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

Introduction

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

Source

/*
 * 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.builtin;

import com.google.common.collect.ImmutableList;
import io.druid.java.util.common.DateTimes;
import io.druid.java.util.common.StringUtils;
import io.druid.query.expression.TimestampExtractExprMacro;
import io.druid.sql.calcite.expression.DruidExpression;
import io.druid.sql.calcite.expression.Expressions;
import io.druid.sql.calcite.expression.OperatorConversions;
import io.druid.sql.calcite.expression.SqlOperatorConversion;
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;

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();

    public static DruidExpression applyTimeExtract(final DruidExpression timeExpression,
            final TimestampExtractExprMacro.Unit unit, final DateTimeZone timeZone) {
        return DruidExpression.fromFunctionCall("timestamp_extract",
                ImmutableList.of(timeExpression,
                        DruidExpression.fromExpression(DruidExpression.stringLiteral(unit.name())),
                        DruidExpression.fromExpression(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(StringUtils.toUpperCase(RexLiteral.stringValue(call.getOperands().get(1))));

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

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