The notification database should be able to read or delete multiple items.

content/browser/notifications/notification_database.cc

Index: content/browser/notifications/notification_database.cc
diff --git a/content/browser/notifications/notification_database.cc b/content/browser/notifications/notification_database.cc
index 1f98f3763ae896bb7edad0520ab43ebc0b6049da..675c07ed1b3c6d56ac7cc042e779573db911ba58 100644
--- a/content/browser/notifications/notification_database.cc
+++ b/content/browser/notifications/notification_database.cc
@@ -11,6 +11,7 @@
 #include "base/strings/stringprintf.h"
 #include "content/browser/notifications/notification_database_data_conversions.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_database_data.h"
 #include "storage/common/database/database_identifier.h"
 #include "third_party/leveldatabase/src/helpers/memenv/memenv.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
@@ -27,7 +28,6 @@
 //
 // key: "NEXT_NOTIFICATION_ID"
 // value: Decimal string which fits into an int64_t.
-//
 
 namespace content {
 namespace {
@@ -42,6 +42,9 @@ const char kKeySeparator = '\x00';
 // The first notification id which to be handed out by the database.
 const int64_t kFirstNotificationId = 1;
 
+// The id used internally to represent an invalid Service Worker registration.
+const int64_t kInvalidServiceWorkerRegistrationId = -1;

[johnme, 2015/03/19 16:17:10]

Nit: Include content/common/service_worker/service_worker_types.h rather than
redefining this.

[Peter Beverloo, 2015/03/19 16:53:42]

Done.

+
 // Converts the LevelDB |status| to one of the notification database's values.
 NotificationDatabase::Status LevelDBStatusToStatus(
     const leveldb::Status& status) {
@@ -55,13 +58,36 @@ NotificationDatabase::Status LevelDBStatusToStatus(
   return NotificationDatabase::STATUS_ERROR_FAILED;
 }
 
-// Creates the compound data key in which notification data is stored.
-std::string CreateDataKey(int64_t notification_id, const GURL& origin) {
-  return base::StringPrintf("%s%s%c%s",
+// Creates a prefix for the data entries based on |origin|.
+std::string CreateDataPrefix(const GURL& origin) {

[johnme, 2015/03/19 16:17:10]

Optional alternative: Why not include the service_worker_registration_id in the
data prefix (after the origin, but before the notification_id)? Then
DeleteAllNotificationDataInternal and ReadAllNotificationDataInternal would be
simpler, as you wouldn't need to filter the notifications (or even deserialize
them in the case of Delete).

(you'd have to pass the s_w_r_id to ReadNotificationData of course)

[Peter Beverloo, 2015/03/19 16:53:42]

I considered this, and actually implemented a few variants of this (including
having an index of it), but neither worked out much nicer.

The main complexity is that the Service Worker Registration ID is part of a
notification's data that users of notifications shouldn't have to care about.
They get an integral ID, which is all reference they need. Increasing their
knowledge to two integral IDs would increase complexity elsewhere.

Additionally, technically service_worker_registration_id is an optional field.
It's not been ruled out that we may use the database for persistent
notifications created by the Chrome Apps extension API, in which case there is
no Service Worker Registration ID.

+  if (!origin.is_valid())
+    return kDataKeyPrefix;
+
+  return base::StringPrintf("%s%s%c",
                             kDataKeyPrefix,
                             storage::GetIdentifierFromOrigin(origin).c_str(),
-                            kKeySeparator,
-                            base::Int64ToString(notification_id).c_str());
+                            kKeySeparator);
+}
+
+// Creates the compound data key in which notification data is stored.
+std::string CreateDataKey(const GURL& origin, int64_t notification_id) {
+  DCHECK(origin.is_valid());
+  return CreateDataPrefix(origin) + base::Int64ToString(notification_id);
+}
+
+// Deserializes data in |serialized_data| to |notification_database_data|.
+// Will return if the deserialization was successful.
+NotificationDatabase::Status DeserializedNotificationData(
+    const std::string& serialized_data,
+    NotificationDatabaseData* notification_database_data) {
+  DCHECK(notification_database_data);
+  if (DeserializeNotificationDatabaseData(serialized_data,
+                                          notification_database_data)) {
+    return NotificationDatabase::STATUS_OK;
+  }
+
+  DLOG(ERROR) << "Unable to deserialize a notification's data.";
+  return NotificationDatabase::STATUS_ERROR_CORRUPTED;
 }
 
 }  // namespace
@@ -117,7 +143,7 @@ NotificationDatabase::Status NotificationDatabase::ReadNotificationData(
   DCHECK(origin.is_valid());
   DCHECK(notification_database_data);
 
-  std::string key = CreateDataKey(notification_id, origin);
+  std::string key = CreateDataKey(origin, notification_id);
   std::string serialized_data;
 
   Status status = LevelDBStatusToStatus(
@@ -125,14 +151,35 @@ NotificationDatabase::Status NotificationDatabase::ReadNotificationData(
   if (status != STATUS_OK)
     return status;
 
-  if (DeserializeNotificationDatabaseData(serialized_data,
-                                          notification_database_data)) {
-    return STATUS_OK;
-  }
+  return DeserializedNotificationData(serialized_data,
+                                      notification_database_data);
+}
+
+NotificationDatabase::Status
+NotificationDatabase::ReadAllNotificationData(
+    std::vector<NotificationDatabaseData>* notification_data_vector) const {
+  return ReadAllNotificationDataInternal(GURL() /* origin */,
+                                         kInvalidServiceWorkerRegistrationId,
+                                         notification_data_vector);
+}
+
+NotificationDatabase::Status
+NotificationDatabase::ReadAllNotificationDataForOrigin(
+    const GURL& origin,
+    std::vector<NotificationDatabaseData>* notification_data_vector) const {
+  return ReadAllNotificationDataInternal(origin,
+                                         kInvalidServiceWorkerRegistrationId,
+                                         notification_data_vector);
+}
 
-  DLOG(ERROR) << "Unable to deserialize data for notification "
-              << notification_id << " belonging to " << origin << ".";
-  return STATUS_ERROR_CORRUPTED;
+NotificationDatabase::Status
+NotificationDatabase::ReadAllNotificationDataForServiceWorkerRegistration(
+    const GURL& origin,
+    int64_t service_worker_registration_id,
+    std::vector<NotificationDatabaseData>* notification_data_vector) const {
+  return ReadAllNotificationDataInternal(origin,
+                                         service_worker_registration_id,
+                                         notification_data_vector);
 }
 
 NotificationDatabase::Status NotificationDatabase::WriteNotificationData(
@@ -155,7 +202,7 @@ NotificationDatabase::Status NotificationDatabase::WriteNotificationData(
   DCHECK_GE(next_notification_id_, kFirstNotificationId);
 
   leveldb::WriteBatch batch;
-  batch.Put(CreateDataKey(next_notification_id_, origin), serialized_data);
+  batch.Put(CreateDataKey(origin, next_notification_id_), serialized_data);
   batch.Put(kNextNotificationIdKey,
             base::Int64ToString(next_notification_id_ + 1));
 
@@ -176,10 +223,29 @@ NotificationDatabase::Status NotificationDatabase::DeleteNotificationData(
   DCHECK_GE(notification_id, kFirstNotificationId);
   DCHECK(origin.is_valid());
 
-  std::string key = CreateDataKey(notification_id, origin);
+  std::string key = CreateDataKey(origin, notification_id);
   return LevelDBStatusToStatus(db_->Delete(leveldb::WriteOptions(), key));
 }
 
+NotificationDatabase::Status
+NotificationDatabase::DeleteAllNotificationDataForOrigin(
+    const GURL& origin,
+    std::set<int64_t>* deleted_notification_set) {
+  return DeleteAllNotificationDataInternal(origin,
+                                           kInvalidServiceWorkerRegistrationId,
+                                           deleted_notification_set);
+}
+
+NotificationDatabase::Status
+NotificationDatabase::DeleteAllNotificationDataForServiceWorkerRegistration(
+    const GURL& origin,
+    int64_t service_worker_registration_id,
+    std::set<int64_t>* deleted_notification_set) {
+  return DeleteAllNotificationDataInternal(origin,
+                                           service_worker_registration_id,
+                                           deleted_notification_set);
+}
+
 NotificationDatabase::Status NotificationDatabase::Destroy() {
   DCHECK(sequence_checker_.CalledOnValidSequencedThread());
 
@@ -219,4 +285,90 @@ NotificationDatabase::Status NotificationDatabase::ReadNextNotificationId() {
   return STATUS_OK;
 }
 
+NotificationDatabase::Status
+NotificationDatabase::ReadAllNotificationDataInternal(
+    const GURL& origin,
+    int64_t service_worker_registration_id,
+    std::vector<NotificationDatabaseData>* notification_data_vector) const {
+  DCHECK(sequence_checker_.CalledOnValidSequencedThread());
+  DCHECK(notification_data_vector);
+
+  const std::string prefix = CreateDataPrefix(origin);
+
+  leveldb::Slice prefix_slice(prefix);
+
+  NotificationDatabaseData notification_database_data;
+  scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(leveldb::ReadOptions()));
+  for (iter->Seek(prefix_slice); iter->Valid(); iter->Next()) {
+    if (!iter->key().starts_with(prefix_slice))
+      break;
+
+    Status status = DeserializedNotificationData(iter->value().ToString(),
+                                                 &notification_database_data);
+    if (status != STATUS_OK)
+      return status;
+
+    if (service_worker_registration_id != kInvalidServiceWorkerRegistrationId &&
+        notification_database_data.service_worker_registration_id !=
+            service_worker_registration_id) {
+      continue;
+    }
+
+    notification_data_vector->push_back(notification_database_data);
+  }
+
+  return LevelDBStatusToStatus(iter->status());
+}
+
+NotificationDatabase::Status
+NotificationDatabase::DeleteAllNotificationDataInternal(
+    const GURL& origin,
+    int64_t service_worker_registration_id,
+    std::set<int64_t>* deleted_notification_set) {
+  DCHECK(sequence_checker_.CalledOnValidSequencedThread());
+  DCHECK(deleted_notification_set);
+  DCHECK(origin.is_valid());
+
+  const std::string prefix = CreateDataPrefix(origin);
+
+  leveldb::Slice prefix_slice(prefix);
+  leveldb::WriteBatch batch;
+
+  NotificationDatabaseData notification_database_data;
+  scoped_ptr<leveldb::Iterator> iter(db_->NewIterator(leveldb::ReadOptions()));
+  for (iter->Seek(prefix_slice); iter->Valid(); iter->Next()) {
+    if (!iter->key().starts_with(prefix_slice))
+      break;
+
+    if (service_worker_registration_id != kInvalidServiceWorkerRegistrationId) {
+      Status status = DeserializedNotificationData(iter->value().ToString(),
+                                                   &notification_database_data);
+      if (status != STATUS_OK)
+        return status;
+
+      if (notification_database_data.service_worker_registration_id !=
+              service_worker_registration_id) {
+        continue;
+      }
+    }
+
+    leveldb::Slice notification_id_slice = iter->key();
+    notification_id_slice.remove_prefix(prefix_slice.size());
+
+    int64_t notification_id = 0;
+    if (!base::StringToInt64(notification_id_slice.ToString(),
+                             &notification_id)) {
+      return STATUS_ERROR_CORRUPTED;
+    }
+
+    deleted_notification_set->insert(notification_id);
+    batch.Delete(iter->key());
+  }
+
+  if (deleted_notification_set->empty())
+    return STATUS_OK;
+
+  return LevelDBStatusToStatus(db_->Write(leveldb::WriteOptions(), &batch));
+}
+
 }  // namespace content