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

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Here is the source code for io.druid.sql.calcite.expression.TimeExtractOperatorConversion.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.collect.ImmutableMap;
import io.druid.query.expression.TimestampExtractExprMacro;
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.type.SqlTypeFamily;
import org.apache.calcite.sql.type.SqlTypeName;
import org.joda.time.DateTimeZone;

import java.util.Map;

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

    // Note that QUARTER is not supported here.
    private static final Map<TimestampExtractExprMacro.Unit, String> EXTRACT_FORMAT_MAP = ImmutableMap.<TimestampExtractExprMacro.Unit, String>builder()
            .put(TimestampExtractExprMacro.Unit.SECOND, "s").put(TimestampExtractExprMacro.Unit.MINUTE, "m")
            .put(TimestampExtractExprMacro.Unit.HOUR, "H").put(TimestampExtractExprMacro.Unit.DAY, "d")
            .put(TimestampExtractExprMacro.Unit.DOW, "e").put(TimestampExtractExprMacro.Unit.DOY, "D")
            .put(TimestampExtractExprMacro.Unit.WEEK, "w").put(TimestampExtractExprMacro.Unit.MONTH, "M")
            .put(TimestampExtractExprMacro.Unit.YEAR, "Y").build();

    public static DruidExpression applyTimeExtract(final DruidExpression timeExpression,
            final TimestampExtractExprMacro.Unit unit, final DateTimeZone timeZone) {
        return timeExpression.map(simpleExtraction -> {
            final String formatString = EXTRACT_FORMAT_MAP.get(unit);
            if (formatString == null) {
                return null;
            } else {
                return TimeFormatOperatorConversion.applyTimestampFormat(simpleExtraction, formatString, timeZone);
            }
        }, expression -> String.format("timestamp_extract(%s,%s,%s)", expression,
                DruidExpression.stringLiteral(unit.name()), DruidExpression.stringLiteral(timeZone.getID())));
    }

    @Override
    public SqlFunction 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 TimestampExtractExprMacro.Unit unit = TimestampExtractExprMacro.Unit
                .valueOf(RexLiteral.stringValue(call.getOperands().get(1)).toUpperCase());

        final DateTimeZone timeZone = call.getOperands().size() > 2
                && !RexLiteral.isNullLiteral(call.getOperands().get(2))
                        ? DateTimeZone.forID(RexLiteral.stringValue(call.getOperands().get(2)))
                        : plannerContext.getTimeZone();

        return applyTimeExtract(timeExpression, unit, timeZone);
    }
}