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- /*
- * Copyright (C) 2008-2010, Google Inc.
- * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
- * 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.storage.pack;
-
- import org.eclipse.jgit.lib.AnyObjectId;
- import org.eclipse.jgit.lib.ObjectId;
- import org.eclipse.jgit.revwalk.RevObject;
- import org.eclipse.jgit.transport.PackedObjectInfo;
-
- /**
- * Per-object state used by {@link PackWriter}.
- * <p>
- * {@code PackWriter} uses this class to track the things it needs to include in
- * the newly generated pack file, and how to efficiently obtain the raw data for
- * each object as they are written to the output stream.
- */
- public class ObjectToPack extends PackedObjectInfo {
- private static final int WANT_WRITE = 1 << 0;
-
- private static final int REUSE_AS_IS = 1 << 1;
-
- private static final int TYPE_SHIFT = 5;
-
- private static final int DELTA_SHIFT = 8;
-
- private static final int NON_DELTA_MASK = 0xff;
-
- /** Other object being packed that this will delta against. */
- private ObjectId deltaBase;
-
- /**
- * Bit field, from bit 0 to bit 31:
- * <ul>
- * <li>1 bit: wantWrite</li>
- * <li>1 bit: canReuseAsIs</li>
- * <li>3 bits: unused</li>
- * <li>3 bits: type</li>
- * <li>--</li>
- * <li>24 bits: deltaDepth</li>
- * </ul>
- */
- private int flags;
-
- /**
- * Construct for the specified object id.
- *
- * @param src
- * object id of object for packing
- * @param type
- * real type code of the object, not its in-pack type.
- */
- public ObjectToPack(AnyObjectId src, final int type) {
- super(src);
- flags = type << TYPE_SHIFT;
- }
-
- /**
- * Construct for the specified object.
- *
- * @param obj
- * identity of the object that will be packed. The object's
- * parsed status is undefined here. Implementers must not rely on
- * the object being parsed.
- */
- public ObjectToPack(RevObject obj) {
- this(obj, obj.getType());
- }
-
- /**
- * @return delta base object id if object is going to be packed in delta
- * representation; null otherwise - if going to be packed as a
- * whole object.
- */
- ObjectId getDeltaBaseId() {
- return deltaBase;
- }
-
- /**
- * @return delta base object to pack if object is going to be packed in
- * delta representation and delta is specified as object to
- * pack; null otherwise - if going to be packed as a whole
- * object or delta base is specified only as id.
- */
- ObjectToPack getDeltaBase() {
- if (deltaBase instanceof ObjectToPack)
- return (ObjectToPack) deltaBase;
- return null;
- }
-
- /**
- * Set delta base for the object. Delta base set by this method is used
- * by {@link PackWriter} to write object - determines its representation
- * in a created pack.
- *
- * @param deltaBase
- * delta base object or null if object should be packed as a
- * whole object.
- *
- */
- void setDeltaBase(ObjectId deltaBase) {
- this.deltaBase = deltaBase;
- }
-
- void clearDeltaBase() {
- this.deltaBase = null;
- }
-
- /**
- * @return true if object is going to be written as delta; false
- * otherwise.
- */
- boolean isDeltaRepresentation() {
- return deltaBase != null;
- }
-
- /**
- * Check if object is already written in a pack. This information is
- * used to achieve delta-base precedence in a pack file.
- *
- * @return true if object is already written; false otherwise.
- */
- boolean isWritten() {
- return getOffset() != 0;
- }
-
- int getType() {
- return (flags >> TYPE_SHIFT) & 0x7;
- }
-
- int getDeltaDepth() {
- return flags >>> DELTA_SHIFT;
- }
-
- void updateDeltaDepth() {
- final int d;
- if (deltaBase instanceof ObjectToPack)
- d = ((ObjectToPack) deltaBase).getDeltaDepth() + 1;
- else if (deltaBase != null)
- d = 1;
- else
- d = 0;
- flags = (d << DELTA_SHIFT) | (flags & NON_DELTA_MASK);
- }
-
- boolean wantWrite() {
- return (flags & WANT_WRITE) != 0;
- }
-
- void markWantWrite() {
- flags |= WANT_WRITE;
- }
-
- boolean isReuseAsIs() {
- return (flags & REUSE_AS_IS) != 0;
- }
-
- void setReuseAsIs() {
- flags |= REUSE_AS_IS;
- }
-
- void clearReuseAsIs() {
- flags &= ~REUSE_AS_IS;
- }
-
- int getFormat() {
- if (isReuseAsIs()) {
- if (isDeltaRepresentation())
- return StoredObjectRepresentation.PACK_DELTA;
- return StoredObjectRepresentation.PACK_WHOLE;
- }
- return StoredObjectRepresentation.FORMAT_OTHER;
- }
-
- // Overload weight into CRC since we don't need them at the same time.
- int getWeight() {
- return getCRC();
- }
-
- void setWeight(int weight) {
- setCRC(weight);
- }
-
- /**
- * Remember a specific representation for reuse at a later time.
- * <p>
- * Implementers should remember the representation chosen, so it can be
- * reused at a later time. {@link PackWriter} may invoke this method
- * multiple times for the same object, each time saving the current best
- * representation found.
- *
- * @param ref
- * the object representation.
- */
- public void select(StoredObjectRepresentation ref) {
- // Empty by default.
- }
- }
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