/*
* Copyright (C) 2009, 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.file;
import static org.eclipse.jgit.internal.storage.pack.PackExt.INDEX;
import static org.eclipse.jgit.internal.storage.pack.PackExt.PACK;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.nio.file.AtomicMoveNotSupportedException;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.atomic.AtomicReference;
import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.PackInvalidException;
import org.eclipse.jgit.errors.PackMismatchException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.internal.storage.pack.ObjectToPack;
import org.eclipse.jgit.internal.storage.pack.PackExt;
import org.eclipse.jgit.internal.storage.pack.PackWriter;
import org.eclipse.jgit.lib.AbbreviatedObjectId;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectDatabase;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.lib.RepositoryCache;
import org.eclipse.jgit.lib.RepositoryCache.FileKey;
import org.eclipse.jgit.util.FS;
import org.eclipse.jgit.util.FileUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Traditional file system based {@link ObjectDatabase}.
* <p>
* This is the classical object database representation for a Git repository,
* where objects are stored loose by hashing them into directories by their
* {@link ObjectId}, or are stored in compressed containers known as
* {@link PackFile}s.
* <p>
* Optionally an object database can reference one or more alternates; other
* ObjectDatabase instances that are searched in addition to the current
* database.
* <p>
* Databases are divided into two halves: a half that is considered to be fast
* to search (the {@code PackFile}s), and a half that is considered to be slow
* to search (loose objects). When alternates are present the fast half is fully
* searched (recursively through all alternates) before the slow half is
* considered.
*/
public class ObjectDirectory extends FileObjectDatabase {
private final static Logger LOG = LoggerFactory
.getLogger(ObjectDirectory.class);
private static final PackList NO_PACKS = new PackList(
FileSnapshot.DIRTY, new PackFile[0]);
/** Maximum number of candidates offered as resolutions of abbreviation. */
private static final int RESOLVE_ABBREV_LIMIT = 256;
private final Config config;
private final File objects;
private final File infoDirectory;
private final File packDirectory;
private final File alternatesFile;
private final AtomicReference<PackList> packList;
private final FS fs;
private final AtomicReference<AlternateHandle[]> alternates;
private final UnpackedObjectCache unpackedObjectCache;
private final File shallowFile;
private FileSnapshot shallowFileSnapshot = FileSnapshot.DIRTY;
private Set<ObjectId> shallowCommitsIds;
/**
* Initialize a reference to an on-disk object directory.
*
* @param cfg
* configuration this directory consults for write settings.
* @param dir
* the location of the <code>objects</code> directory.
* @param alternatePaths
* a list of alternate object directories
* @param fs
* the file system abstraction which will be necessary to perform
* certain file system operations.
* @param shallowFile
* file which contains IDs of shallow commits, null if shallow
* commits handling should be turned off
* @throws IOException
* an alternate object cannot be opened.
*/
public ObjectDirectory(final Config cfg, final File dir,
File[] alternatePaths, FS fs, File shallowFile) throws IOException {
config = cfg;
objects = dir;
infoDirectory = new File(objects, "info"); //$NON-NLS-1$
packDirectory = new File(objects, "pack"); //$NON-NLS-1$
alternatesFile = new File(infoDirectory, "alternates"); //$NON-NLS-1$
packList = new AtomicReference<PackList>(NO_PACKS);
unpackedObjectCache = new UnpackedObjectCache();
this.fs = fs;
this.shallowFile = shallowFile;
alternates = new AtomicReference<AlternateHandle[]>();
if (alternatePaths != null) {
AlternateHandle[] alt;
alt = new AlternateHandle[alternatePaths.length];
for (int i = 0; i < alternatePaths.length; i++)
alt[i] = openAlternate(alternatePaths[i]);
alternates.set(alt);
}
}
/**
* @return the location of the <code>objects</code> directory.
*/
public final File getDirectory() {
return objects;
}
@Override
public boolean exists() {
return fs.exists(objects);
}
@Override
public void create() throws IOException {
FileUtils.mkdirs(objects);
FileUtils.mkdir(infoDirectory);
FileUtils.mkdir(packDirectory);
}
@Override
public ObjectDirectoryInserter newInserter() {
return new ObjectDirectoryInserter(this, config);
}
@Override
public void close() {
unpackedObjectCache.clear();
final PackList packs = packList.get();
if (packs != NO_PACKS && packList.compareAndSet(packs, NO_PACKS)) {
for (PackFile p : packs.packs)
p.close();
}
// Fully close all loaded alternates and clear the alternate list.
AlternateHandle[] alt = alternates.get();
if (alt != null && alternates.compareAndSet(alt, null)) {
for(final AlternateHandle od : alt)
od.close();
}
}
/**
* @return unmodifiable collection of all known pack files local to this
* directory. Most recent packs are presented first. Packs most
* likely to contain more recent objects appear before packs
* containing objects referenced by commits further back in the
* history of the repository.
*/
@Override
public Collection<PackFile> getPacks() {
PackList list = packList.get();
if (list == NO_PACKS)
list = scanPacks(list);
PackFile[] packs = list.packs;
return Collections.unmodifiableCollection(Arrays.asList(packs));
}
/**
* Add a single existing pack to the list of available pack files.
*
* @param pack
* path of the pack file to open.
* @return the pack that was opened and added to the database.
* @throws IOException
* index file could not be opened, read, or is not recognized as
* a Git pack file index.
*/
public PackFile openPack(final File pack)
throws IOException {
final String p = pack.getName();
if (p.length() != 50 || !p.startsWith("pack-") || !p.endsWith(".pack")) //$NON-NLS-1$ //$NON-NLS-2$
throw new IOException(MessageFormat.format(JGitText.get().notAValidPack, pack));
// The pack and index are assumed to exist. The existence of other
// extensions needs to be explicitly checked.
//
int extensions = PACK.getBit() | INDEX.getBit();
final String base = p.substring(0, p.length() - 4);
for (PackExt ext : PackExt.values()) {
if ((extensions & ext.getBit()) == 0) {
final String name = base + ext.getExtension();
if (new File(pack.getParentFile(), name).exists())
extensions |= ext.getBit();
}
}
PackFile res = new PackFile(pack, extensions);
insertPack(res);
return res;
}
@Override
public String toString() {
return "ObjectDirectory[" + getDirectory() + "]"; //$NON-NLS-1$ //$NON-NLS-2$
}
@Override
public boolean has(AnyObjectId objectId) {
return unpackedObjectCache.isUnpacked(objectId)
|| hasPackedInSelfOrAlternate(objectId)
|| hasLooseInSelfOrAlternate(objectId);
}
private boolean hasPackedInSelfOrAlternate(AnyObjectId objectId) {
if (hasPackedObject(objectId))
return true;
for (AlternateHandle alt : myAlternates()) {
if (alt.db.hasPackedInSelfOrAlternate(objectId))
return true;
}
return false;
}
private boolean hasLooseInSelfOrAlternate(AnyObjectId objectId) {
if (fileFor(objectId).exists())
return true;
for (AlternateHandle alt : myAlternates()) {
if (alt.db.hasLooseInSelfOrAlternate(objectId))
return true;
}
return false;
}
boolean hasPackedObject(AnyObjectId objectId) {
PackList pList;
do {
pList = packList.get();
for (PackFile p : pList.packs) {
try {
if (p.hasObject(objectId))
return true;
} catch (IOException e) {
// The hasObject call should have only touched the index,
// so any failure here indicates the index is unreadable
// by this process, and the pack is likewise not readable.
removePack(p);
}
}
} while (searchPacksAgain(pList));
return false;
}
@Override
void resolve(Set<ObjectId> matches, AbbreviatedObjectId id)
throws IOException {
// Go through the packs once. If we didn't find any resolutions
// scan for new packs and check once more.
int oldSize = matches.size();
PackList pList;
do {
pList = packList.get();
for (PackFile p : pList.packs) {
try {
p.resolve(matches, id, RESOLVE_ABBREV_LIMIT);
} catch (IOException e) {
handlePackError(e, p);
}
if (matches.size() > RESOLVE_ABBREV_LIMIT)
return;
}
} while (matches.size() == oldSize && searchPacksAgain(pList));
String fanOut = id.name().substring(0, 2);
String[] entries = new File(getDirectory(), fanOut).list();
if (entries != null) {
for (String e : entries) {
if (e.length() != Constants.OBJECT_ID_STRING_LENGTH - 2)
continue;
try {
ObjectId entId = ObjectId.fromString(fanOut + e);
if (id.prefixCompare(entId) == 0)
matches.add(entId);
} catch (IllegalArgumentException notId) {
continue;
}
if (matches.size() > RESOLVE_ABBREV_LIMIT)
return;
}
}
for (AlternateHandle alt : myAlternates()) {
alt.db.resolve(matches, id);
if (matches.size() > RESOLVE_ABBREV_LIMIT)
return;
}
}
@Override
ObjectLoader openObject(WindowCursor curs, AnyObjectId objectId)
throws IOException {
if (unpackedObjectCache.isUnpacked(objectId)) {
ObjectLoader ldr = openLooseObject(curs, objectId);
if (ldr != null)
return ldr;
}
ObjectLoader ldr = openPackedFromSelfOrAlternate(curs, objectId);
if (ldr != null)
return ldr;
return openLooseFromSelfOrAlternate(curs, objectId);
}
private ObjectLoader openPackedFromSelfOrAlternate(WindowCursor curs,
AnyObjectId objectId) {
ObjectLoader ldr = openPackedObject(curs, objectId);
if (ldr != null)
return ldr;
for (AlternateHandle alt : myAlternates()) {
ldr = alt.db.openPackedFromSelfOrAlternate(curs, objectId);
if (ldr != null)
return ldr;
}
return null;
}
private ObjectLoader openLooseFromSelfOrAlternate(WindowCursor curs,
AnyObjectId objectId) throws IOException {
ObjectLoader ldr = openLooseObject(curs, objectId);
if (ldr != null)
return ldr;
for (AlternateHandle alt : myAlternates()) {
ldr = alt.db.openLooseFromSelfOrAlternate(curs, objectId);
if (ldr != null)
return ldr;
}
return null;
}
ObjectLoader openPackedObject(WindowCursor curs, AnyObjectId objectId) {
PackList pList;
do {
SEARCH: for (;;) {
pList = packList.get();
for (PackFile p : pList.packs) {
try {
ObjectLoader ldr = p.get(curs, objectId);
if (ldr != null)
return ldr;
} catch (PackMismatchException e) {
// Pack was modified; refresh the entire pack list.
if (searchPacksAgain(pList))
continue SEARCH;
} catch (IOException e) {
handlePackError(e, p);
}
}
break SEARCH;
}
} while (searchPacksAgain(pList));
return null;
}
ObjectLoader openLooseObject(WindowCursor curs, AnyObjectId id)
throws IOException {
File path = fileFor(id);
try (FileInputStream in = new FileInputStream(path)) {
unpackedObjectCache.add(id);
return UnpackedObject.open(in, path, id, curs);
} catch (FileNotFoundException noFile) {
if (path.exists()) {
throw noFile;
}
unpackedObjectCache.remove(id);
return null;
}
}
long getObjectSize(WindowCursor curs, AnyObjectId id)
throws IOException {
if (unpackedObjectCache.isUnpacked(id)) {
long len = getLooseObjectSize(curs, id);
if (0 <= len)
return len;
}
long len = getPackedSizeFromSelfOrAlternate(curs, id);
if (0 <= len)
return len;
return getLooseSizeFromSelfOrAlternate(curs, id);
}
private long getPackedSizeFromSelfOrAlternate(WindowCursor curs,
AnyObjectId id) {
long len = getPackedObjectSize(curs, id);
if (0 <= len)
return len;
for (AlternateHandle alt : myAlternates()) {
len = alt.db.getPackedSizeFromSelfOrAlternate(curs, id);
if (0 <= len)
return len;
}
return -1;
}
private long getLooseSizeFromSelfOrAlternate(WindowCursor curs,
AnyObjectId id) throws IOException {
long len = getLooseObjectSize(curs, id);
if (0 <= len)
return len;
for (AlternateHandle alt : myAlternates()) {
len = alt.db.getLooseSizeFromSelfOrAlternate(curs, id);
if (0 <= len)
return len;
}
return -1;
}
private long getPackedObjectSize(WindowCursor curs, AnyObjectId id) {
PackList pList;
do {
SEARCH: for (;;) {
pList = packList.get();
for (PackFile p : pList.packs) {
try {
long len = p.getObjectSize(curs, id);
if (0 <= len)
return len;
} catch (PackMismatchException e) {
// Pack was modified; refresh the entire pack list.
if (searchPacksAgain(pList))
continue SEARCH;
} catch (IOException e) {
handlePackError(e, p);
}
}
break SEARCH;
}
} while (searchPacksAgain(pList));
return -1;
}
private long getLooseObjectSize(WindowCursor curs, AnyObjectId id)
throws IOException {
File f = fileFor(id);
try (FileInputStream in = new FileInputStream(f)) {
unpackedObjectCache.add(id);
return UnpackedObject.getSize(in, id, curs);
} catch (FileNotFoundException noFile) {
if (f.exists()) {
throw noFile;
}
unpackedObjectCache.remove(id);
return -1;
}
}
@Override
void selectObjectRepresentation(PackWriter packer, ObjectToPack otp,
WindowCursor curs) throws IOException {
PackList pList = packList.get();
SEARCH: for (;;) {
for (final PackFile p : pList.packs) {
try {
LocalObjectRepresentation rep = p.representation(curs, otp);
if (rep != null)
packer.select(otp, rep);
} catch (PackMismatchException e) {
// Pack was modified; refresh the entire pack list.
//
pList = scanPacks(pList);
continue SEARCH;
} catch (IOException e) {
handlePackError(e, p);
}
}
break SEARCH;
}
for (AlternateHandle h : myAlternates())
h.db.selectObjectRepresentation(packer, otp, curs);
}
private void handlePackError(IOException e, PackFile p) {
String warnTmpl = null;
if ((e instanceof CorruptObjectException)
|| (e instanceof PackInvalidException)) {
warnTmpl = JGitText.get().corruptPack;
// Assume the pack is corrupted, and remove it from the list.
removePack(p);
} else if (e instanceof FileNotFoundException) {
if (p.getPackFile().exists()) {
warnTmpl = JGitText.get().packInaccessible;
} else {
warnTmpl = JGitText.get().packWasDeleted;
}
removePack(p);
} else if (FileUtils.isStaleFileHandle(e)) {
warnTmpl = JGitText.get().packHandleIsStale;
removePack(p);
}
if (warnTmpl != null) {
if (LOG.isDebugEnabled()) {
LOG.debug(MessageFormat.format(warnTmpl,
p.getPackFile().getAbsolutePath()), e);
} else {
LOG.warn(MessageFormat.format(warnTmpl,
p.getPackFile().getAbsolutePath()));
}
} else {
// Don't remove the pack from the list, as the error may be
// transient.
LOG.error(MessageFormat.format(
JGitText.get().exceptionWhileReadingPack, p.getPackFile()
.getAbsolutePath()), e);
}
}
@Override
InsertLooseObjectResult insertUnpackedObject(File tmp, ObjectId id,
boolean createDuplicate) throws IOException {
// If the object is already in the repository, remove temporary file.
//
if (unpackedObjectCache.isUnpacked(id)) {
FileUtils.delete(tmp, FileUtils.RETRY);
return InsertLooseObjectResult.EXISTS_LOOSE;
}
if (!createDuplicate && has(id)) {
FileUtils.delete(tmp, FileUtils.RETRY);
return InsertLooseObjectResult.EXISTS_PACKED;
}
final File dst = fileFor(id);
if (dst.exists()) {
// We want to be extra careful and avoid replacing an object
// that already exists. We can't be sure renameTo() would
// fail on all platforms if dst exists, so we check first.
//
FileUtils.delete(tmp, FileUtils.RETRY);
return InsertLooseObjectResult.EXISTS_LOOSE;
}
try {
Files.move(tmp.toPath(), dst.toPath(),
StandardCopyOption.ATOMIC_MOVE);
dst.setReadOnly();
unpackedObjectCache.add(id);
return InsertLooseObjectResult.INSERTED;
} catch (AtomicMoveNotSupportedException e) {
LOG.error(e.getMessage(), e);
} catch (IOException e) {
// ignore
}
// Maybe the directory doesn't exist yet as the object
// directories are always lazily created. Note that we
// try the rename first as the directory likely does exist.
//
FileUtils.mkdir(dst.getParentFile(), true);
try {
Files.move(tmp.toPath(), dst.toPath(),
StandardCopyOption.ATOMIC_MOVE);
dst.setReadOnly();
unpackedObjectCache.add(id);
return InsertLooseObjectResult.INSERTED;
} catch (AtomicMoveNotSupportedException e) {
LOG.error(e.getMessage(), e);
} catch (IOException e) {
LOG.debug(e.getMessage(), e);
}
if (!createDuplicate && has(id)) {
FileUtils.delete(tmp, FileUtils.RETRY);
return InsertLooseObjectResult.EXISTS_PACKED;
}
// The object failed to be renamed into its proper
// location and it doesn't exist in the repository
// either. We really don't know what went wrong, so
// fail.
//
FileUtils.delete(tmp, FileUtils.RETRY);
return InsertLooseObjectResult.FAILURE;
}
private boolean searchPacksAgain(PackList old) {
// Whether to trust the pack folder's modification time. If set
// to false we will always scan the .git/objects/pack folder to
// check for new pack files. If set to true (default) we use the
// lastmodified attribute of the folder and assume that no new
// pack files can be in this folder if his modification time has
// not changed.
boolean trustFolderStat = config.getBoolean(
ConfigConstants.CONFIG_CORE_SECTION,
ConfigConstants.CONFIG_KEY_TRUSTFOLDERSTAT, true);
return ((!trustFolderStat) || old.snapshot.isModified(packDirectory))
&& old != scanPacks(old);
}
Config getConfig() {
return config;
}
@Override
FS getFS() {
return fs;
}
@Override
Set<ObjectId> getShallowCommits() throws IOException {
if (shallowFile == null || !shallowFile.isFile())
return Collections.emptySet();
if (shallowFileSnapshot == null
|| shallowFileSnapshot.isModified(shallowFile)) {
shallowCommitsIds = new HashSet<ObjectId>();
final BufferedReader reader = open(shallowFile);
try {
String line;
while ((line = reader.readLine()) != null)
shallowCommitsIds.add(ObjectId.fromString(line));
} finally {
reader.close();
}
shallowFileSnapshot = FileSnapshot.save(shallowFile);
}
return shallowCommitsIds;
}
private void insertPack(final PackFile pf) {
PackList o, n;
do {
o = packList.get();
// If the pack in question is already present in the list
// (picked up by a concurrent thread that did a scan?) we
// do not want to insert it a second time.
//
final PackFile[] oldList = o.packs;
final String name = pf.getPackFile().getName();
for (PackFile p : oldList) {
if (PackFile.SORT.compare(pf, p) < 0)
break;
if (name.equals(p.getPackFile().getName()))
return;
}
final PackFile[] newList = new PackFile[1 + oldList.length];
newList[0] = pf;
System.arraycopy(oldList, 0, newList, 1, oldList.length);
n = new PackList(o.snapshot, newList);
} while (!packList.compareAndSet(o, n));
}
private void removePack(final PackFile deadPack) {
PackList o, n;
do {
o = packList.get();
final PackFile[] oldList = o.packs;
final int j = indexOf(oldList, deadPack);
if (j < 0)
break;
final PackFile[] newList = new PackFile[oldList.length - 1];
System.arraycopy(oldList, 0, newList, 0, j);
System.arraycopy(oldList, j + 1, newList, j, newList.length - j);
n = new PackList(o.snapshot, newList);
} while (!packList.compareAndSet(o, n));
deadPack.close();
}
private static int indexOf(final PackFile[] list, final PackFile pack) {
for (int i = 0; i < list.length; i++) {
if (list[i] == pack)
return i;
}
return -1;
}
private PackList scanPacks(final PackList original) {
synchronized (packList) {
PackList o, n;
do {
o = packList.get();
if (o != original) {
// Another thread did the scan for us, while we
// were blocked on the monitor above.
//
return o;
}
n = scanPacksImpl(o);
if (n == o)
return n;
} while (!packList.compareAndSet(o, n));
return n;
}
}
private PackList scanPacksImpl(final PackList old) {
final Map<String, PackFile> forReuse = reuseMap(old);
final FileSnapshot snapshot = FileSnapshot.save(packDirectory);
final Set<String> names = listPackDirectory();
final List<PackFile> list = new ArrayList<PackFile>(names.size() >> 2);
boolean foundNew = false;
for (final String indexName : names) {
// Must match "pack-[0-9a-f]{40}.idx" to be an index.
//
if (indexName.length() != 49 || !indexName.endsWith(".idx")) //$NON-NLS-1$
continue;
final String base = indexName.substring(0, indexName.length() - 3);
int extensions = 0;
for (PackExt ext : PackExt.values()) {
if (names.contains(base + ext.getExtension()))
extensions |= ext.getBit();
}
if ((extensions & PACK.getBit()) == 0) {
// Sometimes C Git's HTTP fetch transport leaves a
// .idx file behind and does not download the .pack.
// We have to skip over such useless indexes.
//
continue;
}
final String packName = base + PACK.getExtension();
final PackFile oldPack = forReuse.remove(packName);
if (oldPack != null) {
list.add(oldPack);
continue;
}
final File packFile = new File(packDirectory, packName);
list.add(new PackFile(packFile, extensions));
foundNew = true;
}
// If we did not discover any new files, the modification time was not
// changed, and we did not remove any files, then the set of files is
// the same as the set we were given. Instead of building a new object
// return the same collection.
//
if (!foundNew && forReuse.isEmpty() && snapshot.equals(old.snapshot)) {
old.snapshot.setClean(snapshot);
return old;
}
for (final PackFile p : forReuse.values()) {
p.close();
}
if (list.isEmpty())
return new PackList(snapshot, NO_PACKS.packs);
final PackFile[] r = list.toArray(new PackFile[list.size()]);
Arrays.sort(r, PackFile.SORT);
return new PackList(snapshot, r);
}
private static Map<String, PackFile> reuseMap(final PackList old) {
final Map<String, PackFile> forReuse = new HashMap<String, PackFile>();
for (final PackFile p : old.packs) {
if (p.invalid()) {
// The pack instance is corrupted, and cannot be safely used
// again. Do not include it in our reuse map.
//
p.close();
continue;
}
final PackFile prior = forReuse.put(p.getPackFile().getName(), p);
if (prior != null) {
// This should never occur. It should be impossible for us
// to have two pack files with the same name, as all of them
// came out of the same directory. If it does, we promised to
// close any PackFiles we did not reuse, so close the second,
// readers are likely to be actively using the first.
//
forReuse.put(prior.getPackFile().getName(), prior);
p.close();
}
}
return forReuse;
}
private Set<String> listPackDirectory() {
final String[] nameList = packDirectory.list();
if (nameList == null)
return Collections.emptySet();
final Set<String> nameSet = new HashSet<String>(nameList.length << 1);
for (final String name : nameList) {
if (name.startsWith("pack-")) //$NON-NLS-1$
nameSet.add(name);
}
return nameSet;
}
AlternateHandle[] myAlternates() {
AlternateHandle[] alt = alternates.get();
if (alt == null) {
synchronized (alternates) {
alt = alternates.get();
if (alt == null) {
try {
alt = loadAlternates();
} catch (IOException e) {
alt = new AlternateHandle[0];
}
alternates.set(alt);
}
}
}
return alt;
}
private AlternateHandle[] loadAlternates() throws IOException {
final List<AlternateHandle> l = new ArrayList<AlternateHandle>(4);
final BufferedReader br = open(alternatesFile);
try {
String line;
while ((line = br.readLine()) != null) {
l.add(openAlternate(line));
}
} finally {
br.close();
}
return l.toArray(new AlternateHandle[l.size()]);
}
private static BufferedReader open(final File f)
throws FileNotFoundException {
return new BufferedReader(new FileReader(f));
}
private AlternateHandle openAlternate(final String location)
throws IOException {
final File objdir = fs.resolve(objects, location);
return openAlternate(objdir);
}
private AlternateHandle openAlternate(File objdir) throws IOException {
final File parent = objdir.getParentFile();
if (FileKey.isGitRepository(parent, fs)) {
FileKey key = FileKey.exact(parent, fs);
FileRepository db = (FileRepository) RepositoryCache.open(key);
return new AlternateRepository(db);
}
ObjectDirectory db = new ObjectDirectory(config, objdir, null, fs, null);
return new AlternateHandle(db);
}
/**
* Compute the location of a loose object file.
*
* @param objectId
* identity of the loose object to map to the directory.
* @return location of the object, if it were to exist as a loose object.
*/
public File fileFor(AnyObjectId objectId) {
String n = objectId.name();
String d = n.substring(0, 2);
String f = n.substring(2);
return new File(new File(getDirectory(), d), f);
}
private static final class PackList {
/** State just before reading the pack directory. */
final FileSnapshot snapshot;
/** All known packs, sorted by {@link PackFile#SORT}. */
final PackFile[] packs;
PackList(final FileSnapshot monitor, final PackFile[] packs) {
this.snapshot = monitor;
this.packs = packs;
}
}
static class AlternateHandle {
final ObjectDirectory db;
AlternateHandle(ObjectDirectory db) {
this.db = db;
}
void close() {
db.close();
}
}
static class AlternateRepository extends AlternateHandle {
final FileRepository repository;
AlternateRepository(FileRepository r) {
super(r.getObjectDatabase());
repository = r;
}
void close() {
repository.close();
}
}
@Override
public ObjectDatabase newCachedDatabase() {
return newCachedFileObjectDatabase();
}
CachedObjectDirectory newCachedFileObjectDatabase() {
return new CachedObjectDirectory(this);
}
}