ai.rapids.cudf.ColumnFilterOptions Maven / Gradle / Ivy
/*
*
* Copyright (c) 2019-2020, NVIDIA CORPORATION.
*
* 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 ai.rapids.cudf;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.function.Supplier;
/**
* Base options class for input formats that can filter columns.
*/
public abstract class ColumnFilterOptions {
// Names of the columns to be returned (other columns are skipped)
// If empty all columns are returned.
private final String[] includeColumnNames;
protected ColumnFilterOptions(Builder builder) {
includeColumnNames = builder.includeColumnNames.toArray(
new String[builder.includeColumnNames.size()]);
}
String[] getIncludeColumnNames() {
return includeColumnNames;
}
public static class Builder {
final List includeColumnNames = new ArrayList<>();
/**
* Include one or more specific columns. Any column not included will not be read.
* @param names the name of the column, or more than one if you want.
*/
public T includeColumn(String... names) {
for (String name : names) {
includeColumnNames.add(name);
}
return (T) this;
}
/**
* Include one or more specific columns. Any column not included will not be read.
* @param names the name of the column, or more than one if you want.
*/
public T includeColumn(Collection names) {
includeColumnNames.addAll(names);
return (T) this;
}
}
}