1 files changed, 291 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/change/RebaseChangeOp.java b/java/com/google/gerrit/server/change/RebaseChangeOp.java
new file mode 100644
index 0000000000..1f216f0a71
--- /dev/null
+++ b/java/com/google/gerrit/server/change/RebaseChangeOp.java
@@ -0,0 +1,291 @@
+// 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 static com.google.common.base.Preconditions.checkState;
+
+import com.google.gerrit.extensions.api.changes.NotifyHandling;
+import com.google.gerrit.extensions.restapi.MergeConflictException;
+import com.google.gerrit.extensions.restapi.ResourceConflictException;
+import com.google.gerrit.extensions.restapi.RestApiException;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.client.RevId;
+import com.google.gerrit.server.ChangeUtil;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.change.RebaseUtil.Base;
+import com.google.gerrit.server.git.MergeUtil;
+import com.google.gerrit.server.notedb.ChangeNotes;
+import com.google.gerrit.server.permissions.PermissionBackendException;
+import com.google.gerrit.server.project.InvalidChangeOperationException;
+import com.google.gerrit.server.project.NoSuchChangeException;
+import com.google.gerrit.server.project.ProjectCache;
+import com.google.gerrit.server.project.ProjectState;
+import com.google.gerrit.server.update.BatchUpdateOp;
+import com.google.gerrit.server.update.ChangeContext;
+import com.google.gerrit.server.update.Context;
+import com.google.gerrit.server.update.RepoContext;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.assistedinject.Assisted;
+import java.io.IOException;
+import org.eclipse.jgit.lib.CommitBuilder;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.merge.ThreeWayMerger;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+
+public class RebaseChangeOp implements BatchUpdateOp {
+  public interface Factory {
+    RebaseChangeOp create(ChangeNotes notes, PatchSet originalPatchSet, ObjectId baseCommitId);
+  }
+
+  private final PatchSetInserter.Factory patchSetInserterFactory;
+  private final MergeUtil.Factory mergeUtilFactory;
+  private final RebaseUtil rebaseUtil;
+  private final ChangeResource.Factory changeResourceFactory;
+
+  private final ChangeNotes notes;
+  private final PatchSet originalPatchSet;
+  private final IdentifiedUser.GenericFactory identifiedUserFactory;
+  private final ProjectCache projectCache;
+
+  private ObjectId baseCommitId;
+  private PersonIdent committerIdent;
+  private boolean fireRevisionCreated = true;
+  private boolean validate = true;
+  private boolean checkAddPatchSetPermission = true;
+  private boolean forceContentMerge;
+  private boolean copyApprovals = true;
+  private boolean detailedCommitMessage;
+  private boolean postMessage = true;
+  private boolean matchAuthorToCommitterDate = false;
+
+  private RevCommit rebasedCommit;
+  private PatchSet.Id rebasedPatchSetId;
+  private PatchSetInserter patchSetInserter;
+  private PatchSet rebasedPatchSet;
+
+  @Inject
+  RebaseChangeOp(
+      PatchSetInserter.Factory patchSetInserterFactory,
+      MergeUtil.Factory mergeUtilFactory,
+      RebaseUtil rebaseUtil,
+      ChangeResource.Factory changeResourceFactory,
+      IdentifiedUser.GenericFactory identifiedUserFactory,
+      ProjectCache projectCache,
+      @Assisted ChangeNotes notes,
+      @Assisted PatchSet originalPatchSet,
+      @Assisted ObjectId baseCommitId) {
+    this.patchSetInserterFactory = patchSetInserterFactory;
+    this.mergeUtilFactory = mergeUtilFactory;
+    this.rebaseUtil = rebaseUtil;
+    this.changeResourceFactory = changeResourceFactory;
+    this.identifiedUserFactory = identifiedUserFactory;
+    this.projectCache = projectCache;
+    this.notes = notes;
+    this.originalPatchSet = originalPatchSet;
+    this.baseCommitId = baseCommitId;
+  }
+
+  public RebaseChangeOp setCommitterIdent(PersonIdent committerIdent) {
+    this.committerIdent = committerIdent;
+    return this;
+  }
+
+  public RebaseChangeOp setValidate(boolean validate) {
+    this.validate = validate;
+    return this;
+  }
+
+  public RebaseChangeOp setCheckAddPatchSetPermission(boolean checkAddPatchSetPermission) {
+    this.checkAddPatchSetPermission = checkAddPatchSetPermission;
+    return this;
+  }
+
+  public RebaseChangeOp setFireRevisionCreated(boolean fireRevisionCreated) {
+    this.fireRevisionCreated = fireRevisionCreated;
+    return this;
+  }
+
+  public RebaseChangeOp setForceContentMerge(boolean forceContentMerge) {
+    this.forceContentMerge = forceContentMerge;
+    return this;
+  }
+
+  public RebaseChangeOp setCopyApprovals(boolean copyApprovals) {
+    this.copyApprovals = copyApprovals;
+    return this;
+  }
+
+  public RebaseChangeOp setDetailedCommitMessage(boolean detailedCommitMessage) {
+    this.detailedCommitMessage = detailedCommitMessage;
+    return this;
+  }
+
+  public RebaseChangeOp setPostMessage(boolean postMessage) {
+    this.postMessage = postMessage;
+    return this;
+  }
+
+  public RebaseChangeOp setMatchAuthorToCommitterDate(boolean matchAuthorToCommitterDate) {
+    this.matchAuthorToCommitterDate = matchAuthorToCommitterDate;
+    return this;
+  }
+
+  @Override
+  public void updateRepo(RepoContext ctx)
+      throws MergeConflictException, InvalidChangeOperationException, RestApiException, IOException,
+          OrmException, NoSuchChangeException, PermissionBackendException {
+    // Ok that originalPatchSet was not read in a transaction, since we just
+    // need its revision.
+    RevId oldRev = originalPatchSet.getRevision();
+
+    RevWalk rw = ctx.getRevWalk();
+    RevCommit original = rw.parseCommit(ObjectId.fromString(oldRev.get()));
+    rw.parseBody(original);
+    RevCommit baseCommit = rw.parseCommit(baseCommitId);
+    CurrentUser changeOwner = identifiedUserFactory.create(notes.getChange().getOwner());
+
+    String newCommitMessage;
+    if (detailedCommitMessage) {
+      rw.parseBody(baseCommit);
+      newCommitMessage =
+          newMergeUtil()
+              .createCommitMessageOnSubmit(original, baseCommit, notes, originalPatchSet.getId());
+    } else {
+      newCommitMessage = original.getFullMessage();
+    }
+
+    rebasedCommit = rebaseCommit(ctx, original, baseCommit, newCommitMessage);
+    Base base =
+        rebaseUtil.parseBase(
+            new RevisionResource(
+                changeResourceFactory.create(notes, changeOwner), originalPatchSet),
+            baseCommitId.name());
+
+    rebasedPatchSetId =
+        ChangeUtil.nextPatchSetIdFromChangeRefsMap(
+            ctx.getRepoView().getRefs(originalPatchSet.getId().getParentKey().toRefPrefix()),
+            notes.getChange().currentPatchSetId());
+    patchSetInserter =
+        patchSetInserterFactory
+            .create(notes, rebasedPatchSetId, rebasedCommit)
+            .setDescription("Rebase")
+            .setNotify(NotifyHandling.NONE)
+            .setFireRevisionCreated(fireRevisionCreated)
+            .setCopyApprovals(copyApprovals)
+            .setCheckAddPatchSetPermission(checkAddPatchSetPermission)
+            .setValidate(validate);
+    if (postMessage) {
+      patchSetInserter.setMessage(
+          "Patch Set "
+              + rebasedPatchSetId.get()
+              + ": Patch Set "
+              + originalPatchSet.getId().get()
+              + " was rebased");
+    }
+
+    if (base != null) {
+      patchSetInserter.setGroups(base.patchSet().getGroups());
+    }
+    patchSetInserter.updateRepo(ctx);
+  }
+
+  @Override
+  public boolean updateChange(ChangeContext ctx)
+      throws ResourceConflictException, OrmException, IOException {
+    boolean ret = patchSetInserter.updateChange(ctx);
+    rebasedPatchSet = patchSetInserter.getPatchSet();
+    return ret;
+  }
+
+  @Override
+  public void postUpdate(Context ctx) throws OrmException {
+    patchSetInserter.postUpdate(ctx);
+  }
+
+  public RevCommit getRebasedCommit() {
+    checkState(rebasedCommit != null, "getRebasedCommit() only valid after updateRepo");
+    return rebasedCommit;
+  }
+
+  public PatchSet.Id getPatchSetId() {
+    checkState(rebasedPatchSetId != null, "getPatchSetId() only valid after updateRepo");
+    return rebasedPatchSetId;
+  }
+
+  public PatchSet getPatchSet() {
+    checkState(rebasedPatchSet != null, "getPatchSet() only valid after executing update");
+    return rebasedPatchSet;
+  }
+
+  private MergeUtil newMergeUtil() throws IOException {
+    ProjectState project = projectCache.checkedGet(notes.getProjectName());
+    return forceContentMerge
+        ? mergeUtilFactory.create(project, true)
+        : mergeUtilFactory.create(project);
+  }
+
+  /**
+   * Rebase a commit.
+   *
+   * @param ctx repo context.
+   * @param original the commit to rebase.
+   * @param base base to rebase against.
+   * @return the rebased commit.
+   * @throws MergeConflictException the rebase failed due to a merge conflict.
+   * @throws IOException the merge failed for another reason.
+   */
+  private RevCommit rebaseCommit(
+      RepoContext ctx, RevCommit original, ObjectId base, String commitMessage)
+      throws ResourceConflictException, IOException {
+    RevCommit parentCommit = original.getParent(0);
+
+    if (base.equals(parentCommit)) {
+      throw new ResourceConflictException("Change is already up to date.");
+    }
+
+    ThreeWayMerger merger =
+        newMergeUtil().newThreeWayMerger(ctx.getInserter(), ctx.getRepoView().getConfig());
+    merger.setBase(parentCommit);
+    boolean success = merger.merge(original, base);
+
+    if (!success || merger.getResultTreeId() == null) {
+      throw new MergeConflictException(
+          "The change could not be rebased due to a conflict during merge.");
+    }
+
+    CommitBuilder cb = new CommitBuilder();
+    cb.setTreeId(merger.getResultTreeId());
+    cb.setParentId(base);
+    cb.setAuthor(original.getAuthorIdent());
+    cb.setMessage(commitMessage);
+    if (committerIdent != null) {
+      cb.setCommitter(committerIdent);
+    } else {
+      cb.setCommitter(ctx.getIdentifiedUser().newCommitterIdent(ctx.getWhen(), ctx.getTimeZone()));
+    }
+    if (matchAuthorToCommitterDate) {
+      cb.setAuthor(
+          new PersonIdent(
+              cb.getAuthor(), cb.getCommitter().getWhen(), cb.getCommitter().getTimeZone()));
+    }
+    ObjectId objectId = ctx.getInserter().insert(cb);
+    ctx.getInserter().flush();
+    return ctx.getRevWalk().parseCommit(objectId);
+  }
+}