| // Copyright (C) 2010 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.gerrit.server.git.meta; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| |
| import com.google.common.base.MoreObjects; |
| import com.google.common.flogger.FluentLogger; |
| import com.google.gerrit.common.Nullable; |
| import com.google.gerrit.reviewdb.client.Project; |
| import com.google.gerrit.server.git.LockFailureException; |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.StringReader; |
| import java.util.ArrayList; |
| import java.util.List; |
| import java.util.Objects; |
| import org.eclipse.jgit.dircache.DirCache; |
| import org.eclipse.jgit.dircache.DirCacheBuilder; |
| import org.eclipse.jgit.dircache.DirCacheEditor; |
| import org.eclipse.jgit.dircache.DirCacheEditor.DeletePath; |
| import org.eclipse.jgit.dircache.DirCacheEditor.PathEdit; |
| import org.eclipse.jgit.dircache.DirCacheEntry; |
| import org.eclipse.jgit.errors.ConfigInvalidException; |
| import org.eclipse.jgit.errors.IncorrectObjectTypeException; |
| import org.eclipse.jgit.errors.MissingObjectException; |
| import org.eclipse.jgit.lib.AnyObjectId; |
| import org.eclipse.jgit.lib.BatchRefUpdate; |
| import org.eclipse.jgit.lib.CommitBuilder; |
| import org.eclipse.jgit.lib.Config; |
| import org.eclipse.jgit.lib.Constants; |
| import org.eclipse.jgit.lib.FileMode; |
| import org.eclipse.jgit.lib.ObjectId; |
| import org.eclipse.jgit.lib.ObjectInserter; |
| import org.eclipse.jgit.lib.ObjectLoader; |
| import org.eclipse.jgit.lib.ObjectReader; |
| import org.eclipse.jgit.lib.Ref; |
| import org.eclipse.jgit.lib.RefUpdate; |
| import org.eclipse.jgit.lib.Repository; |
| import org.eclipse.jgit.revwalk.RevCommit; |
| import org.eclipse.jgit.revwalk.RevTree; |
| import org.eclipse.jgit.revwalk.RevWalk; |
| import org.eclipse.jgit.transport.ReceiveCommand; |
| import org.eclipse.jgit.treewalk.TreeWalk; |
| import org.eclipse.jgit.util.ChangeIdUtil; |
| import org.eclipse.jgit.util.RawParseUtils; |
| |
| /** |
| * Support for metadata stored within a version controlled branch. |
| * |
| * <p>Implementors are responsible for supplying implementations of the onLoad and onSave methods to |
| * read from the repository, or format an update that can later be written back to the repository. |
| */ |
| public abstract class VersionedMetaData { |
| private static final FluentLogger logger = FluentLogger.forEnclosingClass(); |
| |
| /** |
| * Path information that does not hold references to any repository data structures, allowing the |
| * application to retain this object for long periods of time. |
| */ |
| public static class PathInfo { |
| public final FileMode fileMode; |
| public final String path; |
| public final ObjectId objectId; |
| |
| protected PathInfo(TreeWalk tw) { |
| fileMode = tw.getFileMode(0); |
| path = tw.getPathString(); |
| objectId = tw.getObjectId(0); |
| } |
| } |
| |
| /** The revision at which the data was loaded. Is null for data yet to be created. */ |
| @Nullable protected RevCommit revision; |
| |
| protected Project.NameKey projectName; |
| protected RevWalk rw; |
| protected ObjectReader reader; |
| protected ObjectInserter inserter; |
| protected DirCache newTree; |
| |
| /** @return name of the reference storing this configuration. */ |
| protected abstract String getRefName(); |
| |
| /** Set up the metadata, parsing any state from the loaded revision. */ |
| protected abstract void onLoad() throws IOException, ConfigInvalidException; |
| |
| /** |
| * Save any changes to the metadata in a commit. |
| * |
| * @return true if the commit should proceed, false to abort. |
| * @throws IOException |
| * @throws ConfigInvalidException |
| */ |
| protected abstract boolean onSave(CommitBuilder commit) |
| throws IOException, ConfigInvalidException; |
| |
| /** @return revision of the metadata that was loaded. */ |
| @Nullable |
| public ObjectId getRevision() { |
| return revision != null ? revision.copy() : null; |
| } |
| |
| /** |
| * Load the current version from the branch. |
| * |
| * <p>The repository is not held after the call completes, allowing the application to retain this |
| * object for long periods of time. |
| * |
| * @param projectName the name of the project |
| * @param db repository to access. |
| * @throws IOException |
| * @throws ConfigInvalidException |
| */ |
| public void load(Project.NameKey projectName, Repository db) |
| throws IOException, ConfigInvalidException { |
| Ref ref = db.getRefDatabase().exactRef(getRefName()); |
| load(projectName, db, ref != null ? ref.getObjectId() : null); |
| } |
| |
| /** |
| * Load a specific version from the repository. |
| * |
| * <p>This method is primarily useful for applying updates to a specific revision that was shown |
| * to an end-user in the user interface. If there are conflicts with another user's concurrent |
| * changes, these will be automatically detected at commit time. |
| * |
| * <p>The repository is not held after the call completes, allowing the application to retain this |
| * object for long periods of time. |
| * |
| * @param projectName the name of the project |
| * @param db repository to access. |
| * @param id revision to load. |
| * @throws IOException |
| * @throws ConfigInvalidException |
| */ |
| public void load(Project.NameKey projectName, Repository db, @Nullable ObjectId id) |
| throws IOException, ConfigInvalidException { |
| try (RevWalk walk = new RevWalk(db)) { |
| load(projectName, walk, id); |
| } |
| } |
| |
| /** |
| * Load a specific version from an open walk. |
| * |
| * <p>This method is primarily useful for applying updates to a specific revision that was shown |
| * to an end-user in the user interface. If there are conflicts with another user's concurrent |
| * changes, these will be automatically detected at commit time. |
| * |
| * <p>The caller retains ownership of the walk and is responsible for closing it. However, this |
| * instance does not hold a reference to the walk or the repository after the call completes, |
| * allowing the application to retain this object for long periods of time. |
| * |
| * @param projectName the name of the project |
| * @param walk open walk to access to access. |
| * @param id revision to load. |
| * @throws IOException |
| * @throws ConfigInvalidException |
| */ |
| public void load(Project.NameKey projectName, RevWalk walk, ObjectId id) |
| throws IOException, ConfigInvalidException { |
| this.projectName = projectName; |
| this.rw = walk; |
| this.reader = walk.getObjectReader(); |
| try { |
| revision = id != null ? walk.parseCommit(id) : null; |
| onLoad(); |
| } finally { |
| this.rw = null; |
| this.reader = null; |
| } |
| } |
| |
| public void load(MetaDataUpdate update) throws IOException, ConfigInvalidException { |
| load(update.getProjectName(), update.getRepository()); |
| } |
| |
| public void load(MetaDataUpdate update, ObjectId id) throws IOException, ConfigInvalidException { |
| load(update.getProjectName(), update.getRepository(), id); |
| } |
| |
| /** |
| * Update this metadata branch, recording a new commit on its reference. This method mutates its |
| * receiver. |
| * |
| * @param update helper information to define the update that will occur. |
| * @return the commit that was created |
| * @throws IOException if there is a storage problem and the update cannot be executed as |
| * requested or if it failed because of a concurrent update to the same reference |
| */ |
| public RevCommit commit(MetaDataUpdate update) throws IOException { |
| try (BatchMetaDataUpdate batch = openUpdate(update)) { |
| batch.write(update.getCommitBuilder()); |
| return batch.commit(); |
| } |
| } |
| |
| /** |
| * Creates a new commit and a new ref based on this commit. This method mutates its receiver. |
| * |
| * @param update helper information to define the update that will occur. |
| * @param refName name of the ref that should be created |
| * @return the commit that was created |
| * @throws IOException if there is a storage problem and the update cannot be executed as |
| * requested or if it failed because of a concurrent update to the same reference |
| */ |
| public RevCommit commitToNewRef(MetaDataUpdate update, String refName) throws IOException { |
| try (BatchMetaDataUpdate batch = openUpdate(update)) { |
| batch.write(update.getCommitBuilder()); |
| return batch.createRef(refName); |
| } |
| } |
| |
| public interface BatchMetaDataUpdate extends AutoCloseable { |
| void write(CommitBuilder commit) throws IOException; |
| |
| void write(VersionedMetaData config, CommitBuilder commit) throws IOException; |
| |
| RevCommit createRef(String refName) throws IOException; |
| |
| RevCommit commit() throws IOException; |
| |
| RevCommit commitAt(ObjectId revision) throws IOException; |
| |
| @Override |
| void close(); |
| } |
| |
| /** |
| * Open a batch of updates to the same metadata ref. |
| * |
| * <p>This allows making multiple commits to a single metadata ref, at the end of which is a |
| * single ref update. For batching together updates to multiple refs (each consisting of one or |
| * more commits against their respective refs), create the {@link MetaDataUpdate} with a {@link |
| * BatchRefUpdate}. |
| * |
| * <p>A ref update produced by this {@link BatchMetaDataUpdate} is only committed if there is no |
| * associated {@link BatchRefUpdate}. As a result, the configured ref updated event is not fired |
| * if there is an associated batch. |
| * |
| * @param update helper info about the update. |
| * @throws IOException if the update failed. |
| */ |
| public BatchMetaDataUpdate openUpdate(MetaDataUpdate update) throws IOException { |
| final Repository db = update.getRepository(); |
| |
| inserter = db.newObjectInserter(); |
| reader = inserter.newReader(); |
| final RevWalk rw = new RevWalk(reader); |
| final RevTree tree = revision != null ? rw.parseTree(revision) : null; |
| newTree = readTree(tree); |
| return new BatchMetaDataUpdate() { |
| RevCommit src = revision; |
| AnyObjectId srcTree = tree; |
| |
| @Override |
| public void write(CommitBuilder commit) throws IOException { |
| write(VersionedMetaData.this, commit); |
| } |
| |
| private boolean doSave(VersionedMetaData config, CommitBuilder commit) throws IOException { |
| DirCache nt = config.newTree; |
| ObjectReader r = config.reader; |
| ObjectInserter i = config.inserter; |
| RevCommit c = config.revision; |
| try { |
| config.newTree = newTree; |
| config.reader = reader; |
| config.inserter = inserter; |
| config.revision = src; |
| return config.onSave(commit); |
| } catch (ConfigInvalidException e) { |
| throw new IOException( |
| "Cannot update " + getRefName() + " in " + db.getDirectory() + ": " + e.getMessage(), |
| e); |
| } finally { |
| config.newTree = nt; |
| config.reader = r; |
| config.inserter = i; |
| config.revision = c; |
| } |
| } |
| |
| @Override |
| public void write(VersionedMetaData config, CommitBuilder commit) throws IOException { |
| checkSameRef(config); |
| if (!doSave(config, commit)) { |
| return; |
| } |
| |
| ObjectId res = newTree.writeTree(inserter); |
| if (res.equals(srcTree) && !update.allowEmpty() && (commit.getTreeId() == null)) { |
| // If there are no changes to the content, don't create the commit. |
| return; |
| } |
| |
| // If changes are made to the DirCache and those changes are written as |
| // a commit and then the tree ID is set for the CommitBuilder, then |
| // those previous DirCache changes will be ignored and the commit's |
| // tree will be replaced with the ID in the CommitBuilder. The same is |
| // true if you explicitly set tree ID in a commit and then make changes |
| // to the DirCache; that tree ID will be ignored and replaced by that of |
| // the tree for the updated DirCache. |
| if (commit.getTreeId() == null) { |
| commit.setTreeId(res); |
| } else { |
| // In this case, the caller populated the tree without using DirCache. |
| res = commit.getTreeId(); |
| } |
| |
| if (src != null) { |
| commit.addParentId(src); |
| } |
| |
| if (update.insertChangeId()) { |
| ObjectId id = |
| ChangeIdUtil.computeChangeId( |
| res, |
| getRevision(), |
| commit.getAuthor(), |
| commit.getCommitter(), |
| commit.getMessage()); |
| commit.setMessage(ChangeIdUtil.insertId(commit.getMessage(), id)); |
| } |
| |
| src = rw.parseCommit(inserter.insert(commit)); |
| srcTree = res; |
| } |
| |
| private void checkSameRef(VersionedMetaData other) { |
| String thisRef = VersionedMetaData.this.getRefName(); |
| String otherRef = other.getRefName(); |
| checkArgument( |
| otherRef.equals(thisRef), |
| "cannot add %s for %s to %s on %s", |
| other.getClass().getSimpleName(), |
| otherRef, |
| BatchMetaDataUpdate.class.getSimpleName(), |
| thisRef); |
| } |
| |
| @Override |
| public RevCommit createRef(String refName) throws IOException { |
| if (Objects.equals(src, revision)) { |
| return revision; |
| } |
| return updateRef(ObjectId.zeroId(), src, refName); |
| } |
| |
| @Override |
| public RevCommit commit() throws IOException { |
| return commitAt(revision); |
| } |
| |
| @Override |
| public RevCommit commitAt(ObjectId expected) throws IOException { |
| if (Objects.equals(src, expected)) { |
| return revision; |
| } |
| return updateRef(MoreObjects.firstNonNull(expected, ObjectId.zeroId()), src, getRefName()); |
| } |
| |
| @Override |
| public void close() { |
| newTree = null; |
| |
| rw.close(); |
| if (inserter != null) { |
| inserter.close(); |
| inserter = null; |
| } |
| |
| if (reader != null) { |
| reader.close(); |
| reader = null; |
| } |
| } |
| |
| private RevCommit updateRef(AnyObjectId oldId, AnyObjectId newId, String refName) |
| throws IOException { |
| BatchRefUpdate bru = update.getBatch(); |
| if (bru != null) { |
| bru.addCommand(new ReceiveCommand(oldId.toObjectId(), newId.toObjectId(), refName)); |
| inserter.flush(); |
| revision = rw.parseCommit(newId); |
| return revision; |
| } |
| |
| RefUpdate ru = db.updateRef(refName); |
| ru.setExpectedOldObjectId(oldId); |
| ru.setNewObjectId(newId); |
| ru.setRefLogIdent(update.getCommitBuilder().getAuthor()); |
| String message = update.getCommitBuilder().getMessage(); |
| if (message == null) { |
| message = "meta data update"; |
| } |
| try (BufferedReader reader = new BufferedReader(new StringReader(message))) { |
| // read the subject line and use it as reflog message |
| ru.setRefLogMessage("commit: " + reader.readLine(), true); |
| } |
| inserter.flush(); |
| RefUpdate.Result result = ru.update(); |
| switch (result) { |
| case NEW: |
| case FAST_FORWARD: |
| revision = rw.parseCommit(ru.getNewObjectId()); |
| update.fireGitRefUpdatedEvent(ru); |
| return revision; |
| case LOCK_FAILURE: |
| throw new LockFailureException( |
| "Cannot update " |
| + ru.getName() |
| + " in " |
| + db.getDirectory() |
| + ": " |
| + ru.getResult(), |
| ru); |
| case FORCED: |
| case IO_FAILURE: |
| case NOT_ATTEMPTED: |
| case NO_CHANGE: |
| case REJECTED: |
| case REJECTED_CURRENT_BRANCH: |
| case RENAMED: |
| case REJECTED_MISSING_OBJECT: |
| case REJECTED_OTHER_REASON: |
| default: |
| throw new IOException( |
| "Cannot update " |
| + ru.getName() |
| + " in " |
| + db.getDirectory() |
| + ": " |
| + ru.getResult()); |
| } |
| } |
| }; |
| } |
| |
| protected DirCache readTree(RevTree tree) |
| throws IOException, MissingObjectException, IncorrectObjectTypeException { |
| DirCache dc = DirCache.newInCore(); |
| if (tree != null) { |
| DirCacheBuilder b = dc.builder(); |
| b.addTree(new byte[0], DirCacheEntry.STAGE_0, reader, tree); |
| b.finish(); |
| } |
| return dc; |
| } |
| |
| protected Config readConfig(String fileName) throws IOException, ConfigInvalidException { |
| Config rc = new Config(); |
| String text = readUTF8(fileName); |
| if (!text.isEmpty()) { |
| try { |
| rc.fromText(text); |
| } catch (ConfigInvalidException err) { |
| StringBuilder msg = |
| new StringBuilder("Invalid config file ") |
| .append(fileName) |
| .append(" in commit ") |
| .append(revision.name()); |
| if (err.getCause() != null) { |
| msg.append(": ").append(err.getCause()); |
| } |
| throw new ConfigInvalidException(msg.toString(), err); |
| } |
| } |
| return rc; |
| } |
| |
| protected String readUTF8(String fileName) throws IOException { |
| byte[] raw = readFile(fileName); |
| return raw.length != 0 ? RawParseUtils.decode(raw) : ""; |
| } |
| |
| protected byte[] readFile(String fileName) throws IOException { |
| if (revision == null) { |
| return new byte[] {}; |
| } |
| |
| logger.atFine().log( |
| "Read file '%s' from ref '%s' of project '%s' from revision '%s'", |
| fileName, getRefName(), projectName, revision.name()); |
| try (TreeWalk tw = TreeWalk.forPath(reader, fileName, revision.getTree())) { |
| if (tw != null) { |
| ObjectLoader obj = reader.open(tw.getObjectId(0), Constants.OBJ_BLOB); |
| return obj.getCachedBytes(Integer.MAX_VALUE); |
| } |
| } |
| return new byte[] {}; |
| } |
| |
| @Nullable |
| protected ObjectId getObjectId(String fileName) throws IOException { |
| if (revision == null) { |
| return null; |
| } |
| |
| try (TreeWalk tw = TreeWalk.forPath(reader, fileName, revision.getTree())) { |
| if (tw != null) { |
| return tw.getObjectId(0); |
| } |
| } |
| |
| return null; |
| } |
| |
| public List<PathInfo> getPathInfos(boolean recursive) throws IOException { |
| try (TreeWalk tw = new TreeWalk(reader)) { |
| tw.addTree(revision.getTree()); |
| tw.setRecursive(recursive); |
| List<PathInfo> paths = new ArrayList<>(); |
| while (tw.next()) { |
| paths.add(new PathInfo(tw)); |
| } |
| return paths; |
| } |
| } |
| |
| protected static void set( |
| Config rc, String section, String subsection, String name, String value) { |
| if (value != null) { |
| rc.setString(section, subsection, name, value); |
| } else { |
| rc.unset(section, subsection, name); |
| } |
| } |
| |
| protected static void set( |
| Config rc, String section, String subsection, String name, boolean value) { |
| if (value) { |
| rc.setBoolean(section, subsection, name, value); |
| } else { |
| rc.unset(section, subsection, name); |
| } |
| } |
| |
| protected static <E extends Enum<?>> void set( |
| Config rc, String section, String subsection, String name, E value, E defaultValue) { |
| if (value != defaultValue) { |
| rc.setEnum(section, subsection, name, value); |
| } else { |
| rc.unset(section, subsection, name); |
| } |
| } |
| |
| protected void saveConfig(String fileName, Config cfg) throws IOException { |
| saveUTF8(fileName, cfg.toText()); |
| } |
| |
| protected void saveUTF8(String fileName, String text) throws IOException { |
| saveFile(fileName, text != null ? Constants.encode(text) : null); |
| } |
| |
| protected void saveFile(String fileName, byte[] raw) throws IOException { |
| logger.atFine().log( |
| "Save file '%s' in ref '%s' of project '%s'", fileName, getRefName(), projectName); |
| DirCacheEditor editor = newTree.editor(); |
| if (raw != null && 0 < raw.length) { |
| final ObjectId blobId = inserter.insert(Constants.OBJ_BLOB, raw); |
| editor.add( |
| new PathEdit(fileName) { |
| @Override |
| public void apply(DirCacheEntry ent) { |
| ent.setFileMode(FileMode.REGULAR_FILE); |
| ent.setObjectId(blobId); |
| } |
| }); |
| } else { |
| editor.add(new DeletePath(fileName)); |
| } |
| editor.finish(); |
| } |
| } |
