hyracks-fullstack/algebricks/algebricks-core/src/main/java/org/apache/hyracks/algebricks/core/algebra/operators/logical/UnnestOperator.java

/*
 * 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
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package org.apache.hyracks.algebricks.core.algebra.operators.logical;

import org.apache.commons.lang3.mutable.Mutable;
import org.apache.hyracks.algebricks.common.exceptions.AlgebricksException;
import org.apache.hyracks.algebricks.core.algebra.base.ILogicalExpression;
import org.apache.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;
import org.apache.hyracks.algebricks.core.algebra.expressions.IVariableTypeEnvironment;
import org.apache.hyracks.algebricks.core.algebra.typing.ITypingContext;
import org.apache.hyracks.algebricks.core.algebra.visitors.ILogicalOperatorVisitor;
import org.apache.hyracks.algebricks.runtime.base.IUnnestingPositionWriter;

public class UnnestOperator extends AbstractUnnestNonMapOperator {

    public UnnestOperator(LogicalVariable variable, Mutable<ILogicalExpression> expression) {
        super(variable, expression);
    }

    public UnnestOperator(LogicalVariable variable, Mutable<ILogicalExpression> expression,
            LogicalVariable positionalVariable, Object positionalVariableType,
            IUnnestingPositionWriter positionWriter) {
        super(variable, expression, positionalVariable, positionalVariableType, positionWriter);
    }

    @Override
    public <R, T> R accept(ILogicalOperatorVisitor<R, T> visitor, T arg) throws AlgebricksException {
        return visitor.visitUnnestOperator(this, arg);
    }

    @Override
    public IVariableTypeEnvironment computeOutputTypeEnvironment(ITypingContext ctx) throws AlgebricksException {
        IVariableTypeEnvironment env = createPropagatingAllInputsTypeEnvironment(ctx);
        Object t = env.getType(expression.getValue());
        env.setVarType(variables.get(0), t);
        if (positionalVariable != null) {
            env.setVarType(positionalVariable, positionalVariableType);
        }
        return env;
    }

    @Override
    public LogicalOperatorTag getOperatorTag() {
        return LogicalOperatorTag.UNNEST;
    }
}