimeFormatOperatorConversion.java Source code

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Here is the source code for io.druid.sql.calcite.expression.TimeFormatOperatorConversion.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package io.druid.sql.calcite.expression;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import io.druid.java.util.common.granularity.Granularity;
import io.druid.query.extraction.ExtractionFn;
import io.druid.query.extraction.TimeFormatExtractionFn;
import io.druid.sql.calcite.planner.PlannerContext;
import io.druid.sql.calcite.table.RowSignature;
import org.apache.calcite.rex.RexCall;
import org.apache.calcite.rex.RexLiteral;
import org.apache.calcite.rex.RexNode;
import org.apache.calcite.sql.SqlFunction;
import org.apache.calcite.sql.SqlFunctionCategory;
import org.apache.calcite.sql.SqlOperator;
import org.apache.calcite.sql.type.SqlTypeFamily;
import org.apache.calcite.sql.type.SqlTypeName;
import org.joda.time.DateTimeZone;

import java.util.stream.Collectors;

public class TimeFormatOperatorConversion implements SqlOperatorConversion {
    private static final SqlFunction SQL_FUNCTION = OperatorConversions.operatorBuilder("TIME_FORMAT")
            .operandTypes(SqlTypeFamily.TIMESTAMP, SqlTypeFamily.CHARACTER, SqlTypeFamily.CHARACTER)
            .requiredOperands(1).returnType(SqlTypeName.VARCHAR).functionCategory(SqlFunctionCategory.TIMEDATE)
            .build();

    public static SimpleExtraction applyTimestampFormat(final SimpleExtraction simpleExtraction,
            final String pattern, final DateTimeZone timeZone) {
        Preconditions.checkNotNull(simpleExtraction, "simpleExtraction");
        Preconditions.checkNotNull(pattern, "pattern");
        Preconditions.checkNotNull(timeZone, "timeZone");

        final ExtractionFn baseExtractionFn = simpleExtraction.getExtractionFn();

        if (baseExtractionFn instanceof TimeFormatExtractionFn) {
            final TimeFormatExtractionFn baseTimeFormatFn = (TimeFormatExtractionFn) baseExtractionFn;
            final Granularity queryGranularity = ExtractionFns.toQueryGranularity(baseTimeFormatFn);
            if (queryGranularity != null) {
                // Combine EXTRACT(X FROM FLOOR(Y TO Z)) into a single extractionFn.
                return SimpleExtraction.of(simpleExtraction.getColumn(),
                        new TimeFormatExtractionFn(pattern, timeZone, null, queryGranularity, true));
            }
        }

        return simpleExtraction.cascade(new TimeFormatExtractionFn(pattern, timeZone, null, null, true));
    }

    @Override
    public SqlOperator calciteOperator() {
        return SQL_FUNCTION;
    }

    @Override
    public DruidExpression toDruidExpression(final PlannerContext plannerContext, final RowSignature rowSignature,
            final RexNode rexNode) {
        final RexCall call = (RexCall) rexNode;
        final RexNode timeArg = call.getOperands().get(0);
        final DruidExpression timeExpression = Expressions.toDruidExpression(plannerContext, rowSignature, timeArg);
        if (timeExpression == null) {
            return null;
        }

        final String pattern = call.getOperands().size() > 1 && !RexLiteral.isNullLiteral(call.getOperands().get(1))
                ? RexLiteral.stringValue(call.getOperands().get(1))
                : "yyyy-MM-dd'T'HH:mm:ss.SSSZZ";
        final DateTimeZone timeZone = call.getOperands().size() > 2
                && !RexLiteral.isNullLiteral(call.getOperands().get(2))
                        ? DateTimeZone.forID(RexLiteral.stringValue(call.getOperands().get(2)))
                        : plannerContext.getTimeZone();

        return timeExpression.map(simpleExtraction -> applyTimestampFormat(simpleExtraction, pattern, timeZone),
                expression -> DruidExpression.functionCall("timestamp_format",
                        ImmutableList
                                .of(expression, DruidExpression.stringLiteral(pattern),
                                        DruidExpression.stringLiteral(timeZone.getID()))
                                .stream().map(DruidExpression::fromExpression).collect(Collectors.toList())));
    }
}