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/*
* 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 under the License.
*/
package org.apache.pig.data.utils;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.impl.logicalLayer.schema.Schema.FieldSchema;
public class StructuresHelper {
private StructuresHelper() {
}
/**
* This encapsulates a Schema and allows it to be used in such a way that
* any aliases are ignored in equality.
*/
public static class SchemaKey {
private Schema s;
public SchemaKey(Schema s) {
this.s = s;
}
private static int[] primeList = { 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37,
41, 43, 47, 53, 59, 61, 67, 71, 73, 79,
83, 89, 97, 101, 103, 107, 109, 1133};
/**
* The hashcode logic is taken from the Schema class, including how fields
* are handled. The difference is that aliases are ignored.
*/
@Override
public int hashCode() {
return hashCode(s);
}
public static int hashCode(Schema s) {
if (s == null) {
return 0;
}
int idx = 0 ;
int hashCode = 0 ;
for(FieldSchema fs : s.getFields()) {
hashCode += hashCode(fs) * (primeList[idx % primeList.length]) ;
idx++ ;
}
return hashCode ;
}
private static int hashCode(FieldSchema fs) {
return (fs.type * 17) + ( (fs.schema == null? 0 : hashCode(fs.schema)) * 23 );
}
@Override
public boolean equals(Object o) {
if (!(o instanceof SchemaKey)) {
return false;
}
Schema other = ((SchemaKey)o).get();
return (s == null && other == null) || Schema.equals(s, other, false, true);
}
public Schema get() {
return s;
}
public String toString() {
return s.toString();
}
}
/**
* This is a helper class which makes it easy to have pairs of values,
* and to use them as keys and values in Maps.
*/
public static class Pair {
private final T1 t1;
private final T2 t2;
public Pair(T1 t1, T2 t2) {
this.t1 = t1;
this.t2 = t2;
}
public T1 getFirst() {
return t1;
}
public T2 getSecond() {
return t2;
}
public static Pair make(A t1, B t2) {
return new Pair(t1, t2);
}
@Override
public int hashCode() {
return (t1 == null ? 0 : t1.hashCode()) + (t2 == null ? 0 : 31 * t2.hashCode());
}
@Override
public boolean equals(Object o) {
if (!(o instanceof Pair)) {
return false;
}
Pair pr = (Pair)o;
if (t1 == null) {
return pr.getFirst() == null;
}
if (!t1.equals(pr.getFirst())) {
return false;
}
if (t2 == null) {
return pr.getSecond() == null;
}
return t2.equals(pr.getSecond());
}
@Override
public String toString() {
return new StringBuilder()
.append("[")
.append(t1)
.append(",")
.append(t2)
.append("]")
.toString();
}
}
public static class Triple {
private final T1 t1;
private final T2 t2;
private final T3 t3;
public Triple(T1 t1, T2 t2, T3 t3) {
this.t1 = t1;
this.t2 = t2;
this.t3 = t3;
}
public T1 getFirst() {
return t1;
}
public T2 getSecond() {
return t2;
}
public T3 getThird() {
return t3;
}
public static Triple make(A t1, B t2, C t3) {
return new Triple(t1, t2, t3);
}
@Override
public int hashCode() {
return (t1 == null ? 0 : t1.hashCode())
+ (t2 == null ? 0 : 31 * t2.hashCode())
+ (t3 == null ? 0 : 527 * t3.hashCode());
}
@Override
public boolean equals(Object o) {
if (!(o instanceof Triple)) {
return false;
}
Triple tr = (Triple)o;
if (t1 == null) {
return tr.getFirst() == null;
}
if (!t1.equals(tr.getFirst())) {
return false;
}
if (t2 == null) {
return tr.getSecond() == null;
}
if (!t2.equals(tr.getSecond())) {
return false;
}
if (t3 == null) {
return tr.getThird() ==null;
}
if (!t3.equals(tr.getThird())) {
return false;
}
return true;
}
@Override
public String toString() {
return new StringBuilder()
.append("[")
.append(t1)
.append(",")
.append(t2)
.append(",")
.append(t3)
.append("]")
.toString();
}
}
}