org.neo4j.jdbc.DefaultBookmarkManagerImpl Maven / Gradle / Ivy
/*
* Copyright (c) 2023-2024 "Neo4j,"
* Neo4j Sweden AB [https://neo4j.com]
*
* This file is part of Neo4j.
*
* 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
*
* https://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.neo4j.jdbc;
import java.util.Collection;
import java.util.HashSet;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import java.util.function.Function;
import java.util.stream.Collectors;
/**
* Responsible for storing, updating and retrieving the bookmarks of Neo4j's transaction.
* The original class appeared for the first time in
* Spring Data
* Neo4j 6 by the same author, under the same license.
*
* @author Michael J. Simons
*/
final class DefaultBookmarkManagerImpl implements BookmarkManager {
private final Set bookmarks = new HashSet<>();
private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
private final Lock read = this.lock.readLock();
private final Lock write = this.lock.writeLock();
@Override
public Set getBookmarks(Function transformer) {
try {
this.read.lock();
return this.bookmarks.stream().map(transformer).collect(Collectors.toUnmodifiableSet());
}
finally {
this.read.unlock();
}
}
@Override
public void updateBookmarks(Function transformer, Collection usedBookmarks,
Collection newBookmarks) {
Objects.requireNonNull(transformer, "A function for deriving a String value from a bookmark is required");
Objects.requireNonNull(newBookmarks, "New bookmarks might not be null");
try {
this.write.lock();
if (usedBookmarks != null) {
usedBookmarks.forEach(b -> this.bookmarks.remove(transformer.apply(b)));
}
newBookmarks.forEach(b -> this.bookmarks.add(transformer.apply(b)));
}
finally {
this.write.unlock();
}
}
}