com.hazelcast.org.apache.calcite.rel.core.CorrelationId Maven / Gradle / Ivy
/*
* 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 com.hazelcast.org.apache.calcite.rel.core;
import com.hazelcast.com.google.common.collect.ImmutableSet;
import java.util.Set;
/**
* Describes the necessary parameters for an implementation in order to
* identify and set dynamic variables
*/
public class CorrelationId implements Cloneable, Comparable {
/**
* Prefix to the name of correlating variables.
*/
public static final String CORREL_PREFIX = "$cor";
private final int id;
private final String name;
/**
* Creates a correlation identifier.
*/
private CorrelationId(int id, String name) {
this.id = id;
this.name = name;
}
/**
* Creates a correlation identifier.
* This is a type-safe wrapper over int.
*
* @param id Identifier
*/
public CorrelationId(int id) {
this(id, CORREL_PREFIX + id);
}
/**
* Creates a correlation identifier from a name.
*
* @param name variable name
*/
public CorrelationId(String name) {
this(Integer.parseInt(name.substring(CORREL_PREFIX.length())), name);
assert name.startsWith(CORREL_PREFIX)
: "Correlation name should start with " + CORREL_PREFIX
+ " actual name is " + name;
}
/**
* Returns the identifier.
*
* @return identifier
*/
public int getId() {
return id;
}
/**
* Returns the preferred name of the variable.
*
* @return name
*/
public String getName() {
return name;
}
public String toString() {
return name;
}
public int compareTo(CorrelationId other) {
return id - other.id;
}
@Override public int hashCode() {
return id;
}
@Override public boolean equals(Object obj) {
return this == obj
|| obj instanceof CorrelationId
&& this.id == ((CorrelationId) obj).id;
}
/** Converts a set of correlation ids to a set of names. */
public static ImmutableSet setOf(Set set) {
if (set.isEmpty()) {
return ImmutableSet.of();
}
final ImmutableSet.Builder builder = ImmutableSet.builder();
for (String s : set) {
builder.add(new CorrelationId(s));
}
return builder.build();
}
/** Converts a set of names to a set of correlation ids. */
public static Set names(Set set) {
if (set.isEmpty()) {
return ImmutableSet.of();
}
final ImmutableSet.Builder builder = ImmutableSet.builder();
for (CorrelationId s : set) {
builder.add(s.name);
}
return builder.build();
}
}