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// Copyright 2015 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 COMPONENTS_UPDATE_CLIENT_ACTION_H_
#define COMPONENTS_UPDATE_CLIENT_ACTION_H_
#include <stddef.h>
#include <string>
#include "base/callback.h"
#include "base/macros.h"
#include "base/threading/thread_checker.h"
#include "components/update_client/crx_update_item.h"
#include "components/update_client/update_client.h"
namespace update_client {
enum class Error;
struct CrxUpdateItem;
struct UpdateContext;
// Any update can be broken down as a sequence of discrete steps, such as
// checking for updates, downloading patches, updating, and waiting between
// successive updates. An action is the smallest unit of work executed by
// the update engine.
//
// Defines an abstract interface for a unit of work, executed by the
// update engine as part of an update.
class Action {
public:
virtual ~Action() {}
// Runs the code encapsulated by the action. When an action completes, it can
// chain up and transfer the execution flow to another action or it can
// invoke the |callback| when this function has completed and there is nothing
// else to do.
virtual void Run(UpdateContext* update_context, Callback callback) = 0;
};
// Provides a reusable implementation of common functions needed by actions.
class ActionImpl {
protected:
ActionImpl();
~ActionImpl();
void Run(UpdateContext* update_context, Callback callback);
// Changes the current state of the |item| to the new state |to|.
void ChangeItemState(CrxUpdateItem* item, CrxUpdateItem::State to);
// Changes the state of all items in |update_context_|. Returns the count
// of items affected by the call.
size_t ChangeAllItemsState(CrxUpdateItem::State from,
CrxUpdateItem::State to);
// Returns the item associated with the component |id| or nullptr in case
// of errors.
CrxUpdateItem* FindUpdateItemById(const std::string& id) const;
void NotifyObservers(UpdateClient::Observer::Events event,
const std::string& id);
// Updates the CRX at the front of the CRX queue in this update context.
void UpdateCrx();
// Completes updating the CRX at the front of the queue, and initiates
// the update for the next CRX in the queue, if the queue is not empty.
void UpdateCrxComplete(CrxUpdateItem* item);
// Called when the updates for all CRXs have finished and the execution
// flow must return back to the update engine.
void UpdateComplete(Error error);
base::ThreadChecker thread_checker_;
UpdateContext* update_context_; // Not owned by this class.
Callback callback_;
private:
DISALLOW_COPY_AND_ASSIGN(ActionImpl);
};
} // namespace update_client
#endif // COMPONENTS_UPDATE_CLIENT_ACTION_H_
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