Cole-Greer commented on code in PR #3458: URL: https://github.com/apache/tinkerpop/pull/3458#discussion_r3475649820
########## gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/strategy/verification/ReadOnlyChildVerificationStrategy.java: ########## @@ -0,0 +1,60 @@ +/* + * 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.process.traversal.strategy.verification; + +import org.apache.tinkerpop.gremlin.process.traversal.Step; +import org.apache.tinkerpop.gremlin.process.traversal.Traversal; +import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy; +import org.apache.tinkerpop.gremlin.process.traversal.step.ReadOnlyTraversalParent; +import org.apache.tinkerpop.gremlin.process.traversal.strategy.AbstractTraversalStrategy; +import org.apache.tinkerpop.gremlin.process.traversal.util.ReadOnlyChildValidator; + +/** + * Validates that child traversals in filter, lookup, and mutation steps do not contain mutating steps. + * Serves as a safety net for programmatic traversal construction that bypasses the DSL's + * construction-time validation. + */ +public final class ReadOnlyChildVerificationStrategy + extends AbstractTraversalStrategy<TraversalStrategy.VerificationStrategy> + implements TraversalStrategy.VerificationStrategy { + + private static final ReadOnlyChildVerificationStrategy INSTANCE = new ReadOnlyChildVerificationStrategy(); + + private ReadOnlyChildVerificationStrategy() { + } + + @Override + public void apply(final Traversal.Admin<?, ?> traversal) { + for (final Step<?, ?> step : traversal.getSteps()) { Review Comment: Yes, and we excessively "double up" in one case, if a `ReadOnlyTraversalParent` is itself a descendant of another `ReadOnlyTraversalParent`, the child's children will be needlessly scanned for Mutating steps a second time. I've accepted that as a reasonable trade off for simplicity as I expect that to be a fairly rare case given the intended usage of these steps. If we were to avoid recursing into the descendants of a `ReadOnlyTraversalParent` and instead rely on the recursive application of the strategy to all children, we would instead need to include a test if `traversal` itself is a descendant of a `ReadOnlyTraversalParent` which we don't have a great way to do, and would likely negate any savings from double recursion. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
