src/sync/engine/cryptographer_provider.h

   1 // Copyright 2014 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 SYNC_ENGINE_CRYPTOGRAPHER_PROVIDER_H_
   6 #define SYNC_ENGINE_CRYPTOGRAPHER_PROVIDER_H_
   7
   8 #include "base/memory/scoped_ptr.h"
   9 #include "sync/base/sync_export.h"
  10
  11 namespace syncer {
  12
  13 class Cryptographer;
  14 class ScopedCryptographerRef;
  15 class ScopedCryptographerInternal;
  16
  17 // An interface for providing clients with a ScopedCryptographerRef.
  18 //
  19 // Used to expose the syncable::Directory's cryptographer to clients that
  20 // would otherwise not have access to the Directory.
  21 class SYNC_EXPORT_PRIVATE CryptographerProvider {
  22  public:
  23   CryptographerProvider();
  24   virtual ~CryptographerProvider();
  25
  26   virtual bool InitScopedCryptographerRef(ScopedCryptographerRef* scoped) = 0;
  27 };
  28
  29 // A concrete class representing a reference to a cryptographer.
  30 //
  31 // Access to the cryptographer is lost when this class goes out of scope.
  32 class SYNC_EXPORT_PRIVATE ScopedCryptographerRef {
  33  public:
  34   ScopedCryptographerRef();
  35   ~ScopedCryptographerRef();
  36
  37   bool Initialize(ScopedCryptographerInternal* impl);
  38   bool IsValid() const;
  39   Cryptographer* Get() const;
  40
  41  private:
  42   scoped_ptr<ScopedCryptographerInternal> scoped_cryptographer_internal_;
  43
  44   DISALLOW_COPY_AND_ASSIGN(ScopedCryptographerRef);
  45 };
  46
  47 // An interface class used in the implementation of the ScopedCryptographerRef.
  48 //
  49 // We use this class to allow different implementations of
  50 // CryptographerProvider to implement InitScopedCryptographer in different
  51 // ways.  The ScopedCryptographerRef itself must be stack-allocated, so it
  52 // can't vary depending on which kind of CryptographerProvider is used to
  53 // intialize it.
  54 class SYNC_EXPORT_PRIVATE ScopedCryptographerInternal {
  55  public:
  56   ScopedCryptographerInternal();
  57   virtual ~ScopedCryptographerInternal();
  58
  59   virtual Cryptographer* Get() const = 0;
  60 };
  61
  62 }  // namespace syncer
  63
  64 #endif  // SYNC_ENGINE_CRYPTOGRAPHER_PROVIDER_H_