Tuple and Tuple continuous hash provider

4 files changed, 384 insertions, 0 deletions

diff --git a/model-data/src/main/java/org/eclipse/viatra/solver/data/model/Tuple.java b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/Tuple.java
new file mode 100644
index 00000000..eb99c862
--- /dev/null
+++ b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/Tuple.java
@@ -0,0 +1,131 @@
+package org.eclipse.viatra.solver.data.model;
+
+import java.util.Arrays;
+
+public abstract class Tuple {
+        private static final int CustomTupleSize = 2;
+        
+        public abstract int getSize();
+        public abstract int get(int element);
+        public abstract int[] toArray();
+        @Override
+        public String toString() {
+                StringBuilder b = new StringBuilder();
+                b.append("[");
+                for(int i = 0; i<getSize(); i++) {
+                        if(i!=0) {
+                                b.append(",");
+                        }
+                        b.append(get(i));
+                }
+                b.append("]");
+                return b.toString();
+        }
+        
+        public static Tuple of(int... values) {
+                if(values.length == 0) {
+                        return new Tuple0();
+                } else if(values.length == 1) {
+                        return new Tuple1(values[0]);
+                } else if(values.length == 2) {
+                        return new Tuple2(values[0],values[1]);
+                } else return new TupleN(values);
+        }
+        
+        protected IllegalArgumentException doesNotContain(int element) {
+                return new IllegalArgumentException("Tuple does not contain element "+element);
+        }
+        
+        public static class Tuple0 extends Tuple{
+                protected Tuple0() { }
+                @Override public int getSize() { return 0; }
+                @Override public int get(int element) {
+                        throw doesNotContain(element);
+                }
+                @Override public int[] toArray() {return new int[]{};}
+                @Override public int hashCode() { return TupleHashProvider.singleton().getHash(this, 0); }
+                @Override
+                public boolean equals(Object obj) {
+                        if (this == obj)
+                                return true;
+                        if (obj == null)
+                                return false;
+                        if (getClass() != obj.getClass())
+                                return false;
+                        return true;
+                }
+        }
+        public static class Tuple1 extends Tuple{
+                final int value0;
+                protected Tuple1(int value0) { this.value0 = value0; }
+                @Override public int getSize() { return 1; }
+                @Override public int get(int element) {
+                        if(element == 0) return value0;
+                        throw doesNotContain(element);
+                }
+                @Override public int[] toArray() {return new int[]{ value0 };}
+                @Override public int hashCode() { return TupleHashProvider.singleton().getHash(this, 0); }
+                @Override
+                public boolean equals(Object obj) {
+                        if (this == obj)
+                                return true;
+                        if (obj == null)
+                                return false;
+                        if (getClass() != obj.getClass())
+                                return false;
+                        Tuple1 other = (Tuple1) obj;
+                        return value0 == other.value0;
+                }
+        }
+        public static class Tuple2 extends Tuple{
+                final int value0;
+                final int value1;
+                protected Tuple2(int value0, int value1) { this.value0 = value0; this.value1 = value1; }
+                @Override public int getSize() { return 2; }
+                @Override public int get(int element) {
+                        if(element == 0) return value0;
+                        else if(element == 1) return value1;
+                        throw doesNotContain(element);
+                }
+                @Override public int[] toArray() {return new int[]{ value0,value1 };}
+                @Override public int hashCode() { return TupleHashProvider.singleton().getHash(this, 0); }
+                @Override
+                public boolean equals(Object obj) {
+                        if (this == obj)
+                                return true;
+                        if (obj == null)
+                                return false;
+                        if (getClass() != obj.getClass())
+                                return false;
+                        Tuple2 other = (Tuple2) obj;
+                        return value0 == other.value0 && value1 == other.value1;
+                }
+        }
+        public static class TupleN extends Tuple{
+                final int[] values;
+                protected TupleN(int[] values) { 
+                        if(values.length<CustomTupleSize)
+                                throw new IllegalArgumentException();
+                        this.values = Arrays.copyOf(values, values.length);
+                }
+                @Override public int getSize() { return values.length; }
+                @Override public int get(int element) {
+                        if(0<=element && element < values.length) {
+                                return values[element];
+                        } else throw doesNotContain(element);
+                }
+                @Override public int[] toArray() { return values; }
+                @Override public int hashCode() { return TupleHashProvider.singleton().getHash(this, 0); }
+                @Override
+                public boolean equals(Object obj) {
+                        if (this == obj)
+                                return true;
+                        if (obj == null)
+                                return false;
+                        if (getClass() != obj.getClass())
+                                return false;
+                        TupleN other = (TupleN) obj;
+                        return Arrays.equals(values, other.values);
+                }
+        }
+}
diff --git a/model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProvider.java b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProvider.java
new file mode 100644
index 00000000..6c37aa37
--- /dev/null
+++ b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProvider.java
@@ -0,0 +1,65 @@
+package org.eclipse.viatra.solver.data.model;
+
+import org.eclipse.viatra.solver.data.map.ContinousHashProvider;
+
+public class TupleHashProvider implements ContinousHashProvider<Tuple> {
+        protected static TupleHashProvider instance;
+
+        public static TupleHashProvider singleton() {
+                if (instance == null) {
+                        instance = new TupleHashProvider();
+                }
+                return instance;
+        }
+
+        protected static final int[] primes = new int[] { 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101,
+                        103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211,
+                        223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337,
+                        347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461,
+                        463, 467, 479, 487, 491, 499, 503, 509, 521, 523, 541, 547, 557, 563, 569, 571, 577, 587, 593, 599, 601,
+                        607, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 691, 701, 709, 719, 727, 733, 739,
+                        743, 751, 757, 761, 769, 773, 787, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 877, 881,
+                        883, 887, 907, 911, 919, 929, 937, 941, 947, 953, 967, 971, 977, 983, 991, 997, 1009, 1013, 1019, 1021,
+                        1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151,
+                        1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1279, 1283,
+                        1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429,
+                        1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531, 1543, 1549,
+                        1553, 1559, 1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667,
+                        1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811,
+                        1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973,
+                        1979, 1987, 1993, 1997, 1999, 2003, 2011, 2017, 2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083, 2087, 2089,
+                        2099, 2111, 2113, 2129, 2131, 2137, 2141, 2143, 2153, 2161, 2179, 2203, 2207, 2213, 2221, 2237, 2239, 2243,
+                        2251, 2267, 2269, 2273, 2281, 2287, 2293, 2297, 2309, 2311, 2333, 2339, 2341, 2347, 2351, 2357, 2371, 2377,
+                        2381, 2383, 2389, 2393, 2399, 2411, 2417, 2423, 2437, 2441, 2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531,
+                        2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593, 2609, 2617, 2621, 2633, 2647, 2657, 2659, 2663, 2671, 2677,
+                        2683, 2687, 2689, 2693, 2699, 2707, 2711, 2713, 2719, 2729, 2731, 2741, 2749, 2753, 2767, 2777, 2789, 2791,
+                        2797, 2801, 2803, 2819, 3089, 3109, 3119, 3121, 3137, 3163, 3167, 3169, 3181, 3187, 3191, 3203, 3209, 3217,
+                        3221, 3229, 3251, 3253, 3257, 3259, 3271, 3299, 3301, 3307, 3313, 3319, 3323, 3329, 3331, 3343, 3347, 3359,
+                        3361, 3371, 3373, 3389, 3391, 3407, 3413, 3433, 3449, 3457, 3461, 3463, 3467, 3469, 3491, 3499, 3511, 3517,
+                        3527, 3529, 3533, 3539, 3541, 3547, 3557, 3559, 3571, 3581, 3583, 3593, 3607, 3613, 3617, 3623, 3631, 3637,
+                        3643, 3659, 3671, 3673, 3677, 3691, 3697, 3701, 3709, 3719, 3727, 3733, 3739, 3761, 3767, 3769, 3779, 3793,
+                        3797, 3803, 3821, 3823, 3833, 3847, 3851, 3853, 3863, 3877, 3881, 3889, 3907, 3911 };
+        
+        protected static final long LARGESTPRIME30BITS = 1073741789;
+
+        public TupleHashProvider() {
+                if (primes.length < MAX_PRACTICAL_DEPTH) {
+                        throw new UnsupportedOperationException(
+                                        "Not enough prime numbers to support the practical depth of continuous hash!");
+                }
+        }
+
+        @Override
+        public int getHash(Tuple key, int index) {
+                if (index >= primes.length) {
+                        throw new IllegalArgumentException("Not enough prime numbers to support index");
+                }
+                long accumulator = 0;
+                final int prime = primes[index];
+                for (int i = 0; i < key.getSize(); i++) {
+                        accumulator = (prime * accumulator + key.get(i)) % LARGESTPRIME30BITS;
+                }
+
+                return (int) accumulator;
+        }
+}
diff --git a/model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProviderBitMagic.java b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProviderBitMagic.java
new file mode 100644
index 00000000..2a514d66
--- /dev/null
+++ b/model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProviderBitMagic.java
@@ -0,0 +1,28 @@
+package org.eclipse.viatra.solver.data.model;
+
+import org.eclipse.viatra.solver.data.map.ContinousHashProvider;
+
+public class TupleHashProviderBitMagic implements ContinousHashProvider<Tuple> {
+
+        @Override
+        public int getHash(Tuple key, int index) {
+                if(key.getSize() == 1) {
+                        return key.get(0);
+                }
+                
+                int result = 0;
+                final int startBitIndex = index*30;
+                final int finalBitIndex = startBitIndex+30;
+                final int arity = key.getSize();
+                
+                for(int i = startBitIndex; i<=finalBitIndex; i++) {
+                        final int selectedKey = key.get(i%arity);
+                        final int selectedPosition = 1<<(i/arity);
+                        if((selectedKey&selectedPosition) != 0) {
+                                result |= 1<<(i%30);
+                        }
+                }
+                
+                return result;
+        }
+}
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 @@
+package org.eclipse.viatra.solver.data.model.hashTests;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Random;
+
+import org.eclipse.viatra.solver.data.map.ContinousHashProvider;
+import org.eclipse.viatra.solver.data.model.Tuple;
+import org.eclipse.viatra.solver.data.model.TupleHashProvider;
+import org.eclipse.viatra.solver.data.model.TupleHashProviderBitMagic;
+import org.junit.jupiter.api.Test;
+
+class HashEfficiencyTest {
+
+        private static List<Tuple> permutations(int range, int arity) {
+                if(arity == 1) {
+                        List<Tuple> result = new ArrayList<>(range);
+                        for(int i=0; i<range; i++) {
+                                result.add(Tuple.of(i));
+                        }
+                        return result;
+                } else if(arity > 1) {
+                        List<Tuple> smallers = permutations(range, arity-1);
+                        List<Tuple> result = new ArrayList<>(range*smallers.size());
+                        for(Tuple smaller : smallers) {
+                                for(int i=0; i<range; i++) {
+                                        int[] larger = new int[arity];
+                                        for(int x = 0; x<smaller.getSize(); x++) {
+                                                larger[x] = smaller.get(x);
+                                        }
+                                        larger[arity-1] = i;
+                                        result.add(Tuple.of(larger));
+                                }
+                        }
+                        return result;
+                } else throw new IllegalArgumentException();
+        }
+        
+        private static int amountToRange(int arity, int n) {
+                int range = 1;
+                while(Math.pow(range,arity)<n+0.1) {
+                        range++;
+                }
+                return 1024;
+        }
+        
+        public static List<Tuple> nPermutations(int arity, int n) {
+                int range = amountToRange(arity, n);
+                List<Tuple> permutations = permutations(range, arity);
+                return permutations.subList(0, n);
+        }
+
+        public static List<Tuple> nRandoms(int arity, int n, int seed) {
+                int range = amountToRange(arity, n);
+                List<Tuple> permutations = new ArrayList<>(n);
+                Random r = new Random(seed);
+                for(int i = 0; i<n; i++) {
+                        int[] tuple = new int[arity];
+                        for(int j=0; j<arity; j++) {
+                                tuple[j] = r.nextInt(range);
+                        }
+                        permutations.add(Tuple.of(tuple));
+                }
+                return permutations;
+        }
+        
+        @Test
+        void permutationTest() {
+                List<Tuple> p = permutations(10, 2);
+                assertEquals(p.size(),10*10);
+        }
+//      private void printTuples(List<Tuple> p) {
+//              for(Tuple element : p) {
+//                      System.out.println(element);
+//              }
+//      }
+        @Test
+        void nPermutationTest() {
+                final int amount = 500;
+                List<Tuple> p = nPermutations(2, amount);
+                assertEquals(amount,p.size());
+        }
+        @Test
+        void nRandomTest() {
+                final int amount = 500;
+                List<Tuple> p = nRandoms(2, amount, 1);;
+                assertEquals(amount,p.size());
+        }
+        private static double calculateHashClashes(List<Tuple> tuples, ContinousHashProvider<Tuple> chp) {
+                int sumClashes = 0;
+                
+                for(int i = 0; i<tuples.size(); i++) {
+                        int height = 0;
+                        for(int j=0; j<tuples.size(); j++) {
+                                int clashes = calculateHashClash(chp, tuples.get(i), tuples.get(j));
+                                height = Math.max(height, clashes);
+                        }
+                        sumClashes += height;
+                }
+                return (sumClashes+0.0) / tuples.size();
+        }
+        private static int calculateHashClash(ContinousHashProvider<Tuple> chp, Tuple a, Tuple b) {
+                if(a.equals(b)) return 0;
+                final int bits = 5;
+                final int segments = Integer.SIZE/bits;
+                final int mask = (1<<bits)-1;
+                for(int i = 0;;i++) {
+                        int index = i/segments;
+                        int depth = i%segments;
+                        int aHash = (chp.getHash(a, index)>>(depth*5))&mask;
+                        int bHash = (chp.getHash(b, index)>>(depth*5))&mask;
+                        if(aHash != bHash) {
+                                return i+1;
+                        }
+                        if(i>400) {
+                                throw new IllegalStateException(a+" vs "+b);
+                        }
+                }
+        }
+        private static double caclulateOptimalHashClash(int size) {
+                return (Math.log(size)/Math.log(32));
+        }
+        public static void main(String[] args) {
+                List<String> hashNames = new LinkedList<>();
+                List<ContinousHashProvider<Tuple>> hashes = new LinkedList<>();
+                hashNames.add("PrimeGroup");
+                hashes.add(new TupleHashProvider());
+                hashNames.add("BitMagic");
+                hashes.add(new TupleHashProviderBitMagic());
+                
+                int[] arities = new int[] {2,3,4,5};
+                int[] sizes = new int[] {32*32,32*32*8};
+                
+                System.out.println("Size,Arity,DataSource,Hash,Chashes,Optimal,Badness");
+                for(int size : sizes) {
+                        double optimalClashes = caclulateOptimalHashClash(size);
+                        for(int arity : arities) {
+                                List<String> dataSourceNames = new LinkedList<>();
+                                List<List<Tuple>> dataSources = new LinkedList<>();
+                                
+//                              dataSourceNames.add("Permutation");
+//                              dataSources.add(nPermutations(arity, size));
+                                dataSourceNames.add("Random");
+                                dataSources.add(nRandoms(arity, size, 0));
+                                
+                                for(int dataSourceIndex = 0; dataSourceIndex<dataSourceNames.size(); dataSourceIndex++) {
+                                        for(int hashIndex = 0; hashIndex<hashNames.size(); hashIndex++) {
+                                                double clashes = calculateHashClashes(dataSources.get(dataSourceIndex),hashes.get(hashIndex));
+                                                System.out.println(
+                                                        size+","+arity+","+dataSourceNames.get(dataSourceIndex)+","+hashNames.get(hashIndex)+","+
+                                                        clashes+","+optimalClashes+","+(clashes+0.0)/optimalClashes);
+                                        }
+                                }
+                        }
+                }
+        }
+}