andreachild commented on code in PR #3157: URL: https://github.com/apache/tinkerpop/pull/3157#discussion_r2271997947
########## gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/GValueManager.java: ########## @@ -0,0 +1,169 @@ +/* + * 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; + +import org.apache.tinkerpop.gremlin.process.traversal.step.GValue; + +import java.io.Serializable; +import java.util.Collection; +import java.util.Collections; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Map; +import java.util.Set; + +/** + * The {@code GValueManager} class is responsible for managing the state of {@link GValue} instances and their + * associations with `Step` objects in a traversal. This class ensures that `GValue` instances are properly extracted + * and stored in a registry, allowing for dynamic query optimizations and state management during traversal execution. + * Note that the manager can be locked, at which point it becomes immutable, and any attempt to modify it will result + * in an exception. + */ +public final class GValueManager implements Serializable, Cloneable { + + private final Map<String, GValue<?>> gValueRegistry = new HashMap<>(); + private final Map<String, GValue<?>> pinnedGValues = new HashMap<>(); + + public GValueManager() { + this(Collections.EMPTY_MAP, Collections.EMPTY_MAP); + } + + private GValueManager(final Map<String, GValue<?>> gValueRegistry, final Map<String, GValue<?>> pinnedGValues) { + this.gValueRegistry.putAll(gValueRegistry); + this.pinnedGValues.putAll(pinnedGValues); + } + + /** + * Merges the internal registries of the current {@code GValueManager} into another {@code GValueManager}. + * Transfers the state of the {@code gValueRegistry} and {@code stepRegistry} from the current instance to the + * specified target instance. + * + * @param other the target {@code GValueManager} into which the current instance's registries will be merged + */ + public void mergeInto(final GValueManager other) { + //TODO needs test + other.register(gValueRegistry.values()); + other.pinGValues(pinnedGValues.values()); + } + + /** + * Gets the set of variable names used in this traversal. + */ + public Set<String> getVariableNames() { + return Collections.unmodifiableSet(gValueRegistry.keySet()); + } + + /** + * Gets the set of variable names used in this traversal which have not been pinned to specific values. + */ + public Set<String> getUnpinnedVariableNames() { + Set<String> variableNames = new HashSet<>(); + variableNames.addAll(gValueRegistry.keySet()); + variableNames.removeAll(pinnedGValues.keySet()); + return Collections.unmodifiableSet(variableNames); + } + + /** + * Gets the set of variable names used in this traversal which have not been pinned to specific values. + */ + public Set<String> getPinnedVariableNames() { + return Collections.unmodifiableSet(pinnedGValues.keySet()); + } + + /** + * Gets the set of {@link GValue} objects used in this traversal. + */ + public Set<GValue<?>> getGValues() { + return Collections.unmodifiableSet(new HashSet(gValueRegistry.values())); + } + + /** + * Gets the set of pinned GValues used in this traversal. + */ + public Set<GValue<?>> getPinnedGValues() { + return Collections.unmodifiableSet(new HashSet(pinnedGValues.values())); + } + + /** + * Determines whether the manager has step registrations. + */ + public boolean hasVariables() { + return !getVariableNames().isEmpty(); + } + + /** + * Determines whether the manager has unpinned GValues. + */ + public boolean hasUnpinnedVariables() { + return !getUnpinnedVariableNames().isEmpty(); + } + + /** + * Pins any GValue with the provided name. This should be called anytime an optimization + * alters the Traversal based on the current value of a GValue. This indicates that the resulting traversal is only + * valid for this specific value of a GValue, and is not generalizable to any parameter value. Review Comment: ```suggestion * valid for the current value of this GValue, and is not generalizable to any parameter value. ``` -- 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]
