CachedPack.java
- /*
- * Copyright (C) 2011, Google Inc.
- * and other copyright owners as documented in the project's IP log.
- *
- * 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
- *
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or
- * without modification, are permitted provided that the following
- * conditions are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * - Redistributions in binary form must reproduce the above
- * copyright notice, this list of conditions and the following
- * disclaimer in the documentation and/or other materials provided
- * with the distribution.
- *
- * - Neither the name of the Eclipse Foundation, Inc. nor the
- * names of its contributors may be used to endorse or promote
- * products derived from this software without specific prior
- * written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
- * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
- * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
- package org.eclipse.jgit.internal.storage.pack;
- import java.io.IOException;
- /**
- * Describes a pack file
- * {@link org.eclipse.jgit.internal.storage.pack.ObjectReuseAsIs} can append
- * onto a stream.
- */
- public abstract class CachedPack {
- /**
- * Get the number of objects in this pack.
- *
- * @return the total object count for the pack.
- * @throws java.io.IOException
- * if the object count cannot be read.
- */
- public abstract long getObjectCount() throws IOException;
- /**
- * Get the number of delta objects stored in this pack.
- * <p>
- * This is an optional method, not every cached pack storage system knows
- * the precise number of deltas stored within the pack. This number must be
- * smaller than {@link #getObjectCount()} as deltas are not supposed to span
- * across pack files.
- * <p>
- * This method must be fast, if the only way to determine delta counts is to
- * scan the pack file's contents one object at a time, implementors should
- * return 0 and avoid the high cost of the scan.
- *
- * @return the number of deltas; 0 if the number is not known or there are
- * no deltas.
- * @throws java.io.IOException
- * if the delta count cannot be read.
- */
- public long getDeltaCount() throws IOException {
- return 0;
- }
- /**
- * Determine if this pack contains the object representation given.
- * <p>
- * PackWriter uses this method during the finding sources phase to prune
- * away any objects from the leading thin-pack that already appear within
- * this pack and should not be sent twice.
- * <p>
- * Implementors are strongly encouraged to rely on looking at {@code rep}
- * only and using its internal state to decide if this object is within this
- * pack. Implementors should ensure a representation from this cached pack
- * is tested as part of
- * {@link org.eclipse.jgit.internal.storage.pack.ObjectReuseAsIs#selectObjectRepresentation(PackWriter, org.eclipse.jgit.lib.ProgressMonitor, Iterable)}
- * , ensuring this method would eventually return true if the object would
- * be included by this cached pack.
- *
- * @param obj
- * the object being packed. Can be used as an ObjectId.
- * @param rep
- * representation from the
- * {@link org.eclipse.jgit.internal.storage.pack.ObjectReuseAsIs}
- * instance that originally supplied this CachedPack.
- * @return true if this pack contains this object.
- */
- public abstract boolean hasObject(ObjectToPack obj,
- StoredObjectRepresentation rep);
- }