media/base/cdm_promise.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_H_
   6 #define MEDIA_BASE_CDM_PROMISE_H_
   7
   8 #include <string>
   9
  10 #include "base/basictypes.h"
  11 #include "base/callback.h"
  12 #include "media/base/media_export.h"
  13 #include "media/base/media_keys.h"
  14
  15 namespace media {
  16
  17 // Interface for promises being resolved/rejected in response to various
  18 // session actions. These may be called synchronously or asynchronously.
  19 // The promise must be resolved or rejected exactly once. It is expected that
  20 // the caller free the promise once it is resolved/rejected.
  21 //
  22 // This is only the base class, as parameter to resolve() varies.
  23 class MEDIA_EXPORT CdmPromise {
  24  public:
  25   // A superset of media::MediaKeys::Exception for UMA reporting.
  26   enum ResultCodeForUMA {
  27     SUCCESS,
  28     NOT_SUPPORTED_ERROR,
  29     INVALID_STATE_ERROR,
  30     INVALID_ACCESS_ERROR,
  31     QUOTA_EXCEEDED_ERROR,
  32     UNKNOWN_ERROR,
  33     CLIENT_ERROR,
  34     OUTPUT_ERROR,
  35     NUM_RESULT_CODES
  36   };
  37
  38   typedef base::Callback<void(MediaKeys::Exception exception_code,
  39                               uint32 system_code,
  40                               const std::string& error_message)>
  41       PromiseRejectedCB;
  42
  43   virtual ~CdmPromise();
  44
  45   // Used to indicate that the operation failed. |exception_code| must be
  46   // specified. |system_code| is a Key System-specific value for the error
  47   // that occurred, or 0 if there is no associated status code or such status
  48   // codes are not supported by the Key System. |error_message| is optional.
  49   virtual void reject(MediaKeys::Exception exception_code,
  50                       uint32 system_code,
  51                       const std::string& error_message);
  52
  53  protected:
  54   CdmPromise();
  55   CdmPromise(PromiseRejectedCB reject_cb);
  56
  57   // If constructed with a |uma_name| (which must be the name of a
  58   // CdmPromiseResult UMA), CdmPromise will report the promise result (success
  59   // or rejection code).
  60   CdmPromise(PromiseRejectedCB reject_cb, const std::string& uma_name);
  61
  62   PromiseRejectedCB reject_cb_;
  63
  64   // Keep track of whether the promise hasn't been resolved or rejected yet.
  65   bool is_pending_;
  66
  67   // UMA to report result to.
  68   std::string uma_name_;
  69
  70   DISALLOW_COPY_AND_ASSIGN(CdmPromise);
  71 };
  72
  73 template <typename T>
  74 class MEDIA_EXPORT CdmPromiseTemplate : public CdmPromise {
  75  public:
  76   CdmPromiseTemplate(base::Callback<void(const T&)> resolve_cb,
  77                      PromiseRejectedCB rejected_cb);
  78   CdmPromiseTemplate(base::Callback<void(const T&)> resolve_cb,
  79                      PromiseRejectedCB rejected_cb,
  80                      const std::string& uma_name);
  81   virtual ~CdmPromiseTemplate();
  82   virtual void resolve(const T& result);
  83
  84  protected:
  85   // Allow subclasses to completely override the implementation.
  86   // TODO(jrummell): Remove when derived class SessionLoadedPromise
  87   // (in ppapi_decryptor.cc) is no longer needed.
  88   CdmPromiseTemplate();
  89
  90  private:
  91   base::Callback<void(const T&)> resolve_cb_;
  92
  93   DISALLOW_COPY_AND_ASSIGN(CdmPromiseTemplate);
  94 };
  95
  96 // Specialization for no parameter to resolve().
  97 template <>
  98 class MEDIA_EXPORT CdmPromiseTemplate<void> : public CdmPromise {
  99  public:
 100   CdmPromiseTemplate(base::Callback<void(void)> resolve_cb,
 101                      PromiseRejectedCB rejected_cb);
 102   CdmPromiseTemplate(base::Callback<void(void)> resolve_cb,
 103                      PromiseRejectedCB rejected_cb,
 104                      const std::string& uma_name);
 105   virtual ~CdmPromiseTemplate();
 106   virtual void resolve();
 107
 108  protected:
 109   // Allow subclasses to completely override the implementation.
 110   CdmPromiseTemplate();
 111
 112  private:
 113   base::Callback<void(void)> resolve_cb_;
 114
 115   DISALLOW_COPY_AND_ASSIGN(CdmPromiseTemplate);
 116 };
 117
 118 }  // namespace media
 119
 120 #endif  // MEDIA_BASE_CDM_PROMISE_H_