FileLfsRepository.java

/*
 * Copyright (C) 2015, Matthias Sohn <matthias.sohn@sap.com> 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.lfs.server.fs;

import static org.eclipse.jgit.util.HttpSupport.HDR_AUTHORIZATION;

import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.Collections;

import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.lfs.internal.AtomicObjectOutputStream;
import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
import org.eclipse.jgit.lfs.lib.Constants;
import org.eclipse.jgit.lfs.server.LargeFileRepository;
import org.eclipse.jgit.lfs.server.Response;
import org.eclipse.jgit.lfs.server.Response.Action;

/**
 * Repository storing large objects in the file system
 *
 * @since 4.3
 */
public class FileLfsRepository implements LargeFileRepository {

    private String url;
    private final Path dir;

    /**
     * <p>Constructor for FileLfsRepository.</p>
     *
     * @param url
     *            external URL of this repository
     * @param dir
     *            storage directory
     * @throws java.io.IOException
     */
    public FileLfsRepository(String url, Path dir) throws IOException {
        this.url = url;
        this.dir = dir;
        Files.createDirectories(dir);
    }

    /** {@inheritDoc} */
    @Override
    public Response.Action getDownloadAction(AnyLongObjectId id) {
        return getAction(id);
    }

    /** {@inheritDoc} */
    @Override
    public Action getUploadAction(AnyLongObjectId id, long size) {
        return getAction(id);
    }

    /** {@inheritDoc} */
    @Override
    @Nullable
    public Action getVerifyAction(AnyLongObjectId id) {
        return null;
    }

    /** {@inheritDoc} */
    @Override
    public long getSize(AnyLongObjectId id) throws IOException {
        Path p = getPath(id);
        if (Files.exists(p)) {
            return Files.size(p);
        }
        return -1;
    }

    /**
     * Get the storage directory
     *
     * @return the path of the storage directory
     */
    public Path getDir() {
        return dir;
    }

    /**
     * Get the path where the given object is stored
     *
     * @param id
     *            id of a large object
     * @return path the object's storage path
     */
    protected Path getPath(AnyLongObjectId id) {
        StringBuilder s = new StringBuilder(
                Constants.LONG_OBJECT_ID_STRING_LENGTH + 6);
        s.append(toHexCharArray(id.getFirstByte())).append('/');
        s.append(toHexCharArray(id.getSecondByte())).append('/');
        s.append(id.name());
        return dir.resolve(s.toString());
    }

    private Response.Action getAction(AnyLongObjectId id) {
        Response.Action a = new Response.Action();
        a.href = url + id.getName();
        a.header = Collections.singletonMap(HDR_AUTHORIZATION, "not:required"); //$NON-NLS-1$
        return a;
    }

    ReadableByteChannel getReadChannel(AnyLongObjectId id)
            throws IOException {
        return FileChannel.open(getPath(id), StandardOpenOption.READ);
    }

    AtomicObjectOutputStream getOutputStream(AnyLongObjectId id)
            throws IOException {
        Path path = getPath(id);
        Path parent = path.getParent();
        if (parent != null) {
            Files.createDirectories(parent);
        }
        return new AtomicObjectOutputStream(path, id);
    }

    private static char[] toHexCharArray(int b) {
        final char[] dst = new char[2];
        formatHexChar(dst, 0, b);
        return dst;
    }

    private static final char[] hexchar = { '0', '1', '2', '3', '4', '5', '6',
            '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

    private static void formatHexChar(char[] dst, int p, int b) {
        int o = p + 1;
        while (o >= p && b != 0) {
            dst[o--] = hexchar[b & 0xf];
            b >>>= 4;
        }
        while (o >= p)
            dst[o--] = '0';
    }

    /**
     * @return the url of the content server
     * @since 4.11
     */
    public String getUrl() {
        return url;
    }

    /**
     * @param url
     *            the url of the content server
     * @since 4.11
     */
    public void setUrl(String url) {
        this.url = url;
    }
}