diff options
Diffstat (limited to 'model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProviderBitMagic.java')
-rw-r--r-- | model-data/src/main/java/org/eclipse/viatra/solver/data/model/TupleHashProviderBitMagic.java | 28 |
1 files changed, 28 insertions, 0 deletions
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 @@ | |||
1 | package org.eclipse.viatra.solver.data.model; | ||
2 | |||
3 | import org.eclipse.viatra.solver.data.map.ContinousHashProvider; | ||
4 | |||
5 | public class TupleHashProviderBitMagic implements ContinousHashProvider<Tuple> { | ||
6 | |||
7 | @Override | ||
8 | public int getHash(Tuple key, int index) { | ||
9 | if(key.getSize() == 1) { | ||
10 | return key.get(0); | ||
11 | } | ||
12 | |||
13 | int result = 0; | ||
14 | final int startBitIndex = index*30; | ||
15 | final int finalBitIndex = startBitIndex+30; | ||
16 | final int arity = key.getSize(); | ||
17 | |||
18 | for(int i = startBitIndex; i<=finalBitIndex; i++) { | ||
19 | final int selectedKey = key.get(i%arity); | ||
20 | final int selectedPosition = 1<<(i/arity); | ||
21 | if((selectedKey&selectedPosition) != 0) { | ||
22 | result |= 1<<(i%30); | ||
23 | } | ||
24 | } | ||
25 | |||
26 | return result; | ||
27 | } | ||
28 | } | ||