org.apache.druid.sql.calcite.expression.builtin.TimeParseOperatorConversion.java Source code

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Here is the source code for org.apache.druid.sql.calcite.expression.builtin.TimeParseOperatorConversion.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.apache.druid.sql.calcite.expression.builtin;

import com.google.common.collect.ImmutableList;
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.apache.druid.java.util.common.DateTimes;
import org.apache.druid.sql.calcite.expression.DruidExpression;
import org.apache.druid.sql.calcite.expression.Expressions;
import org.apache.druid.sql.calcite.expression.OperatorConversions;
import org.apache.druid.sql.calcite.expression.SqlOperatorConversion;
import org.apache.druid.sql.calcite.planner.PlannerContext;
import org.apache.druid.sql.calcite.table.RowSignature;
import org.joda.time.DateTimeZone;

import java.util.stream.Collectors;

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

    @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 = OperatorConversions.getOperandWithDefault(call.getOperands(), 1,
                RexLiteral::stringValue, null);

        final DateTimeZone timeZone = OperatorConversions.getOperandWithDefault(call.getOperands(), 2,
                operand -> DateTimes.inferTzFromString(RexLiteral.stringValue(operand)),
                plannerContext.getTimeZone());

        return DruidExpression.fromFunctionCall("timestamp_parse",
                ImmutableList
                        .of(timeExpression.getExpression(), DruidExpression.stringLiteral(pattern),
                                DruidExpression.stringLiteral(timeZone.getID()))
                        .stream().map(DruidExpression::fromExpression).collect(Collectors.toList()));
    }
}