org.jetbrains.kotlin.utils.Interner Maven / Gradle / Ivy
/*
* Copyright 2010-2015 JetBrains s.r.o.
*
* 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 org.jetbrains.kotlin.utils;
import kotlin.collections.CollectionsKt;
import kotlin.jvm.functions.Function1;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public final class Interner {
private final Interner parent;
private final int firstIndex;
private final Map interned = new HashMap();
public Interner(Interner parent) {
this.parent = parent;
this.firstIndex = parent != null ? parent.interned.size() + parent.firstIndex : 0;
}
public Interner() {
this(null);
}
@Nullable
private Integer find(@NotNull T obj) {
assert parent == null || parent.interned.size() + parent.firstIndex == firstIndex :
"Parent changed in parallel with child: indexes will be wrong";
if (parent != null) {
Integer index = parent.find(obj);
if (index != null) return index;
}
return interned.get(obj);
}
public int intern(@NotNull T obj) {
Integer index = find(obj);
if (index != null) return index;
index = firstIndex + interned.size();
interned.put(obj, index);
return index;
}
@NotNull
public List getAllInternedObjects() {
return CollectionsKt.sortedBy(interned.keySet(), new Function1() {
@Override
public Integer invoke(T key) {
return interned.get(key);
}
});
}
public boolean isEmpty() {
return interned.isEmpty() && (parent == null || parent.isEmpty());
}
}