DfsRepository.java

/*
 * Copyright (C) 2011, 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.storage.dfs;

import java.io.IOException;
import java.io.InputStream;
import java.text.MessageFormat;
import java.util.Collections;

import org.eclipse.jgit.attributes.AttributesNode;
import org.eclipse.jgit.attributes.AttributesNodeProvider;
import org.eclipse.jgit.attributes.AttributesRule;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.RefUpdate;
import org.eclipse.jgit.lib.ReflogReader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.lib.StoredConfig;

/**
 * A Git repository on a DFS.
 */
public abstract class DfsRepository extends Repository {
    private final DfsConfig config;

    private final DfsRepositoryDescription description;

    /**
     * Initialize a DFS repository.
     *
     * @param builder
     *            description of the repository.
     */
    protected DfsRepository(DfsRepositoryBuilder builder) {
        super(builder);
        this.config = new DfsConfig();
        this.description = builder.getRepositoryDescription();
    }

    /** {@inheritDoc} */
    @Override
    public abstract DfsObjDatabase getObjectDatabase();

    /**
     * Get the description of this repository.
     *
     * @return the description of this repository.
     */
    public DfsRepositoryDescription getDescription() {
        return description;
    }

    /**
     * Check if the repository already exists.
     *
     * @return true if the repository exists; false if it is new.
     * @throws java.io.IOException
     *             the repository cannot be checked.
     */
    public boolean exists() throws IOException {
        if (getRefDatabase() instanceof DfsRefDatabase) {
            return ((DfsRefDatabase) getRefDatabase()).exists();
        }
        return true;
    }

    /** {@inheritDoc} */
    @Override
    public void create(boolean bare) throws IOException {
        if (exists())
            throw new IOException(MessageFormat.format(
                    JGitText.get().repositoryAlreadyExists, "")); //$NON-NLS-1$

        String master = Constants.R_HEADS + Constants.MASTER;
        RefUpdate.Result result = updateRef(Constants.HEAD, true).link(master);
        if (result != RefUpdate.Result.NEW)
            throw new IOException(result.name());
    }

    /** {@inheritDoc} */
    @Override
    public StoredConfig getConfig() {
        return config;
    }

    /** {@inheritDoc} */
    @Override
    public String getIdentifier() {
        return getDescription().getRepositoryName();
    }

    /** {@inheritDoc} */
    @Override
    public void scanForRepoChanges() throws IOException {
        getRefDatabase().refresh();
        getObjectDatabase().clearCache();
    }

    /** {@inheritDoc} */
    @Override
    public void notifyIndexChanged(boolean internal) {
        // Do not send notifications.
        // There is no index, as there is no working tree.
    }

    /** {@inheritDoc} */
    @Override
    public ReflogReader getReflogReader(String refName) throws IOException {
        throw new UnsupportedOperationException();
    }

    /** {@inheritDoc} */
    @Override
    public AttributesNodeProvider createAttributesNodeProvider() {
        // TODO Check if the implementation used in FileRepository can be used
        // for this kind of repository
        return new EmptyAttributesNodeProvider();
    }

    private static class EmptyAttributesNodeProvider implements
            AttributesNodeProvider {
        private EmptyAttributesNode emptyAttributesNode = new EmptyAttributesNode();

        @Override
        public AttributesNode getInfoAttributesNode() throws IOException {
            return emptyAttributesNode;
        }

        @Override
        public AttributesNode getGlobalAttributesNode() throws IOException {
            return emptyAttributesNode;
        }

        private static class EmptyAttributesNode extends AttributesNode {

            public EmptyAttributesNode() {
                super(Collections.<AttributesRule> emptyList());
            }

            @Override
            public void parse(InputStream in) throws IOException {
                // Do nothing
            }
        }
    }
}