ColumnAliasGenerator.java

// Licensed to the Apache Software Foundation (ASF) under one
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// 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
//
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// software distributed under the License is distributed on an
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// specific language governing permissions and limitations
// under the License.
// This file is copied from
// https://github.com/apache/impala/blob/branch-2.9.0/fe/src/main/java/org/apache/impala/ColumnAliasGenerator.java
// and modified by Doris

package org.apache.doris.common;

import com.google.common.base.Preconditions;

import java.util.List;

public class ColumnAliasGenerator extends AliasGenerator {
    private static final String DEFAULT_COL_ALIAS_PREFIX = "!c!";

    public ColumnAliasGenerator(List<String> existingLabels, String prefix) {
        Preconditions.checkNotNull(existingLabels);
        aliasPrefix = prefix != null ? prefix : DEFAULT_COL_ALIAS_PREFIX;
        usedAliases.addAll(existingLabels);
    }
}