backoff_entry_serializer.h

// 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 NET_BASE_BACKOFF_ENTRY_SERIALIZER_H_
#define NET_BASE_BACKOFF_ENTRY_SERIALIZER_H_

#include <memory>

#include "base/macros.h"
#include "base/time/time.h"
#include "net/base/backoff_entry.h"
#include "net/base/net_export.h"

namespace base {
class Value;
class TickClock;
}

namespace net {

// Serialize or deserialize a BackoffEntry, so it can persist beyond the
// lifetime of the browser.
class NET_EXPORT BackoffEntrySerializer {
 public:
  // Serializes the release time and failure count into a ListValue that can
  // later be passed to Deserialize to re-create the given BackoffEntry. The
  // Policy is not serialized, instead callers must pass an identical Policy*
  // when deserializing. |time_now| should be base::Time::Now(), except for
  // tests that want to simulate time changes. The release time TimeTicks will
  // be converted to an absolute timestamp, thus the time will continue counting
  // down even whilst the device is powered off, and will be partially
  // vulnerable to changes in the system clock time.
  static std::unique_ptr<base::Value> SerializeToValue(
      const BackoffEntry& entry,
      base::Time time_now);

  // Deserializes a ListValue back to a BackoffEntry. |policy| MUST be the same
  // Policy as the serialized entry had. |clock| may be NULL. Both |policy| and
  // |clock| (if not NULL) must enclose lifetime of the returned BackoffEntry.
  // |time_now| should be base::Time::Now(), except for tests that want to
  // simulate time changes. The absolute timestamp that was serialized will be
  // converted back to TimeTicks as best as possible. Returns NULL if
  // deserialization was unsuccessful.
  static std::unique_ptr<BackoffEntry> DeserializeFromValue(
      const base::Value& serialized,
      const BackoffEntry::Policy* policy,
      const base::TickClock* clock,
      base::Time time_now);

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(BackoffEntrySerializer);
};

}  // namespace net

#endif  // NET_BASE_BACKOFF_ENTRY_SERIALIZER_H_