jgit/org.eclipse.jgit/src/org/eclipse/jgit/transport/PostUploadHookChain.java

/*
 * Copyright (C) 2015, Google Inc.
 *
 * 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
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package org.eclipse.jgit.transport;

import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;

import org.eclipse.jgit.storage.pack.PackStatistics;

/**
 * {@link org.eclipse.jgit.transport.PostUploadHook} that delegates to a list of
 * other hooks.
 * <p>
 * Hooks are run in the order passed to the constructor.
 *
 * @since 4.1
 */
public class PostUploadHookChain implements PostUploadHook {
	private final List<PostUploadHook> hooks;

	/**
	 * Create a new hook chaining the given hooks together.
	 *
	 * @param hooks
	 *            hooks to execute, in order.
	 * @return a new chain of the given hooks.
	 */
	public static PostUploadHook newChain(List<PostUploadHook> hooks) {
		List<PostUploadHook> newHooks = hooks.stream()
				.filter(hook -> !hook.equals(PostUploadHook.NULL))
				.collect(Collectors.toList());

		if (newHooks.isEmpty()) {
			return PostUploadHook.NULL;
		} else if (newHooks.size() == 1) {
			return newHooks.get(0);
		} else {
			return new PostUploadHookChain(newHooks);
		}
	}

	/** {@inheritDoc} */
	@Override
	public void onPostUpload(PackStatistics stats) {
		for (PostUploadHook hook : hooks) {
			hook.onPostUpload(stats);
		}
	}

	private PostUploadHookChain(List<PostUploadHook> hooks) {
		this.hooks = Collections.unmodifiableList(hooks);
	}
}