/*
* 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.internal.storage.pack;
import static org.eclipse.jgit.internal.storage.pack.StoredObjectRepresentation.PACK_DELTA;
import static org.eclipse.jgit.internal.storage.pack.StoredObjectRepresentation.PACK_WHOLE;
import static org.eclipse.jgit.lib.Constants.OBJECT_ID_LENGTH;
import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
import static org.eclipse.jgit.lib.Constants.OBJ_TAG;
import static org.eclipse.jgit.lib.Constants.OBJ_TREE;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.ref.WeakReference;
import java.security.MessageDigest;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.zip.CRC32;
import java.util.zip.CheckedOutputStream;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.LargeObjectException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.errors.StoredObjectRepresentationNotAvailableException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.internal.storage.file.PackBitmapIndexBuilder;
import org.eclipse.jgit.internal.storage.file.PackBitmapIndexWriterV1;
import org.eclipse.jgit.internal.storage.file.PackIndexWriter;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.AsyncObjectSizeQueue;
import org.eclipse.jgit.lib.BatchingProgressMonitor;
import org.eclipse.jgit.lib.BitmapIndex;
import org.eclipse.jgit.lib.BitmapIndex.BitmapBuilder;
import org.eclipse.jgit.lib.BitmapObject;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.NullProgressMonitor;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectIdOwnerMap;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.ProgressMonitor;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.lib.ThreadSafeProgressMonitor;
import org.eclipse.jgit.revwalk.AsyncRevObjectQueue;
import org.eclipse.jgit.revwalk.DepthWalk;
import org.eclipse.jgit.revwalk.ObjectWalk;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevFlag;
import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevSort;
import org.eclipse.jgit.revwalk.RevTag;
import org.eclipse.jgit.revwalk.RevTree;
import org.eclipse.jgit.storage.pack.PackConfig;
import org.eclipse.jgit.util.BlockList;
import org.eclipse.jgit.util.TemporaryBuffer;
/**
* <p>
* PackWriter class is responsible for generating pack files from specified set
* of objects from repository. This implementation produce pack files in format
* version 2.
* </p>
* <p>
* Source of objects may be specified in two ways:
* <ul>
* <li>(usually) by providing sets of interesting and uninteresting objects in
* repository - all interesting objects and their ancestors except uninteresting
* objects and their ancestors will be included in pack, or</li>
* <li>by providing iterator of {@link RevObject} specifying exact list and
* order of objects in pack</li>
* </ul>
* <p>
* Typical usage consists of creating instance intended for some pack,
* configuring options, preparing the list of objects by calling
* {@link #preparePack(Iterator)} or
* {@link #preparePack(ProgressMonitor, Collection, Collection)}, and finally
* producing the stream with
* {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)}.
* </p>
* <p>
* Class provide set of configurable options and {@link ProgressMonitor}
* support, as operations may take a long time for big repositories. Deltas
* searching algorithm is <b>NOT IMPLEMENTED</b> yet - this implementation
* relies only on deltas and objects reuse.
* </p>
* <p>
* This class is not thread safe, it is intended to be used in one thread, with
* one instance per created pack. Subsequent calls to writePack result in
* undefined behavior.
* </p>
*/
public class PackWriter {
private static final int PACK_VERSION_GENERATED = 2;
/** A collection of object ids. */
public interface ObjectIdSet {
/**
* Returns true if the objectId is contained within the collection.
*
* @param objectId
* the objectId to find
* @return whether the collection contains the objectId.
*/
boolean contains(AnyObjectId objectId);
}
private static final Map<WeakReference<PackWriter>, Boolean> instances =
new ConcurrentHashMap<WeakReference<PackWriter>, Boolean>();
private static final Iterable<PackWriter> instancesIterable = new Iterable<PackWriter>() {
public Iterator<PackWriter> iterator() {
return new Iterator<PackWriter>() {
private final Iterator<WeakReference<PackWriter>> it =
instances.keySet().iterator();
private PackWriter next;
public boolean hasNext() {
if (next != null)
return true;
while (it.hasNext()) {
WeakReference<PackWriter> ref = it.next();
next = ref.get();
if (next != null)
return true;
it.remove();
}
return false;
}
public PackWriter next() {
if (hasNext()) {
PackWriter result = next;
next = null;
return result;
}
throw new NoSuchElementException();
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
};
/** @return all allocated, non-released PackWriters instances. */
public static Iterable<PackWriter> getInstances() {
return instancesIterable;
}
@SuppressWarnings("unchecked")
private final BlockList<ObjectToPack> objectsLists[] = new BlockList[OBJ_TAG + 1];
{
objectsLists[OBJ_COMMIT] = new BlockList<ObjectToPack>();
objectsLists[OBJ_TREE] = new BlockList<ObjectToPack>();
objectsLists[OBJ_BLOB] = new BlockList<ObjectToPack>();
objectsLists[OBJ_TAG] = new BlockList<ObjectToPack>();
}
private final ObjectIdOwnerMap<ObjectToPack> objectsMap = new ObjectIdOwnerMap<ObjectToPack>();
// edge objects for thin packs
private List<ObjectToPack> edgeObjects = new BlockList<ObjectToPack>();
// Objects the client is known to have already.
private BitmapBuilder haveObjects;
private List<CachedPack> cachedPacks = new ArrayList<CachedPack>(2);
private Set<ObjectId> tagTargets = Collections.emptySet();
private ObjectIdSet[] excludeInPacks;
private ObjectIdSet excludeInPackLast;
private Deflater myDeflater;
private final ObjectReader reader;
/** {@link #reader} recast to the reuse interface, if it supports it. */
private final ObjectReuseAsIs reuseSupport;
private final PackConfig config;
private final Statistics stats;
private final MutableState state;
private final WeakReference<PackWriter> selfRef;
private Statistics.ObjectType typeStats;
private List<ObjectToPack> sortedByName;
private byte packcsum[];
private boolean deltaBaseAsOffset;
private boolean reuseDeltas;
private boolean reuseDeltaCommits;
private boolean reuseValidate;
private boolean thin;
private boolean useCachedPacks;
private boolean useBitmaps;
private boolean ignoreMissingUninteresting = true;
private boolean pruneCurrentObjectList;
private boolean shallowPack;
private boolean canBuildBitmaps;
private boolean indexDisabled;
private int depth;
private Collection<? extends ObjectId> unshallowObjects;
private PackBitmapIndexBuilder writeBitmaps;
private CRC32 crc32;
/**
* Create writer for specified repository.
* <p>
* Objects for packing are specified in {@link #preparePack(Iterator)} or
* {@link #preparePack(ProgressMonitor, Collection, Collection)}.
*
* @param repo
* repository where objects are stored.
*/
public PackWriter(final Repository repo) {
this(repo, repo.newObjectReader());
}
/**
* Create a writer to load objects from the specified reader.
* <p>
* Objects for packing are specified in {@link #preparePack(Iterator)} or
* {@link #preparePack(ProgressMonitor, Collection, Collection)}.
*
* @param reader
* reader to read from the repository with.
*/
public PackWriter(final ObjectReader reader) {
this(new PackConfig(), reader);
}
/**
* Create writer for specified repository.
* <p>
* Objects for packing are specified in {@link #preparePack(Iterator)} or
* {@link #preparePack(ProgressMonitor, Collection, Collection)}.
*
* @param repo
* repository where objects are stored.
* @param reader
* reader to read from the repository with.
*/
public PackWriter(final Repository repo, final ObjectReader reader) {
this(new PackConfig(repo), reader);
}
/**
* Create writer with a specified configuration.
* <p>
* Objects for packing are specified in {@link #preparePack(Iterator)} or
* {@link #preparePack(ProgressMonitor, Collection, Collection)}.
*
* @param config
* configuration for the pack writer.
* @param reader
* reader to read from the repository with.
*/
public PackWriter(final PackConfig config, final ObjectReader reader) {
this.config = config;
this.reader = reader;
if (reader instanceof ObjectReuseAsIs)
reuseSupport = ((ObjectReuseAsIs) reader);
else
reuseSupport = null;
deltaBaseAsOffset = config.isDeltaBaseAsOffset();
reuseDeltas = config.isReuseDeltas();
reuseValidate = true; // be paranoid by default
stats = new Statistics();
state = new MutableState();
selfRef = new WeakReference<PackWriter>(this);
instances.put(selfRef, Boolean.TRUE);
}
/**
* Check whether writer can store delta base as an offset (new style
* reducing pack size) or should store it as an object id (legacy style,
* compatible with old readers).
*
* Default setting: {@value PackConfig#DEFAULT_DELTA_BASE_AS_OFFSET}
*
* @return true if delta base is stored as an offset; false if it is stored
* as an object id.
*/
public boolean isDeltaBaseAsOffset() {
return deltaBaseAsOffset;
}
/**
* Set writer delta base format. Delta base can be written as an offset in a
* pack file (new approach reducing file size) or as an object id (legacy
* approach, compatible with old readers).
*
* Default setting: {@value PackConfig#DEFAULT_DELTA_BASE_AS_OFFSET}
*
* @param deltaBaseAsOffset
* boolean indicating whether delta base can be stored as an
* offset.
*/
public void setDeltaBaseAsOffset(boolean deltaBaseAsOffset) {
this.deltaBaseAsOffset = deltaBaseAsOffset;
}
/**
* Check if the writer will reuse commits that are already stored as deltas.
*
* @return true if the writer would reuse commits stored as deltas, assuming
* delta reuse is already enabled.
*/
public boolean isReuseDeltaCommits() {
return reuseDeltaCommits;
}
/**
* Set the writer to reuse existing delta versions of commits.
*
* @param reuse
* if true, the writer will reuse any commits stored as deltas.
* By default the writer does not reuse delta commits.
*/
public void setReuseDeltaCommits(boolean reuse) {
reuseDeltaCommits = reuse;
}
/**
* Check if the writer validates objects before copying them.
*
* @return true if validation is enabled; false if the reader will handle
* object validation as a side-effect of it consuming the output.
*/
public boolean isReuseValidatingObjects() {
return reuseValidate;
}
/**
* Enable (or disable) object validation during packing.
*
* @param validate
* if true the pack writer will validate an object before it is
* put into the output. This additional validation work may be
* necessary to avoid propagating corruption from one local pack
* file to another local pack file.
*/
public void setReuseValidatingObjects(boolean validate) {
reuseValidate = validate;
}
/** @return true if this writer is producing a thin pack. */
public boolean isThin() {
return thin;
}
/**
* @param packthin
* a boolean indicating whether writer may pack objects with
* delta base object not within set of objects to pack, but
* belonging to party repository (uninteresting/boundary) as
* determined by set; this kind of pack is used only for
* transport; true - to produce thin pack, false - otherwise.
*/
public void setThin(final boolean packthin) {
thin = packthin;
}
/** @return true to reuse cached packs. If true index creation isn't available. */
public boolean isUseCachedPacks() {
return useCachedPacks;
}
/**
* @param useCached
* if set to true and a cached pack is present, it will be
* appended onto the end of a thin-pack, reducing the amount of
* working set space and CPU used by PackWriter. Enabling this
* feature prevents PackWriter from creating an index for the
* newly created pack, so its only suitable for writing to a
* network client, where the client will make the index.
*/
public void setUseCachedPacks(boolean useCached) {
useCachedPacks = useCached;
}
/** @return true to use bitmaps for ObjectWalks, if available. */
public boolean isUseBitmaps() {
return useBitmaps;
}
/**
* @param useBitmaps
* if set to true, bitmaps will be used when preparing a pack.
*/
public void setUseBitmaps(boolean useBitmaps) {
this.useBitmaps = useBitmaps;
}
/** @return true if the index file cannot be created by this PackWriter. */
public boolean isIndexDisabled() {
return indexDisabled || !cachedPacks.isEmpty();
}
/**
* @param noIndex
* true to disable creation of the index file.
*/
public void setIndexDisabled(boolean noIndex) {
this.indexDisabled = noIndex;
}
/**
* @return true to ignore objects that are uninteresting and also not found
* on local disk; false to throw a {@link MissingObjectException}
* out of {@link #preparePack(ProgressMonitor, Collection, Collection)} if an
* uninteresting object is not in the source repository. By default,
* true, permitting gracefully ignoring of uninteresting objects.
*/
public boolean isIgnoreMissingUninteresting() {
return ignoreMissingUninteresting;
}
/**
* @param ignore
* true if writer should ignore non existing uninteresting
* objects during construction set of objects to pack; false
* otherwise - non existing uninteresting objects may cause
* {@link MissingObjectException}
*/
public void setIgnoreMissingUninteresting(final boolean ignore) {
ignoreMissingUninteresting = ignore;
}
/**
* Set the tag targets that should be hoisted earlier during packing.
* <p>
* Callers may put objects into this set before invoking any of the
* preparePack methods to influence where an annotated tag's target is
* stored within the resulting pack. Typically these will be clustered
* together, and hoisted earlier in the file even if they are ancient
* revisions, allowing readers to find tag targets with better locality.
*
* @param objects
* objects that annotated tags point at.
*/
public void setTagTargets(Set<ObjectId> objects) {
tagTargets = objects;
}
/**
* Configure this pack for a shallow clone.
*
* @param depth
* maximum depth to traverse the commit graph
* @param unshallow
* objects which used to be shallow on the client, but are being
* extended as part of this fetch
*/
public void setShallowPack(int depth,
Collection<? extends ObjectId> unshallow) {
this.shallowPack = true;
this.depth = depth;
this.unshallowObjects = unshallow;
}
/**
* Returns objects number in a pack file that was created by this writer.
*
* @return number of objects in pack.
* @throws IOException
* a cached pack cannot supply its object count.
*/
public long getObjectCount() throws IOException {
if (stats.totalObjects == 0) {
long objCnt = 0;
objCnt += objectsLists[OBJ_COMMIT].size();
objCnt += objectsLists[OBJ_TREE].size();
objCnt += objectsLists[OBJ_BLOB].size();
objCnt += objectsLists[OBJ_TAG].size();
for (CachedPack pack : cachedPacks)
objCnt += pack.getObjectCount();
return objCnt;
}
return stats.totalObjects;
}
/**
* Returns the object ids in the pack file that was created by this writer.
*
* This method can only be invoked after
* {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)} has
* been invoked and completed successfully.
*
* @return number of objects in pack.
* @throws IOException
* a cached pack cannot supply its object ids.
*/
public ObjectIdOwnerMap<ObjectIdOwnerMap.Entry> getObjectSet()
throws IOException {
if (!cachedPacks.isEmpty())
throw new IOException(
JGitText.get().cachedPacksPreventsListingObjects);
ObjectIdOwnerMap<ObjectIdOwnerMap.Entry> objs = new ObjectIdOwnerMap<
ObjectIdOwnerMap.Entry>();
for (BlockList<ObjectToPack> objList : objectsLists) {
if (objList != null) {
for (ObjectToPack otp : objList)
objs.add(new ObjectIdOwnerMap.Entry(otp) {
// A new entry that copies the ObjectId
});
}
}
return objs;
}
/**
* Add a pack index whose contents should be excluded from the result.
*
* @param idx
* objects in this index will not be in the output pack.
*/
public void excludeObjects(ObjectIdSet idx) {
if (excludeInPacks == null) {
excludeInPacks = new ObjectIdSet[] { idx };
excludeInPackLast = idx;
} else {
int cnt = excludeInPacks.length;
ObjectIdSet[] newList = new ObjectIdSet[cnt + 1];
System.arraycopy(excludeInPacks, 0, newList, 0, cnt);
newList[cnt] = idx;
excludeInPacks = newList;
}
}
/**
* Prepare the list of objects to be written to the pack stream.
* <p>
* Iterator <b>exactly</b> determines which objects are included in a pack
* and order they appear in pack (except that objects order by type is not
* needed at input). This order should conform general rules of ordering
* objects in git - by recency and path (type and delta-base first is
* internally secured) and responsibility for guaranteeing this order is on
* a caller side. Iterator must return each id of object to write exactly
* once.
* </p>
*
* @param objectsSource
* iterator of object to store in a pack; order of objects within
* each type is important, ordering by type is not needed;
* allowed types for objects are {@link Constants#OBJ_COMMIT},
* {@link Constants#OBJ_TREE}, {@link Constants#OBJ_BLOB} and
* {@link Constants#OBJ_TAG}; objects returned by iterator may be
* later reused by caller as object id and type are internally
* copied in each iteration.
* @throws IOException
* when some I/O problem occur during reading objects.
*/
public void preparePack(final Iterator<RevObject> objectsSource)
throws IOException {
while (objectsSource.hasNext()) {
addObject(objectsSource.next());
}
}
/**
* Prepare the list of objects to be written to the pack stream.
* <p>
* Basing on these 2 sets, another set of objects to put in a pack file is
* created: this set consists of all objects reachable (ancestors) from
* interesting objects, except uninteresting objects and their ancestors.
* This method uses class {@link ObjectWalk} extensively to find out that
* appropriate set of output objects and their optimal order in output pack.
* Order is consistent with general git in-pack rules: sort by object type,
* recency, path and delta-base first.
* </p>
*
* @param countingMonitor
* progress during object enumeration.
* @param want
* collection of objects to be marked as interesting (start
* points of graph traversal).
* @param have
* collection of objects to be marked as uninteresting (end
* points of graph traversal).
* @throws IOException
* when some I/O problem occur during reading objects.
* @deprecated to be removed in 2.0; use the Set version of this method.
*/
@Deprecated
public void preparePack(ProgressMonitor countingMonitor,
final Collection<? extends ObjectId> want,
final Collection<? extends ObjectId> have) throws IOException {
preparePack(countingMonitor, ensureSet(want), ensureSet(have));
}
/**
* Prepare the list of objects to be written to the pack stream.
* <p>
* Basing on these 2 sets, another set of objects to put in a pack file is
* created: this set consists of all objects reachable (ancestors) from
* interesting objects, except uninteresting objects and their ancestors.
* This method uses class {@link ObjectWalk} extensively to find out that
* appropriate set of output objects and their optimal order in output pack.
* Order is consistent with general git in-pack rules: sort by object type,
* recency, path and delta-base first.
* </p>
*
* @param countingMonitor
* progress during object enumeration.
* @param walk
* ObjectWalk to perform enumeration.
* @param interestingObjects
* collection of objects to be marked as interesting (start
* points of graph traversal).
* @param uninterestingObjects
* collection of objects to be marked as uninteresting (end
* points of graph traversal).
* @throws IOException
* when some I/O problem occur during reading objects.
* @deprecated to be removed in 2.0; use the Set version of this method.
*/
@Deprecated
public void preparePack(ProgressMonitor countingMonitor,
ObjectWalk walk,
final Collection<? extends ObjectId> interestingObjects,
final Collection<? extends ObjectId> uninterestingObjects)
throws IOException {
preparePack(countingMonitor, walk,
ensureSet(interestingObjects),
ensureSet(uninterestingObjects));
}
@SuppressWarnings("unchecked")
private static Set<ObjectId> ensureSet(Collection<? extends ObjectId> objs) {
Set<ObjectId> set;
if (objs instanceof Set<?>)
set = (Set<ObjectId>) objs;
else if (objs == null)
set = Collections.emptySet();
else
set = new HashSet<ObjectId>(objs);
return set;
}
/**
* Prepare the list of objects to be written to the pack stream.
* <p>
* Basing on these 2 sets, another set of objects to put in a pack file is
* created: this set consists of all objects reachable (ancestors) from
* interesting objects, except uninteresting objects and their ancestors.
* This method uses class {@link ObjectWalk} extensively to find out that
* appropriate set of output objects and their optimal order in output pack.
* Order is consistent with general git in-pack rules: sort by object type,
* recency, path and delta-base first.
* </p>
*
* @param countingMonitor
* progress during object enumeration.
* @param want
* collection of objects to be marked as interesting (start
* points of graph traversal).
* @param have
* collection of objects to be marked as uninteresting (end
* points of graph traversal).
* @throws IOException
* when some I/O problem occur during reading objects.
*/
public void preparePack(ProgressMonitor countingMonitor,
Set<? extends ObjectId> want,
Set<? extends ObjectId> have) throws IOException {
ObjectWalk ow;
if (shallowPack)
ow = new DepthWalk.ObjectWalk(reader, depth);
else
ow = new ObjectWalk(reader);
preparePack(countingMonitor, ow, want, have);
}
/**
* Prepare the list of objects to be written to the pack stream.
* <p>
* Basing on these 2 sets, another set of objects to put in a pack file is
* created: this set consists of all objects reachable (ancestors) from
* interesting objects, except uninteresting objects and their ancestors.
* This method uses class {@link ObjectWalk} extensively to find out that
* appropriate set of output objects and their optimal order in output pack.
* Order is consistent with general git in-pack rules: sort by object type,
* recency, path and delta-base first.
* </p>
*
* @param countingMonitor
* progress during object enumeration.
* @param walk
* ObjectWalk to perform enumeration.
* @param interestingObjects
* collection of objects to be marked as interesting (start
* points of graph traversal).
* @param uninterestingObjects
* collection of objects to be marked as uninteresting (end
* points of graph traversal).
* @throws IOException
* when some I/O problem occur during reading objects.
*/
public void preparePack(ProgressMonitor countingMonitor,
ObjectWalk walk,
final Set<? extends ObjectId> interestingObjects,
final Set<? extends ObjectId> uninterestingObjects)
throws IOException {
if (countingMonitor == null)
countingMonitor = NullProgressMonitor.INSTANCE;
if (shallowPack && !(walk instanceof DepthWalk.ObjectWalk))
walk = new DepthWalk.ObjectWalk(reader, depth);
findObjectsToPack(countingMonitor, walk, interestingObjects,
uninterestingObjects);
}
/**
* Determine if the pack file will contain the requested object.
*
* @param id
* the object to test the existence of.
* @return true if the object will appear in the output pack file.
* @throws IOException
* a cached pack cannot be examined.
*/
public boolean willInclude(final AnyObjectId id) throws IOException {
ObjectToPack obj = objectsMap.get(id);
return obj != null && !obj.isEdge();
}
/**
* Lookup the ObjectToPack object for a given ObjectId.
*
* @param id
* the object to find in the pack.
* @return the object we are packing, or null.
*/
public ObjectToPack get(AnyObjectId id) {
ObjectToPack obj = objectsMap.get(id);
return obj != null && !obj.isEdge() ? obj : null;
}
/**
* Computes SHA-1 of lexicographically sorted objects ids written in this
* pack, as used to name a pack file in repository.
*
* @return ObjectId representing SHA-1 name of a pack that was created.
*/
public ObjectId computeName() {
final byte[] buf = new byte[OBJECT_ID_LENGTH];
final MessageDigest md = Constants.newMessageDigest();
for (ObjectToPack otp : sortByName()) {
otp.copyRawTo(buf, 0);
md.update(buf, 0, OBJECT_ID_LENGTH);
}
return ObjectId.fromRaw(md.digest());
}
/**
* Returns the index format version that will be written.
* <p>
* This method can only be invoked after
* {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)} has
* been invoked and completed successfully.
*
* @return the index format version.
*/
public int getIndexVersion() {
int indexVersion = config.getIndexVersion();
if (indexVersion <= 0) {
for (BlockList<ObjectToPack> objs : objectsLists)
indexVersion = Math.max(indexVersion,
PackIndexWriter.oldestPossibleFormat(objs));
}
return indexVersion;
}
/**
* Create an index file to match the pack file just written.
* <p>
* This method can only be invoked after
* {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)} has
* been invoked and completed successfully. Writing a corresponding index is
* an optional feature that not all pack users may require.
*
* @param indexStream
* output for the index data. Caller is responsible for closing
* this stream.
* @throws IOException
* the index data could not be written to the supplied stream.
*/
public void writeIndex(final OutputStream indexStream) throws IOException {
if (isIndexDisabled())
throw new IOException(JGitText.get().cachedPacksPreventsIndexCreation);
long writeStart = System.currentTimeMillis();
final PackIndexWriter iw = PackIndexWriter.createVersion(
indexStream, getIndexVersion());
iw.write(sortByName(), packcsum);
stats.timeWriting += System.currentTimeMillis() - writeStart;
}
/**
* Create a bitmap index file to match the pack file just written.
* <p>
* This method can only be invoked after
* {@link #prepareBitmapIndex(ProgressMonitor)} has been invoked and
* completed successfully. Writing a corresponding bitmap index is an
* optional feature that not all pack users may require.
*
* @param bitmapIndexStream
* output for the bitmap index data. Caller is responsible for
* closing this stream.
* @throws IOException
* the index data could not be written to the supplied stream.
*/
public void writeBitmapIndex(final OutputStream bitmapIndexStream)
throws IOException {
if (writeBitmaps == null)
throw new IOException(JGitText.get().bitmapsMustBePrepared);
long writeStart = System.currentTimeMillis();
final PackBitmapIndexWriterV1 iw = new PackBitmapIndexWriterV1(bitmapIndexStream);
iw.write(writeBitmaps, packcsum);
stats.timeWriting += System.currentTimeMillis() - writeStart;
}
private List<ObjectToPack> sortByName() {
if (sortedByName == null) {
int cnt = 0;
cnt += objectsLists[OBJ_COMMIT].size();
cnt += objectsLists[OBJ_TREE].size();
cnt += objectsLists[OBJ_BLOB].size();
cnt += objectsLists[OBJ_TAG].size();
sortedByName = new BlockList<ObjectToPack>(cnt);
sortedByName.addAll(objectsLists[OBJ_COMMIT]);
sortedByName.addAll(objectsLists[OBJ_TREE]);
sortedByName.addAll(objectsLists[OBJ_BLOB]);
sortedByName.addAll(objectsLists[OBJ_TAG]);
Collections.sort(sortedByName);
}
return sortedByName;
}
private void beginPhase(PackingPhase phase, ProgressMonitor monitor,
long cnt) {
state.phase = phase;
String task;
switch (phase) {
case COUNTING:
task = JGitText.get().countingObjects;
break;
case GETTING_SIZES:
task = JGitText.get().searchForSizes;
break;
case FINDING_SOURCES:
task = JGitText.get().searchForReuse;
break;
case COMPRESSING:
task = JGitText.get().compressingObjects;
break;
case WRITING:
task = JGitText.get().writingObjects;
break;
case BUILDING_BITMAPS:
task = JGitText.get().buildingBitmaps;
break;
default:
throw new IllegalArgumentException(
MessageFormat.format(JGitText.get().illegalPackingPhase, phase));
}
monitor.beginTask(task, (int) cnt);
}
private void endPhase(ProgressMonitor monitor) {
monitor.endTask();
}
/**
* Write the prepared pack to the supplied stream.
* <p>
* At first, this method collects and sorts objects to pack, then deltas
* search is performed if set up accordingly, finally pack stream is
* written.
* </p>
* <p>
* All reused objects data checksum (Adler32/CRC32) is computed and
* validated against existing checksum.
* </p>
*
* @param compressMonitor
* progress monitor to report object compression work.
* @param writeMonitor
* progress monitor to report the number of objects written.
* @param packStream
* output stream of pack data. The stream should be buffered by
* the caller. The caller is responsible for closing the stream.
* @throws IOException
* an error occurred reading a local object's data to include in
* the pack, or writing compressed object data to the output
* stream.
*/
public void writePack(ProgressMonitor compressMonitor,
ProgressMonitor writeMonitor, OutputStream packStream)
throws IOException {
if (compressMonitor == null)
compressMonitor = NullProgressMonitor.INSTANCE;
if (writeMonitor == null)
writeMonitor = NullProgressMonitor.INSTANCE;
excludeInPacks = null;
excludeInPackLast = null;
boolean needSearchForReuse = reuseSupport != null && (
reuseDeltas
|| config.isReuseObjects()
|| !cachedPacks.isEmpty());
if (compressMonitor instanceof BatchingProgressMonitor) {
long delay = 1000;
if (needSearchForReuse && config.isDeltaCompress())
delay = 500;
((BatchingProgressMonitor) compressMonitor).setDelayStart(
delay,
TimeUnit.MILLISECONDS);
}
if (needSearchForReuse)
searchForReuse(compressMonitor);
if (config.isDeltaCompress())
searchForDeltas(compressMonitor);
crc32 = new CRC32();
final PackOutputStream out = new PackOutputStream(
writeMonitor,
isIndexDisabled()
? packStream
: new CheckedOutputStream(packStream, crc32),
this);
long objCnt = getObjectCount();
stats.totalObjects = objCnt;
beginPhase(PackingPhase.WRITING, writeMonitor, objCnt);
long writeStart = System.currentTimeMillis();
try {
out.writeFileHeader(PACK_VERSION_GENERATED, objCnt);
out.flush();
writeObjects(out);
if (!edgeObjects.isEmpty() || !cachedPacks.isEmpty()) {
for (Statistics.ObjectType typeStat : stats.objectTypes) {
if (typeStat == null)
continue;
stats.thinPackBytes += typeStat.bytes;
}
}
stats.reusedPacks = Collections.unmodifiableList(cachedPacks);
for (CachedPack pack : cachedPacks) {
long deltaCnt = pack.getDeltaCount();
stats.reusedObjects += pack.getObjectCount();
stats.reusedDeltas += deltaCnt;
stats.totalDeltas += deltaCnt;
reuseSupport.copyPackAsIs(out, pack, reuseValidate);
}
writeChecksum(out);
out.flush();
} finally {
stats.timeWriting = System.currentTimeMillis() - writeStart;
stats.depth = depth;
for (Statistics.ObjectType typeStat : stats.objectTypes) {
if (typeStat == null)
continue;
typeStat.cntDeltas += typeStat.reusedDeltas;
stats.reusedObjects += typeStat.reusedObjects;
stats.reusedDeltas += typeStat.reusedDeltas;
stats.totalDeltas += typeStat.cntDeltas;
}
}
stats.totalBytes = out.length();
reader.release();
endPhase(writeMonitor);
}
/**
* @return description of what this PackWriter did in order to create the
* final pack stream. The object is only available to callers after
* {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)}
*/
public Statistics getStatistics() {
return stats;
}
/** @return snapshot of the current state of this PackWriter. */
public State getState() {
return state.snapshot();
}
/** Release all resources used by this writer. */
public void release() {
reader.release();
if (myDeflater != null) {
myDeflater.end();
myDeflater = null;
}
instances.remove(selfRef);
}
private void searchForReuse(ProgressMonitor monitor) throws IOException {
long cnt = 0;
cnt += objectsLists[OBJ_COMMIT].size();
cnt += objectsLists[OBJ_TREE].size();
cnt += objectsLists[OBJ_BLOB].size();
cnt += objectsLists[OBJ_TAG].size();
long start = System.currentTimeMillis();
beginPhase(PackingPhase.FINDING_SOURCES, monitor, cnt);
if (cnt <= 4096) {
// For small object counts, do everything as one list.
BlockList<ObjectToPack> tmp = new BlockList<ObjectToPack>((int) cnt);
tmp.addAll(objectsLists[OBJ_TAG]);
tmp.addAll(objectsLists[OBJ_COMMIT]);
tmp.addAll(objectsLists[OBJ_TREE]);
tmp.addAll(objectsLists[OBJ_BLOB]);
searchForReuse(monitor, tmp);
if (pruneCurrentObjectList) {
// If the list was pruned, we need to re-prune the main lists.
pruneEdgesFromObjectList(objectsLists[OBJ_COMMIT]);
pruneEdgesFromObjectList(objectsLists[OBJ_TREE]);
pruneEdgesFromObjectList(objectsLists[OBJ_BLOB]);
pruneEdgesFromObjectList(objectsLists[OBJ_TAG]);
}
} else {
searchForReuse(monitor, objectsLists[OBJ_TAG]);
searchForReuse(monitor, objectsLists[OBJ_COMMIT]);
searchForReuse(monitor, objectsLists[OBJ_TREE]);
searchForReuse(monitor, objectsLists[OBJ_BLOB]);
}
endPhase(monitor);
stats.timeSearchingForReuse = System.currentTimeMillis() - start;
if (config.isReuseDeltas() && config.getCutDeltaChains()) {
cutDeltaChains(objectsLists[OBJ_TREE]);
cutDeltaChains(objectsLists[OBJ_BLOB]);
}
}
private void searchForReuse(ProgressMonitor monitor, List<ObjectToPack> list)
throws IOException, MissingObjectException {
pruneCurrentObjectList = false;
reuseSupport.selectObjectRepresentation(this, monitor, list);
if (pruneCurrentObjectList)
pruneEdgesFromObjectList(list);
}
private void cutDeltaChains(BlockList<ObjectToPack> list)
throws IOException {
int max = config.getMaxDeltaDepth();
for (int idx = list.size() - 1; idx >= 0; idx--) {
int d = 0;
ObjectToPack b = list.get(idx).getDeltaBase();
while (b != null) {
if (d < b.getChainLength())
break;
b.setChainLength(++d);
if (d >= max && b.isDeltaRepresentation()) {
reselectNonDelta(b);
break;
}
b = b.getDeltaBase();
}
}
if (config.isDeltaCompress()) {
for (ObjectToPack otp : list)
otp.clearChainLength();
}
}
private void searchForDeltas(ProgressMonitor monitor)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
// Commits and annotated tags tend to have too many differences to
// really benefit from delta compression. Consequently just don't
// bother examining those types here.
//
ObjectToPack[] list = new ObjectToPack[
objectsLists[OBJ_TREE].size()
+ objectsLists[OBJ_BLOB].size()
+ edgeObjects.size()];
int cnt = 0;
cnt = findObjectsNeedingDelta(list, cnt, OBJ_TREE);
cnt = findObjectsNeedingDelta(list, cnt, OBJ_BLOB);
if (cnt == 0)
return;
int nonEdgeCnt = cnt;
// Queue up any edge objects that we might delta against. We won't
// be sending these as we assume the other side has them, but we need
// them in the search phase below.
//
for (ObjectToPack eo : edgeObjects) {
eo.setWeight(0);
list[cnt++] = eo;
}
// Compute the sizes of the objects so we can do a proper sort.
// We let the reader skip missing objects if it chooses. For
// some readers this can be a huge win. We detect missing objects
// by having set the weights above to 0 and allowing the delta
// search code to discover the missing object and skip over it, or
// abort with an exception if we actually had to have it.
//
final long sizingStart = System.currentTimeMillis();
beginPhase(PackingPhase.GETTING_SIZES, monitor, cnt);
AsyncObjectSizeQueue<ObjectToPack> sizeQueue = reader.getObjectSize(
Arrays.<ObjectToPack> asList(list).subList(0, cnt), false);
try {
final long limit = Math.min(
config.getBigFileThreshold(),
Integer.MAX_VALUE);
for (;;) {
try {
if (!sizeQueue.next())
break;
} catch (MissingObjectException notFound) {
monitor.update(1);
if (ignoreMissingUninteresting) {
ObjectToPack otp = sizeQueue.getCurrent();
if (otp != null && otp.isEdge()) {
otp.setDoNotDelta();
continue;
}
otp = objectsMap.get(notFound.getObjectId());
if (otp != null && otp.isEdge()) {
otp.setDoNotDelta();
continue;
}
}
throw notFound;
}
ObjectToPack otp = sizeQueue.getCurrent();
if (otp == null)
otp = objectsMap.get(sizeQueue.getObjectId());
long sz = sizeQueue.getSize();
if (DeltaIndex.BLKSZ < sz && sz < limit)
otp.setWeight((int) sz);
else
otp.setDoNotDelta(); // too small, or too big
monitor.update(1);
}
} finally {
sizeQueue.release();
}
endPhase(monitor);
stats.timeSearchingForSizes = System.currentTimeMillis() - sizingStart;
// Sort the objects by path hash so like files are near each other,
// and then by size descending so that bigger files are first. This
// applies "Linus' Law" which states that newer files tend to be the
// bigger ones, because source files grow and hardly ever shrink.
//
Arrays.sort(list, 0, cnt, new Comparator<ObjectToPack>() {
public int compare(ObjectToPack a, ObjectToPack b) {
int cmp = (a.isDoNotDelta() ? 1 : 0)
- (b.isDoNotDelta() ? 1 : 0);
if (cmp != 0)
return cmp;
cmp = a.getType() - b.getType();
if (cmp != 0)
return cmp;
cmp = (a.getPathHash() >>> 1) - (b.getPathHash() >>> 1);
if (cmp != 0)
return cmp;
cmp = (a.getPathHash() & 1) - (b.getPathHash() & 1);
if (cmp != 0)
return cmp;
cmp = (a.isEdge() ? 0 : 1) - (b.isEdge() ? 0 : 1);
if (cmp != 0)
return cmp;
return b.getWeight() - a.getWeight();
}
});
// Above we stored the objects we cannot delta onto the end.
// Remove them from the list so we don't waste time on them.
while (0 < cnt && list[cnt - 1].isDoNotDelta()) {
if (!list[cnt - 1].isEdge())
nonEdgeCnt--;
cnt--;
}
if (cnt == 0)
return;
final long searchStart = System.currentTimeMillis();
searchForDeltas(monitor, list, cnt);
stats.deltaSearchNonEdgeObjects = nonEdgeCnt;
stats.timeCompressing = System.currentTimeMillis() - searchStart;
for (int i = 0; i < cnt; i++)
if (!list[i].isEdge() && list[i].isDeltaRepresentation())
stats.deltasFound++;
}
private int findObjectsNeedingDelta(ObjectToPack[] list, int cnt, int type) {
for (ObjectToPack otp : objectsLists[type]) {
if (otp.isDoNotDelta()) // delta is disabled for this path
continue;
if (otp.isDeltaRepresentation()) // already reusing a delta
continue;
otp.setWeight(0);
list[cnt++] = otp;
}
return cnt;
}
private void reselectNonDelta(ObjectToPack otp) throws IOException {
otp.clearDeltaBase();
otp.clearReuseAsIs();
boolean old = reuseDeltas;
reuseDeltas = false;
reuseSupport.selectObjectRepresentation(this,
NullProgressMonitor.INSTANCE,
Collections.singleton(otp));
reuseDeltas = old;
}
private void searchForDeltas(final ProgressMonitor monitor,
final ObjectToPack[] list, final int cnt)
throws MissingObjectException, IncorrectObjectTypeException,
LargeObjectException, IOException {
int threads = config.getThreads();
if (threads == 0)
threads = Runtime.getRuntime().availableProcessors();
if (threads <= 1 || cnt <= config.getDeltaSearchWindowSize())
singleThreadDeltaSearch(monitor, list, cnt);
else
parallelDeltaSearch(monitor, list, cnt, threads);
}
private void singleThreadDeltaSearch(ProgressMonitor monitor,
ObjectToPack[] list, int cnt) throws IOException {
long totalWeight = 0;
for (int i = 0; i < cnt; i++) {
ObjectToPack o = list[i];
if (!o.isEdge() && !o.doNotAttemptDelta())
totalWeight += o.getWeight();
}
long bytesPerUnit = 1;
while (DeltaTask.MAX_METER <= (totalWeight / bytesPerUnit))
bytesPerUnit <<= 10;
int cost = (int) (totalWeight / bytesPerUnit);
if (totalWeight % bytesPerUnit != 0)
cost++;
beginPhase(PackingPhase.COMPRESSING, monitor, cost);
new DeltaWindow(config, new DeltaCache(config), reader,
monitor, bytesPerUnit,
list, 0, cnt).search();
endPhase(monitor);
}
private void parallelDeltaSearch(ProgressMonitor monitor,
ObjectToPack[] list, int cnt, int threads) throws IOException {
DeltaCache dc = new ThreadSafeDeltaCache(config);
ThreadSafeProgressMonitor pm = new ThreadSafeProgressMonitor(monitor);
DeltaTask.Block taskBlock = new DeltaTask.Block(threads, config,
reader, dc, pm,
list, 0, cnt);
taskBlock.partitionTasks();
beginPhase(PackingPhase.COMPRESSING, monitor, taskBlock.cost());
pm.startWorkers(taskBlock.tasks.size());
Executor executor = config.getExecutor();
final List<Throwable> errors =
Collections.synchronizedList(new ArrayList<Throwable>(threads));
if (executor instanceof ExecutorService) {
// Caller supplied us a service, use it directly.
runTasks((ExecutorService) executor, pm, taskBlock, errors);
} else if (executor == null) {
// Caller didn't give us a way to run the tasks, spawn up a
// temporary thread pool and make sure it tears down cleanly.
ExecutorService pool = Executors.newFixedThreadPool(threads);
try {
runTasks(pool, pm, taskBlock, errors);
} finally {
pool.shutdown();
for (;;) {
try {
if (pool.awaitTermination(60, TimeUnit.SECONDS))
break;
} catch (InterruptedException e) {
throw new IOException(
JGitText.get().packingCancelledDuringObjectsWriting);
}
}
}
} else {
// The caller gave us an executor, but it might not do
// asynchronous execution. Wrap everything and hope it
// can schedule these for us.
for (final DeltaTask task : taskBlock.tasks) {
executor.execute(new Runnable() {
public void run() {
try {
task.call();
} catch (Throwable failure) {
errors.add(failure);
}
}
});
}
try {
pm.waitForCompletion();
} catch (InterruptedException ie) {
// We can't abort the other tasks as we have no handle.
// Cross our fingers and just break out anyway.
//
throw new IOException(
JGitText.get().packingCancelledDuringObjectsWriting);
}
}
// If any task threw an error, try to report it back as
// though we weren't using a threaded search algorithm.
//
if (!errors.isEmpty()) {
Throwable err = errors.get(0);
if (err instanceof Error)
throw (Error) err;
if (err instanceof RuntimeException)
throw (RuntimeException) err;
if (err instanceof IOException)
throw (IOException) err;
IOException fail = new IOException(err.getMessage());
fail.initCause(err);
throw fail;
}
endPhase(monitor);
}
private static void runTasks(ExecutorService pool,
ThreadSafeProgressMonitor pm,
DeltaTask.Block tb, List<Throwable> errors) throws IOException {
List<Future<?>> futures = new ArrayList<Future<?>>(tb.tasks.size());
for (DeltaTask task : tb.tasks)
futures.add(pool.submit(task));
try {
pm.waitForCompletion();
for (Future<?> f : futures) {
try {
f.get();
} catch (ExecutionException failed) {
errors.add(failed.getCause());
}
}
} catch (InterruptedException ie) {
for (Future<?> f : futures)
f.cancel(true);
throw new IOException(
JGitText.get().packingCancelledDuringObjectsWriting);
}
}
private void writeObjects(PackOutputStream out) throws IOException {
writeObjects(out, objectsLists[OBJ_COMMIT]);
writeObjects(out, objectsLists[OBJ_TAG]);
writeObjects(out, objectsLists[OBJ_TREE]);
writeObjects(out, objectsLists[OBJ_BLOB]);
}
private void writeObjects(PackOutputStream out, List<ObjectToPack> list)
throws IOException {
if (list.isEmpty())
return;
typeStats = stats.objectTypes[list.get(0).getType()];
long beginOffset = out.length();
if (reuseSupport != null) {
reuseSupport.writeObjects(out, list);
} else {
for (ObjectToPack otp : list)
out.writeObject(otp);
}
typeStats.bytes += out.length() - beginOffset;
typeStats.cntObjects = list.size();
}
void writeObject(PackOutputStream out, ObjectToPack otp) throws IOException {
if (!otp.isWritten())
writeObjectImpl(out, otp);
}
private void writeObjectImpl(PackOutputStream out, ObjectToPack otp)
throws IOException {
if (otp.wantWrite()) {
// A cycle exists in this delta chain. This should only occur if a
// selected object representation disappeared during writing
// (for example due to a concurrent repack) and a different base
// was chosen, forcing a cycle. Select something other than a
// delta, and write this object.
reselectNonDelta(otp);
}
otp.markWantWrite();
while (otp.isReuseAsIs()) {
writeBase(out, otp.getDeltaBase());
if (otp.isWritten())
return; // Delta chain cycle caused this to write already.
crc32.reset();
otp.setOffset(out.length());
try {
reuseSupport.copyObjectAsIs(out, otp, reuseValidate);
out.endObject();
otp.setCRC((int) crc32.getValue());
typeStats.reusedObjects++;
if (otp.isDeltaRepresentation()) {
typeStats.reusedDeltas++;
typeStats.deltaBytes += out.length() - otp.getOffset();
}
return;
} catch (StoredObjectRepresentationNotAvailableException gone) {
if (otp.getOffset() == out.length()) {
otp.setOffset(0);
otp.clearDeltaBase();
otp.clearReuseAsIs();
reuseSupport.selectObjectRepresentation(this,
NullProgressMonitor.INSTANCE,
Collections.singleton(otp));
continue;
} else {
// Object writing already started, we cannot recover.
//
CorruptObjectException coe;
coe = new CorruptObjectException(otp, ""); //$NON-NLS-1$
coe.initCause(gone);
throw coe;
}
}
}
// If we reached here, reuse wasn't possible.
//
if (otp.isDeltaRepresentation())
writeDeltaObjectDeflate(out, otp);
else
writeWholeObjectDeflate(out, otp);
out.endObject();
otp.setCRC((int) crc32.getValue());
}
private void writeBase(PackOutputStream out, ObjectToPack base)
throws IOException {
if (base != null && !base.isWritten() && !base.isEdge())
writeObjectImpl(out, base);
}
private void writeWholeObjectDeflate(PackOutputStream out,
final ObjectToPack otp) throws IOException {
final Deflater deflater = deflater();
final ObjectLoader ldr = reader.open(otp, otp.getType());
crc32.reset();
otp.setOffset(out.length());
out.writeHeader(otp, ldr.getSize());
deflater.reset();
DeflaterOutputStream dst = new DeflaterOutputStream(out, deflater);
ldr.copyTo(dst);
dst.finish();
}
private void writeDeltaObjectDeflate(PackOutputStream out,
final ObjectToPack otp) throws IOException {
writeBase(out, otp.getDeltaBase());
crc32.reset();
otp.setOffset(out.length());
DeltaCache.Ref ref = otp.popCachedDelta();
if (ref != null) {
byte[] zbuf = ref.get();
if (zbuf != null) {
out.writeHeader(otp, otp.getCachedSize());
out.write(zbuf);
return;
}
}
TemporaryBuffer.Heap delta = delta(otp);
out.writeHeader(otp, delta.length());
Deflater deflater = deflater();
deflater.reset();
DeflaterOutputStream dst = new DeflaterOutputStream(out, deflater);
delta.writeTo(dst, null);
dst.finish();
typeStats.cntDeltas++;
typeStats.deltaBytes += out.length() - otp.getOffset();
}
private TemporaryBuffer.Heap delta(final ObjectToPack otp)
throws IOException {
DeltaIndex index = new DeltaIndex(buffer(otp.getDeltaBaseId()));
byte[] res = buffer(otp);
// We never would have proposed this pair if the delta would be
// larger than the unpacked version of the object. So using it
// as our buffer limit is valid: we will never reach it.
//
TemporaryBuffer.Heap delta = new TemporaryBuffer.Heap(res.length);
index.encode(delta, res);
return delta;
}
private byte[] buffer(AnyObjectId objId) throws IOException {
return buffer(config, reader, objId);
}
static byte[] buffer(PackConfig config, ObjectReader or, AnyObjectId objId)
throws IOException {
// PackWriter should have already pruned objects that
// are above the big file threshold, so our chances of
// the object being below it are very good. We really
// shouldn't be here, unless the implementation is odd.
return or.open(objId).getCachedBytes(config.getBigFileThreshold());
}
private Deflater deflater() {
if (myDeflater == null)
myDeflater = new Deflater(config.getCompressionLevel());
return myDeflater;
}
private void writeChecksum(PackOutputStream out) throws IOException {
packcsum = out.getDigest();
out.write(packcsum);
}
private void findObjectsToPack(final ProgressMonitor countingMonitor,
final ObjectWalk walker, final Set<? extends ObjectId> want,
Set<? extends ObjectId> have)
throws MissingObjectException, IOException,
IncorrectObjectTypeException {
final long countingStart = System.currentTimeMillis();
beginPhase(PackingPhase.COUNTING, countingMonitor, ProgressMonitor.UNKNOWN);
if (have == null)
have = Collections.emptySet();
stats.interestingObjects = Collections.unmodifiableSet(new HashSet<ObjectId>(want));
stats.uninterestingObjects = Collections.unmodifiableSet(new HashSet<ObjectId>(have));
walker.setRetainBody(false);
canBuildBitmaps = config.isBuildBitmaps()
&& !shallowPack
&& have.isEmpty()
&& (excludeInPacks == null || excludeInPacks.length == 0);
if (!shallowPack && useBitmaps) {
BitmapIndex bitmapIndex = reader.getBitmapIndex();
if (bitmapIndex != null) {
PackWriterBitmapWalker bitmapWalker = new PackWriterBitmapWalker(
walker, bitmapIndex, countingMonitor);
findObjectsToPackUsingBitmaps(bitmapWalker, want, have);
endPhase(countingMonitor);
stats.timeCounting = System.currentTimeMillis() - countingStart;
return;
}
}
List<ObjectId> all = new ArrayList<ObjectId>(want.size() + have.size());
all.addAll(want);
all.addAll(have);
final RevFlag include = walker.newFlag("include"); //$NON-NLS-1$
final RevFlag added = walker.newFlag("added"); //$NON-NLS-1$
walker.carry(include);
int haveEst = have.size();
if (have.isEmpty()) {
walker.sort(RevSort.COMMIT_TIME_DESC);
} else {
walker.sort(RevSort.TOPO);
if (thin)
walker.sort(RevSort.BOUNDARY, true);
}
List<RevObject> wantObjs = new ArrayList<RevObject>(want.size());
List<RevObject> haveObjs = new ArrayList<RevObject>(haveEst);
List<RevTag> wantTags = new ArrayList<RevTag>(want.size());
AsyncRevObjectQueue q = walker.parseAny(all, true);
try {
for (;;) {
try {
RevObject o = q.next();
if (o == null)
break;
if (have.contains(o))
haveObjs.add(o);
if (want.contains(o)) {
o.add(include);
wantObjs.add(o);
if (o instanceof RevTag)
wantTags.add((RevTag) o);
}
} catch (MissingObjectException e) {
if (ignoreMissingUninteresting
&& have.contains(e.getObjectId()))
continue;
throw e;
}
}
} finally {
q.release();
}
if (!wantTags.isEmpty()) {
all = new ArrayList<ObjectId>(wantTags.size());
for (RevTag tag : wantTags)
all.add(tag.getObject());
q = walker.parseAny(all, true);
try {
while (q.next() != null) {
// Just need to pop the queue item to parse the object.
}
} finally {
q.release();
}
}
if (walker instanceof DepthWalk.ObjectWalk) {
DepthWalk.ObjectWalk depthWalk = (DepthWalk.ObjectWalk) walker;
for (RevObject obj : wantObjs)
depthWalk.markRoot(obj);
if (unshallowObjects != null) {
for (ObjectId id : unshallowObjects)
depthWalk.markUnshallow(walker.parseAny(id));
}
} else {
for (RevObject obj : wantObjs)
walker.markStart(obj);
}
for (RevObject obj : haveObjs)
walker.markUninteresting(obj);
final int maxBases = config.getDeltaSearchWindowSize();
Set<RevTree> baseTrees = new HashSet<RevTree>();
BlockList<RevCommit> commits = new BlockList<RevCommit>();
RevCommit c;
while ((c = walker.next()) != null) {
if (exclude(c))
continue;
if (c.has(RevFlag.UNINTERESTING)) {
if (baseTrees.size() <= maxBases)
baseTrees.add(c.getTree());
continue;
}
commits.add(c);
countingMonitor.update(1);
}
if (shallowPack) {
for (RevCommit cmit : commits) {
addObject(cmit, 0);
}
} else {
int commitCnt = 0;
boolean putTagTargets = false;
for (RevCommit cmit : commits) {
if (!cmit.has(added)) {
cmit.add(added);
addObject(cmit, 0);
commitCnt++;
}
for (int i = 0; i < cmit.getParentCount(); i++) {
RevCommit p = cmit.getParent(i);
if (!p.has(added) && !p.has(RevFlag.UNINTERESTING)
&& !exclude(p)) {
p.add(added);
addObject(p, 0);
commitCnt++;
}
}
if (!putTagTargets && 4096 < commitCnt) {
for (ObjectId id : tagTargets) {
RevObject obj = walker.lookupOrNull(id);
if (obj instanceof RevCommit
&& obj.has(include)
&& !obj.has(RevFlag.UNINTERESTING)
&& !obj.has(added)) {
obj.add(added);
addObject(obj, 0);
}
}
putTagTargets = true;
}
}
}
commits = null;
if (thin && !baseTrees.isEmpty()) {
BaseSearch bases = new BaseSearch(countingMonitor, baseTrees, //
objectsMap, edgeObjects, reader);
RevObject o;
while ((o = walker.nextObject()) != null) {
if (o.has(RevFlag.UNINTERESTING))
continue;
if (exclude(o))
continue;
int pathHash = walker.getPathHashCode();
byte[] pathBuf = walker.getPathBuffer();
int pathLen = walker.getPathLength();
bases.addBase(o.getType(), pathBuf, pathLen, pathHash);
addObject(o, pathHash);
countingMonitor.update(1);
}
} else {
RevObject o;
while ((o = walker.nextObject()) != null) {
if (o.has(RevFlag.UNINTERESTING))
continue;
if (exclude(o))
continue;
addObject(o, walker.getPathHashCode());
countingMonitor.update(1);
}
}
for (CachedPack pack : cachedPacks)
countingMonitor.update((int) pack.getObjectCount());
endPhase(countingMonitor);
stats.timeCounting = System.currentTimeMillis() - countingStart;
}
private void findObjectsToPackUsingBitmaps(
PackWriterBitmapWalker bitmapWalker, Set<? extends ObjectId> want,
Set<? extends ObjectId> have)
throws MissingObjectException, IncorrectObjectTypeException,
IOException {
BitmapBuilder haveBitmap = bitmapWalker.findObjects(have, null, true);
bitmapWalker.reset();
BitmapBuilder wantBitmap = bitmapWalker.findObjects(want, haveBitmap,
false);
BitmapBuilder needBitmap = wantBitmap.andNot(haveBitmap);
if (useCachedPacks && reuseSupport != null
&& (excludeInPacks == null || excludeInPacks.length == 0))
cachedPacks.addAll(
reuseSupport.getCachedPacksAndUpdate(needBitmap));
for (BitmapObject obj : needBitmap) {
ObjectId objectId = obj.getObjectId();
if (exclude(objectId)) {
needBitmap.remove(objectId);
continue;
}
addObject(objectId, obj.getType(), 0);
}
if (thin)
haveObjects = haveBitmap;
}
private static void pruneEdgesFromObjectList(List<ObjectToPack> list) {
final int size = list.size();
int src = 0;
int dst = 0;
for (; src < size; src++) {
ObjectToPack obj = list.get(src);
if (obj.isEdge())
continue;
if (dst != src)
list.set(dst, obj);
dst++;
}
while (dst < list.size())
list.remove(list.size() - 1);
}
/**
* Include one object to the output file.
* <p>
* Objects are written in the order they are added. If the same object is
* added twice, it may be written twice, creating a larger than necessary
* file.
*
* @param object
* the object to add.
* @throws IncorrectObjectTypeException
* the object is an unsupported type.
*/
public void addObject(final RevObject object)
throws IncorrectObjectTypeException {
if (!exclude(object))
addObject(object, 0);
}
private void addObject(final RevObject object, final int pathHashCode) {
addObject(object, object.getType(), pathHashCode);
}
private void addObject(
final AnyObjectId src, final int type, final int pathHashCode) {
final ObjectToPack otp;
if (reuseSupport != null)
otp = reuseSupport.newObjectToPack(src, type);
else
otp = new ObjectToPack(src, type);
otp.setPathHash(pathHashCode);
objectsLists[type].add(otp);
objectsMap.add(otp);
}
private boolean exclude(AnyObjectId objectId) {
if (excludeInPacks == null)
return false;
if (excludeInPackLast.contains(objectId))
return true;
for (ObjectIdSet idx : excludeInPacks) {
if (idx.contains(objectId)) {
excludeInPackLast = idx;
return true;
}
}
return false;
}
/**
* Select an object representation for this writer.
* <p>
* An {@link ObjectReader} implementation should invoke this method once for
* each representation available for an object, to allow the writer to find
* the most suitable one for the output.
*
* @param otp
* the object being packed.
* @param next
* the next available representation from the repository.
*/
public void select(ObjectToPack otp, StoredObjectRepresentation next) {
int nFmt = next.getFormat();
if (!cachedPacks.isEmpty()) {
if (otp.isEdge())
return;
if ((nFmt == PACK_WHOLE) | (nFmt == PACK_DELTA)) {
for (CachedPack pack : cachedPacks) {
if (pack.hasObject(otp, next)) {
otp.setEdge();
otp.clearDeltaBase();
otp.clearReuseAsIs();
pruneCurrentObjectList = true;
return;
}
}
}
}
if (nFmt == PACK_DELTA && reuseDeltas && reuseDeltaFor(otp)) {
ObjectId baseId = next.getDeltaBase();
ObjectToPack ptr = objectsMap.get(baseId);
if (ptr != null && !ptr.isEdge()) {
otp.setDeltaBase(ptr);
otp.setReuseAsIs();
} else if (thin && have(ptr, baseId)) {
otp.setDeltaBase(baseId);
otp.setReuseAsIs();
} else {
otp.clearDeltaBase();
otp.clearReuseAsIs();
}
} else if (nFmt == PACK_WHOLE && config.isReuseObjects()) {
int nWeight = next.getWeight();
if (otp.isReuseAsIs() && !otp.isDeltaRepresentation()) {
// We've chosen another PACK_WHOLE format for this object,
// choose the one that has the smaller compressed size.
//
if (otp.getWeight() <= nWeight)
return;
}
otp.clearDeltaBase();
otp.setReuseAsIs();
otp.setWeight(nWeight);
} else {
otp.clearDeltaBase();
otp.clearReuseAsIs();
}
otp.setDeltaAttempted(reuseDeltas & next.wasDeltaAttempted());
otp.select(next);
}
private final boolean have(ObjectToPack ptr, AnyObjectId objectId) {
return (ptr != null && ptr.isEdge())
|| (haveObjects != null && haveObjects.contains(objectId));
}
/**
* Prepares the bitmaps to be written to the pack index. Bitmaps can be used
* to speed up fetches and clones by storing the entire object graph at
* selected commits.
*
* This method can only be invoked after
* {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)} has
* been invoked and completed successfully. Writing a corresponding bitmap
* index is an optional feature that not all pack users may require.
*
* @param pm
* progress monitor to report bitmap building work.
* @return whether a bitmap index may be written.
* @throws IOException
* when some I/O problem occur during reading objects.
*/
public boolean prepareBitmapIndex(ProgressMonitor pm) throws IOException {
if (!canBuildBitmaps || getObjectCount() > Integer.MAX_VALUE
|| !cachedPacks.isEmpty())
return false;
if (pm == null)
pm = NullProgressMonitor.INSTANCE;
writeBitmaps = new PackBitmapIndexBuilder(sortByName());
PackWriterBitmapPreparer bitmapPreparer = new PackWriterBitmapPreparer(
reader, writeBitmaps, pm, stats.interestingObjects);
int numCommits = objectsLists[OBJ_COMMIT].size();
Collection<PackWriterBitmapPreparer.BitmapCommit> selectedCommits =
bitmapPreparer.doCommitSelection(numCommits);
beginPhase(PackingPhase.BUILDING_BITMAPS, pm, selectedCommits.size());
PackWriterBitmapWalker walker = bitmapPreparer.newBitmapWalker();
AnyObjectId last = null;
for (PackWriterBitmapPreparer.BitmapCommit cmit : selectedCommits) {
if (cmit.isReuseWalker())
walker.reset();
else
walker = bitmapPreparer.newBitmapWalker();
BitmapBuilder bitmap = walker.findObjects(
Collections.singleton(cmit), null, false);
if (last != null && cmit.isReuseWalker() && !bitmap.contains(last))
throw new IllegalStateException(MessageFormat.format(
JGitText.get().bitmapMissingObject, cmit.name(),
last.name()));
last = cmit;
writeBitmaps.addBitmap(cmit, bitmap.build(), cmit.getFlags());
pm.update(1);
}
endPhase(pm);
return true;
}
private boolean reuseDeltaFor(ObjectToPack otp) {
int type = otp.getType();
if ((type & 2) != 0) // OBJ_TREE(2) or OBJ_BLOB(3)
return true;
if (type == OBJ_COMMIT)
return reuseDeltaCommits;
if (type == OBJ_TAG)
return false;
return true;
}
/** Summary of how PackWriter created the pack. */
public static class Statistics {
/** Statistics about a single class of object. */
public static class ObjectType {
long cntObjects;
long cntDeltas;
long reusedObjects;
long reusedDeltas;
long bytes;
long deltaBytes;
/**
* @return total number of objects output. This total includes the
* value of {@link #getDeltas()}.
*/
public long getObjects() {
return cntObjects;
}
/**
* @return total number of deltas output. This may be lower than the
* actual number of deltas if a cached pack was reused.
*/
public long getDeltas() {
return cntDeltas;
}
/**
* @return number of objects whose existing representation was
* reused in the output. This count includes
* {@link #getReusedDeltas()}.
*/
public long getReusedObjects() {
return reusedObjects;
}
/**
* @return number of deltas whose existing representation was reused
* in the output, as their base object was also output or
* was assumed present for a thin pack. This may be lower
* than the actual number of reused deltas if a cached pack
* was reused.
*/
public long getReusedDeltas() {
return reusedDeltas;
}
/**
* @return total number of bytes written. This size includes the
* object headers as well as the compressed data. This size
* also includes all of {@link #getDeltaBytes()}.
*/
public long getBytes() {
return bytes;
}
/**
* @return number of delta bytes written. This size includes the
* object headers for the delta objects.
*/
public long getDeltaBytes() {
return deltaBytes;
}
}
Set<ObjectId> interestingObjects;
Set<ObjectId> uninterestingObjects;
Collection<CachedPack> reusedPacks;
int depth;
int deltaSearchNonEdgeObjects;
int deltasFound;
long totalObjects;
long totalDeltas;
long reusedObjects;
long reusedDeltas;
long totalBytes;
long thinPackBytes;
long timeCounting;
long timeSearchingForReuse;
long timeSearchingForSizes;
long timeCompressing;
long timeWriting;
ObjectType[] objectTypes;
{
objectTypes = new ObjectType[5];
objectTypes[OBJ_COMMIT] = new ObjectType();
objectTypes[OBJ_TREE] = new ObjectType();
objectTypes[OBJ_BLOB] = new ObjectType();
objectTypes[OBJ_TAG] = new ObjectType();
}
/**
* @return unmodifiable collection of objects to be included in the
* pack. May be null if the pack was hand-crafted in a unit
* test.
*/
public Set<ObjectId> getInterestingObjects() {
return interestingObjects;
}
/**
* @return unmodifiable collection of objects that should be excluded
* from the pack, as the peer that will receive the pack already
* has these objects.
*/
public Set<ObjectId> getUninterestingObjects() {
return uninterestingObjects;
}
/**
* @return unmodifiable collection of the cached packs that were reused
* in the output, if any were selected for reuse.
*/
public Collection<CachedPack> getReusedPacks() {
return reusedPacks;
}
/**
* @return number of objects in the output pack that went through the
* delta search process in order to find a potential delta base.
*/
public int getDeltaSearchNonEdgeObjects() {
return deltaSearchNonEdgeObjects;
}
/**
* @return number of objects in the output pack that went through delta
* base search and found a suitable base. This is a subset of
* {@link #getDeltaSearchNonEdgeObjects()}.
*/
public int getDeltasFound() {
return deltasFound;
}
/**
* @return total number of objects output. This total includes the value
* of {@link #getTotalDeltas()}.
*/
public long getTotalObjects() {
return totalObjects;
}
/**
* @return total number of deltas output. This may be lower than the
* actual number of deltas if a cached pack was reused.
*/
public long getTotalDeltas() {
return totalDeltas;
}
/**
* @return number of objects whose existing representation was reused in
* the output. This count includes {@link #getReusedDeltas()}.
*/
public long getReusedObjects() {
return reusedObjects;
}
/**
* @return number of deltas whose existing representation was reused in
* the output, as their base object was also output or was
* assumed present for a thin pack. This may be lower than the
* actual number of reused deltas if a cached pack was reused.
*/
public long getReusedDeltas() {
return reusedDeltas;
}
/**
* @return total number of bytes written. This size includes the pack
* header, trailer, thin pack, and reused cached pack(s).
*/
public long getTotalBytes() {
return totalBytes;
}
/**
* @return size of the thin pack in bytes, if a thin pack was generated.
* A thin pack is created when the client already has objects
* and some deltas are created against those objects, or if a
* cached pack is being used and some deltas will reference
* objects in the cached pack. This size does not include the
* pack header or trailer.
*/
public long getThinPackBytes() {
return thinPackBytes;
}
/**
* @param typeCode
* object type code, e.g. OBJ_COMMIT or OBJ_TREE.
* @return information about this type of object in the pack.
*/
public ObjectType byObjectType(int typeCode) {
return objectTypes[typeCode];
}
/** @return true if the resulting pack file was a shallow pack. */
public boolean isShallow() {
return depth > 0;
}
/** @return depth (in commits) the pack includes if shallow. */
public int getDepth() {
return depth;
}
/**
* @return time in milliseconds spent enumerating the objects that need
* to be included in the output. This time includes any restarts
* that occur when a cached pack is selected for reuse.
*/
public long getTimeCounting() {
return timeCounting;
}
/**
* @return time in milliseconds spent matching existing representations
* against objects that will be transmitted, or that the client
* can be assumed to already have.
*/
public long getTimeSearchingForReuse() {
return timeSearchingForReuse;
}
/**
* @return time in milliseconds spent finding the sizes of all objects
* that will enter the delta compression search window. The
* sizes need to be known to better match similar objects
* together and improve delta compression ratios.
*/
public long getTimeSearchingForSizes() {
return timeSearchingForSizes;
}
/**
* @return time in milliseconds spent on delta compression. This is
* observed wall-clock time and does not accurately track CPU
* time used when multiple threads were used to perform the
* delta compression.
*/
public long getTimeCompressing() {
return timeCompressing;
}
/**
* @return time in milliseconds spent writing the pack output, from
* start of header until end of trailer. The transfer speed can
* be approximated by dividing {@link #getTotalBytes()} by this
* value.
*/
public long getTimeWriting() {
return timeWriting;
}
/** @return total time spent processing this pack. */
public long getTimeTotal() {
return timeCounting
+ timeSearchingForReuse
+ timeSearchingForSizes
+ timeCompressing
+ timeWriting;
}
/**
* @return get the average output speed in terms of bytes-per-second.
* {@code getTotalBytes() / (getTimeWriting() / 1000.0)}.
*/
public double getTransferRate() {
return getTotalBytes() / (getTimeWriting() / 1000.0);
}
/** @return formatted message string for display to clients. */
public String getMessage() {
return MessageFormat.format(JGitText.get().packWriterStatistics, //
Long.valueOf(totalObjects), Long.valueOf(totalDeltas), //
Long.valueOf(reusedObjects), Long.valueOf(reusedDeltas));
}
}
private class MutableState {
/** Estimated size of a single ObjectToPack instance. */
// Assume 64-bit pointers, since this is just an estimate.
private static final long OBJECT_TO_PACK_SIZE =
(2 * 8) // Object header
+ (2 * 8) + (2 * 8) // ObjectToPack fields
+ (8 + 8) // PackedObjectInfo fields
+ 8 // ObjectIdOwnerMap fields
+ 40 // AnyObjectId fields
+ 8; // Reference in BlockList
private final long totalDeltaSearchBytes;
private volatile PackingPhase phase;
MutableState() {
phase = PackingPhase.COUNTING;
if (config.isDeltaCompress()) {
int threads = config.getThreads();
if (threads <= 0)
threads = Runtime.getRuntime().availableProcessors();
totalDeltaSearchBytes = (threads * config.getDeltaSearchMemoryLimit())
+ config.getBigFileThreshold();
} else
totalDeltaSearchBytes = 0;
}
State snapshot() {
long objCnt = 0;
objCnt += objectsLists[OBJ_COMMIT].size();
objCnt += objectsLists[OBJ_TREE].size();
objCnt += objectsLists[OBJ_BLOB].size();
objCnt += objectsLists[OBJ_TAG].size();
// Exclude CachedPacks.
long bytesUsed = OBJECT_TO_PACK_SIZE * objCnt;
PackingPhase curr = phase;
if (curr == PackingPhase.COMPRESSING)
bytesUsed += totalDeltaSearchBytes;
return new State(curr, bytesUsed);
}
}
/** Possible states that a PackWriter can be in. */
public static enum PackingPhase {
/** Counting objects phase. */
COUNTING,
/** Getting sizes phase. */
GETTING_SIZES,
/** Finding sources phase. */
FINDING_SOURCES,
/** Compressing objects phase. */
COMPRESSING,
/** Writing objects phase. */
WRITING,
/** Building bitmaps phase. */
BUILDING_BITMAPS;
}
/** Summary of the current state of a PackWriter. */
public class State {
private final PackingPhase phase;
private final long bytesUsed;
State(PackingPhase phase, long bytesUsed) {
this.phase = phase;
this.bytesUsed = bytesUsed;
}
/** @return the PackConfig used to build the writer. */
public PackConfig getConfig() {
return config;
}
/** @return the current phase of the writer. */
public PackingPhase getPhase() {
return phase;
}
/** @return an estimate of the total memory used by the writer. */
public long estimateBytesUsed() {
return bytesUsed;
}
@SuppressWarnings("nls")
@Override
public String toString() {
return "PackWriter.State[" + phase + ", memory=" + bytesUsed + "]";
}
}
}