jgit/org.eclipse.jgit.archive/src/org/eclipse/jgit/archive/FormatActivator.java

/*
 * Copyright (C) 2013 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.
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 * - 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
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 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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package org.eclipse.jgit.archive;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jgit.api.ArchiveCommand;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;

/**
 * This activator registers all format types from the
 * org.eclipse.jgit.archive package for use via the ArchiveCommand
 * API.
 *
 * This registration happens automatically behind the scenes
 * when the package is loaded as an OSGi bundle (and the corresponding
 * deregistration happens when the bundle is unloaded, to avoid
 * leaks).
 *
 * The static start() and stop() methods allow registering the same
 * list of formats manually in cases where OSGi bundle activation
 * cannot be used.
 */
public class FormatActivator implements BundleActivator {
	private static final List<String> myFormats = new ArrayList<String>();

	private static final void register(String name, ArchiveCommand.Format<?> fmt) {
		myFormats.add(name);
		ArchiveCommand.registerFormat(name, fmt);
	}

	/**
	 * Register all included archive formats so they can be used
	 * as arguments to the ArchiveCommand.setFormat() method.
	 *
	 * Should not be called twice without a call to stop() in between.
	 * Not thread-safe.
	 */
	public static void start() {
		register("tar", new TarFormat());
		register("zip", new ZipFormat());
	}

	/**
	 * Clean up by deregistering all formats that were registered
	 * by start().
	 *
	 * Not thread-safe.
	 */
	public static void stop() {
		for (String name : myFormats) {
			ArchiveCommand.unregisterFormat(name);
		}
		myFormats.clear();
	}

	public void start(BundleContext context) throws Exception {
		start();
	}

	public void stop(BundleContext context) throws Exception {
		stop();
	}
}