1 /*
2 * (c) Copyright 2006-2020 by rapiddweller GmbH & Volker Bergmann. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, is permitted under the terms of the
6 * GNU General Public License.
7 *
8 * For redistributing this software or a derivative work under a license other
9 * than the GPL-compatible Free Software License as defined by the Free
10 * Software Foundation or approved by OSI, you must first obtain a commercial
11 * license to this software product from rapiddweller GmbH & Volker Bergmann.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
14 * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
15 * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
17 * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
18 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
20 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
21 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
22 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
23 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
24 * POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 package com.rapiddweller.benerator.distribution.sequence;
28
29 import com.rapiddweller.benerator.GeneratorContext;
30 import com.rapiddweller.benerator.InvalidGeneratorSetupException;
31 import com.rapiddweller.benerator.primitive.number.AbstractNonNullNumberGenerator;
32
33 /**
34 * Long Generator that implements a 'shuffle' Long Sequence:
35 * It starts with min and produced numbers by continuously incrementing the cursor
36 * by a fix <code>increment</code> value; when <code>max</code> is reached, it
37 * repeats the procedure starting by min+granularity, later min+2*granularity and so on.
38 * The generated numbers are unique as long as the generator is not reset.<br/>
39 * <br/>
40 * Created: 18.06.2006 14:40:29
41 *
42 * @author Volker Bergmann
43 * @since 0.1
44 */
45 public class ShuffleLongGenerator extends AbstractNonNullNumberGenerator<Long> {
46
47 private long increment;
48 private Long next;
49
50 /**
51 * Instantiates a new Shuffle long generator.
52 */
53 public ShuffleLongGenerator() {
54 this(Long.MIN_VALUE, Long.MAX_VALUE);
55 }
56
57 /**
58 * Instantiates a new Shuffle long generator.
59 *
60 * @param min the min
61 * @param max the max
62 */
63 public ShuffleLongGenerator(long min, long max) {
64 this(min, max, 2, 1);
65 }
66
67 /**
68 * Instantiates a new Shuffle long generator.
69 *
70 * @param min the min
71 * @param max the max
72 * @param granularity the granularity
73 * @param increment the increment
74 */
75 public ShuffleLongGenerator(long min, long max, long granularity, long increment) {
76 super(Long.class, min, max, granularity);
77 this.increment = increment;
78 reset();
79 }
80
81 // config properties -----------------------------------------------------------------------------------------------
82
83 /**
84 * Gets increment.
85 *
86 * @return the increment
87 */
88 public long getIncrement() {
89 return increment;
90 }
91
92 /**
93 * Sets increment.
94 *
95 * @param increment the increment
96 */
97 public void setIncrement(long increment) {
98 this.increment = increment;
99 }
100
101 // Generator interface ---------------------------------------------------------------------------------------------
102
103 @Override
104 public void init(GeneratorContext context) {
105 assertNotInitialized();
106 if (granularity <= 0) {
107 throw new InvalidGeneratorSetupException("Granularity must be greater than zero, but is " + granularity);
108 }
109 if (min < max && increment <= 0) {
110 throw new InvalidGeneratorSetupException("Unsupported increment value: " + increment);
111 }
112 next = min;
113 super.init(context);
114 }
115
116 @Override
117 public synchronized Long generate() {
118 assertInitialized();
119 if (next == null) {
120 return null;
121 }
122 long result = next;
123 if (next + increment <= max) {
124 next += increment;
125 } else {
126 long newOffset = (next - min + granularity) % increment;
127 next = (newOffset > 0 ? min + newOffset : null);
128 }
129 return result;
130 }
131
132 @Override
133 public synchronized void reset() {
134 this.next = min;
135 }
136
137 }