| /* |
| * 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.metastorage.client; |
| |
| import static org.apache.ignite.internal.util.ExceptionUtils.withCauseAndCode; |
| import static org.apache.ignite.lang.ErrorGroups.MetaStorage.CURSOR_CLOSING_ERR; |
| import static org.apache.ignite.lang.ErrorGroups.MetaStorage.CURSOR_EXECUTION_ERR; |
| |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| import java.util.concurrent.CompletableFuture; |
| import java.util.concurrent.ExecutionException; |
| import java.util.function.Function; |
| import org.apache.ignite.internal.logger.IgniteLogger; |
| import org.apache.ignite.internal.logger.Loggers; |
| import org.apache.ignite.internal.metastorage.common.MetaStorageException; |
| import org.apache.ignite.internal.metastorage.common.command.cursor.CursorCloseCommand; |
| import org.apache.ignite.internal.metastorage.common.command.cursor.CursorHasNextCommand; |
| import org.apache.ignite.internal.metastorage.common.command.cursor.CursorNextCommand; |
| import org.apache.ignite.internal.util.Cursor; |
| import org.apache.ignite.lang.IgniteUuid; |
| import org.apache.ignite.lang.NodeStoppingException; |
| import org.apache.ignite.raft.client.service.RaftGroupService; |
| import org.jetbrains.annotations.Nullable; |
| |
| /** |
| * Meta storage service side implementation of cursor. |
| * |
| * @param <T> Cursor parameter. |
| */ |
| public class CursorImpl<T> implements Cursor<T> { |
| /** The logger. */ |
| private static final IgniteLogger LOG = Loggers.forClass(CursorImpl.class); |
| |
| /** Future that runs meta storage service operation that provides cursor. */ |
| private final CompletableFuture<IgniteUuid> initOp; |
| |
| /** Meta storage raft group service. */ |
| private final RaftGroupService metaStorageRaftGrpSvc; |
| |
| private final Iterator<T> it; |
| |
| /** |
| * Constructor. |
| * |
| * @param metaStorageRaftGrpSvc Meta storage raft group service. |
| * @param initOp Future that runs meta storage service operation that provides cursor. |
| * @param fn Function transforming the result of {@link CursorNextCommand} to the type of {@link T}, |
| * or to the {@link Iterable} of type {@link T} if needed. |
| */ |
| CursorImpl( |
| RaftGroupService metaStorageRaftGrpSvc, |
| CompletableFuture<IgniteUuid> initOp, |
| Function<Object, Object> fn |
| ) { |
| this.metaStorageRaftGrpSvc = metaStorageRaftGrpSvc; |
| this.initOp = initOp; |
| this.it = new InnerIterator(fn); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public void close() { |
| try { |
| initOp.thenCompose( |
| cursorId -> metaStorageRaftGrpSvc.run(new CursorCloseCommand(cursorId))).get(); |
| |
| ((InnerIterator) it).close(); |
| } catch (InterruptedException | ExecutionException e) { |
| if (e.getCause() instanceof NodeStoppingException) { |
| return; |
| } |
| |
| LOG.debug("Unable to evaluate cursor close command", e); |
| |
| throw withCauseAndCode(MetaStorageException::new, CURSOR_CLOSING_ERR, e); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean hasNext() { |
| return it.hasNext(); |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public T next() { |
| return it.next(); |
| } |
| |
| /** |
| * Extension of {@link Iterator}. |
| */ |
| private class InnerIterator implements Iterator<T> { |
| private final Function<Object, Object> fn; |
| |
| @Nullable |
| private Iterator<T> internalCacheIterator; |
| |
| public InnerIterator(Function<Object, Object> fn) { |
| this.fn = fn; |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public boolean hasNext() { |
| try { |
| if (internalCacheIterator != null && internalCacheIterator.hasNext()) { |
| return true; |
| } else { |
| return initOp |
| .thenCompose(cursorId -> metaStorageRaftGrpSvc.<Boolean>run(new CursorHasNextCommand(cursorId))) |
| .get(); |
| } |
| } catch (InterruptedException | ExecutionException e) { |
| if (e.getCause() instanceof NodeStoppingException) { |
| return false; |
| } |
| |
| LOG.debug("Unable to evaluate cursor hasNext command", e); |
| |
| throw withCauseAndCode(MetaStorageException::new, CURSOR_EXECUTION_ERR, e); |
| } |
| } |
| |
| /** {@inheritDoc} */ |
| @Override |
| public T next() { |
| try { |
| if (internalCacheIterator != null && internalCacheIterator.hasNext()) { |
| return internalCacheIterator.next(); |
| } else { |
| Object res = initOp |
| .thenCompose(cursorId -> metaStorageRaftGrpSvc.run(new CursorNextCommand(cursorId))) |
| .get(); |
| |
| Object transformed = fn.apply(res); |
| |
| if (transformed instanceof Iterable) { |
| internalCacheIterator = ((Iterable<T>) transformed).iterator(); |
| |
| return internalCacheIterator.next(); |
| } else { |
| return (T) transformed; |
| } |
| } |
| } catch (InterruptedException | ExecutionException e) { |
| Throwable cause = e.getCause(); |
| |
| if (cause instanceof NodeStoppingException) { |
| throw new NoSuchElementException(); |
| } |
| |
| if (cause instanceof NoSuchElementException) { |
| throw (NoSuchElementException) cause; |
| } |
| |
| LOG.debug("Unable to evaluate cursor hasNext command", e); |
| |
| throw withCauseAndCode(MetaStorageException::new, CURSOR_EXECUTION_ERR, e); |
| } |
| } |
| |
| public void close() { |
| internalCacheIterator = null; |
| } |
| } |
| } |