123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424 |
- /*
- * 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.Constants;
- 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 DO_NOT_DELTA = 1 << 2;
-
- private static final int EDGE = 1 << 3;
-
- private static final int DELTA_ATTEMPTED = 1 << 4;
-
- private static final int ATTEMPT_DELTA_MASK = REUSE_AS_IS | DELTA_ATTEMPTED;
-
- private static final int TYPE_SHIFT = 5;
-
- private static final int EXT_SHIFT = 8;
-
- private static final int EXT_MASK = 0xf;
-
- private static final int DELTA_SHIFT = 12;
-
- private static final int NON_EXT_MASK = ~(EXT_MASK << EXT_SHIFT);
-
- private static final int NON_DELTA_MASK = 0xfff;
-
- /** 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>1 bit: doNotDelta</li>
- * <li>1 bit: edgeObject</li>
- * <li>1 bit: deltaAttempted</li>
- * <li>3 bits: type</li>
- * <li>4 bits: subclass flags (if any)</li>
- * <li>--</li>
- * <li>20 bits: deltaDepth</li>
- * </ul>
- */
- private int flags;
-
- /** Hash of the object's tree path. */
- private int pathHash;
-
- /** If present, deflated delta instruction stream for this object. */
- private DeltaCache.Ref cachedDelta;
-
- /**
- * 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.
- */
- public 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.
- */
- public 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 setCachedDelta(DeltaCache.Ref data){
- cachedDelta = data;
- }
-
- DeltaCache.Ref popCachedDelta() {
- DeltaCache.Ref r = cachedDelta;
- if (r != null)
- cachedDelta = null;
- return r;
- }
-
- void clearDeltaBase() {
- this.deltaBase = null;
-
- if (cachedDelta != null) {
- cachedDelta.clear();
- cachedDelta.enqueue();
- cachedDelta = null;
- }
- }
-
- /**
- * @return true if object is going to be written as delta; false
- * otherwise.
- */
- public 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.
- */
- public boolean isWritten() {
- return getOffset() != 0;
- }
-
- /** @return the type of this object. */
- public int getType() {
- return (flags >> TYPE_SHIFT) & 0x7;
- }
-
- int getDeltaDepth() {
- return flags >>> DELTA_SHIFT;
- }
-
- void setDeltaDepth(int d) {
- flags = (d << DELTA_SHIFT) | (flags & NON_DELTA_MASK);
- }
-
- boolean wantWrite() {
- return (flags & WANT_WRITE) != 0;
- }
-
- void markWantWrite() {
- flags |= WANT_WRITE;
- }
-
- /**
- * @return true if an existing representation was selected to be reused
- * as-is into the pack stream.
- */
- public boolean isReuseAsIs() {
- return (flags & REUSE_AS_IS) != 0;
- }
-
- void setReuseAsIs() {
- flags |= REUSE_AS_IS;
- }
-
- /**
- * Forget the reuse information previously stored.
- * <p>
- * Implementations may subclass this method, but they must also invoke the
- * super version with {@code super.clearReuseAsIs()} to ensure the flag is
- * properly cleared for the writer.
- */
- protected void clearReuseAsIs() {
- flags &= ~REUSE_AS_IS;
- }
-
- boolean isDoNotDelta() {
- return (flags & DO_NOT_DELTA) != 0;
- }
-
- void setDoNotDelta(boolean noDelta) {
- if (noDelta)
- flags |= DO_NOT_DELTA;
- else
- flags &= ~DO_NOT_DELTA;
- }
-
- boolean isEdge() {
- return (flags & EDGE) != 0;
- }
-
- void setEdge() {
- flags |= EDGE;
- }
-
- boolean doNotAttemptDelta() {
- // Do not attempt if delta attempted and object reuse.
- return (flags & ATTEMPT_DELTA_MASK) == ATTEMPT_DELTA_MASK;
- }
-
- boolean isDeltaAttempted() {
- return (flags & DELTA_ATTEMPTED) != 0;
- }
-
- void setDeltaAttempted(boolean deltaAttempted) {
- if (deltaAttempted)
- flags |= DELTA_ATTEMPTED;
- else
- flags &= ~DELTA_ATTEMPTED;
- }
-
- /** @return the extended flags on this object, in the range [0x0, 0xf]. */
- protected int getExtendedFlags() {
- return (flags >>> EXT_SHIFT) & EXT_MASK;
- }
-
- /**
- * Determine if a particular extended flag bit has been set.
- *
- * This implementation may be faster than calling
- * {@link #getExtendedFlags()} and testing the result.
- *
- * @param flag
- * the flag mask to test, must be between 0x0 and 0xf.
- * @return true if any of the bits matching the mask are non-zero.
- */
- protected boolean isExtendedFlag(int flag) {
- return (flags & (flag << EXT_SHIFT)) != 0;
- }
-
- /**
- * Set an extended flag bit.
- *
- * This implementation is more efficient than getting the extended flags,
- * adding the bit, and setting them all back.
- *
- * @param flag
- * the bits to set, must be between 0x0 and 0xf.
- */
- protected void setExtendedFlag(int flag) {
- flags |= (flag & EXT_MASK) << EXT_SHIFT;
- }
-
- /**
- * Clear an extended flag bit.
- *
- * This implementation is more efficient than getting the extended flags,
- * removing the bit, and setting them all back.
- *
- * @param flag
- * the bits to clear, must be between 0x0 and 0xf.
- */
- protected void clearExtendedFlag(int flag) {
- flags &= ~((flag & EXT_MASK) << EXT_SHIFT);
- }
-
- /**
- * Set the extended flags used by the subclass.
- *
- * Subclass implementations may store up to 4 bits of information inside of
- * the internal flags field already used by the base ObjectToPack instance.
- *
- * @param extFlags
- * additional flag bits to store in the flags field. Due to space
- * constraints only values [0x0, 0xf] are permitted.
- */
- protected void setExtendedFlags(int extFlags) {
- flags = ((extFlags & EXT_MASK) << EXT_SHIFT) | (flags & NON_EXT_MASK);
- }
-
- 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);
- }
-
- int getPathHash() {
- return pathHash;
- }
-
- void setPathHash(int hc) {
- pathHash = hc;
- }
-
- int getCachedSize() {
- return pathHash;
- }
-
- void setCachedSize(int sz) {
- pathHash = sz;
- }
-
- /**
- * 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.
- }
-
- @Override
- public String toString() {
- StringBuilder buf = new StringBuilder();
- buf.append("ObjectToPack[");
- buf.append(Constants.typeString(getType()));
- buf.append(" ");
- buf.append(name());
- if (wantWrite())
- buf.append(" wantWrite");
- if (isReuseAsIs())
- buf.append(" reuseAsIs");
- if (isDoNotDelta())
- buf.append(" doNotDelta");
- if (isEdge())
- buf.append(" edge");
- if (getDeltaDepth() > 0)
- buf.append(" depth=" + getDeltaDepth());
- if (isDeltaRepresentation()) {
- if (getDeltaBase() != null)
- buf.append(" base=inpack:" + getDeltaBase().name());
- else
- buf.append(" base=edge:" + getDeltaBaseId().name());
- }
- if (isWritten())
- buf.append(" offset=" + getOffset());
- buf.append("]");
- return buf.toString();
- }
- }
|