[IndexedDB] Propogating changes to observers : Renderer

content/browser/indexed_db/indexed_db_observer_changes.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_OBSERVER_CHANGES_H_
+#define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_OBSERVER_CHANGES_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <map>
+#include <set>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/stl_util.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+class IndexedDBObservation;
+
+class CONTENT_EXPORT IndexedDBObserverChanges {

[dmurph, 2016/07/08 18:40:44]

Ok, so, each set of changes is on a per-connection basis, correct? So let's say
that here. Also, it's very confusion what AddObservationIndex does by looking at
the header file. You need to document this, and possibly name it better. Maybe
"RecordObserverForLastObservation".

[dmurph, 2016/07/08 18:40:44]

Also, instead of having a duplicate changes in the messages, let's just use this
as the message struct. See
https://cs.chromium.org/chromium/src/content/common/fileapi/webblob_messages....

https://cs.chromium.org/chromium/src/storage/common/blob_storage/blob_item_by...

[palakj1, 2016/07/08 22:17:54]

Renamed.

Deferring messages change to next patch 

+ public:
+  IndexedDBObserverChanges();
+  ~IndexedDBObserverChanges();
+
+  void AddObservationIndex(int32_t observer_id);
+  void AddObservation(std::unique_ptr<IndexedDBObservation> observation);
+
+  const std::map<int32_t, std::vector<int32_t>>& observation_index() {
+    return observation_index_;
+  }
+  // TODO(palakj): Can I retrun const here.
+  std::vector<std::unique_ptr<IndexedDBObservation>>& observations() {
+    return observations_;
+  }
+
+ private:
+  // map observer_id to corresponding set of indices in observations.
+  std::map<int32_t, std::vector<int32_t>> observation_index_;
+  std::vector<std::unique_ptr<IndexedDBObservation>> observations_;
+
+  DISALLOW_COPY_AND_ASSIGN(IndexedDBObserverChanges);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_OBSERVER_CHANGES_H_