| 1 | package com.hammurapi.eventbus; |
| 2 | |
| 3 | import java.lang.reflect.Array; |
| 4 | import java.util.Arrays; |
| 5 | import java.util.HashSet; |
| 6 | import java.util.Map; |
| 7 | import java.util.Set; |
| 8 | |
| 9 | import com.hammurapi.eventbus.AbstractEventBus.Handle; |
| 10 | import com.hammurapi.extract.ComparisonResult; |
| 11 | import com.hammurapi.extract.Extractor; |
| 12 | import com.hammurapi.extract.Predicate; |
| 13 | |
| 14 | public class MappedHandlePredicate<T, P extends Comparable<P>, C, K, H extends EventBus.Handle<T, P, C>, S extends EventStore<T,P,C,H,S>> implements Predicate<Handle<T,P,C,K>[], CompositeContext<T, P, C, K, H, S>> { |
| 15 | |
| 16 | private Predicate<T, C> target; |
| 17 | private Mapper<Handle<T,P,C,K>>[] mappers; |
| 18 | private int maxIndex; |
| 19 | private Set<Integer> parameterIndices = new HashSet<Integer>(); |
| 20 | private Class<T> targetClass; |
| 21 | |
| 22 | public MappedHandlePredicate(Predicate<T, C> target, Mapper<Handle<T,P,C,K>>[] mappers, Class<T> targetClass) { |
| 23 | this.target = target; |
| 24 | this.targetClass = targetClass; |
| 25 | this.mappers = mappers; |
| 26 | for (Integer idx:target.parameterIndices()) { |
| 27 | if (idx>maxIndex) { |
| 28 | maxIndex = idx; |
| 29 | } |
| 30 | for (int i=0; i<mappers.length; ++i) { |
| 31 | if (mappers[i].mapsTo(idx)) { |
| 32 | parameterIndices.add(i); |
| 33 | } |
| 34 | } |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | @SuppressWarnings("unchecked") |
| 39 | @Override |
| 40 | public Boolean extract( |
| 41 | CompositeContext<T, P, C, K, H, S> context, |
| 42 | Map<CompositeContext<T, P, C, K, H, S>, Map<Extractor<Handle<T,P,C,K>[], ? super Boolean, CompositeContext<T, P, C, K, H, S>>, ? super Boolean>> cache, |
| 43 | Handle<T,P,C,K>[]... handles) { |
| 44 | Handle<T,P,C,K>[] predicateInputHandles = new Handle[maxIndex+1]; |
| 45 | for (int i=0; i<mappers.length; ++i) { |
| 46 | mappers[i].map(handles[i], predicateInputHandles); |
| 47 | } |
| 48 | |
| 49 | T[] predicateInput = (T[]) Array.newInstance(targetClass, maxIndex+1); |
| 50 | |
| 51 | for (int i=0; i<predicateInputHandles.length; ++i) { |
| 52 | Handle<T,P,C,K> handle = predicateInputHandles[i]; |
| 53 | if (handle!=null) { |
| 54 | if (!handle.isValid()) { |
| 55 | return Boolean.FALSE; |
| 56 | } |
| 57 | predicateInput[i] = handle.getEvent(); |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | // TODO - associate cache for a tuple with Handle[] using a special class instead of |
| 62 | // handle array. |
| 63 | return target.extract(context.getHandlerContext(), null, predicateInput); |
| 64 | } |
| 65 | |
| 66 | @Override |
| 67 | public ComparisonResult compareTo(Extractor<Handle<T,P,C,K>[], Boolean, CompositeContext<T, P, C, K, H, S>> otherPredicate) { |
| 68 | // TODO Implement proper comparison for merging of join networks. |
| 69 | return ComparisonResult.NOT_EQUAL_NM; |
| 70 | } |
| 71 | |
| 72 | @Override |
| 73 | public boolean isContextDependent() { |
| 74 | return target.isContextDependent(); |
| 75 | } |
| 76 | |
| 77 | @Override |
| 78 | public Set<Integer> parameterIndices() { |
| 79 | return parameterIndices; |
| 80 | } |
| 81 | |
| 82 | @Override |
| 83 | public double getCost() { |
| 84 | return target.getCost(); |
| 85 | } |
| 86 | |
| 87 | @Override |
| 88 | public String toString() { |
| 89 | return "MappedHandlePredicate [target=" + target + ", mappers=" |
| 90 | + Arrays.toString(mappers) + ", maxIndex=" + maxIndex |
| 91 | + ", parameterIndices=" + parameterIndices + ", targetClass=" |
| 92 | + targetClass + "]"; |
| 93 | } |
| 94 | |
| 95 | } |