Home | History | Annotate | Download | only in storage 
      1 // Copyright (c) 2012 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 #ifndef CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_STORAGE_QUOTA_ENFORCER_H_
      6 #define CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_STORAGE_QUOTA_ENFORCER_H_
      7 
      8 #include "base/compiler_specific.h"
      9 #include "base/memory/weak_ptr.h"
     10 #include "chrome/browser/value_store/value_store.h"
     11 
     12 namespace extensions {
     13 
     14 // Enforces total quota and a per-setting quota in bytes, and a maximum number
     15 // of setting keys, for a delegate storage area.
     16 class SettingsStorageQuotaEnforcer : public ValueStore {
     17  public:
     18   struct Limits {
     19     // The total quota in bytes.
     20     size_t quota_bytes;
     21 
     22     // The quota for each individual item in bytes.
     23     size_t quota_bytes_per_item;
     24 
     25     // The maximum number of items allowed.
     26     size_t max_items;
     27   };
     28 
     29   SettingsStorageQuotaEnforcer(const Limits& limits, ValueStore* delegate);
     30 
     31   virtual ~SettingsStorageQuotaEnforcer();
     32 
     33   // ValueStore implementation.
     34   virtual size_t GetBytesInUse(const std::string& key) OVERRIDE;
     35   virtual size_t GetBytesInUse(const std::vector<std::string>& keys) OVERRIDE;
     36   virtual size_t GetBytesInUse() OVERRIDE;
     37   virtual ReadResult Get(const std::string& key) OVERRIDE;
     38   virtual ReadResult Get(const std::vector<std::string>& keys) OVERRIDE;
     39   virtual ReadResult Get() OVERRIDE;
     40   virtual WriteResult Set(
     41       WriteOptions options,
     42       const std::string& key,
     43       const Value& value) OVERRIDE;
     44   virtual WriteResult Set(
     45       WriteOptions options, const base::DictionaryValue& values) OVERRIDE;
     46   virtual WriteResult Remove(const std::string& key) OVERRIDE;
     47   virtual WriteResult Remove(const std::vector<std::string>& keys) OVERRIDE;
     48   virtual WriteResult Clear() OVERRIDE;
     49 
     50  private:
     51   // Limits configuration.
     52   const Limits limits_;
     53 
     54   // The delegate storage area.
     55   scoped_ptr<ValueStore> const delegate_;
     56 
     57   // Total bytes in used by |delegate_|. Includes both key lengths and
     58   // JSON-encoded values.
     59   size_t used_total_;
     60 
     61   // Map of item key to its size, including the key itself.
     62   std::map<std::string, size_t> used_per_setting_;
     63 
     64   DISALLOW_COPY_AND_ASSIGN(SettingsStorageQuotaEnforcer);
     65 };
     66 
     67 }  // namespace extensions
     68 
     69 #endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTINGS_STORAGE_QUOTA_ENFORCER_H_
     70