| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.cxf.common.util; |
| |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Comparator; |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| import java.util.SortedSet; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| |
| /** |
| * This class implements most of the <tt>Set</tt> interface, backed by a |
| * sorted Array. This makes iterators very fast, lookups are log(n), but |
| * adds are fairly expensive. |
| * |
| * This class is also threadsafe, but without synchronizations. Lookups |
| * and iterators will iterate over the state of the Set when the iterator |
| * was created. |
| * |
| * If no data is stored in the Set, it uses very little memory. The backing |
| * array is created on demand. |
| * |
| * This class is primarly useful for stuff that will be setup at startup, but |
| * then iterated over MANY times during runtime. |
| * |
| * @param <T> |
| */ |
| public final class SortedArraySet<T> implements SortedSet<T> { |
| final AtomicReference<T[]> data = new AtomicReference<>(); |
| |
| public void clear() { |
| data.set(null); |
| } |
| |
| public boolean isEmpty() { |
| T[] tmp = data.get(); |
| return tmp == null || tmp.length == 0; |
| } |
| |
| public Iterator<T> iterator() { |
| return new SASIterator<>(data.get()); |
| } |
| |
| public int size() { |
| T[] tmp = data.get(); |
| return tmp == null ? 0 : tmp.length; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private T[] newArray(int size) { |
| return (T[])new Object[size]; |
| } |
| |
| public boolean add(T o) { |
| if (!contains(o)) { |
| T[] tmp = data.get(); |
| T[] tmp2; |
| if (tmp == null) { |
| tmp2 = newArray(1); |
| tmp2[0] = o; |
| } else { |
| tmp2 = newArray(tmp.length + 1); |
| System.arraycopy(tmp, 0, tmp2, 0, tmp.length); |
| tmp2[tmp2.length - 1] = o; |
| Arrays.sort(tmp2); |
| } |
| |
| if (!data.compareAndSet(tmp, tmp2)) { |
| return add(o); |
| } |
| return true; |
| } |
| return false; |
| } |
| public boolean addAll(Collection<? extends T> c) { |
| boolean val = false; |
| for (T t : c) { |
| val |= add(t); |
| } |
| return val; |
| } |
| public boolean containsAll(Collection<?> c) { |
| boolean val = false; |
| for (Object t : c) { |
| val |= contains(t); |
| } |
| return val; |
| } |
| |
| public boolean contains(Object o) { |
| T[] tmp = data.get(); |
| if (tmp == null) { |
| return false; |
| } |
| return Arrays.binarySearch(tmp, o) >= 0; |
| } |
| |
| public boolean removeAll(Collection<?> c) { |
| boolean val = false; |
| for (Object t : c) { |
| val |= remove(t); |
| } |
| return val; |
| } |
| public boolean retainAll(Collection<?> c) { |
| boolean val = false; |
| for (T t : this) { |
| if (!c.contains(t)) { |
| val |= remove(t); |
| } |
| } |
| return val; |
| } |
| |
| public boolean remove(Object o) { |
| T[] tmp = data.get(); |
| |
| if (tmp == null) { |
| return false; |
| } |
| int idx = Arrays.binarySearch(tmp, o); |
| if (idx != -1) { |
| if (tmp.length == 1 |
| && !data.compareAndSet(tmp, null)) { |
| return remove(o); |
| } |
| T[] tmp2 = newArray(tmp.length - 1); |
| System.arraycopy(tmp, 0, tmp2, 0, idx); |
| System.arraycopy(tmp, idx + 1, tmp2, idx, tmp.length - 1 - idx); |
| if (!data.compareAndSet(tmp, tmp2)) { |
| return remove(o); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| |
| public Object[] toArray() { |
| T[] tmp = data.get(); |
| if (tmp == null) { |
| return new Object[0]; |
| } |
| T[] tmp2 = newArray(tmp.length); |
| System.arraycopy(tmp, 0, tmp2, 0, tmp.length); |
| return tmp2; |
| } |
| |
| @SuppressWarnings("unchecked") |
| public <X> X[] toArray(X[] a) { |
| T[] tmp = data.get(); |
| if (tmp == null) { |
| if (a.length != 0) { |
| return (X[])java.lang.reflect.Array. |
| newInstance(a.getClass().getComponentType(), 0); |
| } |
| return a; |
| } |
| |
| if (a.length < tmp.length) { |
| a = (X[])java.lang.reflect.Array. |
| newInstance(a.getClass().getComponentType(), tmp.length); |
| } |
| System.arraycopy(tmp, 0, a, 0, tmp.length); |
| if (a.length > tmp.length) { |
| a[tmp.length] = null; |
| } |
| return a; |
| } |
| |
| @SuppressWarnings("unchecked") |
| public boolean equals(Object o) { |
| if (!(o instanceof SortedArraySet)) { |
| return false; |
| } |
| SortedArraySet<T> as = (SortedArraySet<T>)o; |
| return Arrays.equals(data.get(), as.data.get()); |
| } |
| public String toString() { |
| return Arrays.toString(data.get()); |
| } |
| public int hashCode() { |
| return Arrays.hashCode(data.get()); |
| } |
| |
| |
| private class SASIterator<X> implements Iterator<X> { |
| final X[] data; |
| int idx; |
| |
| SASIterator(X[] d) { |
| data = d; |
| } |
| |
| public boolean hasNext() { |
| return data != null && idx != data.length; |
| } |
| |
| public X next() { |
| if (data == null || idx == data.length) { |
| throw new NoSuchElementException(); |
| } |
| return data[idx++]; |
| } |
| |
| @Override |
| public void remove() { |
| if (idx > 0) { |
| SortedArraySet.this.remove((Object)data[idx - 1]); |
| } |
| } |
| } |
| |
| |
| public Comparator<? super T> comparator() { |
| return null; |
| } |
| |
| public T first() { |
| T[] tmp = data.get(); |
| if (tmp == null || tmp.length == 0) { |
| return null; |
| } |
| return tmp[0]; |
| } |
| |
| public T last() { |
| T[] tmp = data.get(); |
| if (tmp == null || tmp.length == 0) { |
| return null; |
| } |
| return tmp[tmp.length - 1]; |
| } |
| |
| public SortedSet<T> headSet(T toElement) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public SortedSet<T> subSet(T fromElement, T toElement) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| public SortedSet<T> tailSet(T fromElement) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| } |