001 /*
002 * Java Genetic Algorithm Library (jenetics-6.1.0).
003 * Copyright (c) 2007-2020 Franz Wilhelmstötter
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 *
017 * Author:
018 * Franz Wilhelmstötter (franz.wilhelmstoetter@gmail.com)
019 */
020 package io.jenetics.engine;
021
022 import static java.lang.String.format;
023 import static java.util.Objects.requireNonNull;
024 import static io.jenetics.internal.util.Hashes.hash;
025 import static io.jenetics.internal.util.SerialIO.readLong;
026 import static io.jenetics.internal.util.SerialIO.writeLong;
027
028 import java.io.IOException;
029 import java.io.InvalidObjectException;
030 import java.io.ObjectInput;
031 import java.io.ObjectInputStream;
032 import java.io.ObjectOutput;
033 import java.io.Serializable;
034 import java.util.Objects;
035
036 import io.jenetics.Gene;
037 import io.jenetics.Genotype;
038 import io.jenetics.internal.util.Requires;
039 import io.jenetics.util.ISeq;
040
041 /**
042 * Represents the initialization value of an evolution stream/iterator.
043 *
044 * @see EvolutionStart
045 * @see EvolutionStreamable#stream(EvolutionInit)
046 *
047 * @param <G> the gene type
048 *
049 * @implNote
050 * This class is immutable and thread-safe.
051 *
052 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
053 * @version 6.0
054 * @since 4.1
055 */
056 public final /*record*/ class EvolutionInit<G extends Gene<?, G>>
057 implements Serializable
058 {
059
060 private static final long serialVersionUID = 1L;
061
062 private final ISeq<Genotype<G>> _population;
063 private final long _generation;
064
065 private EvolutionInit(
066 final ISeq<Genotype<G>> population,
067 final long generation
068 ) {
069 _population = requireNonNull(population);
070 _generation = Requires.positive(generation);
071 }
072
073 /**
074 * Return the initial population.
075 *
076 * @return the initial population
077 */
078 public ISeq<Genotype<G>> population() {
079 return _population;
080 }
081
082 /**
083 * Return the generation of the start population.
084 *
085 * @return the start generation
086 */
087 public long generation() {
088 return _generation;
089 }
090
091 @Override
092 public int hashCode() {
093 return hash(_generation, hash(_population));
094 }
095
096 @Override
097 public boolean equals(final Object obj) {
098 return obj == this ||
099 obj instanceof EvolutionInit &&
100 _generation == ((EvolutionInit)obj)._generation &&
101 Objects.equals(_population, ((EvolutionInit)obj)._population);
102 }
103
104 @Override
105 public String toString() {
106 return format(
107 "EvolutionStart[population-size=%d, generation=%d]",
108 _population.size(), _generation
109 );
110 }
111
112 /**
113 * Create a new evolution start object with the given population and for the
114 * given generation.
115 *
116 * @param <G> the gene type
117 * @param population the start population.
118 * @param generation the start generation of the population
119 * @return a new evolution start object
120 * @throws java.lang.NullPointerException if the given {@code population} is
121 * {@code null}.
122 * @throws IllegalArgumentException if the given {@code generation} is
123 * smaller then one
124 */
125 public static <G extends Gene<?, G>>
126 EvolutionInit<G> of(
127 final ISeq<Genotype<G>> population,
128 final long generation
129 ) {
130 return new EvolutionInit<>(population, generation);
131 }
132
133
134 /* *************************************************************************
135 * Java object serialization
136 * ************************************************************************/
137
138 private Object writeReplace() {
139 return new Serial(Serial.EVOLUTION_INIT, this);
140 }
141
142 private void readObject(final ObjectInputStream stream)
143 throws InvalidObjectException
144 {
145 throw new InvalidObjectException("Serialization proxy required.");
146 }
147
148 void write(final ObjectOutput out) throws IOException {
149 out.writeObject(_population);
150 writeLong(_generation, out);
151 }
152
153 @SuppressWarnings({"unchecked", "rawtypes"})
154 static Object read(final ObjectInput in)
155 throws IOException, ClassNotFoundException
156 {
157 return new EvolutionInit(
158 (ISeq)in.readObject(),
159 readLong(in)
160 );
161 }
162
163 }
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