Moved c/b/e/*idle* to c/b/e/api/idle/

chrome/browser/extensions/extension_idle_api.cc

-// Copyright (c) 2012 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.
-
-#include "chrome/browser/extensions/extension_idle_api.h"
-
-#include <algorithm>
-#include <map>
-#include <string>
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "base/json/json_writer.h"
-#include "base/message_loop.h"
-#include "base/stl_util.h"
-#include "base/time.h"
-#include "chrome/browser/extensions/extension_event_router.h"
-#include "chrome/browser/extensions/extension_host.h"
-#include "chrome/browser/extensions/extension_idle_api_constants.h"
-#include "chrome/browser/extensions/extension_service.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/common/extensions/extension.h"
-#include "content/public/browser/render_view_host.h"
-
-namespace keys = extension_idle_api_constants;
-
-namespace {
-
-const int kIdlePollInterval = 1;  // Number of seconds between status checks
-                                  // when polling for active.
-const int kThrottleInterval = 1;  // Number of seconds to throttle idle checks
-                                  // for. Return the previously checked idle
-                                  // state if the next check is faster than this
-const int kMinThreshold = 15;  // In seconds.  Set >1 sec for security concerns.
-const int kMaxThreshold = 4*60*60;  // Four hours, in seconds. Not set
-                                    // arbitrarily high for security concerns.
-const unsigned int kMaxCacheSize = 100;  // Number of state queries to cache.
-
-// Calculates the error query interval has in respect to idle interval.
-// The error is defined as amount of the query interval that is not part of the
-// idle interval.
-double QueryErrorFromIdle(double idle_start,
-                          double idle_end,
-                          double query_start,
-                          double query_end) {
-  return query_end - idle_end + std::max(0., idle_start - query_start);
-}
-
-// Internal class which is used to poll for changes in the system idle state.
-class ExtensionIdlePollingTask {
- public:
-  explicit ExtensionIdlePollingTask(int threshold, IdleState last_state,
-      Profile* profile) : threshold_(threshold), last_state_(last_state),
-                          profile_(profile) {}
-
-  // Check if we're active; then restart the polling task. Do this till we are
-  // are in active state.
-  void CheckIdleState();
-  void IdleStateCallback(IdleState state);
-
-  // Create a poll task to check for Idle state
-  static void CreateNewPollTask(int threshold, IdleState state,
-                                Profile* profile);
-
- private:
-  int threshold_;
-  IdleState last_state_;
-  Profile* profile_;
-
-  static bool poll_task_running_;
-
-  DISALLOW_COPY_AND_ASSIGN(ExtensionIdlePollingTask);
-};
-
-// Implementation of ExtensionIdlePollingTask.
-bool ExtensionIdlePollingTask::poll_task_running_ = false;
-
-void ExtensionIdlePollingTask::IdleStateCallback(IdleState current_state) {
-  // If we just came into an active state, notify the extension.
-  if (IDLE_STATE_ACTIVE == current_state && last_state_ != current_state)
-    ExtensionIdleEventRouter::OnIdleStateChange(profile_, current_state);
-
-  ExtensionIdlePollingTask::poll_task_running_ = false;
-
-  ExtensionIdleCache::UpdateCache(threshold_, current_state);
-
-  // Startup another polling task as we exit.
-  if (current_state != IDLE_STATE_ACTIVE)
-    ExtensionIdlePollingTask::CreateNewPollTask(threshold_, current_state,
-                                                profile_);
-
-  // This instance won't be needed anymore.
-  delete this;
-}
-
-void ExtensionIdlePollingTask::CheckIdleState() {
-  CalculateIdleState(threshold_,
-      base::Bind(&ExtensionIdlePollingTask::IdleStateCallback,
-                 base::Unretained(this)));
-}
-
-// static
-void ExtensionIdlePollingTask::CreateNewPollTask(int threshold, IdleState state,
-                                                 Profile* profile) {
-  if (ExtensionIdlePollingTask::poll_task_running_) return;
-
-  ExtensionIdlePollingTask::poll_task_running_ = true;
-  MessageLoop::current()->PostDelayedTask(
-      FROM_HERE,
-      base::Bind(&ExtensionIdlePollingTask::CheckIdleState, base::Unretained(
-          new ExtensionIdlePollingTask(threshold, state, profile))),
-      base::TimeDelta::FromSeconds(kIdlePollInterval));
-}
-
-
-const char* IdleStateToDescription(IdleState state) {
-  if (IDLE_STATE_ACTIVE == state)
-    return keys::kStateActive;
-  if (IDLE_STATE_IDLE == state)
-    return keys::kStateIdle;
-  return keys::kStateLocked;
-};
-
-// Helper function for reporting the idle state.  The lifetime of the object
-// returned is controlled by the caller.
-StringValue* CreateIdleValue(IdleState idle_state) {
-  StringValue* result = new StringValue(IdleStateToDescription(idle_state));
-  return result;
-}
-
-int CheckThresholdBounds(int timeout) {
-  if (timeout < kMinThreshold) return kMinThreshold;
-  if (timeout > kMaxThreshold) return kMaxThreshold;
-  return timeout;
-}
-
-};  // namespace
-
-void ExtensionIdleEventRouter::OnIdleStateChange(Profile* profile,
-                                                 IdleState state) {
-  // Prepare the single argument of the current state.
-  ListValue args;
-  args.Append(CreateIdleValue(state));
-  std::string json_args;
-  base::JSONWriter::Write(&args, &json_args);
-
-  profile->GetExtensionEventRouter()->DispatchEventToRenderers(
-      keys::kOnStateChanged, json_args, profile, GURL(), EventFilteringInfo());
-}
-
-bool ExtensionIdleQueryStateFunction::RunImpl() {
-  int threshold;
-  EXTENSION_FUNCTION_VALIDATE(args_->GetInteger(0, &threshold));
-  threshold = CheckThresholdBounds(threshold);
-
-  IdleState state = ExtensionIdleCache::CalculateIdleState(threshold);
-  if (state != IDLE_STATE_UNKNOWN) {
-    SetResult(CreateIdleValue(state));
-    SendResponse(true);
-    return true;
-  }
-
-  CalculateIdleState(threshold,
-      base::Bind(&ExtensionIdleQueryStateFunction::IdleStateCallback,
-                 this, threshold));
-  // Don't send the response, it'll be sent by our callback
-  return true;
-}
-
-void ExtensionIdleQueryStateFunction::IdleStateCallback(int threshold,
-                                                        IdleState state) {
-  // If our state is not active, make sure we're running a polling task to check
-  // for active state and report it when it changes to active.
-  if (state != IDLE_STATE_ACTIVE) {
-    ExtensionIdlePollingTask::CreateNewPollTask(threshold, state, profile_);
-  }
-
-  SetResult(CreateIdleValue(state));
-
-  ExtensionIdleCache::UpdateCache(threshold, state);
-
-  SendResponse(true);
-}
-
-ExtensionIdleCache::CacheData ExtensionIdleCache::cached_data =
-    {-1, -1, -1, -1};
-
-IdleState ExtensionIdleCache::CalculateIdleState(int threshold) {
-  return CalculateState(threshold, base::Time::Now().ToDoubleT());
-}
-
-void ExtensionIdleCache::UpdateCache(int threshold, IdleState state) {
-  Update(threshold, state, base::Time::Now().ToDoubleT());
-}
-
-IdleState ExtensionIdleCache::CalculateState(int threshold, double now) {
-  if (threshold < kMinThreshold)
-    return IDLE_STATE_UNKNOWN;
-  double threshold_moment = now - static_cast<double>(threshold);
-  double throttle_interval = static_cast<double>(kThrottleInterval);
-
-  // We test for IDEL_STATE_LOCKED first, because the result should be
-  // independent of the data for idle and active state. If last state was
-  // LOCKED and test for LOCKED is satisfied we should always return LOCKED.
-  if (cached_data.latest_locked > 0 &&
-      now - cached_data.latest_locked < throttle_interval)
-    return IDLE_STATE_LOCKED;
-
-  // If thershold moment is beyond the moment after whih we are certain we have
-  // been active, return active state. We allow kThrottleInterval error.
-  if (cached_data.latest_known_active > 0 &&
-      threshold_moment - cached_data.latest_known_active < throttle_interval)
-    return IDLE_STATE_ACTIVE;
-
-  // If total error that query interval has in respect to last recorded idle
-  // interval is less than kThrottleInterval, return IDLE state.
-  // query interval is the interval [now, now - threshold] and the error is
-  // defined as amount of query interval that is outside of idle interval.
-  double error_from_idle =
-      QueryErrorFromIdle(cached_data.idle_interval_start,
-          cached_data.idle_interval_end, threshold_moment, now);
-  if (cached_data.idle_interval_end > 0 &&
-      error_from_idle < throttle_interval)
-    return IDLE_STATE_IDLE;
-
-  return IDLE_STATE_UNKNOWN;
-}
-
-void ExtensionIdleCache::Update(int threshold, IdleState state, double now) {
-  if (threshold < kMinThreshold)
-    return;
-  double threshold_moment = now - static_cast<double>(threshold);
-  switch (state) {
-    case IDLE_STATE_IDLE:
-      if (threshold_moment > cached_data.idle_interval_end) {
-        // Cached and new interval don't overlap. We disregard the cached one.
-        cached_data.idle_interval_start = threshold_moment;
-      } else {
-        // Cached and new interval overlap, so we can combine them. We set
-        // the cached interval begining to less recent one.
-        cached_data.idle_interval_start =
-            std::min(cached_data.idle_interval_start, threshold_moment);
-      }
-      cached_data.idle_interval_end = now;
-      // Reset data for LOCKED state, since the last query result is not
-      // LOCKED.
-      cached_data.latest_locked = -1;
-      break;
-    case IDLE_STATE_ACTIVE:
-      if (threshold_moment > cached_data.latest_known_active)
-        cached_data.latest_known_active = threshold_moment;
-      // Reset data for LOCKED state, since the last query result is not
-      // LOCKED.
-      cached_data.latest_locked = -1;
-      break;
-    case IDLE_STATE_LOCKED:
-      if (threshold_moment > cached_data.latest_locked)
-        cached_data.latest_locked = now;
-      break;
-    default:
-      return;
-  }
-}
-
-int ExtensionIdleCache::get_min_threshold() {
-  return kMinThreshold;
-}
-
-double ExtensionIdleCache::get_throttle_interval() {
-  return static_cast<double>(kThrottleInterval);
-}