| /* |
| * 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.ignite.internal.util; |
| |
| import java.util.NoSuchElementException; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| import org.apache.ignite.IgniteCheckedException; |
| import org.apache.ignite.internal.util.lang.GridCloseableIterator; |
| import org.apache.ignite.internal.util.lang.GridIteratorAdapter; |
| |
| /** |
| * Adapter for closeable iterator that can be safely closed concurrently. |
| */ |
| public abstract class GridCloseableIteratorAdapterEx<T> extends GridIteratorAdapter<T> |
| implements GridCloseableIterator<T> { |
| /** */ |
| private static final long serialVersionUID = 0L; |
| |
| /** Closed flag. */ |
| private final AtomicBoolean closed = new AtomicBoolean(); |
| |
| /** {@inheritDoc} */ |
| @Override public final T nextX() throws IgniteCheckedException { |
| if (closed.get()) |
| return null; |
| |
| try { |
| if (!onHasNext()) |
| throw new NoSuchElementException(); |
| |
| return onNext(); |
| } |
| catch (IgniteCheckedException e) { |
| if (closed.get()) |
| return null; |
| else |
| throw e; |
| } |
| } |
| |
| /** |
| * @return Next element. |
| * @throws IgniteCheckedException If failed. |
| * @throws NoSuchElementException If no element found. |
| */ |
| protected abstract T onNext() throws IgniteCheckedException; |
| |
| /** {@inheritDoc} */ |
| @Override public final boolean hasNextX() throws IgniteCheckedException { |
| if (closed.get()) |
| return false; |
| |
| try { |
| return onHasNext(); |
| } |
| catch (IgniteCheckedException e) { |
| if (closed.get()) |
| return false; |
| else |
| throw e; |
| } |
| } |
| |
| /** |
| * @return {@code True} if iterator has next element. |
| * @throws IgniteCheckedException If failed. |
| */ |
| protected abstract boolean onHasNext() throws IgniteCheckedException; |
| |
| /** {@inheritDoc} */ |
| @Override public final void removeX() throws IgniteCheckedException { |
| if (closed.get()) |
| throw new NoSuchElementException("Iterator has been closed."); |
| |
| try { |
| onRemove(); |
| } |
| catch (IgniteCheckedException e) { |
| if (!closed.get()) |
| throw e; |
| } |
| } |
| |
| /** |
| * Called on remove from iterator. |
| * |
| * @throws IgniteCheckedException If failed. |
| */ |
| protected void onRemove() throws IgniteCheckedException { |
| throw new UnsupportedOperationException("Remove is not supported."); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public final void close() throws IgniteCheckedException { |
| if (closed.compareAndSet(false, true)) |
| onClose(); |
| } |
| |
| /** |
| * Invoked on iterator close. |
| * |
| * @throws IgniteCheckedException If closing failed. |
| */ |
| protected void onClose() throws IgniteCheckedException { |
| // No-op. |
| } |
| |
| /** {@inheritDoc} */ |
| @Override public boolean isClosed() { |
| return closed.get(); |
| } |
| } |