| // Copyright 2018 The Bazel Authors. All rights reserved. |
| // |
| // Licensed 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 com.google.devtools.build.lib.skylarkdebug.server; |
| |
| import java.util.Map; |
| import java.util.concurrent.ConcurrentHashMap; |
| import java.util.concurrent.atomic.AtomicLong; |
| import javax.annotation.Nullable; |
| |
| /** |
| * A map of identifier to value for all the values with children which have been communicated to the |
| * debug client for a particular, currently-paused thread. |
| * |
| * <p>Objects without children (as defined by the debugging protocol) should not be stored here. |
| * |
| * <p>Object identifiers apply only to a single thread, and aren't relevant to other threads. |
| * |
| * <p>This state is retained only while the thread is paused. |
| */ |
| final class ThreadObjectMap { |
| private final AtomicLong lastId = new AtomicLong(1); |
| private final Map<Long, Object> objectMap = new ConcurrentHashMap<>(); |
| |
| /** |
| * Assigns and returns a unique identifier for this object, and stores a reference in the |
| * identifier to object map. |
| * |
| * <p>If called multiple times for a given object, a different identifier will be returned each |
| * time. The object can be retrieved by all such identifiers. |
| */ |
| long registerValue(Object value) { |
| long id = lastId.getAndIncrement(); |
| objectMap.put(id, value); |
| return id; |
| } |
| |
| /** Returns the object corresponding to the given identifier, if one exists. */ |
| @Nullable |
| Object getValue(long identifier) { |
| return objectMap.get(identifier); |
| } |
| } |