1 files changed, 174 insertions, 0 deletions
diff --git a/java/com/google/gerrit/server/git/BanCommit.java b/java/com/google/gerrit/server/git/BanCommit.java
new file mode 100644
index 0000000000..49917156c7
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+++ b/java/com/google/gerrit/server/git/BanCommit.java
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+// 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;
+
+import static com.google.gerrit.reviewdb.client.RefNames.REFS_REJECT_COMMITS;
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.reviewdb.client.Project;
+import com.google.gerrit.reviewdb.client.RefNames;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.GerritPersonIdent;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.permissions.PermissionBackend;
+import com.google.gerrit.server.permissions.PermissionBackendException;
+import com.google.gerrit.server.permissions.ProjectPermission;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+import com.google.inject.Singleton;
+import java.io.IOException;
+import java.util.Date;
+import java.util.List;
+import java.util.TimeZone;
+import org.eclipse.jgit.errors.IncorrectObjectTypeException;
+import org.eclipse.jgit.errors.MissingObjectException;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectInserter;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.notes.Note;
+import org.eclipse.jgit.notes.NoteMap;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.revwalk.RevWalk;
+
+@Singleton
+public class BanCommit {
+  /**
+   * Loads a list of commits to reject from {@code refs/meta/reject-commits}.
+   *
+   * @param repo repository from which the rejected commits should be loaded
+   * @param walk open revwalk on repo.
+   * @return NoteMap of commits to be rejected, null if there are none.
+   * @throws IOException the map cannot be loaded.
+   */
+  public static NoteMap loadRejectCommitsMap(Repository repo, RevWalk walk) throws IOException {
+    try {
+      Ref ref = repo.getRefDatabase().exactRef(RefNames.REFS_REJECT_COMMITS);
+      if (ref == null) {
+        return NoteMap.newEmptyMap();
+      }
+
+      RevCommit map = walk.parseCommit(ref.getObjectId());
+      return NoteMap.read(walk.getObjectReader(), map);
+    } catch (IOException badMap) {
+      throw new IOException("Cannot load " + RefNames.REFS_REJECT_COMMITS, badMap);
+    }
+  }
+
+  private final Provider<IdentifiedUser> currentUser;
+  private final GitRepositoryManager repoManager;
+  private final TimeZone tz;
+  private final PermissionBackend permissionBackend;
+  private NotesBranchUtil.Factory notesBranchUtilFactory;
+
+  @Inject
+  BanCommit(
+      Provider<IdentifiedUser> currentUser,
+      GitRepositoryManager repoManager,
+      @GerritPersonIdent PersonIdent gerritIdent,
+      NotesBranchUtil.Factory notesBranchUtilFactory,
+      PermissionBackend permissionBackend) {
+    this.currentUser = currentUser;
+    this.repoManager = repoManager;
+    this.notesBranchUtilFactory = notesBranchUtilFactory;
+    this.permissionBackend = permissionBackend;
+    this.tz = gerritIdent.getTimeZone();
+  }
+
+  public BanCommitResult ban(
+      Project.NameKey project, CurrentUser user, List<ObjectId> commitsToBan, String reason)
+      throws AuthException, LockFailureException, IOException, PermissionBackendException {
+    permissionBackend.user(user).project(project).check(ProjectPermission.BAN_COMMIT);
+
+    final BanCommitResult result = new BanCommitResult();
+    NoteMap banCommitNotes = NoteMap.newEmptyMap();
+    // Add a note for each banned commit to notes.
+    try (Repository repo = repoManager.openRepository(project);
+        RevWalk revWalk = new RevWalk(repo);
+        ObjectInserter inserter = repo.newObjectInserter()) {
+      ObjectId noteId = null;
+      for (ObjectId commitToBan : commitsToBan) {
+        try {
+          revWalk.parseCommit(commitToBan);
+        } catch (MissingObjectException e) {
+          // Ignore exception, non-existing commits can be banned.
+        } catch (IncorrectObjectTypeException e) {
+          result.notACommit(commitToBan);
+          continue;
+        }
+        if (noteId == null) {
+          noteId = createNoteContent(reason, inserter);
+        }
+        banCommitNotes.set(commitToBan, noteId);
+      }
+      NotesBranchUtil notesBranchUtil = notesBranchUtilFactory.create(project, repo, inserter);
+      NoteMap newlyCreated =
+          notesBranchUtil.commitNewNotes(
+              banCommitNotes,
+              REFS_REJECT_COMMITS,
+              createPersonIdent(),
+              buildCommitMessage(commitsToBan, reason));
+
+      for (Note n : banCommitNotes) {
+        if (newlyCreated.contains(n)) {
+          result.commitBanned(n);
+        } else {
+          result.commitAlreadyBanned(n);
+        }
+      }
+      return result;
+    }
+  }
+
+  private ObjectId createNoteContent(String reason, ObjectInserter inserter) throws IOException {
+    String noteContent = reason != null ? reason : "";
+    if (noteContent.length() > 0 && !noteContent.endsWith("\n")) {
+      noteContent = noteContent + "\n";
+    }
+    return inserter.insert(Constants.OBJ_BLOB, noteContent.getBytes(UTF_8));
+  }
+
+  private PersonIdent createPersonIdent() {
+    Date now = new Date();
+    return currentUser.get().newCommitterIdent(now, tz);
+  }
+
+  private static String buildCommitMessage(List<ObjectId> bannedCommits, String reason) {
+    final StringBuilder commitMsg = new StringBuilder();
+    commitMsg.append("Banning ");
+    commitMsg.append(bannedCommits.size());
+    commitMsg.append(" ");
+    commitMsg.append(bannedCommits.size() == 1 ? "commit" : "commits");
+    commitMsg.append("\n\n");
+    if (reason != null) {
+      commitMsg.append("Reason: ");
+      commitMsg.append(reason);
+      commitMsg.append("\n\n");
+    }
+    commitMsg.append("The following commits are banned:\n");
+    final StringBuilder commitList = new StringBuilder();
+    for (ObjectId c : bannedCommits) {
+      if (commitList.length() > 0) {
+        commitList.append(",\n");
+      }
+      commitList.append(c.getName());
+    }
+    commitMsg.append(commitList);
+    return commitMsg.toString();
+  }
+}