| // Copyright 2018 The Bazel Authors. All rights reserved. |
| // |
| // 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.devtools.build.lib.analysis.config; |
| |
| import static com.google.common.base.Predicates.not; |
| |
| import com.google.common.collect.Collections2; |
| import com.google.common.collect.ImmutableSortedSet; |
| import com.google.common.collect.Interner; |
| import com.google.common.collect.Sets; |
| import com.google.devtools.build.lib.concurrent.BlazeInterners; |
| import com.google.devtools.build.lib.skyframe.serialization.autocodec.SerializationConstant; |
| import com.google.devtools.build.lib.util.ClassName; |
| import java.util.AbstractSet; |
| import java.util.Collection; |
| import java.util.Comparator; |
| import java.util.Iterator; |
| import javax.annotation.concurrent.Immutable; |
| |
| /** |
| * A wrapper class for an {@code ImmutableSortedSet<Class<? extends Fragment>>}. Interning these |
| * objects allows us to do cheap reference equality checks when these sets are in frequently used |
| * keys. |
| */ |
| @Immutable |
| public final class FragmentClassSet extends AbstractSet<Class<? extends Fragment>> { |
| |
| /** |
| * Sorts fragments by class name. This produces a stable order which, e.g., facilitates consistent |
| * output from buildMnemonic. |
| */ |
| @SerializationConstant |
| public static final Comparator<Class<? extends Fragment>> LEXICAL_FRAGMENT_SORTER = |
| Comparator.comparing(Class::getName); |
| |
| private static final Interner<FragmentClassSet> interner = BlazeInterners.newWeakInterner(); |
| |
| public static FragmentClassSet of(Collection<Class<? extends Fragment>> fragments) { |
| ImmutableSortedSet<Class<? extends Fragment>> sortedFragments = |
| ImmutableSortedSet.copyOf(LEXICAL_FRAGMENT_SORTER, fragments); |
| return interner.intern(new FragmentClassSet(sortedFragments, sortedFragments.hashCode())); |
| } |
| |
| private final ImmutableSortedSet<Class<? extends Fragment>> fragments; |
| private final int hashCode; |
| |
| private FragmentClassSet(ImmutableSortedSet<Class<? extends Fragment>> fragments, int hashCode) { |
| this.fragments = fragments; |
| this.hashCode = hashCode; |
| } |
| |
| @Override |
| public int size() { |
| return fragments.size(); |
| } |
| |
| @Override |
| public boolean contains(Object o) { |
| return fragments.contains(o); |
| } |
| |
| /** Returns a set of fragment classes identical to this one but without the given fragment. */ |
| public FragmentClassSet trim(Class<? extends Fragment> fragment) { |
| if (!contains(fragment)) { |
| return this; |
| } |
| return of(Sets.filter(fragments, not(fragment::equals))); |
| } |
| |
| @Override |
| public Iterator<Class<? extends Fragment>> iterator() { |
| return fragments.iterator(); |
| } |
| |
| @Override |
| public boolean equals(Object other) { |
| if (this == other) { |
| return true; |
| } |
| if (!(other instanceof FragmentClassSet)) { |
| return false; |
| } |
| FragmentClassSet that = (FragmentClassSet) other; |
| return hashCode == that.hashCode && fragments.equals(that.fragments); |
| } |
| |
| @Override |
| public int hashCode() { |
| return hashCode; |
| } |
| |
| @Override |
| public String toString() { |
| return Collections2.transform(fragments, ClassName::getSimpleNameWithOuter).toString(); |
| } |
| } |