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- /*
- * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
- * Copyright (C) 2009-2010, Google Inc.
- * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
- * Copyright (C) 2006, Shawn O. Pearce <spearce@spearce.org>
- * 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.lib.Constants.CHARSET;
- import static org.eclipse.jgit.lib.Constants.HEAD;
- import static org.eclipse.jgit.lib.Constants.LOGS;
- import static org.eclipse.jgit.lib.Constants.OBJECT_ID_STRING_LENGTH;
- import static org.eclipse.jgit.lib.Constants.PACKED_REFS;
- import static org.eclipse.jgit.lib.Constants.R_HEADS;
- import static org.eclipse.jgit.lib.Constants.R_REFS;
- import static org.eclipse.jgit.lib.Constants.R_TAGS;
- import static org.eclipse.jgit.lib.Ref.Storage.LOOSE;
- import static org.eclipse.jgit.lib.Ref.Storage.NEW;
- import static org.eclipse.jgit.lib.Ref.Storage.PACKED;
-
- import java.io.BufferedReader;
- import java.io.File;
- import java.io.FileInputStream;
- import java.io.FileNotFoundException;
- import java.io.IOException;
- import java.io.InputStreamReader;
- import java.io.InterruptedIOException;
- import java.nio.file.DirectoryNotEmptyException;
- import java.nio.file.Files;
- import java.security.DigestInputStream;
- import java.security.MessageDigest;
- import java.text.MessageFormat;
- import java.util.Arrays;
- import java.util.Collection;
- import java.util.Collections;
- import java.util.LinkedList;
- import java.util.List;
- import java.util.Map;
- import java.util.concurrent.atomic.AtomicInteger;
- import java.util.concurrent.atomic.AtomicReference;
- import java.util.concurrent.locks.ReentrantLock;
-
- import org.eclipse.jgit.annotations.NonNull;
- import org.eclipse.jgit.annotations.Nullable;
- import org.eclipse.jgit.errors.InvalidObjectIdException;
- import org.eclipse.jgit.errors.LockFailedException;
- import org.eclipse.jgit.errors.MissingObjectException;
- import org.eclipse.jgit.errors.ObjectWritingException;
- import org.eclipse.jgit.events.RefsChangedEvent;
- import org.eclipse.jgit.internal.JGitText;
- import org.eclipse.jgit.lib.ConfigConstants;
- import org.eclipse.jgit.lib.Constants;
- import org.eclipse.jgit.lib.ObjectId;
- import org.eclipse.jgit.lib.ObjectIdRef;
- import org.eclipse.jgit.lib.Ref;
- import org.eclipse.jgit.lib.RefComparator;
- import org.eclipse.jgit.lib.RefDatabase;
- import org.eclipse.jgit.lib.RefUpdate;
- import org.eclipse.jgit.lib.RefWriter;
- import org.eclipse.jgit.lib.Repository;
- import org.eclipse.jgit.lib.SymbolicRef;
- import org.eclipse.jgit.revwalk.RevObject;
- import org.eclipse.jgit.revwalk.RevTag;
- import org.eclipse.jgit.revwalk.RevWalk;
- import org.eclipse.jgit.util.FS;
- import org.eclipse.jgit.util.FileUtils;
- import org.eclipse.jgit.util.IO;
- import org.eclipse.jgit.util.RawParseUtils;
- import org.eclipse.jgit.util.RefList;
- import org.eclipse.jgit.util.RefMap;
- import org.slf4j.Logger;
- import org.slf4j.LoggerFactory;
-
- /**
- * Traditional file system based {@link org.eclipse.jgit.lib.RefDatabase}.
- * <p>
- * This is the classical reference database representation for a Git repository.
- * References are stored in two formats: loose, and packed.
- * <p>
- * Loose references are stored as individual files within the {@code refs/}
- * directory. The file name matches the reference name and the file contents is
- * the current {@link org.eclipse.jgit.lib.ObjectId} in string form.
- * <p>
- * Packed references are stored in a single text file named {@code packed-refs}.
- * In the packed format, each reference is stored on its own line. This file
- * reduces the number of files needed for large reference spaces, reducing the
- * overall size of a Git repository on disk.
- */
- public class RefDirectory extends RefDatabase {
- private final static Logger LOG = LoggerFactory
- .getLogger(RefDirectory.class);
-
- /** Magic string denoting the start of a symbolic reference file. */
- public static final String SYMREF = "ref: "; //$NON-NLS-1$
-
- /** Magic string denoting the header of a packed-refs file. */
- public static final String PACKED_REFS_HEADER = "# pack-refs with:"; //$NON-NLS-1$
-
- /** If in the header, denotes the file has peeled data. */
- public static final String PACKED_REFS_PEELED = " peeled"; //$NON-NLS-1$
-
- /** The names of the additional refs supported by this class */
- private static final String[] additionalRefsNames = new String[] {
- Constants.MERGE_HEAD, Constants.FETCH_HEAD, Constants.ORIG_HEAD,
- Constants.CHERRY_PICK_HEAD };
-
- @SuppressWarnings("boxing")
- private static final List<Integer> RETRY_SLEEP_MS =
- Collections.unmodifiableList(Arrays.asList(0, 100, 200, 400, 800, 1600));
-
- private final FileRepository parent;
-
- private final File gitDir;
-
- final File refsDir;
-
- final File packedRefsFile;
-
- final File logsDir;
-
- final File logsRefsDir;
-
- /**
- * Immutable sorted list of loose references.
- * <p>
- * Symbolic references in this collection are stored unresolved, that is
- * their target appears to be a new reference with no ObjectId. These are
- * converted into resolved references during a get operation, ensuring the
- * live value is always returned.
- */
- private final AtomicReference<RefList<LooseRef>> looseRefs = new AtomicReference<>();
-
- /** Immutable sorted list of packed references. */
- final AtomicReference<PackedRefList> packedRefs = new AtomicReference<>();
-
- /**
- * Lock for coordinating operations within a single process that may contend
- * on the {@code packed-refs} file.
- * <p>
- * All operations that write {@code packed-refs} must still acquire a
- * {@link LockFile} on {@link #packedRefsFile}, even after they have acquired
- * this lock, since there may be multiple {@link RefDirectory} instances or
- * other processes operating on the same repo on disk.
- * <p>
- * This lock exists so multiple threads in the same process can wait in a fair
- * queue without trying, failing, and retrying to acquire the on-disk lock. If
- * {@code RepositoryCache} is used, this lock instance will be used by all
- * threads.
- */
- final ReentrantLock inProcessPackedRefsLock = new ReentrantLock(true);
-
- /**
- * Number of modifications made to this database.
- * <p>
- * This counter is incremented when a change is made, or detected from the
- * filesystem during a read operation.
- */
- private final AtomicInteger modCnt = new AtomicInteger();
-
- /**
- * Last {@link #modCnt} that we sent to listeners.
- * <p>
- * This value is compared to {@link #modCnt}, and a notification is sent to
- * the listeners only when it differs.
- */
- private final AtomicInteger lastNotifiedModCnt = new AtomicInteger();
-
- private List<Integer> retrySleepMs = RETRY_SLEEP_MS;
-
- RefDirectory(final FileRepository db) {
- final FS fs = db.getFS();
- parent = db;
- gitDir = db.getDirectory();
- refsDir = fs.resolve(gitDir, R_REFS);
- logsDir = fs.resolve(gitDir, LOGS);
- logsRefsDir = fs.resolve(gitDir, LOGS + '/' + R_REFS);
- packedRefsFile = fs.resolve(gitDir, PACKED_REFS);
-
- looseRefs.set(RefList.<LooseRef> emptyList());
- packedRefs.set(NO_PACKED_REFS);
- }
-
- Repository getRepository() {
- return parent;
- }
-
- ReflogWriter newLogWriter(boolean force) {
- return new ReflogWriter(this, force);
- }
-
- /**
- * Locate the log file on disk for a single reference name.
- *
- * @param name
- * name of the ref, relative to the Git repository top level
- * directory (so typically starts with refs/).
- * @return the log file location.
- */
- public File logFor(String name) {
- if (name.startsWith(R_REFS)) {
- name = name.substring(R_REFS.length());
- return new File(logsRefsDir, name);
- }
- return new File(logsDir, name);
- }
-
- /** {@inheritDoc} */
- @Override
- public void create() throws IOException {
- FileUtils.mkdir(refsDir);
- FileUtils.mkdir(new File(refsDir, R_HEADS.substring(R_REFS.length())));
- FileUtils.mkdir(new File(refsDir, R_TAGS.substring(R_REFS.length())));
- newLogWriter(false).create();
- }
-
- /** {@inheritDoc} */
- @Override
- public void close() {
- clearReferences();
- }
-
- private void clearReferences() {
- looseRefs.set(RefList.<LooseRef> emptyList());
- packedRefs.set(NO_PACKED_REFS);
- }
-
- /** {@inheritDoc} */
- @Override
- public void refresh() {
- super.refresh();
- clearReferences();
- }
-
- /** {@inheritDoc} */
- @Override
- public boolean isNameConflicting(String name) throws IOException {
- RefList<Ref> packed = getPackedRefs();
- RefList<LooseRef> loose = getLooseRefs();
-
- // Cannot be nested within an existing reference.
- int lastSlash = name.lastIndexOf('/');
- while (0 < lastSlash) {
- String needle = name.substring(0, lastSlash);
- if (loose.contains(needle) || packed.contains(needle))
- return true;
- lastSlash = name.lastIndexOf('/', lastSlash - 1);
- }
-
- // Cannot be the container of an existing reference.
- String prefix = name + '/';
- int idx;
-
- idx = -(packed.find(prefix) + 1);
- if (idx < packed.size() && packed.get(idx).getName().startsWith(prefix))
- return true;
-
- idx = -(loose.find(prefix) + 1);
- if (idx < loose.size() && loose.get(idx).getName().startsWith(prefix))
- return true;
-
- return false;
- }
-
- private RefList<LooseRef> getLooseRefs() {
- final RefList<LooseRef> oldLoose = looseRefs.get();
-
- LooseScanner scan = new LooseScanner(oldLoose);
- scan.scan(ALL);
-
- RefList<LooseRef> loose;
- if (scan.newLoose != null) {
- loose = scan.newLoose.toRefList();
- if (looseRefs.compareAndSet(oldLoose, loose))
- modCnt.incrementAndGet();
- } else
- loose = oldLoose;
- return loose;
- }
-
- /** {@inheritDoc} */
- @Override
- public Ref exactRef(String name) throws IOException {
- RefList<Ref> packed = getPackedRefs();
- Ref ref;
- try {
- ref = readRef(name, packed);
- if (ref != null) {
- ref = resolve(ref, 0, null, null, packed);
- }
- } catch (IOException e) {
- if (name.contains("/") //$NON-NLS-1$
- || !(e.getCause() instanceof InvalidObjectIdException)) {
- throw e;
- }
-
- // While looking for a ref outside of refs/ (e.g., 'config'), we
- // found a non-ref file (e.g., a config file) instead. Treat this
- // as a ref-not-found condition.
- ref = null;
- }
- fireRefsChanged();
- return ref;
- }
-
- /** {@inheritDoc} */
- @Override
- public Ref getRef(final String needle) throws IOException {
- final RefList<Ref> packed = getPackedRefs();
- Ref ref = null;
- for (String prefix : SEARCH_PATH) {
- try {
- ref = readRef(prefix + needle, packed);
- if (ref != null) {
- ref = resolve(ref, 0, null, null, packed);
- }
- if (ref != null) {
- break;
- }
- } catch (IOException e) {
- if (!(!needle.contains("/") && "".equals(prefix) && e //$NON-NLS-1$ //$NON-NLS-2$
- .getCause() instanceof InvalidObjectIdException)) {
- throw e;
- }
- }
- }
- fireRefsChanged();
- return ref;
- }
-
- /** {@inheritDoc} */
- @Override
- public Map<String, Ref> getRefs(String prefix) throws IOException {
- final RefList<LooseRef> oldLoose = looseRefs.get();
- LooseScanner scan = new LooseScanner(oldLoose);
- scan.scan(prefix);
- final RefList<Ref> packed = getPackedRefs();
-
- RefList<LooseRef> loose;
- if (scan.newLoose != null) {
- scan.newLoose.sort();
- loose = scan.newLoose.toRefList();
- if (looseRefs.compareAndSet(oldLoose, loose))
- modCnt.incrementAndGet();
- } else
- loose = oldLoose;
- fireRefsChanged();
-
- RefList.Builder<Ref> symbolic = scan.symbolic;
- for (int idx = 0; idx < symbolic.size();) {
- final Ref symbolicRef = symbolic.get(idx);
- final Ref resolvedRef = resolve(symbolicRef, 0, prefix, loose, packed);
- if (resolvedRef != null && resolvedRef.getObjectId() != null) {
- symbolic.set(idx, resolvedRef);
- idx++;
- } else {
- // A broken symbolic reference, we have to drop it from the
- // collections the client is about to receive. Should be a
- // rare occurrence so pay a copy penalty.
- symbolic.remove(idx);
- final int toRemove = loose.find(symbolicRef.getName());
- if (0 <= toRemove)
- loose = loose.remove(toRemove);
- }
- }
- symbolic.sort();
-
- return new RefMap(prefix, packed, upcast(loose), symbolic.toRefList());
- }
-
- /** {@inheritDoc} */
- @Override
- public List<Ref> getAdditionalRefs() throws IOException {
- List<Ref> ret = new LinkedList<>();
- for (String name : additionalRefsNames) {
- Ref r = getRef(name);
- if (r != null)
- ret.add(r);
- }
- return ret;
- }
-
- @SuppressWarnings("unchecked")
- private RefList<Ref> upcast(RefList<? extends Ref> loose) {
- return (RefList<Ref>) loose;
- }
-
- private class LooseScanner {
- private final RefList<LooseRef> curLoose;
-
- private int curIdx;
-
- final RefList.Builder<Ref> symbolic = new RefList.Builder<>(4);
-
- RefList.Builder<LooseRef> newLoose;
-
- LooseScanner(final RefList<LooseRef> curLoose) {
- this.curLoose = curLoose;
- }
-
- void scan(String prefix) {
- if (ALL.equals(prefix)) {
- scanOne(HEAD);
- scanTree(R_REFS, refsDir);
-
- // If any entries remain, they are deleted, drop them.
- if (newLoose == null && curIdx < curLoose.size())
- newLoose = curLoose.copy(curIdx);
-
- } else if (prefix.startsWith(R_REFS) && prefix.endsWith("/")) { //$NON-NLS-1$
- curIdx = -(curLoose.find(prefix) + 1);
- File dir = new File(refsDir, prefix.substring(R_REFS.length()));
- scanTree(prefix, dir);
-
- // Skip over entries still within the prefix; these have
- // been removed from the directory.
- while (curIdx < curLoose.size()) {
- if (!curLoose.get(curIdx).getName().startsWith(prefix))
- break;
- if (newLoose == null)
- newLoose = curLoose.copy(curIdx);
- curIdx++;
- }
-
- // Keep any entries outside of the prefix space, we
- // do not know anything about their status.
- if (newLoose != null) {
- while (curIdx < curLoose.size())
- newLoose.add(curLoose.get(curIdx++));
- }
- }
- }
-
- private boolean scanTree(String prefix, File dir) {
- final String[] entries = dir.list(LockFile.FILTER);
- if (entries == null) // not a directory or an I/O error
- return false;
- if (0 < entries.length) {
- for (int i = 0; i < entries.length; ++i) {
- String e = entries[i];
- File f = new File(dir, e);
- if (f.isDirectory())
- entries[i] += '/';
- }
- Arrays.sort(entries);
- for (String name : entries) {
- if (name.charAt(name.length() - 1) == '/')
- scanTree(prefix + name, new File(dir, name));
- else
- scanOne(prefix + name);
- }
- }
- return true;
- }
-
- private void scanOne(String name) {
- LooseRef cur;
-
- if (curIdx < curLoose.size()) {
- do {
- cur = curLoose.get(curIdx);
- int cmp = RefComparator.compareTo(cur, name);
- if (cmp < 0) {
- // Reference is not loose anymore, its been deleted.
- // Skip the name in the new result list.
- if (newLoose == null)
- newLoose = curLoose.copy(curIdx);
- curIdx++;
- cur = null;
- continue;
- }
-
- if (cmp > 0) // Newly discovered loose reference.
- cur = null;
- break;
- } while (curIdx < curLoose.size());
- } else
- cur = null; // Newly discovered loose reference.
-
- LooseRef n;
- try {
- n = scanRef(cur, name);
- } catch (IOException notValid) {
- n = null;
- }
-
- if (n != null) {
- if (cur != n && newLoose == null)
- newLoose = curLoose.copy(curIdx);
- if (newLoose != null)
- newLoose.add(n);
- if (n.isSymbolic())
- symbolic.add(n);
- } else if (cur != null) {
- // Tragically, this file is no longer a loose reference.
- // Kill our cached entry of it.
- if (newLoose == null)
- newLoose = curLoose.copy(curIdx);
- }
-
- if (cur != null)
- curIdx++;
- }
- }
-
- /** {@inheritDoc} */
- @Override
- public Ref peel(final Ref ref) throws IOException {
- final Ref leaf = ref.getLeaf();
- if (leaf.isPeeled() || leaf.getObjectId() == null)
- return ref;
-
- ObjectIdRef newLeaf = doPeel(leaf);
-
- // Try to remember this peeling in the cache, so we don't have to do
- // it again in the future, but only if the reference is unchanged.
- if (leaf.getStorage().isLoose()) {
- RefList<LooseRef> curList = looseRefs.get();
- int idx = curList.find(leaf.getName());
- if (0 <= idx && curList.get(idx) == leaf) {
- LooseRef asPeeled = ((LooseRef) leaf).peel(newLeaf);
- RefList<LooseRef> newList = curList.set(idx, asPeeled);
- looseRefs.compareAndSet(curList, newList);
- }
- }
-
- return recreate(ref, newLeaf);
- }
-
- private ObjectIdRef doPeel(final Ref leaf) throws MissingObjectException,
- IOException {
- try (RevWalk rw = new RevWalk(getRepository())) {
- RevObject obj = rw.parseAny(leaf.getObjectId());
- if (obj instanceof RevTag) {
- return new ObjectIdRef.PeeledTag(leaf.getStorage(), leaf
- .getName(), leaf.getObjectId(), rw.peel(obj).copy());
- } else {
- return new ObjectIdRef.PeeledNonTag(leaf.getStorage(), leaf
- .getName(), leaf.getObjectId());
- }
- }
- }
-
- private static Ref recreate(final Ref old, final ObjectIdRef leaf) {
- if (old.isSymbolic()) {
- Ref dst = recreate(old.getTarget(), leaf);
- return new SymbolicRef(old.getName(), dst);
- }
- return leaf;
- }
-
- void storedSymbolicRef(RefDirectoryUpdate u, FileSnapshot snapshot,
- String target) {
- putLooseRef(newSymbolicRef(snapshot, u.getRef().getName(), target));
- fireRefsChanged();
- }
-
- /** {@inheritDoc} */
- @Override
- public RefDirectoryUpdate newUpdate(String name, boolean detach)
- throws IOException {
- boolean detachingSymbolicRef = false;
- final RefList<Ref> packed = getPackedRefs();
- Ref ref = readRef(name, packed);
- if (ref != null)
- ref = resolve(ref, 0, null, null, packed);
- if (ref == null)
- ref = new ObjectIdRef.Unpeeled(NEW, name, null);
- else {
- detachingSymbolicRef = detach && ref.isSymbolic();
- }
- RefDirectoryUpdate refDirUpdate = new RefDirectoryUpdate(this, ref);
- if (detachingSymbolicRef)
- refDirUpdate.setDetachingSymbolicRef();
- return refDirUpdate;
- }
-
- /** {@inheritDoc} */
- @Override
- public RefDirectoryRename newRename(String fromName, String toName)
- throws IOException {
- RefDirectoryUpdate from = newUpdate(fromName, false);
- RefDirectoryUpdate to = newUpdate(toName, false);
- return new RefDirectoryRename(from, to);
- }
-
- /** {@inheritDoc} */
- @Override
- public PackedBatchRefUpdate newBatchUpdate() {
- return new PackedBatchRefUpdate(this);
- }
-
- /** {@inheritDoc} */
- @Override
- public boolean performsAtomicTransactions() {
- return true;
- }
-
- void stored(RefDirectoryUpdate update, FileSnapshot snapshot) {
- final ObjectId target = update.getNewObjectId().copy();
- final Ref leaf = update.getRef().getLeaf();
- putLooseRef(new LooseUnpeeled(snapshot, leaf.getName(), target));
- }
-
- private void putLooseRef(LooseRef ref) {
- RefList<LooseRef> cList, nList;
- do {
- cList = looseRefs.get();
- nList = cList.put(ref);
- } while (!looseRefs.compareAndSet(cList, nList));
- modCnt.incrementAndGet();
- fireRefsChanged();
- }
-
- void delete(RefDirectoryUpdate update) throws IOException {
- Ref dst = update.getRef();
- if (!update.isDetachingSymbolicRef()) {
- dst = dst.getLeaf();
- }
- String name = dst.getName();
-
- // Write the packed-refs file using an atomic update. We might
- // wind up reading it twice, before and after the lock, to ensure
- // we don't miss an edit made externally.
- final PackedRefList packed = getPackedRefs();
- if (packed.contains(name)) {
- inProcessPackedRefsLock.lock();
- try {
- LockFile lck = lockPackedRefsOrThrow();
- try {
- PackedRefList cur = readPackedRefs();
- int idx = cur.find(name);
- if (0 <= idx) {
- commitPackedRefs(lck, cur.remove(idx), packed, true);
- }
- } finally {
- lck.unlock();
- }
- } finally {
- inProcessPackedRefsLock.unlock();
- }
- }
-
- RefList<LooseRef> curLoose, newLoose;
- do {
- curLoose = looseRefs.get();
- int idx = curLoose.find(name);
- if (idx < 0)
- break;
- newLoose = curLoose.remove(idx);
- } while (!looseRefs.compareAndSet(curLoose, newLoose));
-
- int levels = levelsIn(name) - 2;
- delete(logFor(name), levels);
- if (dst.getStorage().isLoose()) {
- update.unlock();
- delete(fileFor(name), levels);
- }
-
- modCnt.incrementAndGet();
- fireRefsChanged();
- }
-
- /**
- * Adds a set of refs to the set of packed-refs. Only non-symbolic refs are
- * added. If a ref with the given name already existed in packed-refs it is
- * updated with the new value. Each loose ref which was added to the
- * packed-ref file is deleted. If a given ref can't be locked it will not be
- * added to the pack file.
- *
- * @param refs
- * the refs to be added. Must be fully qualified.
- * @throws java.io.IOException
- */
- public void pack(List<String> refs) throws IOException {
- pack(refs, Collections.emptyMap());
- }
-
- PackedRefList pack(Map<String, LockFile> heldLocks) throws IOException {
- return pack(heldLocks.keySet(), heldLocks);
- }
-
- private PackedRefList pack(Collection<String> refs,
- Map<String, LockFile> heldLocks) throws IOException {
- for (LockFile ol : heldLocks.values()) {
- ol.requireLock();
- }
- if (refs.size() == 0) {
- return null;
- }
- FS fs = parent.getFS();
-
- // Lock the packed refs file and read the content
- inProcessPackedRefsLock.lock();
- try {
- LockFile lck = lockPackedRefsOrThrow();
- try {
- final PackedRefList packed = getPackedRefs();
- RefList<Ref> cur = readPackedRefs();
-
- // Iterate over all refs to be packed
- boolean dirty = false;
- for (String refName : refs) {
- Ref oldRef = readRef(refName, cur);
- if (oldRef == null) {
- continue; // A non-existent ref is already correctly packed.
- }
- if (oldRef.isSymbolic()) {
- continue; // can't pack symbolic refs
- }
- // Add/Update it to packed-refs
- Ref newRef = peeledPackedRef(oldRef);
- if (newRef == oldRef) {
- // No-op; peeledPackedRef returns the input ref only if it's already
- // packed, and readRef returns a packed ref only if there is no
- // loose ref.
- continue;
- }
-
- dirty = true;
- int idx = cur.find(refName);
- if (idx >= 0) {
- cur = cur.set(idx, newRef);
- } else {
- cur = cur.add(idx, newRef);
- }
- }
- if (!dirty) {
- // All requested refs were already packed accurately
- return packed;
- }
-
- // The new content for packed-refs is collected. Persist it.
- PackedRefList result = commitPackedRefs(lck, cur, packed,
- false);
-
- // Now delete the loose refs which are now packed
- for (String refName : refs) {
- // Lock the loose ref
- File refFile = fileFor(refName);
- if (!fs.exists(refFile)) {
- continue;
- }
-
- LockFile rLck = heldLocks.get(refName);
- boolean shouldUnlock;
- if (rLck == null) {
- rLck = new LockFile(refFile);
- if (!rLck.lock()) {
- continue;
- }
- shouldUnlock = true;
- } else {
- shouldUnlock = false;
- }
-
- try {
- LooseRef currentLooseRef = scanRef(null, refName);
- if (currentLooseRef == null || currentLooseRef.isSymbolic()) {
- continue;
- }
- Ref packedRef = cur.get(refName);
- ObjectId clr_oid = currentLooseRef.getObjectId();
- if (clr_oid != null
- && clr_oid.equals(packedRef.getObjectId())) {
- RefList<LooseRef> curLoose, newLoose;
- do {
- curLoose = looseRefs.get();
- int idx = curLoose.find(refName);
- if (idx < 0) {
- break;
- }
- newLoose = curLoose.remove(idx);
- } while (!looseRefs.compareAndSet(curLoose, newLoose));
- int levels = levelsIn(refName) - 2;
- delete(refFile, levels, rLck);
- }
- } finally {
- if (shouldUnlock) {
- rLck.unlock();
- }
- }
- }
- // Don't fire refsChanged. The refs have not change, only their
- // storage.
- return result;
- } finally {
- lck.unlock();
- }
- } finally {
- inProcessPackedRefsLock.unlock();
- }
- }
-
- @Nullable
- LockFile lockPackedRefs() throws IOException {
- LockFile lck = new LockFile(packedRefsFile);
- for (int ms : getRetrySleepMs()) {
- sleep(ms);
- if (lck.lock()) {
- return lck;
- }
- }
- return null;
- }
-
- private LockFile lockPackedRefsOrThrow() throws IOException {
- LockFile lck = lockPackedRefs();
- if (lck == null) {
- throw new LockFailedException(packedRefsFile);
- }
- return lck;
- }
-
- /**
- * Make sure a ref is peeled and has the Storage PACKED. If the given ref
- * has this attributes simply return it. Otherwise create a new peeled
- * {@link ObjectIdRef} where Storage is set to PACKED.
- *
- * @param f
- * @return a ref for Storage PACKED having the same name, id, peeledId as f
- * @throws MissingObjectException
- * @throws IOException
- */
- private Ref peeledPackedRef(Ref f)
- throws MissingObjectException, IOException {
- if (f.getStorage().isPacked() && f.isPeeled()) {
- return f;
- }
- if (!f.isPeeled()) {
- f = peel(f);
- }
- ObjectId peeledObjectId = f.getPeeledObjectId();
- if (peeledObjectId != null) {
- return new ObjectIdRef.PeeledTag(PACKED, f.getName(),
- f.getObjectId(), peeledObjectId);
- } else {
- return new ObjectIdRef.PeeledNonTag(PACKED, f.getName(),
- f.getObjectId());
- }
- }
-
- void log(boolean force, RefUpdate update, String msg, boolean deref)
- throws IOException {
- newLogWriter(force).log(update, msg, deref);
- }
-
- private Ref resolve(final Ref ref, int depth, String prefix,
- RefList<LooseRef> loose, RefList<Ref> packed) throws IOException {
- if (ref.isSymbolic()) {
- Ref dst = ref.getTarget();
-
- if (MAX_SYMBOLIC_REF_DEPTH <= depth)
- return null; // claim it doesn't exist
-
- // If the cached value can be assumed to be current due to a
- // recent scan of the loose directory, use it.
- if (loose != null && dst.getName().startsWith(prefix)) {
- int idx;
- if (0 <= (idx = loose.find(dst.getName())))
- dst = loose.get(idx);
- else if (0 <= (idx = packed.find(dst.getName())))
- dst = packed.get(idx);
- else
- return ref;
- } else {
- dst = readRef(dst.getName(), packed);
- if (dst == null)
- return ref;
- }
-
- dst = resolve(dst, depth + 1, prefix, loose, packed);
- if (dst == null)
- return null;
- return new SymbolicRef(ref.getName(), dst);
- }
- return ref;
- }
-
- PackedRefList getPackedRefs() throws IOException {
- boolean trustFolderStat = getRepository().getConfig().getBoolean(
- ConfigConstants.CONFIG_CORE_SECTION,
- ConfigConstants.CONFIG_KEY_TRUSTFOLDERSTAT, true);
-
- final PackedRefList curList = packedRefs.get();
- if (trustFolderStat && !curList.snapshot.isModified(packedRefsFile)) {
- return curList;
- }
-
- final PackedRefList newList = readPackedRefs();
- if (packedRefs.compareAndSet(curList, newList)
- && !curList.id.equals(newList.id)) {
- modCnt.incrementAndGet();
- }
- return newList;
- }
-
- private PackedRefList readPackedRefs() throws IOException {
- int maxStaleRetries = 5;
- int retries = 0;
- while (true) {
- final FileSnapshot snapshot = FileSnapshot.save(packedRefsFile);
- final BufferedReader br;
- final MessageDigest digest = Constants.newMessageDigest();
- try {
- br = new BufferedReader(new InputStreamReader(
- new DigestInputStream(new FileInputStream(packedRefsFile),
- digest), CHARSET));
- } catch (FileNotFoundException noPackedRefs) {
- if (packedRefsFile.exists()) {
- throw noPackedRefs;
- }
- // Ignore it and leave the new list empty.
- return NO_PACKED_REFS;
- }
- try {
- return new PackedRefList(parsePackedRefs(br), snapshot,
- ObjectId.fromRaw(digest.digest()));
- } catch (IOException e) {
- if (FileUtils.isStaleFileHandleInCausalChain(e)
- && retries < maxStaleRetries) {
- if (LOG.isDebugEnabled()) {
- LOG.debug(MessageFormat.format(
- JGitText.get().packedRefsHandleIsStale,
- Integer.valueOf(retries)), e);
- }
- retries++;
- continue;
- }
- throw e;
- } finally {
- br.close();
- }
- }
- }
-
- private RefList<Ref> parsePackedRefs(final BufferedReader br)
- throws IOException {
- RefList.Builder<Ref> all = new RefList.Builder<>();
- Ref last = null;
- boolean peeled = false;
- boolean needSort = false;
-
- String p;
- while ((p = br.readLine()) != null) {
- if (p.charAt(0) == '#') {
- if (p.startsWith(PACKED_REFS_HEADER)) {
- p = p.substring(PACKED_REFS_HEADER.length());
- peeled = p.contains(PACKED_REFS_PEELED);
- }
- continue;
- }
-
- if (p.charAt(0) == '^') {
- if (last == null)
- throw new IOException(JGitText.get().peeledLineBeforeRef);
-
- ObjectId id = ObjectId.fromString(p.substring(1));
- last = new ObjectIdRef.PeeledTag(PACKED, last.getName(), last
- .getObjectId(), id);
- all.set(all.size() - 1, last);
- continue;
- }
-
- int sp = p.indexOf(' ');
- if (sp < 0) {
- throw new IOException(MessageFormat.format(
- JGitText.get().packedRefsCorruptionDetected,
- packedRefsFile.getAbsolutePath()));
- }
- ObjectId id = ObjectId.fromString(p.substring(0, sp));
- String name = copy(p, sp + 1, p.length());
- ObjectIdRef cur;
- if (peeled)
- cur = new ObjectIdRef.PeeledNonTag(PACKED, name, id);
- else
- cur = new ObjectIdRef.Unpeeled(PACKED, name, id);
- if (last != null && RefComparator.compareTo(last, cur) > 0)
- needSort = true;
- all.add(cur);
- last = cur;
- }
-
- if (needSort)
- all.sort();
- return all.toRefList();
- }
-
- private static String copy(final String src, final int off, final int end) {
- // Don't use substring since it could leave a reference to the much
- // larger existing string. Force construction of a full new object.
- return new StringBuilder(end - off).append(src, off, end).toString();
- }
-
- PackedRefList commitPackedRefs(final LockFile lck, final RefList<Ref> refs,
- final PackedRefList oldPackedList, boolean changed)
- throws IOException {
- // Can't just return packedRefs.get() from this method; it might have been
- // updated again after writePackedRefs() returns.
- AtomicReference<PackedRefList> result = new AtomicReference<>();
- new RefWriter(refs) {
- @Override
- protected void writeFile(String name, byte[] content)
- throws IOException {
- lck.setFSync(true);
- lck.setNeedSnapshot(true);
- try {
- lck.write(content);
- } catch (IOException ioe) {
- throw new ObjectWritingException(MessageFormat.format(JGitText.get().unableToWrite, name), ioe);
- }
- try {
- lck.waitForStatChange();
- } catch (InterruptedException e) {
- lck.unlock();
- throw new ObjectWritingException(MessageFormat.format(JGitText.get().interruptedWriting, name));
- }
- if (!lck.commit())
- throw new ObjectWritingException(MessageFormat.format(JGitText.get().unableToWrite, name));
-
- byte[] digest = Constants.newMessageDigest().digest(content);
- PackedRefList newPackedList = new PackedRefList(
- refs, lck.getCommitSnapshot(), ObjectId.fromRaw(digest));
-
- // This thread holds the file lock, so no other thread or process should
- // be able to modify the packed-refs file on disk. If the list changed,
- // it means something is very wrong, so throw an exception.
- //
- // However, we can't use a naive compareAndSet to check whether the
- // update was successful, because another thread might _read_ the
- // packed refs file that was written out by this thread while holding
- // the lock, and update the packedRefs reference to point to that. So
- // compare the actual contents instead.
- PackedRefList afterUpdate = packedRefs.updateAndGet(
- p -> p.id.equals(oldPackedList.id) ? newPackedList : p);
- if (!afterUpdate.id.equals(newPackedList.id)) {
- throw new ObjectWritingException(
- MessageFormat.format(JGitText.get().unableToWrite, name));
- }
- if (changed) {
- modCnt.incrementAndGet();
- }
- result.set(newPackedList);
- }
- }.writePackedRefs();
- return result.get();
- }
-
- private Ref readRef(String name, RefList<Ref> packed) throws IOException {
- final RefList<LooseRef> curList = looseRefs.get();
- final int idx = curList.find(name);
- if (0 <= idx) {
- final LooseRef o = curList.get(idx);
- final LooseRef n = scanRef(o, name);
- if (n == null) {
- if (looseRefs.compareAndSet(curList, curList.remove(idx)))
- modCnt.incrementAndGet();
- return packed.get(name);
- }
-
- if (o == n)
- return n;
- if (looseRefs.compareAndSet(curList, curList.set(idx, n)))
- modCnt.incrementAndGet();
- return n;
- }
-
- final LooseRef n = scanRef(null, name);
- if (n == null)
- return packed.get(name);
-
- // check whether the found new ref is the an additional ref. These refs
- // should not go into looseRefs
- for (int i = 0; i < additionalRefsNames.length; i++)
- if (name.equals(additionalRefsNames[i]))
- return n;
-
- if (looseRefs.compareAndSet(curList, curList.add(idx, n)))
- modCnt.incrementAndGet();
- return n;
- }
-
- LooseRef scanRef(LooseRef ref, String name) throws IOException {
- final File path = fileFor(name);
- FileSnapshot currentSnapshot = null;
-
- if (ref != null) {
- currentSnapshot = ref.getSnapShot();
- if (!currentSnapshot.isModified(path))
- return ref;
- name = ref.getName();
- }
-
- final int limit = 4096;
- final byte[] buf;
- FileSnapshot otherSnapshot = FileSnapshot.save(path);
- try {
- buf = IO.readSome(path, limit);
- } catch (FileNotFoundException noFile) {
- if (path.exists() && path.isFile()) {
- throw noFile;
- }
- return null; // doesn't exist or no file; not a reference.
- }
-
- int n = buf.length;
- if (n == 0)
- return null; // empty file; not a reference.
-
- if (isSymRef(buf, n)) {
- if (n == limit)
- return null; // possibly truncated ref
-
- // trim trailing whitespace
- while (0 < n && Character.isWhitespace(buf[n - 1]))
- n--;
- if (n < 6) {
- String content = RawParseUtils.decode(buf, 0, n);
- throw new IOException(MessageFormat.format(JGitText.get().notARef, name, content));
- }
- final String target = RawParseUtils.decode(buf, 5, n);
- if (ref != null && ref.isSymbolic()
- && ref.getTarget().getName().equals(target)) {
- assert(currentSnapshot != null);
- currentSnapshot.setClean(otherSnapshot);
- return ref;
- }
- return newSymbolicRef(otherSnapshot, name, target);
- }
-
- if (n < OBJECT_ID_STRING_LENGTH)
- return null; // impossibly short object identifier; not a reference.
-
- final ObjectId id;
- try {
- id = ObjectId.fromString(buf, 0);
- if (ref != null && !ref.isSymbolic()
- && id.equals(ref.getTarget().getObjectId())) {
- assert(currentSnapshot != null);
- currentSnapshot.setClean(otherSnapshot);
- return ref;
- }
-
- } catch (IllegalArgumentException notRef) {
- while (0 < n && Character.isWhitespace(buf[n - 1]))
- n--;
- String content = RawParseUtils.decode(buf, 0, n);
-
- throw new IOException(MessageFormat.format(JGitText.get().notARef,
- name, content), notRef);
- }
- return new LooseUnpeeled(otherSnapshot, name, id);
- }
-
- private static boolean isSymRef(final byte[] buf, int n) {
- if (n < 6)
- return false;
- return /**/buf[0] == 'r' //
- && buf[1] == 'e' //
- && buf[2] == 'f' //
- && buf[3] == ':' //
- && buf[4] == ' ';
- }
-
- /**
- * Detect if we are in a clone command execution
- *
- * @return {@code true} if we are currently cloning a repository
- * @throws IOException
- */
- boolean isInClone() throws IOException {
- return hasDanglingHead() && !packedRefsFile.exists() && !hasLooseRef();
- }
-
- private boolean hasDanglingHead() throws IOException {
- Ref head = exactRef(Constants.HEAD);
- if (head != null) {
- ObjectId id = head.getObjectId();
- return id == null || id.equals(ObjectId.zeroId());
- }
- return false;
- }
-
- private boolean hasLooseRef() throws IOException {
- return Files.walk(refsDir.toPath()).anyMatch(Files::isRegularFile);
- }
-
- /** If the parent should fire listeners, fires them. */
- void fireRefsChanged() {
- final int last = lastNotifiedModCnt.get();
- final int curr = modCnt.get();
- if (last != curr && lastNotifiedModCnt.compareAndSet(last, curr) && last != 0)
- parent.fireEvent(new RefsChangedEvent());
- }
-
- /**
- * Create a reference update to write a temporary reference.
- *
- * @return an update for a new temporary reference.
- * @throws IOException
- * a temporary name cannot be allocated.
- */
- RefDirectoryUpdate newTemporaryUpdate() throws IOException {
- File tmp = File.createTempFile("renamed_", "_ref", refsDir); //$NON-NLS-1$ //$NON-NLS-2$
- String name = Constants.R_REFS + tmp.getName();
- Ref ref = new ObjectIdRef.Unpeeled(NEW, name, null);
- return new RefDirectoryUpdate(this, ref);
- }
-
- /**
- * Locate the file on disk for a single reference name.
- *
- * @param name
- * name of the ref, relative to the Git repository top level
- * directory (so typically starts with refs/).
- * @return the loose file location.
- */
- File fileFor(String name) {
- if (name.startsWith(R_REFS)) {
- name = name.substring(R_REFS.length());
- return new File(refsDir, name);
- }
- return new File(gitDir, name);
- }
-
- static int levelsIn(final String name) {
- int count = 0;
- for (int p = name.indexOf('/'); p >= 0; p = name.indexOf('/', p + 1))
- count++;
- return count;
- }
-
- static void delete(final File file, final int depth) throws IOException {
- delete(file, depth, null);
- }
-
- private static void delete(final File file, final int depth, LockFile rLck)
- throws IOException {
- if (!file.delete() && file.isFile()) {
- throw new IOException(MessageFormat.format(
- JGitText.get().fileCannotBeDeleted, file));
- }
-
- if (rLck != null) {
- rLck.unlock(); // otherwise cannot delete dir below
- }
- File dir = file.getParentFile();
- for (int i = 0; i < depth; ++i) {
- try {
- Files.deleteIfExists(dir.toPath());
- } catch (DirectoryNotEmptyException e) {
- // Don't log; normal case when there are other refs with the
- // same prefix
- break;
- } catch (IOException e) {
- LOG.warn(MessageFormat.format(JGitText.get().unableToRemovePath,
- dir), e);
- break;
- }
- dir = dir.getParentFile();
- }
- }
-
- /**
- * Get times to sleep while retrying a possibly contentious operation.
- * <p>
- * For retrying an operation that might have high contention, such as locking
- * the {@code packed-refs} file, the caller may implement a retry loop using
- * the returned values:
- *
- * <pre>
- * for (int toSleepMs : getRetrySleepMs()) {
- * sleep(toSleepMs);
- * if (isSuccessful(doSomething())) {
- * return success;
- * }
- * }
- * return failure;
- * </pre>
- *
- * The first value in the returned iterable is 0, and the caller should treat
- * a fully-consumed iterator as a timeout.
- *
- * @return iterable of times, in milliseconds, that the caller should sleep
- * before attempting an operation.
- */
- Iterable<Integer> getRetrySleepMs() {
- return retrySleepMs;
- }
-
- void setRetrySleepMs(List<Integer> retrySleepMs) {
- if (retrySleepMs == null || retrySleepMs.isEmpty()
- || retrySleepMs.get(0).intValue() != 0) {
- throw new IllegalArgumentException();
- }
- this.retrySleepMs = retrySleepMs;
- }
-
- /**
- * Sleep with {@link Thread#sleep(long)}, converting {@link
- * InterruptedException} to {@link InterruptedIOException}.
- *
- * @param ms
- * time to sleep, in milliseconds; zero or negative is a no-op.
- * @throws InterruptedIOException
- * if sleeping was interrupted.
- */
- static void sleep(long ms) throws InterruptedIOException {
- if (ms <= 0) {
- return;
- }
- try {
- Thread.sleep(ms);
- } catch (InterruptedException e) {
- InterruptedIOException ie = new InterruptedIOException();
- ie.initCause(e);
- throw ie;
- }
- }
-
- static class PackedRefList extends RefList<Ref> {
-
- private final FileSnapshot snapshot;
-
- private final ObjectId id;
-
- private PackedRefList(RefList<Ref> src, FileSnapshot s, ObjectId i) {
- super(src);
- snapshot = s;
- id = i;
- }
- }
-
- private static final PackedRefList NO_PACKED_REFS = new PackedRefList(
- RefList.emptyList(), FileSnapshot.MISSING_FILE,
- ObjectId.zeroId());
-
- private static LooseSymbolicRef newSymbolicRef(FileSnapshot snapshot,
- String name, String target) {
- Ref dst = new ObjectIdRef.Unpeeled(NEW, target, null);
- return new LooseSymbolicRef(snapshot, name, dst);
- }
-
- private static interface LooseRef extends Ref {
- FileSnapshot getSnapShot();
-
- LooseRef peel(ObjectIdRef newLeaf);
- }
-
- private final static class LoosePeeledTag extends ObjectIdRef.PeeledTag
- implements LooseRef {
- private final FileSnapshot snapShot;
-
- LoosePeeledTag(FileSnapshot snapshot, @NonNull String refName,
- @NonNull ObjectId id, @NonNull ObjectId p) {
- super(LOOSE, refName, id, p);
- this.snapShot = snapshot;
- }
-
- @Override
- public FileSnapshot getSnapShot() {
- return snapShot;
- }
-
- @Override
- public LooseRef peel(ObjectIdRef newLeaf) {
- return this;
- }
- }
-
- private final static class LooseNonTag extends ObjectIdRef.PeeledNonTag
- implements LooseRef {
- private final FileSnapshot snapShot;
-
- LooseNonTag(FileSnapshot snapshot, @NonNull String refName,
- @NonNull ObjectId id) {
- super(LOOSE, refName, id);
- this.snapShot = snapshot;
- }
-
- @Override
- public FileSnapshot getSnapShot() {
- return snapShot;
- }
-
- @Override
- public LooseRef peel(ObjectIdRef newLeaf) {
- return this;
- }
- }
-
- private final static class LooseUnpeeled extends ObjectIdRef.Unpeeled
- implements LooseRef {
- private FileSnapshot snapShot;
-
- LooseUnpeeled(FileSnapshot snapShot, @NonNull String refName,
- @NonNull ObjectId id) {
- super(LOOSE, refName, id);
- this.snapShot = snapShot;
- }
-
- @Override
- public FileSnapshot getSnapShot() {
- return snapShot;
- }
-
- @NonNull
- @Override
- public ObjectId getObjectId() {
- ObjectId id = super.getObjectId();
- assert id != null; // checked in constructor
- return id;
- }
-
- @Override
- public LooseRef peel(ObjectIdRef newLeaf) {
- ObjectId peeledObjectId = newLeaf.getPeeledObjectId();
- ObjectId objectId = getObjectId();
- if (peeledObjectId != null) {
- return new LoosePeeledTag(snapShot, getName(),
- objectId, peeledObjectId);
- } else {
- return new LooseNonTag(snapShot, getName(),
- objectId);
- }
- }
- }
-
- private final static class LooseSymbolicRef extends SymbolicRef implements
- LooseRef {
- private final FileSnapshot snapShot;
-
- LooseSymbolicRef(FileSnapshot snapshot, @NonNull String refName,
- @NonNull Ref target) {
- super(refName, target);
- this.snapShot = snapshot;
- }
-
- @Override
- public FileSnapshot getSnapShot() {
- return snapShot;
- }
-
- @Override
- public LooseRef peel(ObjectIdRef newLeaf) {
- // We should never try to peel the symbolic references.
- throw new UnsupportedOperationException();
- }
- }
- }
|