#ifndef CHROME_BROWSER_EXTENSIONS_UPDATER_EXTENSION_CACHE_IMPL_H_
#define CHROME_BROWSER_EXTENSIONS_UPDATER_EXTENSION_CACHE_IMPL_H_
#include <set>
#include <string>
#include <vector>
#include "base/callback_forward.h"
#include "base/files/file_path.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "chrome/browser/extensions/updater/extension_cache.h"
#include "content/public/browser/notification_observer.h"
#include "content/public/browser/notification_registrar.h"
template <typename T> struct DefaultSingletonTraits;
namespace extensions {
class LocalExtensionCache;
class ExtensionCacheImpl : public ExtensionCache,
                           public content::NotificationObserver {
 public:
  static ExtensionCacheImpl* GetInstance();
  
  virtual void Start(const base::Closure& callback) OVERRIDE;
  virtual void Shutdown(const base::Closure& callback) OVERRIDE;
  virtual void AllowCaching(const std::string& id) OVERRIDE;
  virtual bool GetExtension(const std::string& id,
                            base::FilePath* file_path,
                            std::string* version) OVERRIDE;
  virtual void PutExtension(const std::string& id,
                            const base::FilePath& file_path,
                            const std::string& version,
                            const PutExtensionCallback& callback) OVERRIDE;
  
  virtual void Observe(int type,
                       const content::NotificationSource& source,
                       const content::NotificationDetails& details) OVERRIDE;
 private:
  friend struct DefaultSingletonTraits<ExtensionCacheImpl>;
  ExtensionCacheImpl();
  virtual ~ExtensionCacheImpl();
  
  void OnCacheInitialized();
  
  base::WeakPtrFactory<ExtensionCacheImpl> weak_ptr_factory_;
  
  scoped_ptr<LocalExtensionCache> cache_;
  
  std::set<std::string> allowed_extensions_;
  
  std::vector<base::Closure> init_callbacks_;
  
  content::NotificationRegistrar notification_registrar_;
  DISALLOW_COPY_AND_ASSIGN(ExtensionCacheImpl);
};
}  
#endif