diff options
Diffstat (limited to 'model-data/src/test/java/org/eclipse/viatra/solver')
-rw-r--r-- | model-data/src/test/java/org/eclipse/viatra/solver/data/model/hashTests/HashEfficiencyTest.java | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/model-data/src/test/java/org/eclipse/viatra/solver/data/model/hashTests/HashEfficiencyTest.java b/model-data/src/test/java/org/eclipse/viatra/solver/data/model/hashTests/HashEfficiencyTest.java new file mode 100644 index 00000000..c4d98a43 --- /dev/null +++ b/model-data/src/test/java/org/eclipse/viatra/solver/data/model/hashTests/HashEfficiencyTest.java | |||
@@ -0,0 +1,160 @@ | |||
1 | package org.eclipse.viatra.solver.data.model.hashTests; | ||
2 | |||
3 | import static org.junit.jupiter.api.Assertions.assertEquals; | ||
4 | |||
5 | import java.util.ArrayList; | ||
6 | import java.util.LinkedList; | ||
7 | import java.util.List; | ||
8 | import java.util.Random; | ||
9 | |||
10 | import org.eclipse.viatra.solver.data.map.ContinousHashProvider; | ||
11 | import org.eclipse.viatra.solver.data.model.Tuple; | ||
12 | import org.eclipse.viatra.solver.data.model.TupleHashProvider; | ||
13 | import org.eclipse.viatra.solver.data.model.TupleHashProviderBitMagic; | ||
14 | import org.junit.jupiter.api.Test; | ||
15 | |||
16 | class HashEfficiencyTest { | ||
17 | |||
18 | private static List<Tuple> permutations(int range, int arity) { | ||
19 | if(arity == 1) { | ||
20 | List<Tuple> result = new ArrayList<>(range); | ||
21 | for(int i=0; i<range; i++) { | ||
22 | result.add(Tuple.of(i)); | ||
23 | } | ||
24 | return result; | ||
25 | } else if(arity > 1) { | ||
26 | List<Tuple> smallers = permutations(range, arity-1); | ||
27 | List<Tuple> result = new ArrayList<>(range*smallers.size()); | ||
28 | for(Tuple smaller : smallers) { | ||
29 | for(int i=0; i<range; i++) { | ||
30 | int[] larger = new int[arity]; | ||
31 | for(int x = 0; x<smaller.getSize(); x++) { | ||
32 | larger[x] = smaller.get(x); | ||
33 | } | ||
34 | larger[arity-1] = i; | ||
35 | result.add(Tuple.of(larger)); | ||
36 | } | ||
37 | } | ||
38 | return result; | ||
39 | } else throw new IllegalArgumentException(); | ||
40 | } | ||
41 | |||
42 | private static int amountToRange(int arity, int n) { | ||
43 | int range = 1; | ||
44 | while(Math.pow(range,arity)<n+0.1) { | ||
45 | range++; | ||
46 | } | ||
47 | return 1024; | ||
48 | } | ||
49 | |||
50 | public static List<Tuple> nPermutations(int arity, int n) { | ||
51 | int range = amountToRange(arity, n); | ||
52 | List<Tuple> permutations = permutations(range, arity); | ||
53 | return permutations.subList(0, n); | ||
54 | } | ||
55 | |||
56 | public static List<Tuple> nRandoms(int arity, int n, int seed) { | ||
57 | int range = amountToRange(arity, n); | ||
58 | List<Tuple> permutations = new ArrayList<>(n); | ||
59 | Random r = new Random(seed); | ||
60 | for(int i = 0; i<n; i++) { | ||
61 | int[] tuple = new int[arity]; | ||
62 | for(int j=0; j<arity; j++) { | ||
63 | tuple[j] = r.nextInt(range); | ||
64 | } | ||
65 | permutations.add(Tuple.of(tuple)); | ||
66 | } | ||
67 | return permutations; | ||
68 | } | ||
69 | |||
70 | @Test | ||
71 | void permutationTest() { | ||
72 | List<Tuple> p = permutations(10, 2); | ||
73 | assertEquals(p.size(),10*10); | ||
74 | } | ||
75 | // private void printTuples(List<Tuple> p) { | ||
76 | // for(Tuple element : p) { | ||
77 | // System.out.println(element); | ||
78 | // } | ||
79 | // } | ||
80 | @Test | ||
81 | void nPermutationTest() { | ||
82 | final int amount = 500; | ||
83 | List<Tuple> p = nPermutations(2, amount); | ||
84 | assertEquals(amount,p.size()); | ||
85 | } | ||
86 | @Test | ||
87 | void nRandomTest() { | ||
88 | final int amount = 500; | ||
89 | List<Tuple> p = nRandoms(2, amount, 1);; | ||
90 | assertEquals(amount,p.size()); | ||
91 | } | ||
92 | private static double calculateHashClashes(List<Tuple> tuples, ContinousHashProvider<Tuple> chp) { | ||
93 | int sumClashes = 0; | ||
94 | |||
95 | for(int i = 0; i<tuples.size(); i++) { | ||
96 | int height = 0; | ||
97 | for(int j=0; j<tuples.size(); j++) { | ||
98 | int clashes = calculateHashClash(chp, tuples.get(i), tuples.get(j)); | ||
99 | height = Math.max(height, clashes); | ||
100 | } | ||
101 | sumClashes += height; | ||
102 | } | ||
103 | return (sumClashes+0.0) / tuples.size(); | ||
104 | } | ||
105 | private static int calculateHashClash(ContinousHashProvider<Tuple> chp, Tuple a, Tuple b) { | ||
106 | if(a.equals(b)) return 0; | ||
107 | final int bits = 5; | ||
108 | final int segments = Integer.SIZE/bits; | ||
109 | final int mask = (1<<bits)-1; | ||
110 | for(int i = 0;;i++) { | ||
111 | int index = i/segments; | ||
112 | int depth = i%segments; | ||
113 | int aHash = (chp.getHash(a, index)>>(depth*5))&mask; | ||
114 | int bHash = (chp.getHash(b, index)>>(depth*5))&mask; | ||
115 | if(aHash != bHash) { | ||
116 | return i+1; | ||
117 | } | ||
118 | if(i>400) { | ||
119 | throw new IllegalStateException(a+" vs "+b); | ||
120 | } | ||
121 | } | ||
122 | } | ||
123 | private static double caclulateOptimalHashClash(int size) { | ||
124 | return (Math.log(size)/Math.log(32)); | ||
125 | } | ||
126 | public static void main(String[] args) { | ||
127 | List<String> hashNames = new LinkedList<>(); | ||
128 | List<ContinousHashProvider<Tuple>> hashes = new LinkedList<>(); | ||
129 | hashNames.add("PrimeGroup"); | ||
130 | hashes.add(new TupleHashProvider()); | ||
131 | hashNames.add("BitMagic"); | ||
132 | hashes.add(new TupleHashProviderBitMagic()); | ||
133 | |||
134 | int[] arities = new int[] {2,3,4,5}; | ||
135 | int[] sizes = new int[] {32*32,32*32*8}; | ||
136 | |||
137 | System.out.println("Size,Arity,DataSource,Hash,Chashes,Optimal,Badness"); | ||
138 | for(int size : sizes) { | ||
139 | double optimalClashes = caclulateOptimalHashClash(size); | ||
140 | for(int arity : arities) { | ||
141 | List<String> dataSourceNames = new LinkedList<>(); | ||
142 | List<List<Tuple>> dataSources = new LinkedList<>(); | ||
143 | |||
144 | // dataSourceNames.add("Permutation"); | ||
145 | // dataSources.add(nPermutations(arity, size)); | ||
146 | dataSourceNames.add("Random"); | ||
147 | dataSources.add(nRandoms(arity, size, 0)); | ||
148 | |||
149 | for(int dataSourceIndex = 0; dataSourceIndex<dataSourceNames.size(); dataSourceIndex++) { | ||
150 | for(int hashIndex = 0; hashIndex<hashNames.size(); hashIndex++) { | ||
151 | double clashes = calculateHashClashes(dataSources.get(dataSourceIndex),hashes.get(hashIndex)); | ||
152 | System.out.println( | ||
153 | size+","+arity+","+dataSourceNames.get(dataSourceIndex)+","+hashNames.get(hashIndex)+","+ | ||
154 | clashes+","+optimalClashes+","+(clashes+0.0)/optimalClashes); | ||
155 | } | ||
156 | } | ||
157 | } | ||
158 | } | ||
159 | } | ||
160 | } | ||