Add Promises for EME (Chromium side)

content/renderer/media/android/proxy_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 CONTENT_RENDERER_MEDIA_ANDROID_PROXY_MEDIA_KEYS_H_
 #define CONTENT_RENDERER_MEDIA_ANDROID_PROXY_MEDIA_KEYS_H_
 
+#include <map>
+#include <string>
+
 #include "base/basictypes.h"
+#include "base/containers/hash_tables.h"
 #include "media/base/media_keys.h"
 
 class GURL;
 
 namespace content {
 
 class RendererMediaPlayerManager;
 
 // A MediaKeys proxy that wraps the EME part of RendererMediaPlayerManager.
 // TODO(xhwang): Instead of accessing RendererMediaPlayerManager directly, let
 // RendererMediaPlayerManager return a MediaKeys object that can be used by
 // ProxyDecryptor directly. Then we can remove this class!
 class ProxyMediaKeys : public media::MediaKeys {
  public:
   static scoped_ptr<ProxyMediaKeys> Create(
       const std::string& key_system,
       const GURL& security_origin,
       RendererMediaPlayerManager* manager,
-      const media::SessionCreatedCB& session_created_cb,
       const media::SessionMessageCB& session_message_cb,
       const media::SessionReadyCB& session_ready_cb,
       const media::SessionClosedCB& session_closed_cb,
       const media::SessionErrorCB& session_error_cb);
 
   virtual ~ProxyMediaKeys();
 
   // MediaKeys implementation.
-  virtual bool CreateSession(uint32 session_id,
-                             const std::string& content_type,
-                             const uint8* init_data,
-                             int init_data_length) OVERRIDE;
-  virtual void LoadSession(uint32 session_id,
-                           const std::string& web_session_id) OVERRIDE;
-  virtual void UpdateSession(uint32 session_id,
-                             const uint8* response,
-                             int response_length) OVERRIDE;
-  virtual void ReleaseSession(uint32 session_id) OVERRIDE;
+  virtual void CreateSession(
+      const std::string& init_data_type,
+      const uint8* init_data,
+      int init_data_length,
+      SessionType session_type,
+      scoped_ptr<media::CdmPromise<std::string> > promise) OVERRIDE;
+  virtual void LoadSession(
+      const std::string& web_session_id,
+      scoped_ptr<media::CdmPromise<std::string> > promise) OVERRIDE;
+  virtual void UpdateSession(
+      const std::string& web_session_id,
+      const uint8* response,
+      int response_length,
+      scoped_ptr<media::CdmPromise<void> > promise) OVERRIDE;
+  virtual void ReleaseSession(
+      const std::string& web_session_id,
+      scoped_ptr<media::CdmPromise<void> > promise) OVERRIDE;
 
   // Callbacks.
   void OnSessionCreated(uint32 session_id, const std::string& web_session_id);
   void OnSessionMessage(uint32 session_id,
                         const std::vector<uint8>& message,
                         const std::string& destination_url);
   void OnSessionReady(uint32 session_id);
   void OnSessionClosed(uint32 session_id);
   void OnSessionError(uint32 session_id,
                       media::MediaKeys::KeyError error_code,
                       uint32 system_code);
 
   int GetCdmId() const;
 
  private:
+  typedef base::hash_map<std::string, uint32_t> SessionMap;
+  typedef std::map<uint32_t, media::CdmPromise<void>*> VoidPromiseMap;
+  typedef std::map<uint32_t, media::CdmPromise<std::string>*> SessionPromiseMap;
+
   ProxyMediaKeys(RendererMediaPlayerManager* manager,
-                 const media::SessionCreatedCB& session_created_cb,
                  const media::SessionMessageCB& session_message_cb,
                  const media::SessionReadyCB& session_ready_cb,
                  const media::SessionClosedCB& session_closed_cb,
                  const media::SessionErrorCB& session_error_cb);
 
   void InitializeCdm(const std::string& key_system,
                      const GURL& security_origin);
 
+  // The Android API uses integer session ids (basically a reference id),
+  // but media::MediaKeys bases everything on web_session_id (a string
+  // representing the actual session id as generated by the CDM). These
+  // functions keep track of session_ids <-> web_session_ids mappings.
+  // TODO(jrummell): Remove this once the Android API changes to support
+  // string session ids.
+  uint32_t CreateSessionId();
+  void AssignWebSessionId(uint32_t session_id,
+                          const std::string& web_session_id);
+  uint32_t LookupSessionId(const std::string& web_session_id);
+  std::string LookupWebSessionId(uint32_t session_id);
+  void DropWebSessionId(std::string web_session_id);
+
+  // Helper function to keep track of promises. Adding takes ownership of the
+  // promise, transferred back to caller on lookup.
+  void RegisterVoidPromise(uint32_t session_id,
+                           scoped_ptr<media::CdmPromise<void> > promise);
+  scoped_ptr<media::CdmPromise<void> > RetrieveVoidPromise(uint32_t session_id);
+  void RegisterSessionPromise(
+      uint32_t session_id,
+      scoped_ptr<media::CdmPromise<std::string> > promise);
+  scoped_ptr<media::CdmPromise<std::string> > RetrieveSessionPromise(
+      uint32_t session_id);
+
   // CDM ID should be unique per renderer process.
   // TODO(xhwang): Use uint32 to prevent undefined overflow behavior.
   static int next_cdm_id_;
 
   RendererMediaPlayerManager* manager_;
   int cdm_id_;
-  media::SessionCreatedCB session_created_cb_;
   media::SessionMessageCB session_message_cb_;
   media::SessionReadyCB session_ready_cb_;
   media::SessionClosedCB session_closed_cb_;
   media::SessionErrorCB session_error_cb_;
 
+  uint32_t next_session_id_;
+  SessionMap web_session_to_session_id_map_;
+
+  // Keep track of outstanding promises. These maps owns the promise object.
+  VoidPromiseMap session_id_to_promise_map_;
+  SessionPromiseMap session_id_to_new_session_promise_map_;
+
   DISALLOW_COPY_AND_ASSIGN(ProxyMediaKeys);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_ANDROID_PROXY_MEDIA_KEYS_H_