src/chrome/browser/chromeos/policy/server_backed_state_keys_broker.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/chromeos/policy/server_backed_state_keys_broker.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/location.h"
  11 #include "base/task_runner.h"
  12 #include "chromeos/dbus/session_manager_client.h"
  13
  14 namespace policy {
  15
  16 namespace {
  17
  18 // Refresh interval for state keys. There's a quantized time component in
  19 // state key generation, so they rotate over time. The quantum size is pretty
  20 // coarse though (currently 2^23 seconds), so simply polling for a new state
  21 // keys once a day is good enough.
  22 const int kPollIntervalSeconds = 60 * 60 * 24;
  23
  24 }  // namespace
  25
  26 ServerBackedStateKeysBroker::ServerBackedStateKeysBroker(
  27     chromeos::SessionManagerClient* session_manager_client,
  28     scoped_refptr<base::TaskRunner> delayed_task_runner)
  29     : session_manager_client_(session_manager_client),
  30       delayed_task_runner_(delayed_task_runner),
  31       requested_(false),
  32       initial_retrieval_completed_(false),
  33       weak_factory_(this) {
  34 }
  35
  36 ServerBackedStateKeysBroker::~ServerBackedStateKeysBroker() {
  37 }
  38
  39 ServerBackedStateKeysBroker::Subscription
  40 ServerBackedStateKeysBroker::RegisterUpdateCallback(
  41     const base::Closure& callback) {
  42   if (!available())
  43     FetchStateKeys();
  44   return update_callbacks_.Add(callback);
  45 }
  46
  47 void ServerBackedStateKeysBroker::RequestStateKeys(
  48     const StateKeysCallback& callback) {
  49   if (pending()) {
  50     request_callbacks_.push_back(callback);
  51     FetchStateKeys();
  52     return;
  53   }
  54
  55   if (!callback.is_null())
  56     callback.Run(state_keys_);
  57   return;
  58 }
  59
  60 void ServerBackedStateKeysBroker::FetchStateKeys() {
  61   if (!requested_) {
  62     requested_ = true;
  63     session_manager_client_->GetServerBackedStateKeys(
  64         base::Bind(&ServerBackedStateKeysBroker::StoreStateKeys,
  65                    weak_factory_.GetWeakPtr()));
  66   }
  67 }
  68
  69 void ServerBackedStateKeysBroker::StoreStateKeys(
  70     const std::vector<std::string>& state_keys) {
  71   bool send_notification = !initial_retrieval_completed_;
  72
  73   requested_ = false;
  74   initial_retrieval_completed_ = true;
  75   if (state_keys.empty()) {
  76     LOG(WARNING) << "Failed to obtain server-backed state keys.";
  77   } else if (state_keys.end() !=
  78              std::find(state_keys.begin(), state_keys.end(), std::string())) {
  79     LOG(WARNING) << "Bad state keys.";
  80   } else {
  81     send_notification |= state_keys_ != state_keys;
  82     state_keys_ = state_keys;
  83   }
  84
  85   if (send_notification)
  86     update_callbacks_.Notify();
  87
  88   std::vector<StateKeysCallback> callbacks;
  89   request_callbacks_.swap(callbacks);
  90   for (std::vector<StateKeysCallback>::const_iterator callback(
  91            callbacks.begin());
  92        callback != callbacks.end();
  93        ++callback) {
  94     if (!callback->is_null())
  95       callback->Run(state_keys_);
  96   }
  97
  98   delayed_task_runner_->PostDelayedTask(
  99       FROM_HERE,
 100       base::Bind(&ServerBackedStateKeysBroker::FetchStateKeys,
 101                  weak_factory_.GetWeakPtr()),
 102       base::TimeDelta::FromSeconds(kPollIntervalSeconds));
 103 }
 104
 105 }  // namespace policy