| /* |
| * 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.tinkerpop.gremlin.driver.remote; |
| |
| import org.apache.commons.lang3.exception.ExceptionUtils; |
| import org.apache.tinkerpop.gremlin.driver.Client; |
| import org.apache.tinkerpop.gremlin.driver.Host; |
| import org.apache.tinkerpop.gremlin.driver.Result; |
| import org.apache.tinkerpop.gremlin.driver.Tokens; |
| import org.apache.tinkerpop.gremlin.driver.message.RequestMessage; |
| import org.apache.tinkerpop.gremlin.process.remote.traversal.AbstractRemoteTraversalSideEffects; |
| import org.apache.tinkerpop.gremlin.process.traversal.TraversalSideEffects; |
| import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.GraphTraversal; |
| |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.UUID; |
| import java.util.concurrent.CompletableFuture; |
| |
| /** |
| * Java driver implementation of {@link TraversalSideEffects}. This class is not thread safe. |
| * |
| * @author Stephen Mallette (http://stephen.genoprime.com) |
| * @deprecated As of release 3.3.8, not directly replaced, prefer use of {@link GraphTraversal#cap(String, String...)} |
| * to return the result as part of the traversal iteration. |
| */ |
| @Deprecated |
| public class DriverRemoteTraversalSideEffects extends AbstractRemoteTraversalSideEffects { |
| |
| private final Client client; |
| private Set<String> keys = Collections.emptySet(); |
| private final UUID serverSideEffect; |
| private final Host host; |
| |
| private final Map<String, Object> sideEffects = new HashMap<>(); |
| |
| private boolean closed = false; |
| private boolean retrievedAllKeys = false; |
| private final CompletableFuture<Void> ready; |
| |
| public DriverRemoteTraversalSideEffects(final Client client, final UUID serverSideEffect, final Host host, |
| final CompletableFuture<Void> ready) { |
| this.client = client; |
| this.serverSideEffect = serverSideEffect; |
| this.host = host; |
| this.ready = ready; |
| } |
| |
| @Override |
| public <V> V get(final String key) throws IllegalArgumentException { |
| // wait for the read to complete (i.e. iteration on the server) before allowing the caller to get the |
| // side-effect. calling prior to this will result in the side-effect not being found. of course, the |
| // bad part here is that the method blocks indefinitely waiting for the result, but it prevents the |
| // test failure problems that happen on slower systems. in practice, it's unlikely that a user would |
| // try to get a side-effect prior to iteration, but since the API allows it, this at least prevents |
| // the error. |
| ready.join(); |
| |
| if (!keys().contains(key)) throw TraversalSideEffects.Exceptions.sideEffectKeyDoesNotExist(key); |
| |
| if (!sideEffects.containsKey(key)) { |
| |
| if (closed) throw new IllegalStateException("Traversal has been closed - no new side-effects can be retrieved"); |
| |
| // specify the ARGS_HOST so that the LoadBalancingStrategy is subverted and the connection is forced |
| // from the specified host (i.e. the host from the previous request as that host will hold the side-effects) |
| final RequestMessage msg = RequestMessage.build(Tokens.OPS_GATHER) |
| .addArg(Tokens.ARGS_SIDE_EFFECT, serverSideEffect) |
| .addArg(Tokens.ARGS_SIDE_EFFECT_KEY, key) |
| .addArg(Tokens.ARGS_HOST, host) |
| .processor("traversal").create(); |
| try { |
| final Result result = client.submitAsync(msg).get().all().get().get(0); |
| sideEffects.put(key, null == result ? null : result.getObject()); |
| } catch (Exception ex) { |
| // we use to try to catch "no found" situations returned from the server here and then null the |
| // side-effect for the requested key. doesn't seem like there is a need for that now because calls |
| // to get() now initially trigger a call the keys() so you would know all of the keys available on |
| // the server and would validate them up front throwing sideEffectKeyDoesNotExist(key) which thus |
| // produces behavior similar to the non-remote side-effect implementations. if we get an exception |
| // here at this point then we likely have a legit error in communicating to the remote server. |
| throw new RuntimeException("Could not get side-effect for " + serverSideEffect + " with key of " + key, ex); |
| } |
| } |
| |
| return (V) sideEffects.get(key); |
| } |
| |
| @Override |
| public Set<String> keys() { |
| // wait for the read to complete (i.e. iteration on the server) before allowing the caller to get the |
| // side-effect. calling prior to this will result in the side-effect not being found. of course, the |
| // bad part here is that the method blocks indefinitely waiting for the result, but it prevents the |
| // test failure problems that happen on slower systems. in practice, it's unlikely that a user would |
| // try to get a side-effect prior to iteration, but since the API allows it, this at least prevents |
| // the error. |
| ready.join(); |
| |
| if (closed && !retrievedAllKeys) throw new IllegalStateException("Traversal has been closed - side-effect keys cannot be retrieved"); |
| |
| if (!retrievedAllKeys) { |
| // specify the ARGS_HOST so that the LoadBalancingStrategy is subverted and the connection is forced |
| // from the specified host (i.e. the host from the previous request as that host will hold the side-effects) |
| final RequestMessage msg = RequestMessage.build(Tokens.OPS_KEYS) |
| .addArg(Tokens.ARGS_SIDE_EFFECT, serverSideEffect) |
| .addArg(Tokens.ARGS_HOST, host) |
| .processor("traversal").create(); |
| try { |
| if (keys.equals(Collections.emptySet())) |
| keys = new HashSet<>(); |
| |
| client.submitAsync(msg).get().all().get().forEach(r -> keys.add(r.getString())); |
| |
| // only need to retrieve all keys once |
| retrievedAllKeys = true; |
| } catch (Exception ex) { |
| final Throwable root = ExceptionUtils.getRootCause(ex); |
| throw new RuntimeException("Could not get keys", null == root ? ex : root); |
| } |
| } |
| |
| return keys; |
| } |
| |
| @Override |
| public void close() throws Exception { |
| if (!closed) { |
| final RequestMessage msg = RequestMessage.build(Tokens.OPS_CLOSE) |
| .addArg(Tokens.ARGS_SIDE_EFFECT, serverSideEffect) |
| .addArg(Tokens.ARGS_HOST, host) |
| .processor("traversal").create(); |
| try { |
| client.submitAsync(msg).get(); |
| closed = true; |
| } catch (Exception ex) { |
| final Throwable root = ExceptionUtils.getRootCause(ex); |
| throw new RuntimeException("Error on closing side effects", null == root ? ex : root); |
| } |
| } |
| } |
| |
| @Override |
| public String toString() { |
| // have to override the implementation from TraversalSideEffects because it relies on calls to keys() as |
| // calling that too early can cause unintended failures (i.e. in the debugger, toString() gets called when |
| // introspecting the object from the moment of construction). |
| return "sideEffects[size:" + keys.size() + "]"; |
| } |
| } |