Add extension point for storing reviewed flags

At the moment the reviewed flags are stored in ReviewDb, but to fully
migrate to NoteDb they must be moved to a different storage. Different
options how to implement this storage were discussed on the Gerrit
mailing list [1,2]. Standalone Gerrit servers can benefit from a
simple storage in a local H2 database, while multi-master
installations must care to replicate this data between the master
nodes. To support both cases well this extension point makes the store
implementation pluggable. Gerrit itself implements the extension
point, but plugins can replace this implementation. For now the
implementation of this extension point in Gerrit just wraps the access
to the ReviewDb, but in a follow-up change another storage and a data
migration will be implemented.

[1] https://groups.google.com/forum/#!msg/repo-discuss/KhXKMKTJNMs/Tq3XaB8wCgAJ
[2] https://groups.google.com/d/msg/repo-discuss/KhXKMKTJNMs/hHoCa1_5CwAJ

Change-Id: Iaaacd9f0af977ccd505b5ad541f4a616afa214a4
Signed-off-by: Edwin Kempin <ekempin@google.com>

Documentation/dev-plugins.txt

@@ -2121,6 +2121,31 @@ public class S3LargeFileRepository extends S3Repository {
 }
 ----
 
+[[account-patch-review-store]]
+== AccountPatchReviewStore
+
+The AccountPatchReviewStore is used to store reviewed flags on changes.
+A reviewed flag is a tuple of (patch set ID, file, account ID) and
+records whether the user has reviewed a file in a patch set. Each user
+can easily have thousands of reviewed flags and the number of reviewed
+flags is growing without bound. The store must be able handle this data
+volume efficiently.
+
+Gerrit implements this extension point, but plugins may bind another
+implementation, e.g. one that supports multi-master.
+
+----
+DynamicItem.bind(binder(), AccountPatchReviewStore.class)
+    .to(MultiMasterAccountPatchReviewStore.class);
+
+...
+
+public class MultiMasterAccountPatchReviewStore
+    implements AccountPatchReviewStore {
+  ...
+}
+----
+
 [[documentation]]
 == Documentation
 

gerrit-pgm/src/main/java/com/google/gerrit/pgm/Daemon.java

@@ -50,6 +50,7 @@ import com.google.gerrit.pgm.util.SiteProgram;
 import com.google.gerrit.reviewdb.client.AuthType;
 import com.google.gerrit.server.account.InternalAccountDirectory;
 import com.google.gerrit.server.cache.h2.DefaultCacheFactory;
+import com.google.gerrit.server.change.AccountPatchReviewStoreImpl;
 import com.google.gerrit.server.change.ChangeCleanupRunner;
 import com.google.gerrit.server.config.AuthConfig;
 import com.google.gerrit.server.config.AuthConfigModule;
@@ -342,6 +343,7 @@ public class Daemon extends SiteProgram {
     modules.add(new WorkQueue.Module());
     modules.add(new ChangeHookRunner.Module());
     modules.add(new EventBroker.Module());
+    modules.add(new AccountPatchReviewStoreImpl.Module());
     modules.add(new ReceiveCommitsExecutorModule());
     modules.add(new DiffExecutorModule());
     modules.add(new MimeUtil2Module());

gerrit-server/src/main/java/com/google/gerrit/server/change/AccountPatchReviewStore.java

@@ -0,0 +1,93 @@
+// Copyright (C) 2016 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 com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gwtorm.server.OrmException;
+
+import java.util.Collection;
+
+/**
+ * Store for reviewed flags on changes.
+ *
+ * A reviewed flag is a tuple of (patch set ID, file, account ID) and records
+ * whether the user has reviewed a file in a patch set. Each user can easily
+ * have thousands of reviewed flags and the number of reviewed flags is growing
+ * without bound. The store must be able handle this data volume efficiently.
+ *
+ * For a multi-master setup the store must replicate the data between the
+ * masters.
+ */
+public interface AccountPatchReviewStore {
+  /**
+   * Marks the given file in the given patch set as reviewed by the given user.
+   *
+   * @param psId patch set ID
+   * @param accountId account ID of the user
+   * @param path file path
+   * @return {@code true} if the reviewed flag was updated, {@code false} if the
+   *         reviewed flag was already set
+   * @throws OrmException thrown if updating the reviewed flag failed
+   */
+  boolean markReviewed(PatchSet.Id psId, Account.Id accountId, String path)
+      throws OrmException;
+
+  /**
+   * Marks the given files in the given patch set as reviewed by the given user.
+   *
+   * @param psId patch set ID
+   * @param accountId account ID of the user
+   * @param paths file paths
+   * @throws OrmException thrown if updating the reviewed flag failed
+   */
+  void markReviewed(PatchSet.Id psId, Account.Id accountId,
+      Collection<String> paths) throws OrmException;
+
+  /**
+   * Clears the reviewed flag for the given file in the given patch set for the
+   * given user.
+   *
+   * @param psId patch set ID
+   * @param accountId account ID of the user
+   * @param path file path
+   * @throws OrmException thrown if clearing the reviewed flag failed
+   */
+  void clearReviewed(PatchSet.Id psId, Account.Id accountId, String path)
+      throws OrmException;
+
+  /**
+   * Clears the reviewed flags for all files in the given patch set for all
+   * users.
+   *
+   * @param psId patch set ID
+   * @throws OrmException thrown if clearing the reviewed flags failed
+   */
+  void clearReviewed(PatchSet.Id psId) throws OrmException;
+
+
+  /**
+   * Returns the paths of all files in the given patch set the have been
+   * reviewed by the given user.
+   *
+   * @param psId patch set ID
+   * @param accountId account ID of the user
+   * @return the paths of all files in the given patch set the have been
+   *         reviewed by the given user
+   * @throws OrmException thrown if accessing the reviewed flags failed
+   */
+  Collection<String> findReviewed(PatchSet.Id psId, Account.Id accountId)
+      throws OrmException;
+}

gerrit-server/src/main/java/com/google/gerrit/server/change/AccountPatchReviewStoreImpl.java

@@ -0,0 +1,132 @@
+// Copyright (C) 2016 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 com.google.common.base.Function;
+import com.google.common.collect.Collections2;
+import com.google.common.collect.Iterables;
+import com.google.gerrit.extensions.registration.DynamicItem;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.reviewdb.client.AccountPatchReview;
+import com.google.gerrit.reviewdb.client.Patch;
+import com.google.gerrit.reviewdb.client.PatchSet;
+import com.google.gerrit.reviewdb.server.ReviewDb;
+import com.google.gwtorm.server.OrmDuplicateKeyException;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.AbstractModule;
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+
+import java.util.Collection;
+import java.util.Collections;
+
+import javax.inject.Singleton;
+
+@Singleton
+public class AccountPatchReviewStoreImpl implements AccountPatchReviewStore {
+  private final Provider<ReviewDb> dbProvider;
+
+  public static class Module extends AbstractModule {
+    @Override
+    protected void configure() {
+      DynamicItem.itemOf(binder(), AccountPatchReviewStore.class);
+      DynamicItem.bind(binder(), AccountPatchReviewStore.class)
+          .to(AccountPatchReviewStoreImpl.class);
+    }
+  }
+
+  @Inject
+  AccountPatchReviewStoreImpl(Provider<ReviewDb> dbProvider) {
+    this.dbProvider = dbProvider;
+  }
+
+  @Override
+  public boolean markReviewed(PatchSet.Id psId, Account.Id accountId,
+      String path) throws OrmException {
+    ReviewDb db = dbProvider.get();
+    AccountPatchReview apr = getExisting(db, psId, path, accountId);
+    if (apr != null) {
+      return false;
+    }
+
+    try {
+      db.accountPatchReviews().insert(Collections.singleton(
+          new AccountPatchReview(new Patch.Key(psId, path), accountId)));
+      return true;
+    } catch (OrmDuplicateKeyException e) {
+      // Ignored
+      return false;
+    }
+  }
+
+  @Override
+  public void markReviewed(final PatchSet.Id psId, final Account.Id accountId,
+      final Collection<String> paths) throws OrmException {
+    if (paths == null || paths.isEmpty()) {
+      return;
+    } else if (paths.size() == 1) {
+      markReviewed(psId, accountId, Iterables.getOnlyElement(paths));
+      return;
+    }
+
+    paths.removeAll(findReviewed(psId, accountId));
+    if (paths.isEmpty()) {
+      return;
+    }
+    dbProvider.get().accountPatchReviews().insert(Collections2.transform(paths,
+        new Function<String, AccountPatchReview>() {
+          @Override
+          public AccountPatchReview apply(String path) {
+            return new AccountPatchReview(new Patch.Key(psId, path), accountId);
+          }
+        }));
+  }
+
+  @Override
+  public void clearReviewed(PatchSet.Id psId, Account.Id accountId, String path)
+      throws OrmException {
+    ReviewDb db = dbProvider.get();
+    AccountPatchReview apr = getExisting(db, psId, path, accountId);
+    if (apr != null) {
+      db.accountPatchReviews().delete(Collections.singleton(apr));
+    }
+  }
+
+  @Override
+  public void clearReviewed(PatchSet.Id psId) throws OrmException {
+    dbProvider.get().accountPatchReviews()
+        .delete(dbProvider.get().accountPatchReviews().byPatchSet(psId));
+  }
+
+  @Override
+  public Collection<String> findReviewed(PatchSet.Id psId, Account.Id accountId)
+      throws OrmException {
+    return Collections2.transform(dbProvider.get().accountPatchReviews()
+        .byReviewer(accountId, psId).toList(),
+        new Function<AccountPatchReview, String>() {
+          @Override
+          public String apply(AccountPatchReview apr) {
+            return apr.getKey().getPatchKey().getFileName();
+          }
+        });
+  }
+
+  private static AccountPatchReview getExisting(ReviewDb db, PatchSet.Id psId,
+      String path, Account.Id accountId) throws OrmException {
+    AccountPatchReview.Key key =
+        new AccountPatchReview.Key(new Patch.Key(psId, path), accountId);
+    return db.accountPatchReviews().get(key);
+  }
+}

gerrit-server/src/main/java/com/google/gerrit/server/change/ConsistencyChecker.java

@@ -33,6 +33,7 @@ import com.google.gerrit.common.TimeUtil;
 import com.google.gerrit.extensions.api.changes.FixInput;
 import com.google.gerrit.extensions.common.ProblemInfo;
 import com.google.gerrit.extensions.common.ProblemInfo.Status;
+import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.restapi.RestApiException;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.PatchSet;
@@ -125,6 +126,7 @@ public class ConsistencyChecker {
   private final ChangeControl.GenericFactory changeControlFactory;
   private final ChangeNotes.Factory notesFactory;
   private final ChangeUpdate.Factory changeUpdateFactory;
+  private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore;
 
   private FixInput fix;
   private Change change;
@@ -151,7 +153,8 @@ public class ConsistencyChecker {
       ChangeIndexer indexer,
       ChangeControl.GenericFactory changeControlFactory,
       ChangeNotes.Factory notesFactory,
-      ChangeUpdate.Factory changeUpdateFactory) {
+      ChangeUpdate.Factory changeUpdateFactory,
+      DynamicItem<AccountPatchReviewStore> accountPatchReviewStore) {
     this.db = db;
     this.notesMigration = notesMigration;
     this.repoManager = repoManager;
@@ -165,6 +168,7 @@ public class ConsistencyChecker {
     this.changeControlFactory = changeControlFactory;
     this.notesFactory = notesFactory;
     this.changeUpdateFactory = changeUpdateFactory;
+    this.accountPatchReviewStore = accountPatchReviewStore;
     reset();
   }
 
@@ -619,8 +623,7 @@ public class ConsistencyChecker {
         // Delete dangling primary key references. Don't delete ChangeMessages,
         // which don't use patch sets as a primary key, and may provide useful
         // historical information.
-        db.accountPatchReviews().delete(
+        accountPatchReviewStore.get().clearReviewed(psId);
-            db.accountPatchReviews().byPatchSet(psId));
         db.patchSetApprovals().delete(
             db.patchSetApprovals().byPatchSet(psId));
         db.patchComments().delete(

gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraftChangeOp.java

@@ -17,6 +17,7 @@ package com.google.gerrit.server.change;
 import static com.google.common.base.Preconditions.checkState;
 
 import com.google.common.collect.ImmutableList;
+import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.MethodNotAllowedException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -65,6 +66,7 @@ class DeleteDraftChangeOp extends BatchUpdate.Op {
 
   private final PatchSetUtil psUtil;
   private final StarredChangesUtil starredChangesUtil;
+  private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore;
   private final boolean allowDrafts;
 
   private Change.Id id;
@@ -72,9 +74,11 @@ class DeleteDraftChangeOp extends BatchUpdate.Op {
   @Inject
   DeleteDraftChangeOp(PatchSetUtil psUtil,
       StarredChangesUtil starredChangesUtil,
+      DynamicItem<AccountPatchReviewStore> accountPatchReviewStore,
       @GerritServerConfig Config cfg) {
     this.psUtil = psUtil;
     this.starredChangesUtil = starredChangesUtil;
+    this.accountPatchReviewStore = accountPatchReviewStore;
     this.allowDrafts = allowDrafts(cfg);
   }
 
@@ -105,8 +109,7 @@ class DeleteDraftChangeOp extends BatchUpdate.Op {
         throw new ResourceConflictException("Cannot delete draft change " + id
             + ": patch set " + ps.getPatchSetId() + " is not a draft");
       }
-      db.accountPatchReviews().delete(
+      accountPatchReviewStore.get().clearReviewed(ps.getId());
-          db.accountPatchReviews().byPatchSet(ps.getId()));
     }
 
     // Only delete from ReviewDb here; deletion from NoteDb is handled in

gerrit-server/src/main/java/com/google/gerrit/server/change/DeleteDraftPatchSet.java

@@ -15,6 +15,7 @@
 package com.google.gerrit.server.change;
 
 import com.google.gerrit.common.TimeUtil;
+import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.MethodNotAllowedException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
@@ -59,6 +60,7 @@ public class DeleteDraftPatchSet implements RestModifyView<RevisionResource, Inp
   private final PatchSetInfoFactory patchSetInfoFactory;
   private final PatchSetUtil psUtil;
   private final Provider<DeleteDraftChangeOp> deleteChangeOpProvider;
+  private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore;
   private final boolean allowDrafts;
 
   @Inject
@@ -67,12 +69,14 @@ public class DeleteDraftPatchSet implements RestModifyView<RevisionResource, Inp
       PatchSetInfoFactory patchSetInfoFactory,
       PatchSetUtil psUtil,
       Provider<DeleteDraftChangeOp> deleteChangeOpProvider,
+      DynamicItem<AccountPatchReviewStore> accountPatchReviewStore,
       @GerritServerConfig Config cfg) {
     this.db = db;
     this.updateFactory = updateFactory;
     this.patchSetInfoFactory = patchSetInfoFactory;
     this.psUtil = psUtil;
     this.deleteChangeOpProvider = deleteChangeOpProvider;
+    this.accountPatchReviewStore = accountPatchReviewStore;
     this.allowDrafts = cfg.getBoolean("change", "allowDrafts", true);
   }
 
@@ -141,8 +145,8 @@ public class DeleteDraftPatchSet implements RestModifyView<RevisionResource, Inp
       // automatically filtered out when patch sets are deleted.
       psUtil.delete(ctx.getDb(), ctx.getUpdate(patchSet.getId()), patchSet);
 
+      accountPatchReviewStore.get().clearReviewed(psId);
       ReviewDb db = DeleteDraftChangeOp.unwrap(ctx.getDb());
-      db.accountPatchReviews().delete(db.accountPatchReviews().byPatchSet(psId));
       db.changeMessages().delete(db.changeMessages().byPatchSet(psId));
       db.patchComments().delete(db.patchComments().byPatchSet(psId));
       db.patchSetApprovals().delete(db.patchSetApprovals().byPatchSet(psId));

gerrit-server/src/main/java/com/google/gerrit/server/change/Files.java

@@ -17,6 +17,7 @@ package com.google.gerrit.server.change;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import com.google.gerrit.extensions.common.FileInfo;
+import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.registration.DynamicMap;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.BadRequestException;
@@ -28,8 +29,6 @@ import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.reviewdb.client.Account;
-import com.google.gerrit.reviewdb.client.AccountPatchReview;
-import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gerrit.reviewdb.client.Project;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -109,6 +108,7 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
     private final GitRepositoryManager gitManager;
     private final PatchListCache patchListCache;
     private final PatchSetUtil psUtil;
+    private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore;
 
     @Inject
     ListFiles(Provider<ReviewDb> db,
@@ -117,7 +117,8 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
         Revisions revisions,
         GitRepositoryManager gitManager,
         PatchListCache patchListCache,
-        PatchSetUtil psUtil) {
+        PatchSetUtil psUtil,
+        DynamicItem<AccountPatchReviewStore> accountPatchReviewStore) {
       this.db = db;
       this.self = self;
       this.fileInfoJson = fileInfoJson;
@@ -125,6 +126,7 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
       this.gitManager = gitManager;
       this.patchListCache = patchListCache;
       this.psUtil = psUtil;
+      this.accountPatchReviewStore = accountPatchReviewStore;
     }
 
     public ListFiles setReviewed(boolean r) {
@@ -202,7 +204,7 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
       }
     }
 
-    private List<String> reviewed(RevisionResource resource)
+    private Collection<String> reviewed(RevisionResource resource)
         throws AuthException, OrmException {
       CurrentUser user = self.get();
       if (!(user.isIdentifiedUser())) {
@@ -210,11 +212,13 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
       }
 
       Account.Id userId = user.getAccountId();
-      List<String> r = scan(userId, resource.getPatchSet().getId());
+      Collection<String> r = accountPatchReviewStore.get()
+          .findReviewed(resource.getPatchSet().getId(), userId);
 
       if (r.isEmpty() && 1 < resource.getPatchSet().getPatchSetId()) {
         for (PatchSet ps : reversePatchSets(resource)) {
-          List<String> o = scan(userId, ps.getId());
+          Collection<String> o =
+              accountPatchReviewStore.get().findReviewed(ps.getId(), userId);
           if (!o.isEmpty()) {
             try {
               r = copy(Sets.newHashSet(o), ps.getId(), resource, userId);
@@ -229,16 +233,6 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
       return r;
     }
 
-    private List<String> scan(Account.Id userId, PatchSet.Id psId)
-        throws OrmException {
-      List<String> r = new ArrayList<>();
-      for (AccountPatchReview w : db.get().accountPatchReviews()
-          .byReviewer(userId, psId)) {
-        r.add(w.getKey().getPatchKey().getFileName());
-      }
-      return r;
-    }
-
     private List<PatchSet> reversePatchSets(RevisionResource resource)
         throws OrmException {
       Collection<PatchSet> patchSets =
@@ -266,7 +260,6 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
             resource.getPatchSet());
 
         int sz = paths.size();
-        List<AccountPatchReview> inserts = Lists.newArrayListWithCapacity(sz);
         List<String> pathList = Lists.newArrayListWithCapacity(sz);
 
         tw.setFilter(PathFilterGroup.createFromStrings(paths));
@@ -291,11 +284,6 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
               && paths.contains(path)) {
             // File exists in previously reviewed oldList and in curList.
             // File content is identical.
-            inserts.add(new AccountPatchReview(
-                new Patch.Key(
-                    resource.getPatchSet().getId(),
-                    path),
-                  userId));
             pathList.add(path);
           } else if (op >= 0 && cp >= 0
               && tw.getRawMode(o) == 0 && tw.getRawMode(c) == 0
@@ -305,15 +293,11 @@ public class Files implements ChildCollection<RevisionResource, FileResource> {
             // File was deleted in previously reviewed oldList and curList.
             // File exists in ancestor of oldList and curList.
             // File content is identical in ancestors.
-            inserts.add(new AccountPatchReview(
-                new Patch.Key(
-                    resource.getPatchSet().getId(),
-                    path),
-                  userId));
             pathList.add(path);
           }
         }
-        db.get().accountPatchReviews().insert(inserts);
+        accountPatchReviewStore.get()
+            .markReviewed(resource.getPatchSet().getId(), userId, pathList);
         return pathList;
       }
     }

gerrit-server/src/main/java/com/google/gerrit/server/change/Reviewed.java

@@ -14,44 +14,33 @@
 
 package com.google.gerrit.server.change;
 
+import com.google.gerrit.extensions.registration.DynamicItem;
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestModifyView;
-import com.google.gerrit.reviewdb.client.AccountPatchReview;
-import com.google.gerrit.reviewdb.server.ReviewDb;
-import com.google.gwtorm.server.OrmDuplicateKeyException;
 import com.google.gwtorm.server.OrmException;
 import com.google.inject.Inject;
-import com.google.inject.Provider;
 import com.google.inject.Singleton;
 
-import java.util.Collections;
-
 public class Reviewed {
   public static class Input {
   }
 
   @Singleton
-  public static class PutReviewed implements RestModifyView<FileResource, Input> {
+  public static class PutReviewed
-    private final Provider<ReviewDb> dbProvider;
+      implements RestModifyView<FileResource, Input> {
+    private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore;
 
     @Inject
-    PutReviewed(Provider<ReviewDb> dbProvider) {
+    PutReviewed(DynamicItem<AccountPatchReviewStore> accountPatchReviewStore) {
-      this.dbProvider = dbProvider;
+      this.accountPatchReviewStore = accountPatchReviewStore;
     }
 
     @Override
     public Response<String> apply(FileResource resource, Input input)
         throws OrmException {
-      ReviewDb db = dbProvider.get();
+      if (accountPatchReviewStore.get().markReviewed(
-      AccountPatchReview apr = getExisting(db, resource);
+          resource.getPatchKey().getParentKey(), resource.getAccountId(),
-      if (apr == null) {
+          resource.getPatchKey().getFileName())) {
-        try {
-          db.accountPatchReviews().insert(
-              Collections.singleton(new AccountPatchReview(resource.getPatchKey(),
-                  resource.getAccountId())));
-        } catch (OrmDuplicateKeyException e) {
-          return Response.ok("");
-        }
         return Response.created("");
       }
       return Response.ok("");
@@ -59,33 +48,26 @@ public class Reviewed {
   }
 
   @Singleton
-  public static class DeleteReviewed implements RestModifyView<FileResource, Input> {
+  public static class DeleteReviewed
-    private final Provider<ReviewDb> dbProvider;
+      implements RestModifyView<FileResource, Input> {
+    private final DynamicItem<AccountPatchReviewStore> accountPatchReviewStore;
 
     @Inject
-    DeleteReviewed(Provider<ReviewDb> dbProvider) {
+    DeleteReviewed(
-      this.dbProvider = dbProvider;
+        DynamicItem<AccountPatchReviewStore> accountPatchReviewStore) {
+      this.accountPatchReviewStore = accountPatchReviewStore;
     }
 
     @Override
     public Response<?> apply(FileResource resource, Input input)
         throws OrmException {
-      ReviewDb db = dbProvider.get();
+      accountPatchReviewStore.get().clearReviewed(
-      AccountPatchReview apr = getExisting(db, resource);
+          resource.getPatchKey().getParentKey(), resource.getAccountId(),
-      if (apr != null) {
+          resource.getPatchKey().getFileName());
-        db.accountPatchReviews().delete(Collections.singleton(apr));
-      }
       return Response.none();
     }
   }
 
-  private static AccountPatchReview getExisting(ReviewDb db,
-      FileResource resource) throws OrmException {
-    AccountPatchReview.Key key = new AccountPatchReview.Key(
-        resource.getPatchKey(), resource.getAccountId());
-    return db.accountPatchReviews().get(key);
-  }
-
   private Reviewed() {
   }
 }

gerrit-server/src/test/java/com/google/gerrit/testutil/InMemoryModule.java

@@ -28,6 +28,7 @@ import com.google.gerrit.reviewdb.server.ReviewDb;
 import com.google.gerrit.server.GerritPersonIdent;
 import com.google.gerrit.server.GerritPersonIdentProvider;
 import com.google.gerrit.server.cache.h2.DefaultCacheFactory;
+import com.google.gerrit.server.change.AccountPatchReviewStoreImpl;
 import com.google.gerrit.server.config.AllProjectsName;
 import com.google.gerrit.server.config.AllProjectsNameProvider;
 import com.google.gerrit.server.config.AllUsersName;
@@ -198,6 +199,7 @@ public class InMemoryModule extends FactoryModule {
     install(new FakeEmailSender.Module());
     install(new SignedTokenEmailTokenVerifier.Module());
     install(new GpgModule(cfg));
+    install(new AccountPatchReviewStoreImpl.Module());
 
     IndexType indexType = null;
     try {

gerrit-war/src/main/java/com/google/gerrit/httpd/WebAppInitializer.java

@@ -32,6 +32,7 @@ import com.google.gerrit.metrics.dropwizard.DropWizardMetricMaker;
 import com.google.gerrit.reviewdb.client.AuthType;
 import com.google.gerrit.server.account.InternalAccountDirectory;
 import com.google.gerrit.server.cache.h2.DefaultCacheFactory;
+import com.google.gerrit.server.change.AccountPatchReviewStoreImpl;
 import com.google.gerrit.server.change.ChangeCleanupRunner;
 import com.google.gerrit.server.config.AuthConfig;
 import com.google.gerrit.server.config.AuthConfigModule;
@@ -295,6 +296,7 @@ public class WebAppInitializer extends GuiceServletContextListener
     final List<Module> modules = new ArrayList<>();
     modules.add(new DropWizardMetricMaker.RestModule());
     modules.add(new EventBroker.Module());
+    modules.add(new AccountPatchReviewStoreImpl.Module());
     modules.add(cfgInjector.getInstance(GitRepositoryManagerModule.class));
     modules.add(new ChangeHookRunner.Module());
     modules.add(new ReceiveCommitsExecutorModule());