// Copyright (C) 2015 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.change;
import com.google.auto.value.AutoValue;
import com.google.common.primitives.Ints;
import com.google.gerrit.extensions.restapi.ResourceConflictException;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.extensions.restapi.UnprocessableEntityException;
import com.google.gerrit.reviewdb.client.Branch;
import com.google.gerrit.reviewdb.client.Change;
import com.google.gerrit.reviewdb.client.Change.Status;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gerrit.reviewdb.client.RevId;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.PatchSetUtil;
import com.google.gerrit.server.notedb.ChangeNotes;
import com.google.gerrit.server.project.ChangeControl;
import com.google.gerrit.server.query.change.ChangeData;
import com.google.gerrit.server.query.change.InternalChangeQuery;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import java.io.IOException;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/** Utility methods related to rebasing changes. */
public class RebaseUtil {
private static final Logger log = LoggerFactory.getLogger(RebaseUtil.class);
private final Provider<InternalChangeQuery> queryProvider;
private final ChangeNotes.Factory notesFactory;
private final Provider<ReviewDb> dbProvider;
private final PatchSetUtil psUtil;
@Inject
RebaseUtil(
Provider<InternalChangeQuery> queryProvider,
ChangeNotes.Factory notesFactory,
Provider<ReviewDb> dbProvider,
PatchSetUtil psUtil) {
this.queryProvider = queryProvider;
this.notesFactory = notesFactory;
this.dbProvider = dbProvider;
this.psUtil = psUtil;
}
public boolean canRebase(PatchSet patchSet, Branch.NameKey dest, Repository git, RevWalk rw) {
try {
findBaseRevision(patchSet, dest, git, rw);
return true;
} catch (RestApiException e) {
return false;
} catch (OrmException | IOException e) {
log.warn(
String.format(
"Error checking if patch set %s on %s can be rebased", patchSet.getId(), dest),
e);
return false;
}
}
@AutoValue
abstract static class Base {
private static Base create(ChangeControl ctl, PatchSet ps) {
if (ctl == null) {
return null;
}
return new AutoValue_RebaseUtil_Base(ctl, ps);
}
abstract ChangeControl control();
abstract PatchSet patchSet();
}
Base parseBase(RevisionResource rsrc, String base) throws OrmException {
ReviewDb db = dbProvider.get();
// Try parsing the base as a ref string.
PatchSet.Id basePatchSetId = PatchSet.Id.fromRef(base);
if (basePatchSetId != null) {
Change.Id baseChangeId = basePatchSetId.getParentKey();
ChangeControl baseCtl = controlFor(rsrc, baseChangeId);
if (baseCtl != null) {
return Base.create(
controlFor(rsrc, basePatchSetId.getParentKey()),
psUtil.get(db, baseCtl.getNotes(), basePatchSetId));
}
}
// Try parsing base as a change number (assume current patch set).
Integer baseChangeId = Ints.tryParse(base);
if (baseChangeId != null) {
ChangeControl baseCtl = controlFor(rsrc, new Change.Id(baseChangeId));
if (baseCtl != null) {
return Base.create(baseCtl, psUtil.current(db, baseCtl.getNotes()));
}
}
// Try parsing as SHA-1.
Base ret = null;
for (ChangeData cd : queryProvider.get().byProjectCommit(rsrc.getProject(), base)) {
for (PatchSet ps : cd.patchSets()) {
if (!ps.getRevision().matches(base)) {
continue;
}
if (ret == null || ret.patchSet().getId().get() < ps.getId().get()) {
ret = Base.create(rsrc.getControl().getProjectControl().controlFor(cd.notes()), ps);
}
}
}
return ret;
}
private ChangeControl controlFor(RevisionResource rsrc, Change.Id id) throws OrmException {
if (rsrc.getChange().getId().equals(id)) {
return rsrc.getControl();
}
ChangeNotes notes = notesFactory.createChecked(dbProvider.get(), rsrc.getProject(), id);
return rsrc.getControl().getProjectControl().controlFor(notes);
}
/**
* Find the commit onto which a patch set should be rebased.
*
* <p>This is defined as the latest patch set of the change corresponding to this commit's parent,
* or the destination branch tip in the case where the parent's change is merged.
*
* @param patchSet patch set for which the new base commit should be found.
* @param destBranch the destination branch.
* @param git the repository.
* @param rw the RevWalk.
* @return the commit onto which the patch set should be rebased.
* @throws RestApiException if rebase is not possible.
* @throws IOException if accessing the repository fails.
* @throws OrmException if accessing the database fails.
*/
ObjectId findBaseRevision(
PatchSet patchSet, Branch.NameKey destBranch, Repository git, RevWalk rw)
throws RestApiException, IOException, OrmException {
String baseRev = null;
RevCommit commit = rw.parseCommit(ObjectId.fromString(patchSet.getRevision().get()));
if (commit.getParentCount() > 1) {
throw new UnprocessableEntityException("Cannot rebase a change with multiple parents.");
} else if (commit.getParentCount() == 0) {
throw new UnprocessableEntityException(
"Cannot rebase a change without any parents (is this the initial commit?).");
}
RevId parentRev = new RevId(commit.getParent(0).name());
CHANGES:
for (ChangeData cd : queryProvider.get().byBranchCommit(destBranch, parentRev.get())) {
for (PatchSet depPatchSet : cd.patchSets()) {
if (!depPatchSet.getRevision().equals(parentRev)) {
continue;
}
Change depChange = cd.change();
if (depChange.getStatus() == Status.ABANDONED) {
throw new ResourceConflictException(
"Cannot rebase a change with an abandoned parent: " + depChange.getKey());
}
if (depChange.getStatus().isOpen()) {
if (depPatchSet.getId().equals(depChange.currentPatchSetId())) {
throw new ResourceConflictException(
"Change is already based on the latest patch set of the dependent change.");
}
baseRev = cd.currentPatchSet().getRevision().get();
}
break CHANGES;
}
}
if (baseRev == null) {
// We are dependent on a merged PatchSet or have no PatchSet
// dependencies at all.
Ref destRef = git.getRefDatabase().exactRef(destBranch.get());
if (destRef == null) {
throw new UnprocessableEntityException(
"The destination branch does not exist: " + destBranch.get());
}
baseRev = destRef.getObjectId().getName();
if (baseRev.equals(parentRev.get())) {
throw new ResourceConflictException("Change is already up to date.");
}
}
return ObjectId.fromString(baseRev);
}
}