| // Copyright (C) 2009 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.gerrit.index.query; |
| |
| import static com.google.common.base.Preconditions.checkState; |
| import static com.google.common.collect.ImmutableList.toImmutableList; |
| |
| import com.google.common.collect.ImmutableList; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.List; |
| |
| /** Requires all predicates to be true. */ |
| public class AndPredicate<T> extends Predicate<T> |
| implements Matchable<T>, Comparator<Predicate<T>> { |
| private final List<Predicate<T>> children; |
| private final int cost; |
| |
| @SafeVarargs |
| protected AndPredicate(Predicate<T>... that) { |
| this(Arrays.asList(that)); |
| } |
| |
| protected AndPredicate(Collection<? extends Predicate<T>> that) { |
| List<Predicate<T>> t = new ArrayList<>(that.size()); |
| int c = 0; |
| for (Predicate<T> p : sort(that)) { |
| if (getClass() == p.getClass()) { |
| for (Predicate<T> gp : p.getChildren()) { |
| t.add(gp); |
| c += gp.estimateCost(); |
| } |
| } else { |
| t.add(p); |
| c += p.estimateCost(); |
| } |
| } |
| children = t; |
| cost = c; |
| } |
| |
| @Override |
| public final List<Predicate<T>> getChildren() { |
| return Collections.unmodifiableList(children); |
| } |
| |
| @Override |
| public final int getChildCount() { |
| return children.size(); |
| } |
| |
| @Override |
| public final Predicate<T> getChild(int i) { |
| return children.get(i); |
| } |
| |
| @Override |
| public Predicate<T> copy(Collection<? extends Predicate<T>> children) { |
| return new AndPredicate<>(children); |
| } |
| |
| @Override |
| public boolean isMatchable() { |
| for (Predicate<T> c : children) { |
| if (!c.isMatchable()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| @Override |
| public boolean match(T object) { |
| for (Predicate<T> c : children) { |
| checkState( |
| c.isMatchable(), |
| "match invoked, but child predicate %s doesn't implement %s", |
| c, |
| Matchable.class.getName()); |
| if (!c.asMatchable().match(object)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| @Override |
| public int getCost() { |
| return cost; |
| } |
| |
| @Override |
| public int hashCode() { |
| return getChild(0).hashCode() * 31 + getChild(1).hashCode(); |
| } |
| |
| // Suppress the EqualsGetClass warning as this is legacy code. |
| @SuppressWarnings("EqualsGetClass") |
| @Override |
| public boolean equals(Object other) { |
| if (other == null) { |
| return false; |
| } |
| return getClass() == other.getClass() |
| && getChildren().equals(((Predicate<?>) other).getChildren()); |
| } |
| |
| private ImmutableList<Predicate<T>> sort(Collection<? extends Predicate<T>> that) { |
| return that.stream().sorted(this).collect(toImmutableList()); |
| } |
| |
| @Override |
| public int compare(Predicate<T> a, Predicate<T> b) { |
| int ai = a instanceof DataSource ? 0 : 1; |
| int bi = b instanceof DataSource ? 0 : 1; |
| int cmp = ai - bi; |
| |
| if (cmp == 0) { |
| cmp = a.estimateCost() - b.estimateCost(); |
| } |
| |
| if (cmp == 0 && a instanceof DataSource) { |
| DataSource<?> as = (DataSource<?>) a; |
| DataSource<?> bs = (DataSource<?>) b; |
| cmp = as.getCardinality() - bs.getCardinality(); |
| } |
| return cmp; |
| } |
| |
| @Override |
| public String toString() { |
| final StringBuilder r = new StringBuilder(); |
| r.append("("); |
| for (int i = 0; i < getChildCount(); i++) { |
| if (i != 0) { |
| r.append(" "); |
| } |
| r.append(getChild(i)); |
| } |
| r.append(")"); |
| return r.toString(); |
| } |
| } |