Add Promises for EME (Chromium side)

content/renderer/media/crypto/proxy_media_keys.h

 // Copyright 2014 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_CRYPTO_PROXY_MEDIA_KEYS_H_
 #define CONTENT_RENDERER_MEDIA_CRYPTO_PROXY_MEDIA_KEYS_H_
 
+#include <map>
+#include <string>
+
 #include "base/basictypes.h"
+#include "base/containers/hash_tables.h"
+#include "base/containers/scoped_ptr_hash_map.h"
+#include "media/base/cdm_promise.h"
 #include "media/base/media_keys.h"
 
 class GURL;
 
 namespace content {
 
 class RendererCdmManager;
 
 // A MediaKeys proxy that wraps the EME part of RendererCdmManager.
 class ProxyMediaKeys : public media::MediaKeys {
  public:
   static scoped_ptr<ProxyMediaKeys> Create(
       const std::string& key_system,
       const GURL& security_origin,
       RendererCdmManager* 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::NewSessionCdmPromise> promise) OVERRIDE;
+  virtual void LoadSession(
+      const std::string& web_session_id,
+      scoped_ptr<media::NewSessionCdmPromise> promise) OVERRIDE;
+  virtual void UpdateSession(
+      const std::string& web_session_id,
+      const uint8* response,
+      int response_length,
+      scoped_ptr<media::SimpleCdmPromise> promise) OVERRIDE;
+  virtual void ReleaseSession(
+      const std::string& web_session_id,
+      scoped_ptr<media::SimpleCdmPromise> 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 GURL& 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:
+  // The Android-specific code that handles sessions 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). SessionIdMap is used to map between the web_session_id and
+  // the session_id used by the Android-specific code.
+  typedef base::hash_map<std::string, uint32_t> SessionIdMap;
+
+  // The following types keep track of Promises. The index is the
+  // Android-specific session_id, so that returning results can be matched to
+  // the corresponding promise.
+  typedef base::ScopedPtrHashMap<uint32_t, media::CdmPromise> PromiseMap;
+
   ProxyMediaKeys(RendererCdmManager* 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);
 
+  // These functions keep track of Android-specific session_ids <->
+  // web_session_ids mappings.
+  // TODO(jrummell): Remove this once the Android-specific code changes to
+  // support string web 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) const;
+  std::string LookupWebSessionId(uint32_t session_id) const;
+  void DropWebSessionId(const std::string& web_session_id);
+
+  // Helper function to keep track of promises. Adding takes ownership of the
+  // promise, transferred back to caller on take.
+  void SavePromise(uint32_t session_id, scoped_ptr<media::CdmPromise> promise);
+  scoped_ptr<media::CdmPromise> TakePromise(uint32_t session_id);
+
   RendererCdmManager* 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_;
 
+  // Android-specific. See comment above CreateSessionId().
+  uint32_t next_session_id_;
+  SessionIdMap web_session_to_session_id_map_;
+
+  // Keep track of outstanding promises. This map owns the promise object.
+  PromiseMap session_id_to_promise_map_;
+
   DISALLOW_COPY_AND_ASSIGN(ProxyMediaKeys);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_CRYPTO_PROXY_MEDIA_KEYS_H_