Start plumbing connections from the BudgetManager to the BudgetDatabase

chrome/browser/budget_service/budget_manager.h

 // Copyright 2016 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_BUDGET_SERVICE_BUDGET_MANAGER_H_
 #define CHROME_BROWSER_BUDGET_SERVICE_BUDGET_MANAGER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
+#include "chrome/browser/budget_service/budget_database.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "third_party/WebKit/public/platform/modules/budget_service/budget_service.mojom.h"
 #include "url/gurl.h"
 
 class Profile;
 
 namespace base {
 class Clock;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 // A budget manager to help Chrome decide how much background work a service
 // worker should be able to do on behalf of the user. The budget is calculated
 // based on the Site Engagment Score and is consumed when a origin does
 // background work on behalf of the user.
 class BudgetManager : public KeyedService {
  public:
   explicit BudgetManager(Profile* profile);
   ~BudgetManager() override;
 
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // Query for the base cost for any background processing.
   static double GetCost(blink::mojom::BudgetOperationType type);
 
   using GetBudgetCallback = base::Callback<void(double budget)>;
+  using ReserveCallback = base::Callback<void(bool success)>;
+  using ConsumeCallback = base::Callback<void(bool success)>;
 
   // Get the budget associated with the origin. This is passed to the
   // callback. Budget will be a value between 0.0 and
   // SiteEngagementScore::kMaxPoints.
   void GetBudget(const GURL& origin, const GetBudgetCallback& callback);
 
   // Store the budget associated with the origin. Budget should be a value
   // between 0.0 and SiteEngagementScore::kMaxPoints. closure will be called
   // when the store completes.
   void StoreBudget(const GURL& origin,
                    double budget,
                    const base::Closure& closure);
 
+  // Spend enough budget to cover the cost of the desired action and create
+  // a reservation for that action. If this returns true to the callback, then
+  // the next action will consume that reservation and not cost any budget.
+  void Reserve(const GURL& origin,
+               blink::mojom::BudgetOperationType type,
+               const ReserveCallback& callback);
+
+  // Spend budget, first consuming a reservation if one exists, or spend
+  // directly from the budget.
+  void Consume(const GURL& origin,
+               blink::mojom::BudgetOperationType type,
+               const ConsumeCallback& callback);
+
  private:
   friend class BudgetManagerTest;
 
+  // Called as a callback from BudgetDatabase after it has made a reserve
+  // decision.
+  void DidReserve(const GURL& origin,
+                  blink::mojom::BudgetOperationType type,
+                  const ReserveCallback& callback,
+                  bool success);
+
   // Used to allow tests to fast forward/reverse time.
   void SetClockForTesting(std::unique_ptr<base::Clock> clock);
 
   // The clock used to vend times.
   std::unique_ptr<base::Clock> clock_;
 
   Profile* profile_;
+  BudgetDatabase db_;
+
+  std::unordered_map<std::string, int> reservation_map_;
+  base::WeakPtrFactory<BudgetManager> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(BudgetManager);
 };
 
 #endif  // CHROME_BROWSER_BUDGET_SERVICE_BUDGET_MANAGER_H_