Connect Mojo budget_service to BudgetManager implementation of Reserve.

chrome/browser/budget_service/budget_database.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_DATABASE_H_
 #define CHROME_BROWSER_BUDGET_SERVICE_BUDGET_DATABASE_H_
 
 #include <list>
 #include <memory>
 #include <unordered_map>
@@ skipping 14 matching lines @@
 class Budget;
 }
 
 class GURL;
 class Profile;
 
 // A class used to asynchronously read and write details of the budget
 // assigned to an origin. The class uses an underlying LevelDB.
 class BudgetDatabase {
  public:
-  // Callback for setting a budget value.
-  using StoreBudgetCallback = base::Callback<void(bool success)>;
-
   // Callback for getting a list of all budget chunks.
   using GetBudgetCallback = blink::mojom::BudgetService::GetBudgetCallback;
 
+  // Callback for SpendBudget. This will be invoked only after the spend has
+  // been written to the database. It takes two values, an error type which
+  // indicates if there was a particular error, and a bool that indicates
+  // whether the origin had budget to spend.
+  using SpendBudgetCallback = blink::mojom::BudgetService::ReserveCallback;

[Peter Beverloo, 2016/09/08 17:16:06]

We should probably just redefine the callback format. A reader interested in
spending budget now suddenly has to look up what reserving budget means (but I
want to spend it!), which lives in a generated file.

That'd also save you from having to explain the arguments in English, as you do
above.

[harkness, 2016/09/13 13:41:28]

Done.

+
   // The database_dir specifies the location of the budget information on
   // disk. The task_runner is used by the ProtoDatabase to handle all blocking
   // calls and disk access.
   BudgetDatabase(Profile* profile,
                  const base::FilePath& database_dir,
                  const scoped_refptr<base::SequencedTaskRunner>& task_runner);
   ~BudgetDatabase();
 
   // Get the full budget expectation for the origin. This will return a
   // sequence of time points and the expected budget at those times.
   void GetBudgetDetails(const GURL& origin, const GetBudgetCallback& callback);
 
-  // Spend a particular amount of budget for an origin. The callback takes
-  // a boolean which indicates whether the origin had enough budget to spend.
-  // If it returns success, then the budget was deducted and the result written
-  // to the database.
+  // Spend a particular amount of budget for an origin. The callback indicates
+  // whether there was an error and if the origin had enough budget.
   void SpendBudget(const GURL& origin,
                    double amount,
-                   const StoreBudgetCallback& callback);
+                   const SpendBudgetCallback& callback);
 
  private:
   friend class BudgetDatabaseTest;
 
   // Used to allow tests to change time for testing.
   void SetClockForTesting(std::unique_ptr<base::Clock> clock);
 
   // Holds information about individual pieces of awarded budget. There is a
   // one-to-one mapping of these to the chunks in the underlying database.
   struct BudgetChunk {
@@ skipping 16 matching lines @@
     BudgetInfo();
     BudgetInfo(const BudgetInfo&& other);
     ~BudgetInfo();
 
     base::Time last_engagement_award;
     BudgetChunks chunks;
 
     DISALLOW_COPY_AND_ASSIGN(BudgetInfo);
   };
 
-  using AddToCacheCallback = base::Callback<void(bool success)>;
-  using SyncCacheCallback = base::Callback<void(bool success)>;
+  // Callback for writing budget values to the database.
+  using StoreBudgetCallback = base::Callback<void(bool success)>;
+
+  using CacheCallback = base::Callback<void(bool success)>;
 
   void OnDatabaseInit(bool success);
 
   bool IsCached(const GURL& origin) const;
 
   double GetBudget(const GURL& origin) const;
 
   void AddToCache(const GURL& origin,
-                  const AddToCacheCallback& callback,
+                  const CacheCallback& callback,
                   bool success,
                   std::unique_ptr<budget_service::Budget> budget);
 
   void GetBudgetAfterSync(const GURL& origin,
                           const GetBudgetCallback& callback,
                           bool success);
 
   void SpendBudgetAfterSync(const GURL& origin,
                             double amount,
-                            const StoreBudgetCallback& callback,
+                            const SpendBudgetCallback& callback,
                             bool success);
 
+  void SpendBudgetAfterWrite(const SpendBudgetCallback& callback, bool success);
+
   void WriteCachedValuesToDatabase(const GURL& origin,
                                    const StoreBudgetCallback& callback);
 
-  void SyncCache(const GURL& origin, const SyncCacheCallback& callback);
+  void SyncCache(const GURL& origin, const CacheCallback& callback);
   void SyncLoadedCache(const GURL& origin,
-                       const SyncCacheCallback& callback,
+                       const CacheCallback& callback,
                        bool success);
 
   // Add budget based on engagement with an origin. The method queries for the
   // engagement score of the origin, and then calculates when engagement budget
   // was last awarded and awards a portion of the score based on that.
   // This only writes budget to the cache.
   void AddEngagementBudget(const GURL& origin);
 
   bool CleanupExpiredBudget(const GURL& origin);
 
   Profile* profile_;
 
   // The database for storing budget information.
   std::unique_ptr<leveldb_proto::ProtoDatabase<budget_service::Budget>> db_;
 
   // Cached data for the origins which have been loaded.
   std::unordered_map<std::string, BudgetInfo> budget_map_;
 
   // The clock used to vend times.
   std::unique_ptr<base::Clock> clock_;
 
   base::WeakPtrFactory<BudgetDatabase> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BudgetDatabase);
 };
 
 #endif  // CHROME_BROWSER_BUDGET_SERVICE_BUDGET_DATABASE_H_