Add Promises for EME (Chromium side)

media/base/media_keys.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_MEDIA_KEYS_H_
 #define MEDIA_BASE_MEDIA_KEYS_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "media/base/media_export.h"
 
 namespace media {
 
 class Decryptor;
 
+template <typename T>
+class CdmPromise;
+
+typedef CdmPromise<std::string> NewSessionCdmPromise;
+typedef CdmPromise<void> SimpleCdmPromise;
+
 // Performs media key operations.
 //
 // All key operations are called on the renderer thread. Therefore, these calls
 // should be fast and nonblocking; key events should be fired asynchronously.
 class MEDIA_EXPORT MediaKeys {
  public:
   // Reported to UMA, so never reuse a value!
   // Must be kept in sync with blink::WebMediaPlayerClient::MediaKeyErrorCode
   // (enforced in webmediaplayer_impl.cc).
   enum KeyError {

[ddorwin, 2014/05/23 16:41:09]

This is no longer used in this header, so it probably doesn't belong here. Do we
now only need it in ProxyDecryptor?

[jrummell, 2014/05/29 00:54:40]

And in android/proxy_media_keys (which might get fixed when I get to the recent
Android changes). Added a TODO as a reminder.

     kUnknownError = 1,
     kClientError,
     // The commented v0.1b values below have never been used.
     // kServiceError,
     kOutputError = 4,
     // kHardwareChangeError,
     // kDomainError,
     kMaxKeyError  // Must be last and greater than any legit value.
   };
 
+  // Must be a superset of cdm::MediaKeyException.
+  enum Exception {
+    EXCEPTION_NO_MODIFICATION_ALLOWED_ERROR,
+    EXCEPTION_NOT_FOUND_ERROR,
+    EXCEPTION_NOT_SUPPORTED_ERROR,
+    EXCEPTION_INVALID_STATE_ERROR,
+    EXCEPTION_INVALID_MODIFICATION_ERROR,
+    EXCEPTION_INVALID_ACCESS_ERROR,
+    EXCEPTION_SECURITY_ERROR,
+    EXCEPTION_ABORT_ERROR,
+    EXCEPTION_QUOTA_EXCEEDED_ERROR,
+    EXCEPTION_TIMEOUT_ERROR,
+    EXCEPTION_UNKNOWN_ERROR,
+    EXCEPTION_DATA_ERROR,
+    EXCEPTION_VERSION_ERROR,
+    EXCEPTION_NOT_READABLE_ERROR,
+    EXCEPTION_OPERATION_ERROR,
+    EXCEPTION_CLIENT_ERROR,
+    EXCEPTION_OUTPUT_ERROR

[xhwang, 2014/05/23 06:01:23]

Hmm, DOM "exceptions" are all "error"s... Generally enums should start with the
enum name (in this case EXCEPTION). But "EXCEPTION" and "ERROR" seems redundant.
I'am fine with dropping the "EXCEPTION" prefix... WDYT? +ddorwin for comments.

[ddorwin, 2014/05/23 16:41:09]

I don't think there is a general *requirement* for prefixes. (The Content API
and other areas may impose one.) I think it's fine to drop EXCEPTION, especially
since ...ERROR is consistent with the DOM error names.

We should try to be consistent in the enum below too. WDYT?
Maybe TEMPORARY_SESSION?

[xhwang, 2014/05/23 16:47:36]

I have no strong opinion on this one :)

[jrummell, 2014/05/29 00:54:40]

Done.

[jrummell, 2014/05/29 00:54:40]

Done.

+  };
+
+  // Type of license required when creating/loading a session.
+  // Must be consistent with the values specified in the spec:
+  // https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#extensions
+  enum SessionType {
+    SESSION_TYPE_TEMPORARY,
+    SESSION_TYPE_PERSISTENT
+  };
+
   const static uint32 kInvalidSessionId = 0;
 
   MediaKeys();
   virtual ~MediaKeys();
 
-  // Creates a session with the |content_type| and |init_data| provided.
-  // Returns true if a session is successfully created, false otherwise.
+  // Creates a session with the |init_data_type|, |init_data| and |session_type|
+  // provided.
   // Note: UpdateSession() and ReleaseSession() should only be called after
-  // SessionCreatedCB is fired.
-  // TODO(jrummell): Remove return value when prefixed API is removed.
-  // See http://crbug.com/342510
-  virtual bool CreateSession(uint32 session_id,
-                             const std::string& content_type,
+  // |promise| is resolved.
+  virtual void CreateSession(const std::string& init_data_type,
                              const uint8* init_data,
-                             int init_data_length) = 0;
+                             int init_data_length,
+                             SessionType session_type,
+                             scoped_ptr<NewSessionCdmPromise> promise) = 0;
 
   // Loads a session with the |web_session_id| provided.
   // Note: UpdateSession() and ReleaseSession() should only be called after
-  // SessionCreatedCB is fired.
-  virtual void LoadSession(uint32 session_id,
-                           const std::string& web_session_id) = 0;
+  // |promise| is resolved.
+  virtual void LoadSession(const std::string& web_session_id,
+                           scoped_ptr<NewSessionCdmPromise> promise) = 0;
 
-  // Updates a session specified by |session_id| with |response|.
-  virtual void UpdateSession(uint32 session_id,
+  // Updates a session specified by |web_session_id| with |response|.
+  virtual void UpdateSession(const std::string& web_session_id,
                              const uint8* response,
-                             int response_length) = 0;
+                             int response_length,
+                             scoped_ptr<SimpleCdmPromise> promise) = 0;
 
-  // Releases the session specified by |session_id|.
-  virtual void ReleaseSession(uint32 session_id) = 0;
+  // Releases the session specified by |web_session_id|.
+  virtual void ReleaseSession(const std::string& web_session_id,
+                              scoped_ptr<SimpleCdmPromise> promise) = 0;
 
   // Gets the Decryptor object associated with the MediaKeys. Returns NULL if
   // no Decryptor object is associated. The returned object is only guaranteed
   // to be valid during the MediaKeys' lifetime.
   virtual Decryptor* GetDecryptor();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MediaKeys);
 };
 
 // Key event callbacks. See the spec for details:
 // https://dvcs.w3.org/hg/html-media/raw-file/default/encrypted-media/encrypted-media.html#event-summary
-typedef base::Callback<
-    void(uint32 session_id, const std::string& web_session_id)>
-    SessionCreatedCB;
-
 // TODO(xhwang): Use GURL for |destination_url|. See http://crbug.com/372877
-typedef base::Callback<void(uint32 session_id,
+typedef base::Callback<void(const std::string& web_session_id,
                             const std::vector<uint8>& message,
                             const std::string& destination_url)>
     SessionMessageCB;
 
-typedef base::Callback<void(uint32 session_id)> SessionReadyCB;
+typedef base::Callback<void(const std::string& web_session_id)> SessionReadyCB;
 
-typedef base::Callback<void(uint32 session_id)> SessionClosedCB;
+typedef base::Callback<void(const std::string& web_session_id)> SessionClosedCB;
 
-typedef base::Callback<void(uint32 session_id,
-                            media::MediaKeys::KeyError error_code,
-                            uint32 system_code)> SessionErrorCB;
+typedef base::Callback<void(const std::string& web_session_id,
+                            MediaKeys::Exception exception_code,
+                            uint32 system_code,
+                            const std::string& error_message)> SessionErrorCB;
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_MEDIA_KEYS_H_