chromium/components/feed/core/v2/xsurface_datastore.h

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_FEED_CORE_V2_XSURFACE_DATASTORE_H_
#define COMPONENTS_FEED_CORE_V2_XSURFACE_DATASTORE_H_

#include <map>
#include <string>
#include <vector>

#include "base/observer_list.h"

// This file defines some types related to the XSurface datastore.
// The XSurface datastore is a generic key-value store, which can affect the
// display of UI elements. In some cases, we populate data store with
// information source by the Feed component.
namespace feed {

// Write-access to something that stores data store elements.
class XsurfaceDatastoreDataWriter { … };

// Read-access to something that stores data store elements.
class XsurfaceDatastoreDataReader { … };

// A set of data exported to the XSurface datastore.
class XsurfaceDatastoreSlice : public XsurfaceDatastoreDataReader,
                               public XsurfaceDatastoreDataWriter { … };

// Combines multiple `XsurfaceDatastoreDataReader`s, to provide access to all
// stored data. This implementation assumes that each contained
// `XsurfaceDatastoreDataReader` provides a disjoint set of keys, so that there
// can be no key collision between `sources`.
class XsurfaceDatastoreAggregate
    : public XsurfaceDatastoreDataReader,
      public XsurfaceDatastoreDataReader::Observer { … };

}  // namespace feed

#endif  // COMPONENTS_FEED_CORE_V2_XSURFACE_DATASTORE_H_