imbajin commented on code in PR #3331: URL: https://github.com/apache/hugegraph/pull/3331#discussion_r4264344967
########## hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/LoadingMode.java: ########## @@ -0,0 +1,113 @@ +/* + * 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.hugegraph; + +import java.util.HashMap; +import java.util.Map; +import java.util.Objects; +import java.util.UUID; + +import org.apache.hugegraph.type.define.GraphMode; +import org.apache.hugegraph.util.E; + +import com.google.common.collect.ImmutableMap; + +/** Same graph-instance ownership; this state is neither persisted nor distributed. */ +public final class LoadingMode { + + private static final int MAX_RELEASED = 1024; + + private final String instance = UUID.randomUUID().toString(); + private final Map<String, String> active = new HashMap<>(); + private final Map<String, String> released = new HashMap<>(); + private long epoch; + private volatile GraphMode mode = GraphMode.NONE; + + public GraphMode mode() { + return this.mode; + } + + public synchronized void mode(GraphMode mode) { + Objects.requireNonNull(mode, "mode"); + E.checkState(this.active.isEmpty(), "Loading owners are active; release them before setting graph mode"); + this.mode = mode; + } + + public synchronized Map<String, Object> capability() { + return ImmutableMap.of("protocol", 1, "instance", this.instance, "epoch", this.epoch); + } + + public synchronized Map<String, Object> update(String action, String instance, long epoch, + String token, String principal) { + E.checkArgument("acquire".equals(action) || "release".equals(action), + "Loading owner action must be acquire or release"); + E.checkArgument(this.instance.equals(instance), "Loading owner belongs to another graph instance"); + E.checkArgument(epoch >= 0 && epoch <= this.epoch, "Invalid loading owner epoch"); + E.checkArgument(token != null && token.length() == 36 && UUID.fromString(token).toString().equals(token), + "Loading owner token must be a canonical UUID"); + Objects.requireNonNull(principal, "principal"); + String key = epoch + "/" + token; + String owner = this.active.get(key); + if (owner != null) { + E.checkState(owner.equals(principal), "Loading owner belongs to another authenticated principal"); + if ("acquire".equals(action)) { + return this.receipt(epoch, token, "active"); + } + // Exhaustion must fail before changing an active registration. + E.checkState(epoch != this.epoch || this.released.size() < MAX_RELEASED || + this.epoch < Long.MAX_VALUE, "Loading owner epoch exhausted"); + this.active.remove(key); + if (this.active.isEmpty()) { + this.mode = GraphMode.NONE; + } + } else if ("acquire".equals(action)) { + if (epoch < this.epoch || this.released.containsKey(key)) { Review Comment: The capacity-rotation first-acquire race is confirmed on the frozen Server and Client classes: a never-acquired old handle and an already-cancelled old handle both receive the same terminal state, while an active old handle remains usable until release. We are keeping this availability thread open separately from privileged recovery. Merely returning stale and automatically minting a new token would lose cancellation fencing; safe refresh needs to account for the context lifecycle, unknown acquire outcomes, and the distinction between automatic rotation and administrator recovery. The current increment preserves permanent terminal old tuples and does not add that automatic retry. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
