RefAdvertiser: Avoid object parsing
It isn't strictly necessary to validate every reference's target
object is reachable in the repository before advertising it to a
client. This is an expensive operation when there are thousands of
references, and its very unlikely that a reference uses a missing
object, because garbage collection proceeds from the references and
walks down through the graph. So trying to hide a dangling reference
from clients is relatively pointless.
Even if we are trying to avoid giving a client a corrupt repository,
this simple check isn't sufficient. It is possible for a reference to
point to a valid commit, but that commit to have a missing blob in its
root tree. This can be caused by staging a file into the index,
waiting several weeks, then committing that file while also racing
against a prune. The prune may delete the blob, since its
modification time is more than 2 weeks ago, but retain the commit,
since its modification time is right now.
Such graph corruption is already caught during PackWriter as it
enumerates the graph from the client's want list and digs back
to the roots or common base. Leave the reference validation also
for that same phase, where we know we have to parse the object to
support the enumeration.
Change-Id: Iee70ead0d3ed2d2fcc980417d09d7a69b05f5c2f
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
13 jaren geleden |
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415 |
- /*
- * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
- * Copyright (C) 2008-2010, Google Inc.
- * Copyright (C) 2006-2010, Robin Rosenberg <robin.rosenberg@dewire.com>
- * Copyright (C) 2006-2008, 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.storage.file;
-
- import java.io.File;
- import java.io.IOException;
- import java.text.MessageFormat;
- import java.util.HashSet;
- import java.util.Set;
-
- import org.eclipse.jgit.errors.ConfigInvalidException;
- import org.eclipse.jgit.events.ConfigChangedEvent;
- import org.eclipse.jgit.events.ConfigChangedListener;
- import org.eclipse.jgit.events.IndexChangedEvent;
- import org.eclipse.jgit.internal.JGitText;
- import org.eclipse.jgit.lib.BaseRepositoryBuilder;
- import org.eclipse.jgit.lib.ConfigConstants;
- import org.eclipse.jgit.lib.Constants;
- import org.eclipse.jgit.lib.ObjectId;
- import org.eclipse.jgit.lib.Ref;
- import org.eclipse.jgit.lib.RefDatabase;
- import org.eclipse.jgit.lib.RefUpdate;
- import org.eclipse.jgit.lib.Repository;
- import org.eclipse.jgit.storage.file.FileObjectDatabase.AlternateHandle;
- import org.eclipse.jgit.storage.file.FileObjectDatabase.AlternateRepository;
- import org.eclipse.jgit.util.FileUtils;
- import org.eclipse.jgit.util.SystemReader;
-
- /**
- * Represents a Git repository. A repository holds all objects and refs used for
- * managing source code (could by any type of file, but source code is what
- * SCM's are typically used for).
- *
- * In Git terms all data is stored in GIT_DIR, typically a directory called
- * .git. A work tree is maintained unless the repository is a bare repository.
- * Typically the .git directory is located at the root of the work dir.
- *
- * <ul>
- * <li>GIT_DIR
- * <ul>
- * <li>objects/ - objects</li>
- * <li>refs/ - tags and heads</li>
- * <li>config - configuration</li>
- * <li>info/ - more configurations</li>
- * </ul>
- * </li>
- * </ul>
- * <p>
- * This class is thread-safe.
- * <p>
- * This implementation only handles a subtly undocumented subset of git features.
- *
- */
- public class FileRepository extends Repository {
- private final FileBasedConfig systemConfig;
-
- private final FileBasedConfig userConfig;
-
- private final FileBasedConfig repoConfig;
-
- private final RefDatabase refs;
-
- private final ObjectDirectory objectDatabase;
-
- private FileSnapshot snapshot;
-
- /**
- * Construct a representation of a Git repository.
- * <p>
- * The work tree, object directory, alternate object directories and index
- * file locations are deduced from the given git directory and the default
- * rules by running {@link FileRepositoryBuilder}. This constructor is the
- * same as saying:
- *
- * <pre>
- * new FileRepositoryBuilder().setGitDir(gitDir).build()
- * </pre>
- *
- * @param gitDir
- * GIT_DIR (the location of the repository metadata).
- * @throws IOException
- * the repository appears to already exist but cannot be
- * accessed.
- * @see FileRepositoryBuilder
- */
- public FileRepository(final File gitDir) throws IOException {
- this(new FileRepositoryBuilder().setGitDir(gitDir).setup());
- }
-
- /**
- * A convenience API for {@link #FileRepository(File)}.
- *
- * @param gitDir
- * GIT_DIR (the location of the repository metadata).
- * @throws IOException
- * the repository appears to already exist but cannot be
- * accessed.
- * @see FileRepositoryBuilder
- */
- public FileRepository(final String gitDir) throws IOException {
- this(new File(gitDir));
- }
-
- /**
- * Create a repository using the local file system.
- *
- * @param options
- * description of the repository's important paths.
- * @throws IOException
- * the user configuration file or repository configuration file
- * cannot be accessed.
- */
- public FileRepository(final BaseRepositoryBuilder options) throws IOException {
- super(options);
-
- systemConfig = SystemReader.getInstance().openSystemConfig(null, getFS());
- userConfig = SystemReader.getInstance().openUserConfig(systemConfig,
- getFS());
- repoConfig = new FileBasedConfig(userConfig, getFS().resolve(
- getDirectory(), Constants.CONFIG),
- getFS());
-
- loadSystemConfig();
- loadUserConfig();
- loadRepoConfig();
-
- repoConfig.addChangeListener(new ConfigChangedListener() {
- public void onConfigChanged(ConfigChangedEvent event) {
- fireEvent(event);
- }
- });
-
- refs = new RefDirectory(this);
- objectDatabase = new ObjectDirectory(repoConfig, //
- options.getObjectDirectory(), //
- options.getAlternateObjectDirectories(), //
- getFS());
-
- if (objectDatabase.exists()) {
- final long repositoryFormatVersion = getConfig().getLong(
- ConfigConstants.CONFIG_CORE_SECTION, null,
- ConfigConstants.CONFIG_KEY_REPO_FORMAT_VERSION, 0);
- if (repositoryFormatVersion > 0)
- throw new IOException(MessageFormat.format(
- JGitText.get().unknownRepositoryFormat2,
- Long.valueOf(repositoryFormatVersion)));
- }
-
- if (!isBare())
- snapshot = FileSnapshot.save(getIndexFile());
- }
-
- private void loadSystemConfig() throws IOException {
- try {
- systemConfig.load();
- } catch (ConfigInvalidException e1) {
- IOException e2 = new IOException(MessageFormat.format(JGitText
- .get().systemConfigFileInvalid, systemConfig.getFile()
- .getAbsolutePath(), e1));
- e2.initCause(e1);
- throw e2;
- }
- }
-
- private void loadUserConfig() throws IOException {
- try {
- userConfig.load();
- } catch (ConfigInvalidException e1) {
- IOException e2 = new IOException(MessageFormat.format(JGitText
- .get().userConfigFileInvalid, userConfig.getFile()
- .getAbsolutePath(), e1));
- e2.initCause(e1);
- throw e2;
- }
- }
-
- private void loadRepoConfig() throws IOException {
- try {
- repoConfig.load();
- } catch (ConfigInvalidException e1) {
- IOException e2 = new IOException(JGitText.get().unknownRepositoryFormat);
- e2.initCause(e1);
- throw e2;
- }
- }
-
- /**
- * Create a new Git repository initializing the necessary files and
- * directories.
- *
- * @param bare
- * if true, a bare repository is created.
- *
- * @throws IOException
- * in case of IO problem
- */
- public void create(boolean bare) throws IOException {
- final FileBasedConfig cfg = getConfig();
- if (cfg.getFile().exists()) {
- throw new IllegalStateException(MessageFormat.format(
- JGitText.get().repositoryAlreadyExists, getDirectory()));
- }
- FileUtils.mkdirs(getDirectory(), true);
- refs.create();
- objectDatabase.create();
-
- FileUtils.mkdir(new File(getDirectory(), "branches"));
- FileUtils.mkdir(new File(getDirectory(), "hooks"));
-
- RefUpdate head = updateRef(Constants.HEAD);
- head.disableRefLog();
- head.link(Constants.R_HEADS + Constants.MASTER);
-
- final boolean fileMode;
- if (getFS().supportsExecute()) {
- File tmp = File.createTempFile("try", "execute", getDirectory());
-
- getFS().setExecute(tmp, true);
- final boolean on = getFS().canExecute(tmp);
-
- getFS().setExecute(tmp, false);
- final boolean off = getFS().canExecute(tmp);
- FileUtils.delete(tmp);
-
- fileMode = on && !off;
- } else {
- fileMode = false;
- }
-
- cfg.setInt(ConfigConstants.CONFIG_CORE_SECTION, null,
- ConfigConstants.CONFIG_KEY_REPO_FORMAT_VERSION, 0);
- cfg.setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null,
- ConfigConstants.CONFIG_KEY_FILEMODE, fileMode);
- if (bare)
- cfg.setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null,
- ConfigConstants.CONFIG_KEY_BARE, true);
- cfg.setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null,
- ConfigConstants.CONFIG_KEY_LOGALLREFUPDATES, !bare);
- cfg.save();
- }
-
- /**
- * @return the directory containing the objects owned by this repository.
- */
- public File getObjectsDirectory() {
- return objectDatabase.getDirectory();
- }
-
- /**
- * @return the object database which stores this repository's data.
- */
- public ObjectDirectory getObjectDatabase() {
- return objectDatabase;
- }
-
- /** @return the reference database which stores the reference namespace. */
- public RefDatabase getRefDatabase() {
- return refs;
- }
-
- /**
- * @return the configuration of this repository
- */
- public FileBasedConfig getConfig() {
- if (systemConfig.isOutdated()) {
- try {
- loadSystemConfig();
- } catch (IOException e) {
- throw new RuntimeException(e);
- }
- }
- if (userConfig.isOutdated()) {
- try {
- loadUserConfig();
- } catch (IOException e) {
- throw new RuntimeException(e);
- }
- }
- if (repoConfig.isOutdated()) {
- try {
- loadRepoConfig();
- } catch (IOException e) {
- throw new RuntimeException(e);
- }
- }
- return repoConfig;
- }
-
- /**
- * Objects known to exist but not expressed by {@link #getAllRefs()}.
- * <p>
- * When a repository borrows objects from another repository, it can
- * advertise that it safely has that other repository's references, without
- * exposing any other details about the other repository. This may help
- * a client trying to push changes avoid pushing more than it needs to.
- *
- * @return unmodifiable collection of other known objects.
- */
- public Set<ObjectId> getAdditionalHaves() {
- HashSet<ObjectId> r = new HashSet<ObjectId>();
- for (AlternateHandle d : objectDatabase. myAlternates()) {
- if (d instanceof AlternateRepository) {
- Repository repo;
-
- repo = ((AlternateRepository) d).repository;
- for (Ref ref : repo.getAllRefs().values()) {
- if (ref.getObjectId() != null)
- r.add(ref.getObjectId());
- if (ref.getPeeledObjectId() != null)
- r.add(ref.getPeeledObjectId());
- }
- r.addAll(repo.getAdditionalHaves());
- }
- }
- return r;
- }
-
- /**
- * Add a single existing pack to the list of available pack files.
- *
- * @param pack
- * path of the pack file to open.
- * @param idx
- * path of the corresponding index file.
- * @throws IOException
- * index file could not be opened, read, or is not recognized as
- * a Git pack file index.
- */
- public void openPack(final File pack, final File idx) throws IOException {
- objectDatabase.openPack(pack, idx);
- }
-
- @Override
- public void scanForRepoChanges() throws IOException {
- getAllRefs(); // This will look for changes to refs
- detectIndexChanges();
- }
-
- /**
- * Detect index changes.
- */
- private void detectIndexChanges() {
- if (isBare())
- return;
-
- File indexFile = getIndexFile();
- if (snapshot == null)
- snapshot = FileSnapshot.save(indexFile);
- else if (snapshot.isModified(indexFile))
- notifyIndexChanged();
- }
-
- @Override
- public void notifyIndexChanged() {
- snapshot = FileSnapshot.save(getIndexFile());
- fireEvent(new IndexChangedEvent());
- }
-
- /**
- * @param refName
- * @return a {@link ReflogReader} for the supplied refname, or null if the
- * named ref does not exist.
- * @throws IOException the ref could not be accessed.
- */
- public ReflogReader getReflogReader(String refName) throws IOException {
- Ref ref = getRef(refName);
- if (ref != null)
- return new ReflogReader(this, ref.getName());
- return null;
- }
- }
|