Browse Source

Ketch: Simple map of running leader instances

Supports use in basic daemons where RepositoryCache is also effective.

Change-Id: Ia736b32c2c710b5a802233badc0d30818de763cd
stable-4.3
Shawn Pearce 9 years ago
parent
commit
b718e3d304
  1. 126
      org.eclipse.jgit/src/org/eclipse/jgit/internal/ketch/KetchLeaderCache.java

126
org.eclipse.jgit/src/org/eclipse/jgit/internal/ketch/KetchLeaderCache.java

@ -0,0 +1,126 @@
/*
* Copyright (C) 2016, Google Inc.
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
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.
* <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.
*
* @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.
*
* @param repo
* repository to get the leader for.
* @return the leader instance for the repository.
* @throws 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();
}
}
Loading…
Cancel
Save