AdvertiseRefsHookChain.java

/*
 * Copyright (C) 2012, 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.transport;

import java.io.IOException;
import java.util.List;

/**
 * {@link org.eclipse.jgit.transport.AdvertiseRefsHook} that delegates to a list
 * of other hooks.
 * <p>
 * Hooks are run in the order passed to the constructor. A hook may inspect or
 * modify the results of the previous hooks in the chain by calling
 * {@link org.eclipse.jgit.transport.UploadPack#getAdvertisedRefs()}, or
 * {@link org.eclipse.jgit.transport.ReceivePack#getAdvertisedRefs()} or
 * {@link org.eclipse.jgit.transport.ReceivePack#getAdvertisedObjects()}.
 */
public class AdvertiseRefsHookChain implements AdvertiseRefsHook {
    private final AdvertiseRefsHook[] hooks;
    private final int count;

    /**
     * Create a new hook chaining the given hooks together.
     *
     * @param hooks
     *            hooks to execute, in order.
     * @return a new hook chain of the given hooks.
     */
    public static AdvertiseRefsHook newChain(List<? extends AdvertiseRefsHook> hooks) {
        AdvertiseRefsHook[] newHooks = new AdvertiseRefsHook[hooks.size()];
        int i = 0;
        for (AdvertiseRefsHook hook : hooks)
            if (hook != AdvertiseRefsHook.DEFAULT)
                newHooks[i++] = hook;
        switch (i) {
        case 0:
            return AdvertiseRefsHook.DEFAULT;
        case 1:
            return newHooks[0];
        default:
            return new AdvertiseRefsHookChain(newHooks, i);
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void advertiseRefs(ReceivePack rp)
            throws IOException {
        for (int i = 0; i < count; i++)
            hooks[i].advertiseRefs(rp);
    }

    /** {@inheritDoc} */
    @Override
    public void advertiseRefs(UploadPack rp)
            throws ServiceMayNotContinueException {
        for (int i = 0; i < count; i++)
            hooks[i].advertiseRefs(rp);
    }

    private AdvertiseRefsHookChain(AdvertiseRefsHook[] hooks, int count) {
        this.hooks = hooks;
        this.count = count;
    }
}