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// Copyright 2014 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 CHROME_BROWSER_CHROMEOS_POLICY_SERVER_BACKED_STATE_KEYS_BROKER_H_
#define CHROME_BROWSER_CHROMEOS_POLICY_SERVER_BACKED_STATE_KEYS_BROKER_H_
#include <string>
#include <vector>
#include "base/callback.h"
#include "base/callback_list.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
namespace base {
class TaskRunner;
}
namespace chromeos {
class SessionManagerClient;
}
namespace policy {
// Brokers server-backed state keys for the device. Retrieves them from session
// manager via DBus and refreshes them periodically. Consumers can register
// callbacks to invoke when the state keys change.
class ServerBackedStateKeysBroker {
public:
typedef scoped_ptr<base::CallbackList<void()>::Subscription> Subscription;
typedef base::Callback<void(const std::vector<std::string>&, bool)>
StateKeysCallback;
ServerBackedStateKeysBroker(
chromeos::SessionManagerClient* session_manager_client,
scoped_refptr<base::TaskRunner> delayed_task_runner);
~ServerBackedStateKeysBroker();
// Registers a callback to be invoked whenever the state keys get updated.
// Note that consuming code needs to hold on to the returned Subscription as
// long as it wants to receive the callback. If the state keys haven't been
// requested yet, calling this will also trigger their initial fetch.
Subscription RegisterUpdateCallback(const base::Closure& callback);
// Requests state keys asynchronously. Invokes the passed callback exactly
// once (unless |this| gets destroyed before the callback happens), with the
// current state keys passed as a parameter to the callback. If there's a
// problem determining the state keys, the passed vector will be empty.
void RequestStateKeys(const StateKeysCallback& callback);
// Get the set of current state keys. Empty if state keys are unavailable
// or pending retrieval.
const std::vector<std::string>& state_keys() const { return state_keys_; }
// Returns the state key for the current point in time. Returns an empty
// string if state keys are unavailable or pending retrieval.
std::string current_state_key() const {
return state_keys_.empty() ? std::string() : state_keys_.front();
}
// Whether state key retrieval is pending.
bool pending() const { return !initial_retrieval_completed_; }
// Whether state keys are available.
bool available() const { return !state_keys_.empty(); }
private:
// Asks |session_manager_client_| to provide current state keys..
void FetchStateKeys();
// Stores newly-received state keys and notifies consumers.
void StoreStateKeys(const std::vector<std::string>& state_keys,
bool first_boot);
chromeos::SessionManagerClient* session_manager_client_;
scoped_refptr<base::TaskRunner> delayed_task_runner_;
// The current set of state keys.
std::vector<std::string> state_keys_;
// Set to true on first run after factory reset.
bool first_boot_;
// Whether a request for state keys is pending.
bool requested_;
// Whether the initial retrieval operation completed.
bool initial_retrieval_completed_;
// List of callbacks to receive update notifications.
base::CallbackList<void()> update_callbacks_;
// List of pending one-shot state key request callbacks.
std::vector<StateKeysCallback> request_callbacks_;
base::WeakPtrFactory<ServerBackedStateKeysBroker> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(ServerBackedStateKeysBroker);
};
} // namespace policy
#endif // CHROME_BROWSER_CHROMEOS_POLICY_SERVER_BACKED_STATE_KEYS_BROKER_H_