1 // Protocol Buffers - Google's data interchange format
2 // Copyright 2008 Google Inc.  All rights reserved.
3 // https://developers.google.com/protocol-buffers/
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30 
31 package com.google.protobuf;
32 
33 import java.util.Random;
34 
35 /** Utility class that provides data primitives for filling out protobuf messages. */
36 public final class ExperimentalTestDataProvider {
37   private static final Random RANDOM = new Random(100);
38 
39   private final Varint32Provider varint32s = new Varint32Provider();
40   private final Varint64Provider varint64s = new Varint64Provider();
41   private final int stringLength;
42 
ExperimentalTestDataProvider(int stringLength)43   public ExperimentalTestDataProvider(int stringLength) {
44     this.stringLength = stringLength;
45   }
46 
getDouble()47   public double getDouble() {
48     double value = 0.0;
49     while (Double.compare(0.0, value) == 0) {
50       value = RANDOM.nextDouble();
51     }
52     return value;
53   }
54 
getFloat()55   public float getFloat() {
56     float value = 0.0f;
57     while (Float.compare(0.0f, value) == 0) {
58       value = RANDOM.nextFloat();
59     }
60     return value;
61   }
62 
getLong()63   public long getLong() {
64     return varint64s.getLong();
65   }
66 
getInt()67   public int getInt() {
68     return varint32s.getInt();
69   }
70 
getBool()71   public boolean getBool() {
72     return true;
73   }
74 
getEnum()75   public int getEnum() {
76     return Math.abs(getInt()) % 3;
77   }
78 
getString()79   public String getString() {
80     StringBuilder builder = new StringBuilder(stringLength);
81     for (int i = 0; i < stringLength; ++i) {
82       builder.append((char) (RANDOM.nextInt('z' - 'a') + 'a'));
83     }
84     return builder.toString();
85   }
86 
getBytes()87   public ByteString getBytes() {
88     return ByteString.copyFromUtf8(getString());
89   }
90 
91   /**
92    * Iterator over integer values. Uses a simple distribution over 32-bit varints (generally
93    * favoring smaller values).
94    */
95   private static final class Varint32Provider {
96     private static final int[][] VALUES = {
97       new int[] {1, 50, 100, 127}, // 1 byte values
98       new int[] {128, 500, 10000, 16383}, // 2 bytes values
99       new int[] {16384, 50000, 1000000, 2097151}, // 3 bytes values
100       new int[] {2097152, 10000000, 200000000, 268435455}, // 4 bytes values
101       new int[] {268435456, 0x30000000, 0x7FFFFFFF, 0xFFFFFFFF} // 5 bytes values
102     };
103 
104     /** Number of samples that should be taken from each value array. */
105     private static final int[] NUM_SAMPLES = {3, 2, 1, 1, 2};
106 
107     /**
108      * The index into the {@link #VALUES} array that identifies the list of samples currently being
109      * iterated over.
110      */
111     private int listIndex;
112 
113     /** The index of the next sample within a list. */
114     private int sampleIndex;
115 
116     /** The number of successive samples that have been taken from the current list. */
117     private int samplesTaken;
118 
getInt()119     public int getInt() {
120       if (samplesTaken++ > NUM_SAMPLES[listIndex]) {
121         // Done taking samples from this list. Go to the next one.
122         listIndex = (listIndex + 1) % VALUES.length;
123         sampleIndex = 0;
124         samplesTaken = 0;
125       }
126 
127       int value = VALUES[listIndex][sampleIndex];
128 
129       // All lists are exactly 4 long (i.e. power of 2), so we can optimize the mod operation
130       // with masking.
131       sampleIndex = (sampleIndex + 1) & 3;
132 
133       return value;
134     }
135   }
136 
137   /**
138    * Iterator over integer values. Uses a simple distribution over 64-bit varints (generally
139    * favoring smaller values).
140    */
141   private static final class Varint64Provider {
142     private static final long[][] VALUES = {
143       new long[] {1, 50, 100, 127},
144       new long[] {128, 500, 10000, 16383},
145       new long[] {16384, 50000, 1000000, 2097151},
146       new long[] {2097152, 10000000, 200000000, 268435455},
147       new long[] {268435456, 0x30000000, 0x7FFFFFFF, 34359738367L},
148       new long[] {34359738368L, 2000000000000L, 4000000000000L, 4398046511103L},
149       new long[] {4398046511104L, 200000000000000L, 500000000000000L, 562949953421311L},
150       new long[] {0x4000000000000L, 0x5000000000000L, 0x6000000000000L, 0x0FFFFFFFFFFFFFFL},
151       new long[] {0x100000000000000L, 0x3FFFFFFFFFFFFFFFL, 0x5FFFFFFFFFFFFFFL, 0x7FFFFFFFFFFFFFFFL},
152       new long[] {
153         0xFFFFFFFFFFFFFFFFL, 0xFFFFFFFFFFFFFFFFL, 0xFFFFFFFFFFFFFFFFL, 0xFFFFFFFFFFFFFFFFL
154       }
155     };
156 
157     /** Number of samples that should be taken from each value array. */
158     private static final int[] NUM_SAMPLES = {4, 2, 2, 1, 1, 1, 1, 2, 2, 4};
159 
160     /**
161      * The index into the {@link #VALUES} array that identifies the list of samples currently being
162      * iterated over.
163      */
164     private int listIndex;
165 
166     /** The index of the next sample within a list. */
167     private int sampleIndex;
168 
169     /** The number of successive samples that have been taken from the current list. */
170     private int samplesTaken;
171 
getLong()172     public long getLong() {
173       if (samplesTaken++ > NUM_SAMPLES[listIndex]) {
174         // Done taking samples from this list. Go to the next one.
175         listIndex = (listIndex + 1) % VALUES.length;
176         sampleIndex = 0;
177         samplesTaken = 0;
178       }
179 
180       long value = VALUES[listIndex][sampleIndex];
181 
182       // All lists are exactly 4 long (i.e. power of 2), so we can optimize the mod operation
183       // with masking.
184       sampleIndex = (sampleIndex + 1) & 3;
185 
186       return value;
187     }
188   }
189 }
190