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   enum ResolveParameterType {
  39     VOID_TYPE,
  40     STRING_TYPE,
  41     KEY_IDS_VECTOR_TYPE
  42   };
  43
  44   typedef base::Callback<void(MediaKeys::Exception exception_code,
  45                               uint32 system_code,
  46                               const std::string& error_message)>
  47       PromiseRejectedCB;
  48
  49   virtual ~CdmPromise();
  50
  51   // Used to indicate that the operation failed. |exception_code| must be
  52   // specified. |system_code| is a Key System-specific value for the error
  53   // that occurred, or 0 if there is no associated status code or such status
  54   // codes are not supported by the Key System. |error_message| is optional.
  55   virtual void reject(MediaKeys::Exception exception_code,
  56                       uint32 system_code,
  57                       const std::string& error_message);
  58
  59   ResolveParameterType GetResolveParameterType() const {
  60     return parameter_type_;
  61   }
  62
  63  protected:
  64   explicit CdmPromise(ResolveParameterType parameter_type);
  65   CdmPromise(ResolveParameterType parameter_type, PromiseRejectedCB reject_cb);
  66
  67   // If constructed with a |uma_name| (which must be the name of a
  68   // CdmPromiseResult UMA), CdmPromise will report the promise result (success
  69   // or rejection code).
  70   CdmPromise(ResolveParameterType parameter_type,
  71              PromiseRejectedCB reject_cb,
  72              const std::string& uma_name);
  73
  74   // Called by all resolve()/reject() methods to report the UMA result if
  75   // applicable, and update |is_pending_|.
  76   void ReportResultToUMA(ResultCodeForUMA result);
  77
  78   const ResolveParameterType parameter_type_;
  79   PromiseRejectedCB reject_cb_;
  80
  81   // Keep track of whether the promise hasn't been resolved or rejected yet.
  82   bool is_pending_;
  83
  84   // UMA name to report result to.
  85   std::string uma_name_;
  86
  87   DISALLOW_COPY_AND_ASSIGN(CdmPromise);
  88 };
  89
  90 template <typename T>
  91 class MEDIA_EXPORT CdmPromiseTemplate : public CdmPromise {
  92  public:
  93   CdmPromiseTemplate(base::Callback<void(const T&)> resolve_cb,
  94                      PromiseRejectedCB rejected_cb);
  95   CdmPromiseTemplate(base::Callback<void(const T&)> resolve_cb,
  96                      PromiseRejectedCB rejected_cb,
  97                      const std::string& uma_name);
  98   virtual void resolve(const T& result);
  99
 100  protected:
 101   // Allow subclasses to completely override the implementation.
 102   CdmPromiseTemplate();
 103
 104  private:
 105   base::Callback<void(const T&)> resolve_cb_;
 106
 107   DISALLOW_COPY_AND_ASSIGN(CdmPromiseTemplate);
 108 };
 109
 110 // Specialization for no parameter to resolve().
 111 template <>
 112 class MEDIA_EXPORT CdmPromiseTemplate<void> : public CdmPromise {
 113  public:
 114   CdmPromiseTemplate(base::Callback<void(void)> resolve_cb,
 115                      PromiseRejectedCB rejected_cb);
 116   CdmPromiseTemplate(base::Callback<void(void)> resolve_cb,
 117                      PromiseRejectedCB rejected_cb,
 118                      const std::string& uma_name);
 119   virtual void resolve();
 120
 121  protected:
 122   // Allow subclasses to completely override the implementation.
 123   CdmPromiseTemplate();
 124
 125  private:
 126   base::Callback<void(void)> resolve_cb_;
 127
 128   DISALLOW_COPY_AND_ASSIGN(CdmPromiseTemplate);
 129 };
 130
 131 }  // namespace media
 132
 133 #endif  // MEDIA_BASE_CDM_PROMISE_H_