parquet.hadoop.metadata.EncodingList Maven / Gradle / Ivy
/**
* Copyright 2012 Twitter, 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 parquet.hadoop.metadata;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import parquet.column.Encoding;
public class EncodingList implements Iterable {
private static Map encodingLists = new HashMap();
public static EncodingList getEncodingList(List encodings) {
EncodingList key = new EncodingList(encodings);
EncodingList cached = encodingLists.get(key);
if (cached == null) {
cached = key;
encodingLists.put(key, cached);
}
return cached;
}
private final List encodings;
private EncodingList(List encodings) {
super();
this.encodings = Collections.unmodifiableList(encodings);
}
@Override
public boolean equals(Object obj) {
if (obj instanceof EncodingList) {
List other = ((EncodingList)obj).encodings;
final int size = other.size();
if (size != encodings.size()) {
return false;
}
for (int i = 0; i < size; i++) {
if (!other.get(i).equals(encodings.get(i))) {
return false;
}
}
return true;
}
return false;
}
@Override
public int hashCode() {
int result = 1;
for (parquet.column.Encoding element : encodings)
result = 31 * result + (element == null ? 0 : element.hashCode());
return result;
}
public List toList() {
return encodings;
}
@Override
public Iterator iterator() {
return encodings.iterator();
}
public int size() {
return encodings.size();
}
}