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

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Here is the source code for io.druid.sql.calcite.expression.builtin.MillisToTimestampOperatorConversion.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.builtin;

import com.google.common.collect.Iterables;
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.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;

public class MillisToTimestampOperatorConversion implements SqlOperatorConversion {
    private static final SqlFunction SQL_FUNCTION = OperatorConversions.operatorBuilder("MILLIS_TO_TIMESTAMP")
            .operandTypes(SqlTypeFamily.EXACT_NUMERIC).returnType(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) {
        // Nothing to do, just leave the operand unchanged. Druid treats millis and timestamps the same internally.
        final RexCall call = (RexCall) rexNode;
        return Expressions.toDruidExpression(plannerContext, rowSignature,
                Iterables.getOnlyElement(call.getOperands()));
    }
}