ColumnAliasGenerator.java

Go to the documentation of this file.

// Copyright 2014 Cloudera Inc.
//
// Licensed 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 com.cloudera.impala.common;

import java.util.List;

import com.google.common.base.Preconditions;

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);
  }
}