media/base/cdm_promise_adapter.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 MEDIA_BASE_CDM_PROMISE_ADAPTER_H_
   6 #define MEDIA_BASE_CDM_PROMISE_ADAPTER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/containers/scoped_ptr_hash_map.h"
  10 #include "base/macros.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "media/base/cdm_promise.h"
  13 #include "media/base/media_export.h"
  14
  15 namespace media {
  16
  17 // Helps convert CdmPromises to an integer identifier and vice versa. The
  18 // integer identifier is needed where we cannot pass CdmPromises through, such
  19 // as PPAPI, IPC and JNI.
  20 class MEDIA_EXPORT CdmPromiseAdapter {
  21  public:
  22   CdmPromiseAdapter();
  23   ~CdmPromiseAdapter();
  24
  25   // Takes ownership of |promise| and returns an integer promise ID.
  26   uint32_t SavePromise(scoped_ptr<media::CdmPromise> promise);
  27
  28   // Takes the promise for |promise_id|, sanity checks its |type|, and resolves
  29   // it with |result|.
  30   template <typename... T>
  31   void ResolvePromise(uint32_t promise_id, const T&... result);
  32
  33   // Takes the promise for |promise_id| and rejects it with |exception_code|,
  34   // |system_code| and |error_message|.
  35   void RejectPromise(uint32_t promise_id,
  36                      MediaKeys::Exception exception_code,
  37                      uint32 system_code,
  38                      const std::string& error_message);
  39
  40   // Rejects and clears all |promises_|.
  41   void Clear();
  42
  43  private:
  44   // A map between promise IDs and CdmPromises. It owns the CdmPromises.
  45   typedef base::ScopedPtrHashMap<uint32_t, CdmPromise> PromiseMap;
  46
  47   // Finds, takes the ownership of and returns the promise for |promise_id|.
  48   // Returns null if no promise can be found.
  49   scoped_ptr<CdmPromise> TakePromise(uint32_t promise_id);
  50
  51   uint32_t next_promise_id_;
  52   PromiseMap promises_;
  53
  54   DISALLOW_COPY_AND_ASSIGN(CdmPromiseAdapter);
  55 };
  56
  57 }  // namespace media
  58
  59 #endif  // MEDIA_BASE_CDM_PROMISE_ADAPTER_H_