Add in expiring budget

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>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "components/leveldb_proto/proto_database.h"
 
 namespace base {
 class Clock;
 class SequencedTaskRunner;
+class Time;
 }
 
 namespace budget_service {
 class Budget;
 }
 
 class GURL;
 
 // 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:
   // Data structure for returing the budget decay expectations to the caller.
-  using BudgetExpectation = std::list<std::pair<double, double>>;
+  using BudgetExpectation = std::list<std::pair<double, base::Time>>;
 
   // Callback for setting a budget value.
   using StoreBudgetCallback = base::Callback<void(bool success)>;
 
   // Callback for getting a list of all budget chunks.
   using GetBudgetDetailsCallback = base::Callback<
       void(bool success, double debt, const BudgetExpectation& expectation)>;
 
   // 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(const base::FilePath& database_dir,
                  const scoped_refptr<base::SequencedTaskRunner>& task_runner);
   ~BudgetDatabase();
 
   // Get the full budget expectation for the origin. This will return any
   // debt as well as a sequence of time points and the expected budget at
   // those times.
   void GetBudgetDetails(const GURL& origin,
                         const GetBudgetDetailsCallback& callback);
 
   // Add budget for an origin. The caller specifies the amount, and the method
   // adds the amount to the cache with the correct expiration. Callback is
-  // invoked only after the newly cached value is written to storage.
+  // invoked only after the newly cached value is written to storage. This
+  // should only be called after the budget has been read from the database.
   void AddBudget(const GURL& origin,
                  double amount,
                  const StoreBudgetCallback& callback);
 
  private:
   friend class BudgetDatabaseTest;
 
   // Used to allow tests to change time for testing.
   void SetClockForTesting(std::unique_ptr<base::Clock> clock);
 
   // Data structure for caching budget information.
-  using BudgetChunks = std::vector<std::pair<double, double>>;
+  using BudgetChunks = std::vector<std::pair<double, base::Time>>;
   using BudgetInfo = std::pair<double, BudgetChunks>;
 
   using AddToCacheCallback = base::Callback<void(bool success)>;
 
   void OnDatabaseInit(bool success);
 
+  bool IsCached(const GURL& origin) const;
+
   void AddToCache(const GURL& origin,
                   const AddToCacheCallback& callback,
                   bool success,
                   std::unique_ptr<budget_service::Budget> budget);
 
   void DidGetBudget(const GURL& origin,
                     const GetBudgetDetailsCallback& callback,
                     bool success);
 
   void WriteCachedValuesToDatabase(const GURL& origin,
                                    const StoreBudgetCallback& callback);
 
+  void CleanupExpiredBudget(const GURL& origin);
+
   // 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_