LocalObjectRepresentation.java

/*
 * Copyright (C) 2010, 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.file;

import java.io.IOException;

import org.eclipse.jgit.internal.storage.pack.StoredObjectRepresentation;
import org.eclipse.jgit.lib.ObjectId;

class LocalObjectRepresentation extends StoredObjectRepresentation {
    static LocalObjectRepresentation newWhole(Pack pack, long offset, long length) {
        LocalObjectRepresentation r = new LocalObjectRepresentation() {
            @Override
            public int getFormat() {
                return PACK_WHOLE;
            }
        };
        r.pack = pack;
        r.offset = offset;
        r.length = length;
        return r;
    }

    static LocalObjectRepresentation newDelta(Pack pack, long offset, long length,
            ObjectId base) {
        LocalObjectRepresentation r = new Delta();
        r.pack = pack;
        r.offset = offset;
        r.length = length;
        r.baseId = base;
        return r;
    }

    static LocalObjectRepresentation newDelta(Pack pack, long offset, long length,
            long base) {
        LocalObjectRepresentation r = new Delta();
        r.pack = pack;
        r.offset = offset;
        r.length = length;
        r.baseOffset = base;
        return r;
    }

    Pack pack;

    long offset;

    long length;

    private long baseOffset;

    private ObjectId baseId;

    /** {@inheritDoc} */
    @Override
    public int getWeight() {
        return (int) Math.min(length, Integer.MAX_VALUE);
    }

    /** {@inheritDoc} */
    @Override
    public ObjectId getDeltaBase() {
        if (baseId == null && getFormat() == PACK_DELTA) {
            try {
                baseId = pack.findObjectForOffset(baseOffset);
            } catch (IOException error) {
                return null;
            }
        }
        return baseId;
    }

    private static final class Delta extends LocalObjectRepresentation {
        @Override
        public int getFormat() {
            return PACK_DELTA;
        }
    }
}