JGitKeyCache.java

/*
 * Copyright (C) 2018, Thomas Wolf <thomas.wolf@paranor.ch> and others
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0 which is available at
 * https://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */
package org.eclipse.jgit.transport.sshd;

import java.nio.file.Path;
import java.security.KeyPair;
import java.security.PrivateKey;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Function;

import javax.security.auth.DestroyFailedException;

/**
 * A simple {@link KeyCache}. JGit uses one such cache in its
 * {@link SshdSessionFactory} to avoid loading keys multiple times.
 *
 * @since 5.2
 */
public class JGitKeyCache implements KeyCache {

    private AtomicReference<Map<Path, KeyPair>> cache = new AtomicReference<>(
            new ConcurrentHashMap<>());

    @Override
    public KeyPair get(Path path,
            Function<? super Path, ? extends KeyPair> loader) {
        return cache.get().computeIfAbsent(path, loader);
    }

    @Override
    public void close() {
        Map<Path, KeyPair> map = cache.getAndSet(null);
        if (map == null) {
            return;
        }
        for (KeyPair k : map.values()) {
            PrivateKey p = k.getPrivate();
            try {
                p.destroy();
            } catch (DestroyFailedException e) {
                // Ignore here. We did our best.
            }
        }
        map.clear();
    }
}