Merge "Add extension point invoked between NoteDb migration states" into stable-2.15

gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/server/notedb/OnlineNoteDbMigrationIT.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.acceptance.server.notedb;
 
 import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.Truth.assert_;
 import static com.google.common.truth.Truth8.assertThat;
 import static com.google.common.truth.TruthJUnit.assume;
 import static com.google.gerrit.server.notedb.NotesMigrationState.NOTE_DB;
@@ -24,6 +25,10 @@ import static com.google.gerrit.server.notedb.NotesMigrationState.READ_WRITE_WIT
 import static com.google.gerrit.server.notedb.NotesMigrationState.REVIEW_DB;
 import static com.google.gerrit.server.notedb.NotesMigrationState.WRITE;
 import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.easymock.EasyMock.createStrictMock;
+import static org.easymock.EasyMock.expectLastCall;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -33,6 +38,8 @@ import com.google.gerrit.acceptance.NoHttpd;
 import com.google.gerrit.acceptance.PushOneCommit;
 import com.google.gerrit.acceptance.Sandboxed;
 import com.google.gerrit.acceptance.UseLocalDisk;
+import com.google.gerrit.extensions.registration.DynamicSet;
+import com.google.gerrit.extensions.registration.RegistrationHandle;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.client.RefNames;
@@ -45,12 +52,15 @@ import com.google.gerrit.server.notedb.NoteDbChangeState.RefState;
 import com.google.gerrit.server.notedb.NotesMigrationState;
 import com.google.gerrit.server.notedb.rebuild.MigrationException;
 import com.google.gerrit.server.notedb.rebuild.NoteDbMigrator;
+import com.google.gerrit.server.notedb.rebuild.NotesMigrationStateListener;
 import com.google.gerrit.server.schema.ReviewDbFactory;
 import com.google.gerrit.testutil.ConfigSuite;
 import com.google.gerrit.testutil.NoteDbMode;
 import com.google.gwtorm.server.SchemaFactory;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
+import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 import org.eclipse.jgit.junit.TestRepository;
 import org.eclipse.jgit.lib.Config;
@@ -62,6 +72,7 @@ import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.storage.file.FileBasedConfig;
 import org.eclipse.jgit.util.FS;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -86,8 +97,10 @@ public class OnlineNoteDbMigrationIT extends AbstractDaemonTest {
   @Inject private SitePaths sitePaths;
   @Inject private Provider<NoteDbMigrator.Builder> migratorBuilderProvider;
   @Inject private Sequences sequences;
+  @Inject private DynamicSet<NotesMigrationStateListener> listeners;
 
   private FileBasedConfig noteDbConfig;
+  private List<RegistrationHandle> addedListeners;
 
   @Before
   public void setUp() throws Exception {
@@ -95,6 +108,15 @@ public class OnlineNoteDbMigrationIT extends AbstractDaemonTest {
     // Unlike in the running server, for tests, we don't stack notedb.config on gerrit.config.
     noteDbConfig = new FileBasedConfig(sitePaths.notedb_config.toFile(), FS.detect());
     assertNotesMigrationState(REVIEW_DB, false, false);
+    addedListeners = new ArrayList<>();
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    if (addedListeners != null) {
+      addedListeners.forEach(RegistrationHandle::remove);
+      addedListeners = null;
+    }
   }
 
   @Test
@@ -413,6 +435,50 @@ public class OnlineNoteDbMigrationIT extends AbstractDaemonTest {
     assertNotesMigrationState(NOTE_DB, false, false);
   }
 
+  @Test
+  public void notesMigrationStateListener() throws Exception {
+    NotesMigrationStateListener listener = createStrictMock(NotesMigrationStateListener.class);
+    listener.preStateChange(REVIEW_DB, WRITE);
+    expectLastCall();
+    listener.preStateChange(WRITE, READ_WRITE_NO_SEQUENCE);
+    expectLastCall();
+    listener.preStateChange(READ_WRITE_NO_SEQUENCE, READ_WRITE_WITH_SEQUENCE_REVIEW_DB_PRIMARY);
+    expectLastCall();
+    listener.preStateChange(
+        READ_WRITE_WITH_SEQUENCE_REVIEW_DB_PRIMARY, READ_WRITE_WITH_SEQUENCE_NOTE_DB_PRIMARY);
+    listener.preStateChange(READ_WRITE_WITH_SEQUENCE_NOTE_DB_PRIMARY, NOTE_DB);
+    expectLastCall();
+    replay(listener);
+    addListener(listener);
+
+    createChange();
+    migrate(b -> b);
+    assertNotesMigrationState(NOTE_DB, false, false);
+    verify(listener);
+  }
+
+  @Test
+  public void notesMigrationStateListenerFails() throws Exception {
+    NotesMigrationStateListener listener = createStrictMock(NotesMigrationStateListener.class);
+    listener.preStateChange(REVIEW_DB, WRITE);
+    expectLastCall();
+    listener.preStateChange(WRITE, READ_WRITE_NO_SEQUENCE);
+    IOException listenerException = new IOException("Listener failed");
+    expectLastCall().andThrow(listenerException);
+    replay(listener);
+    addListener(listener);
+
+    createChange();
+    try {
+      migrate(b -> b);
+      assert_().fail("expected IOException");
+    } catch (IOException e) {
+      assertThat(e).isSameAs(listenerException);
+    }
+    assertNotesMigrationState(WRITE, false, false);
+    verify(listener);
+  }
+
   private void assertNotesMigrationState(
       NotesMigrationState expected, boolean autoMigrate, boolean trialMode) throws Exception {
     assertThat(NotesMigrationState.forNotesMigration(notesMigration)).hasValue(expected);
@@ -461,4 +527,8 @@ public class OnlineNoteDbMigrationIT extends AbstractDaemonTest {
       assertThat(e).hasMessageThat().contains(expectMessageContains);
     }
   }
+
+  private void addListener(NotesMigrationStateListener listener) {
+    addedListeners.add(listeners.add(listener));
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/notedb/NoteDbModule.java

@@ -17,6 +17,7 @@ package com.google.gerrit.server.notedb;
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
 import com.google.gerrit.extensions.config.FactoryModule;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Change.Id;
 import com.google.gerrit.reviewdb.client.Project;
@@ -24,6 +25,7 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.notedb.NoteDbUpdateManager.Result;
 import com.google.gerrit.server.notedb.rebuild.ChangeRebuilder;
 import com.google.gerrit.server.notedb.rebuild.ChangeRebuilderImpl;
+import com.google.gerrit.server.notedb.rebuild.NotesMigrationStateListener;
 import com.google.inject.TypeLiteral;
 import com.google.inject.name.Names;
 import org.eclipse.jgit.lib.Config;
@@ -54,6 +56,7 @@ public class NoteDbModule extends FactoryModule {
     factory(NoteDbUpdateManager.Factory.class);
     factory(RobotCommentNotes.Factory.class);
     factory(RobotCommentUpdate.Factory.class);
+    DynamicSet.setOf(binder(), NotesMigrationStateListener.class);
 
     if (!useTestBindings) {
       install(ChangeNotesCache.module());

gerrit-server/src/main/java/com/google/gerrit/server/notedb/rebuild/NoteDbMigrator.java

@@ -42,6 +42,7 @@ import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
 import com.google.gerrit.common.FormatUtil;
 import com.google.gerrit.common.Nullable;
+import com.google.gerrit.extensions.registration.DynamicSet;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -125,6 +126,7 @@ public class NoteDbMigrator implements AutoCloseable {
     private final WorkQueue workQueue;
     private final MutableNotesMigration globalNotesMigration;
     private final PrimaryStorageMigrator primaryStorageMigrator;
+    private final DynamicSet<NotesMigrationStateListener> listeners;
 
     private int threads;
     private ImmutableList<Project.NameKey> projects = ImmutableList.of();
@@ -148,7 +150,8 @@ public class NoteDbMigrator implements AutoCloseable {
         ChangeRebuilder rebuilder,
         WorkQueue workQueue,
         MutableNotesMigration globalNotesMigration,
-        PrimaryStorageMigrator primaryStorageMigrator) {
+        PrimaryStorageMigrator primaryStorageMigrator,
+        DynamicSet<NotesMigrationStateListener> listeners) {
       // Reload gerrit.config/notedb.config on each migrator invocation, in case a previous
       // migration in the same process modified the on-disk contents. This ensures the defaults for
       // trial/autoMigrate get set correctly below.
@@ -163,6 +166,7 @@ public class NoteDbMigrator implements AutoCloseable {
       this.workQueue = workQueue;
       this.globalNotesMigration = globalNotesMigration;
       this.primaryStorageMigrator = primaryStorageMigrator;
+      this.listeners = listeners;
       this.trial = getTrialMode(cfg);
       this.autoMigrate = getAutoMigrate(cfg);
     }
@@ -320,6 +324,7 @@ public class NoteDbMigrator implements AutoCloseable {
           rebuilder,
           globalNotesMigration,
           primaryStorageMigrator,
+          listeners,
           threads > 1
               ? MoreExecutors.listeningDecorator(workQueue.createQueue(threads, "RebuildChange"))
               : MoreExecutors.newDirectExecutorService(),
@@ -344,6 +349,7 @@ public class NoteDbMigrator implements AutoCloseable {
   private final ChangeRebuilder rebuilder;
   private final MutableNotesMigration globalNotesMigration;
   private final PrimaryStorageMigrator primaryStorageMigrator;
+  private final DynamicSet<NotesMigrationStateListener> listeners;
 
   private final ListeningExecutorService executor;
   private final ImmutableList<Project.NameKey> projects;
@@ -365,6 +371,7 @@ public class NoteDbMigrator implements AutoCloseable {
       ChangeRebuilder rebuilder,
       MutableNotesMigration globalNotesMigration,
       PrimaryStorageMigrator primaryStorageMigrator,
+      DynamicSet<NotesMigrationStateListener> listeners,
       ListeningExecutorService executor,
       ImmutableList<Project.NameKey> projects,
       ImmutableList<Change.Id> changes,
@@ -390,6 +397,7 @@ public class NoteDbMigrator implements AutoCloseable {
     this.userFactory = userFactory;
     this.globalNotesMigration = globalNotesMigration;
     this.primaryStorageMigrator = primaryStorageMigrator;
+    this.listeners = listeners;
     this.executor = executor;
     this.projects = projects;
     this.changes = changes;
@@ -614,6 +622,9 @@ public class NoteDbMigrator implements AutoCloseable {
                     ? "But found this state:\n" + actualOldState.get().toText()
                     : "But could not parse the current state"));
       }
+
+      preStateChange(expectedOldState, newState);
+
       newState.setConfigValues(noteDbConfig);
       additionalUpdates.accept(noteDbConfig);
       noteDbConfig.save();
@@ -625,6 +636,13 @@ public class NoteDbMigrator implements AutoCloseable {
     }
   }
 
+  private void preStateChange(NotesMigrationState oldState, NotesMigrationState newState)
+      throws IOException {
+    for (NotesMigrationStateListener listener : listeners) {
+      listener.preStateChange(oldState, newState);
+    }
+  }
+
   private void setControlFlags() throws MigrationException {
     synchronized (globalNotesMigration) {
       try {

gerrit-server/src/main/java/com/google/gerrit/server/notedb/rebuild/NotesMigrationStateListener.java

@@ -0,0 +1,35 @@
+// Copyright (C) 2017 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.notedb.rebuild;
+
+import com.google.gerrit.extensions.annotations.ExtensionPoint;
+import com.google.gerrit.server.notedb.NotesMigrationState;
+import java.io.IOException;
+
+/** Listener for state changes performed by {@link OnlineNoteDbMigrator}. */
+@ExtensionPoint
+public interface NotesMigrationStateListener {
+  /**
+   * Invoked just before saving the new migration state.
+   *
+   * @param oldState state prior to this state change.
+   * @param newState state after this state change.
+   * @throws IOException if an error occurred, which will cause the migration to abort. Exceptions
+   *     that should be considered non-fatal must be caught (and ideally logged) by the
+   *     implementation rather than thrown.
+   */
+  void preStateChange(NotesMigrationState oldState, NotesMigrationState newState)
+      throws IOException;
+}