Java tutorial
// 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.registration.DynamicItem; import com.google.gerrit.extensions.restapi.MethodNotAllowedException; import com.google.gerrit.extensions.restapi.ResourceConflictException; import com.google.gerrit.extensions.restapi.RestApiException; import com.google.gerrit.reviewdb.client.Change; import com.google.gerrit.reviewdb.client.PatchSet; import com.google.gerrit.reviewdb.server.ReviewDb; import com.google.gerrit.reviewdb.server.ReviewDbUtil; import com.google.gerrit.server.PatchSetUtil; import com.google.gerrit.server.StarredChangesUtil; import com.google.gerrit.server.project.NoSuchChangeException; import com.google.gerrit.server.update.BatchUpdateOp; import com.google.gerrit.server.update.BatchUpdateReviewDb; import com.google.gerrit.server.update.ChangeContext; import com.google.gerrit.server.update.Order; import com.google.gerrit.server.update.RepoContext; import com.google.gwtorm.server.OrmException; import com.google.inject.Inject; import java.io.IOException; import java.util.Collection; import java.util.Map; import java.util.Optional; import org.eclipse.jgit.lib.Config; import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.revwalk.RevWalk; class DeleteChangeOp implements BatchUpdateOp { static boolean allowDrafts(Config cfg) { return cfg.getBoolean("change", "allowDrafts", true); } static ReviewDb unwrap(ReviewDb db) { // This is special. We want to delete exactly the rows that are present in // the database, even when reading everything else from NoteDb, so we need // to bypass the write-only wrapper. if (db instanceof BatchUpdateReviewDb) { db = ((BatchUpdateReviewDb) db).unsafeGetDelegate(); } return ReviewDbUtil.unwrapDb(db); } private final PatchSetUtil psUtil; private final StarredChangesUtil starredChangesUtil; private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore; private Change.Id id; @Inject DeleteChangeOp(PatchSetUtil psUtil, StarredChangesUtil starredChangesUtil, DynamicItem<AccountPatchReviewStore> accountPatchReviewStore) { this.psUtil = psUtil; this.starredChangesUtil = starredChangesUtil; this.accountPatchReviewStore = accountPatchReviewStore; } @Override public boolean updateChange(ChangeContext ctx) throws RestApiException, OrmException, IOException, NoSuchChangeException { checkState(ctx.getOrder() == Order.DB_BEFORE_REPO, "must use DeleteChangeOp with DB_BEFORE_REPO"); checkState(id == null, "cannot reuse DeleteChangeOp"); id = ctx.getChange().getId(); Collection<PatchSet> patchSets = psUtil.byChange(ctx.getDb(), ctx.getNotes()); ensureDeletable(ctx, id, patchSets); // Cleaning up is only possible as long as the change and its elements are // still part of the database. cleanUpReferences(ctx, id, patchSets); deleteChangeElementsFromDb(ctx, id); ctx.deleteChange(); return true; } private void ensureDeletable(ChangeContext ctx, Change.Id id, Collection<PatchSet> patchSets) throws ResourceConflictException, MethodNotAllowedException, IOException { Change.Status status = ctx.getChange().getStatus(); if (status == Change.Status.MERGED) { throw new MethodNotAllowedException("Deleting merged change " + id + " is not allowed"); } for (PatchSet patchSet : patchSets) { if (isPatchSetMerged(ctx, patchSet)) { throw new ResourceConflictException(String.format( "Cannot delete change %s: patch set %s is already merged", id, patchSet.getPatchSetId())); } } if (status == Change.Status.DRAFT) { for (PatchSet ps : patchSets) { if (!ps.isDraft()) { throw new ResourceConflictException("Cannot delete draft change " + id + ": patch set " + ps.getPatchSetId() + " is not a draft"); } } } } private boolean isPatchSetMerged(ChangeContext ctx, PatchSet patchSet) throws IOException { Optional<ObjectId> destId = ctx.getRepoView().getRef(ctx.getChange().getDest().get()); if (!destId.isPresent()) { return false; } RevWalk revWalk = ctx.getRevWalk(); ObjectId objectId = ObjectId.fromString(patchSet.getRevision().get()); return revWalk.isMergedInto(revWalk.parseCommit(objectId), revWalk.parseCommit(destId.get())); } private void deleteChangeElementsFromDb(ChangeContext ctx, Change.Id id) throws OrmException { // Only delete from ReviewDb here; deletion from NoteDb is handled in // BatchUpdate. ReviewDb db = unwrap(ctx.getDb()); db.patchComments().delete(db.patchComments().byChange(id)); db.patchSetApprovals().delete(db.patchSetApprovals().byChange(id)); db.patchSets().delete(db.patchSets().byChange(id)); db.changeMessages().delete(db.changeMessages().byChange(id)); } private void cleanUpReferences(ChangeContext ctx, Change.Id id, Collection<PatchSet> patchSets) throws OrmException, NoSuchChangeException { for (PatchSet ps : patchSets) { accountPatchReviewStore.get().clearReviewed(ps.getId()); } // Non-atomic operation on Accounts table; not much we can do to make it // atomic. starredChangesUtil.unstarAll(ctx.getChange().getProject(), id); } @Override public void updateRepo(RepoContext ctx) throws IOException { String prefix = new PatchSet.Id(id, 1).toRefName(); prefix = prefix.substring(0, prefix.length() - 1); for (Map.Entry<String, ObjectId> e : ctx.getRepoView().getRefs(prefix).entrySet()) { ctx.addRefUpdate(e.getValue(), ObjectId.zeroId(), prefix + e.getKey()); } } }