/*
 * Copyright (C) 2016, Google Inc. 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.internal.ketch;

import java.net.URISyntaxException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import org.eclipse.jgit.internal.storage.dfs.DfsRepository;
import org.eclipse.jgit.lib.Repository;

A cache of live leader instances, keyed by repository.

Ketch only assigns a leader to a repository when needed. If get(Repository) is called for a repository that does not have a leader, the leader is created and added to the cache.

/** * A cache of live leader instances, keyed by repository. * <p> * Ketch only assigns a leader to a repository when needed. If * {@link #get(Repository)} is called for a repository that does not have a * leader, the leader is created and added to the cache. */
public class KetchLeaderCache { private final KetchSystem system; private final ConcurrentMap<String, KetchLeader> leaders; private final Lock startLock;
Initialize a new leader cache.
Params:
  • system – system configuration for the leaders
/** * Initialize a new leader cache. * * @param system * system configuration for the leaders */
public KetchLeaderCache(KetchSystem system) { this.system = system; leaders = new ConcurrentHashMap<>(); startLock = new ReentrantLock(true /* fair */); }
Lookup the leader instance for a given repository.
Params:
  • repo – repository to get the leader for.
Throws:
Returns:the leader instance for the repository.
/** * Lookup the leader instance for a given repository. * * @param repo * repository to get the leader for. * @return the leader instance for the repository. * @throws java.net.URISyntaxException * remote configuration contains an invalid URL. */
public KetchLeader get(Repository repo) throws URISyntaxException { String key = computeKey(repo); KetchLeader leader = leaders.get(key); if (leader != null) { return leader; } return startLeader(key, repo); } private KetchLeader startLeader(String key, Repository repo) throws URISyntaxException { startLock.lock(); try { KetchLeader leader = leaders.get(key); if (leader != null) { return leader; } leader = system.createLeader(repo); leaders.put(key, leader); return leader; } finally { startLock.unlock(); } } private static String computeKey(Repository repo) { if (repo instanceof DfsRepository) { DfsRepository dfs = (DfsRepository) repo; return dfs.getDescription().getRepositoryName(); } if (repo.getDirectory() != null) { return repo.getDirectory().toURI().toString(); } throw new IllegalArgumentException(); } }