Java tutorial
// Copyright (C) 2012 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.strategy; import com.google.common.collect.Lists; import com.google.gerrit.common.TimeUtil; import com.google.gerrit.reviewdb.client.Change; import com.google.gerrit.reviewdb.client.PatchSet; import com.google.gerrit.reviewdb.client.PatchSetAncestor; import com.google.gerrit.reviewdb.client.PatchSetApproval; import com.google.gerrit.reviewdb.client.RevId; import com.google.gerrit.reviewdb.server.ReviewDb; import com.google.gerrit.server.ChangeUtil; import com.google.gerrit.server.extensions.events.GitReferenceUpdated; import com.google.gerrit.server.git.CodeReviewCommit; import com.google.gerrit.server.git.CommitMergeStatus; import com.google.gerrit.server.git.GroupCollector; import com.google.gerrit.server.git.MergeConflictException; import com.google.gerrit.server.git.MergeException; import com.google.gerrit.server.git.MergeIdenticalTreeException; import com.google.gerrit.server.git.MergeTip; import com.google.gerrit.server.patch.PatchSetInfoFactory; import com.google.gerrit.server.project.NoSuchChangeException; import com.google.gwtorm.server.OrmException; import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.lib.PersonIdent; import org.eclipse.jgit.lib.RefUpdate; import org.eclipse.jgit.revwalk.RevCommit; import java.io.IOException; import java.util.ArrayList; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; public class CherryPick extends SubmitStrategy { private final PatchSetInfoFactory patchSetInfoFactory; private final GitReferenceUpdated gitRefUpdated; private final Map<Change.Id, CodeReviewCommit> newCommits; CherryPick(SubmitStrategy.Arguments args, PatchSetInfoFactory patchSetInfoFactory, GitReferenceUpdated gitRefUpdated) { super(args); this.patchSetInfoFactory = patchSetInfoFactory; this.gitRefUpdated = gitRefUpdated; this.newCommits = new HashMap<>(); } @Override protected MergeTip _run(CodeReviewCommit branchTip, Collection<CodeReviewCommit> toMerge) throws MergeException { MergeTip mergeTip = new MergeTip(branchTip, toMerge); List<CodeReviewCommit> sorted = CodeReviewCommit.ORDER.sortedCopy(toMerge); while (!sorted.isEmpty()) { CodeReviewCommit n = sorted.remove(0); try { if (mergeTip.getCurrentTip() == null) { cherryPickUnbornRoot(n, mergeTip); } else if (n.getParentCount() == 0) { cherryPickRootOntoBranch(n); } else if (n.getParentCount() == 1) { cherryPickOne(n, mergeTip); } else { cherryPickMultipleParents(n, mergeTip); } } catch (NoSuchChangeException | IOException | OrmException e) { throw new MergeException("Cannot merge " + n.name(), e); } } return mergeTip; } private void cherryPickUnbornRoot(CodeReviewCommit n, MergeTip mergeTip) { // The branch is unborn. Take fast-forward resolution to create the branch. mergeTip.moveTipTo(n, n); n.setStatusCode(CommitMergeStatus.CLEAN_MERGE); } private void cherryPickRootOntoBranch(CodeReviewCommit n) { // Refuse to merge a root commit into an existing branch, we cannot obtain a // delta for the cherry-pick to apply. n.setStatusCode(CommitMergeStatus.CANNOT_CHERRY_PICK_ROOT); } private void cherryPickOne(CodeReviewCommit n, MergeTip mergeTip) throws NoSuchChangeException, OrmException, IOException { // If there is only one parent, a cherry-pick can be done by taking the // delta relative to that one parent and redoing that on the current merge // tip. // // Keep going in the case of a single merge failure; the goal is to // cherry-pick as many commits as possible. try { CodeReviewCommit merge = writeCherryPickCommit(mergeTip.getCurrentTip(), n); mergeTip.moveTipTo(merge, merge); newCommits.put(mergeTip.getCurrentTip().getPatchsetId().getParentKey(), mergeTip.getCurrentTip()); } catch (MergeConflictException mce) { n.setStatusCode(CommitMergeStatus.PATH_CONFLICT); } catch (MergeIdenticalTreeException mie) { n.setStatusCode(CommitMergeStatus.ALREADY_MERGED); } } private void cherryPickMultipleParents(CodeReviewCommit n, MergeTip mergeTip) throws IOException, MergeException { // There are multiple parents, so this is a merge commit. We don't want // to cherry-pick the merge as clients can't easily rebase their history // with that merge present and replaced by an equivalent merge with a // different first parent. So instead behave as though MERGE_IF_NECESSARY // was configured. if (!args.mergeUtil.hasMissingDependencies(args.mergeSorter, n)) { if (args.rw.isMergedInto(mergeTip.getCurrentTip(), n)) { mergeTip.moveTipTo(n, n); } else { PersonIdent myIdent = args.serverIdent.get(); CodeReviewCommit result = args.mergeUtil.mergeOneCommit(myIdent, myIdent, args.repo, args.rw, args.inserter, args.canMergeFlag, args.destBranch, mergeTip.getCurrentTip(), n); mergeTip.moveTipTo(result, n); } args.mergeUtil.markCleanMerges(args.rw, args.canMergeFlag, mergeTip.getCurrentTip(), args.alreadyAccepted); setRefLogIdent(); } else { // One or more dependencies were not met. The status was already marked on // the commit so we have nothing further to perform at this time. } } private CodeReviewCommit writeCherryPickCommit(CodeReviewCommit mergeTip, CodeReviewCommit n) throws IOException, OrmException, NoSuchChangeException, MergeConflictException, MergeIdenticalTreeException { args.rw.parseBody(n); String cherryPickCmtMsg = args.mergeUtil.createCherryPickCommitMessage(n); PersonIdent committer = args.caller.newCommitterIdent(TimeUtil.nowTs(), args.serverIdent.get().getTimeZone()); CodeReviewCommit newCommit = args.mergeUtil.createCherryPickFromCommit(args.repo, args.inserter, mergeTip, n, committer, cherryPickCmtMsg, args.rw); PatchSet.Id id = ChangeUtil.nextPatchSetId(args.repo, n.change().currentPatchSetId()); PatchSet ps = new PatchSet(id); ps.setCreatedOn(TimeUtil.nowTs()); ps.setUploader(args.caller.getAccountId()); ps.setRevision(new RevId(newCommit.getId().getName())); RefUpdate ru; args.db.changes().beginTransaction(n.change().getId()); try { insertAncestors(args.db, ps.getId(), newCommit); ps.setGroups(GroupCollector.getCurrentGroups(args.db, n.change())); args.db.patchSets().insert(Collections.singleton(ps)); n.change().setCurrentPatchSet(patchSetInfoFactory.get(newCommit, ps.getId())); args.db.changes().update(Collections.singletonList(n.change())); List<PatchSetApproval> approvals = Lists.newArrayList(); for (PatchSetApproval a : args.approvalsUtil.byPatchSet(args.db, n.getControl(), n.getPatchsetId())) { approvals.add(new PatchSetApproval(ps.getId(), a)); } args.db.patchSetApprovals().insert(approvals); ru = args.repo.updateRef(ps.getRefName()); ru.setExpectedOldObjectId(ObjectId.zeroId()); ru.setNewObjectId(newCommit); ru.disableRefLog(); if (ru.update(args.rw) != RefUpdate.Result.NEW) { throw new IOException(String.format("Failed to create ref %s in %s: %s", ps.getRefName(), n.change().getDest().getParentKey().get(), ru.getResult())); } args.db.commit(); } finally { args.db.rollback(); } gitRefUpdated.fire(n.change().getProject(), ru); newCommit.copyFrom(n); newCommit.setStatusCode(CommitMergeStatus.CLEAN_PICK); newCommit.setControl(args.changeControlFactory.controlFor(n.change(), args.caller)); newCommits.put(newCommit.getPatchsetId().getParentKey(), newCommit); setRefLogIdent(); return newCommit; } private static void insertAncestors(ReviewDb db, PatchSet.Id id, RevCommit src) throws OrmException { int cnt = src.getParentCount(); List<PatchSetAncestor> toInsert = new ArrayList<>(cnt); for (int p = 0; p < cnt; p++) { PatchSetAncestor a; a = new PatchSetAncestor(new PatchSetAncestor.Id(id, p + 1)); a.setAncestorRevision(new RevId(src.getParent(p).getId().name())); toInsert.add(a); } db.patchSetAncestors().insert(toInsert); } @Override public Map<Change.Id, CodeReviewCommit> getNewCommits() { return newCommits; } @Override public boolean dryRun(CodeReviewCommit mergeTip, CodeReviewCommit toMerge) throws MergeException { return args.mergeUtil.canCherryPick(args.mergeSorter, args.repo, mergeTip, args.rw, toMerge); } }