Add Promises for EME (Chromium side)

content/renderer/media/crypto/proxy_decryptor.cc

 // 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.
 
 #include "content/renderer/media/crypto/proxy_decryptor.h"
 
 #include <cstring>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "content/renderer/media/crypto/content_decryption_module_factory.h"
+#include "media/base/cdm_promise.h"
 #include "media/cdm/json_web_key.h"
 #include "media/cdm/key_system_names.h"
 
 #if defined(ENABLE_PEPPER_CDMS)
 #include "content/renderer/media/crypto/pepper_cdm_wrapper.h"
 #endif  // defined(ENABLE_PEPPER_CDMS)
 
 #if defined(OS_ANDROID)
 #include "content/renderer/media/android/renderer_media_player_manager.h"
 #endif  // defined(OS_ANDROID)
 
 namespace content {
 
-// Since these reference IDs may conflict with the ones generated in
-// WebContentDecryptionModuleSessionImpl for the short time both paths are
-// active, start with 100000 and generate the IDs from there.
-// TODO(jrummell): Only allow one path http://crbug.com/306680.
-uint32 ProxyDecryptor::next_session_id_ = 100000;
-
-const uint32 kInvalidSessionId = 0;
-
 // Special system code to signal a closed persistent session in a SessionError()
 // call. This is needed because there is no SessionClosed() call in the prefixed
 // EME API.
 const int kSessionClosedSystemCode = 29127;
 
 ProxyDecryptor::ProxyDecryptor(
 #if defined(ENABLE_PEPPER_CDMS)
     const CreatePepperCdmCB& create_pepper_cdm_cb,
 #elif defined(OS_ANDROID)
     RendererMediaPlayerManager* manager,
@@ skipping 53 matching lines @@
 // Returns true if |data| is prefixed with |header| and has data after the
 // |header|.
 bool HasHeader(const uint8* data, int data_length, const std::string& header) {
   return static_cast<size_t>(data_length) > header.size() &&
          std::equal(data, data + header.size(), header.begin());
 }
 
 bool ProxyDecryptor::GenerateKeyRequest(const std::string& content_type,
                                         const uint8* init_data,
                                         int init_data_length) {
-  // Use a unique reference id for this request.
-  uint32 session_id = next_session_id_++;
-
   const char kPrefixedApiPersistentSessionHeader[] = "PERSISTENT|";
   const char kPrefixedApiLoadSessionHeader[] = "LOAD_SESSION|";
+  DVLOG(1) << "GenerateKeyRequest()";

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

nit: usually we put this log in the first line of the function body.

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

Done.

 
   if (HasHeader(init_data, init_data_length, kPrefixedApiLoadSessionHeader)) {
-    persistent_sessions_.insert(session_id);
+    scoped_ptr<media::NewSessionCdmPromise> promise(
+        new media::NewSessionCdmPromise(
+            base::Bind(&ProxyDecryptor::SetSessionId,
+                       weak_ptr_factory_.GetWeakPtr(),
+                       true),  // Persistent session.
+            base::Bind(&ProxyDecryptor::OnSessionError,
+                       weak_ptr_factory_.GetWeakPtr(),
+                       std::string())));  // No session id until created.
     media_keys_->LoadSession(
-        session_id,
         std::string(reinterpret_cast<const char*>(
                         init_data + strlen(kPrefixedApiLoadSessionHeader)),
-                    init_data_length - strlen(kPrefixedApiLoadSessionHeader)));
+                    init_data_length - strlen(kPrefixedApiLoadSessionHeader)),
+        promise.Pass());
     return true;
   }
 
-  if (HasHeader(
-          init_data, init_data_length, kPrefixedApiPersistentSessionHeader))
-    persistent_sessions_.insert(session_id);
+  bool persistent = HasHeader(
+      init_data, init_data_length, kPrefixedApiPersistentSessionHeader);
+  media::MediaKeys::SessionType session_type =
+      persistent ? media::MediaKeys::SESSION_TYPE_PERSISTENT
+                 : media::MediaKeys::SESSION_TYPE_TEMPORARY;
 
-  return media_keys_->CreateSession(
-      session_id, content_type, init_data, init_data_length);
+  scoped_ptr<media::NewSessionCdmPromise> promise(
+      new media::NewSessionCdmPromise(
+          base::Bind(&ProxyDecryptor::SetSessionId,
+                     weak_ptr_factory_.GetWeakPtr(),
+                     persistent),
+          base::Bind(&ProxyDecryptor::OnSessionError,
+                     weak_ptr_factory_.GetWeakPtr(),
+                     std::string())));

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

Can we avoid creating this promise in two places? We can first figure out
1, persistent
2, load or create session.

Then we can create a promise with |persistent| (1), then call either
CreateSession or LoadSession based on (2).

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

Done.

+  media_keys_->CreateSession(
+      content_type, init_data, init_data_length, session_type, promise.Pass());
+  return true;
 }
 
 void ProxyDecryptor::AddKey(const uint8* key,
                             int key_length,
                             const uint8* init_data,
                             int init_data_length,
                             const std::string& web_session_id) {
   DVLOG(1) << "AddKey()";
 
-  // WebMediaPlayerImpl ensures GenerateKeyRequest() has been called.
-  uint32 session_id = LookupSessionId(web_session_id);
-  if (session_id == kInvalidSessionId) {
-    // Session hasn't been referenced before, so it is an error.
-    // Note that the specification says "If sessionId is not null and is
-    // unrecognized, throw an INVALID_ACCESS_ERR." However, for backwards
-    // compatibility the error is not thrown, but rather reported as a
-    // KeyError.
-    key_error_cb_.Run(std::string(), media::MediaKeys::kUnknownError, 0);
-    return;
+  // If |web_session_id| is null, then use the single reference id.

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

Can you elaborate more in which case this could happen?

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

Done.

+  std::string session_id(web_session_id);
+  if (session_id.empty()) {
+    if (active_sessions_.size() == 1) {
+      std::set<std::string>::iterator it = active_sessions_.begin();
+      session_id = *it;
+    } else {
+      OnSessionError(std::string(),
+                     media::MediaKeys::EXCEPTION_NOT_SUPPORTED_ERROR,
+                     0,
+                     "SessionId not specified.");
+      return;
+    }
   }
 
+  scoped_ptr<media::SimpleCdmPromise> promise(
+      new media::SimpleCdmPromise(base::Bind(&ProxyDecryptor::OnSessionReady,
+                                             weak_ptr_factory_.GetWeakPtr(),
+                                             web_session_id),
+                                  base::Bind(&ProxyDecryptor::OnSessionError,
+                                             weak_ptr_factory_.GetWeakPtr(),
+                                             web_session_id)));
+
   // EME WD spec only supports a single array passed to the CDM. For
   // Clear Key using v0.1b, both arrays are used (|init_data| is key_id).
   // Since the EME WD spec supports the key as a JSON Web Key,
   // convert the 2 arrays to a JWK and pass it as the single array.
   if (is_clear_key_) {
     // Decryptor doesn't support empty key ID (see http://crbug.com/123265).
     // So ensure a non-empty value is passed.
     if (!init_data) {
       static const uint8 kDummyInitData[1] = {0};
       init_data = kDummyInitData;
       init_data_length = arraysize(kDummyInitData);
     }
 
     std::string jwk =
         media::GenerateJWKSet(key, key_length, init_data, init_data_length);
     DCHECK(!jwk.empty());
-    media_keys_->UpdateSession(
-        session_id, reinterpret_cast<const uint8*>(jwk.data()), jwk.size());
+    media_keys_->UpdateSession(session_id,
+                               reinterpret_cast<const uint8*>(jwk.data()),
+                               jwk.size(),
+                               promise.Pass());
     return;
   }
 
-  media_keys_->UpdateSession(session_id, key, key_length);
+  media_keys_->UpdateSession(session_id, key, key_length, promise.Pass());
 }
 
-void ProxyDecryptor::CancelKeyRequest(const std::string& session_id) {
+void ProxyDecryptor::CancelKeyRequest(const std::string& web_session_id) {
   DVLOG(1) << "CancelKeyRequest()";
 
-  // WebMediaPlayerImpl ensures GenerateKeyRequest() has been called.
-  uint32 session_reference_id = LookupSessionId(session_id);
-  if (session_reference_id == kInvalidSessionId) {
-    // Session hasn't been created, so it is an error.
-    key_error_cb_.Run(
-        std::string(), media::MediaKeys::kUnknownError, 0);
-  }
-  else {
-    media_keys_->ReleaseSession(session_reference_id);
-  }
+  scoped_ptr<media::SimpleCdmPromise> promise(
+      new media::SimpleCdmPromise(base::Bind(&ProxyDecryptor::OnSessionClosed,
+                                             weak_ptr_factory_.GetWeakPtr(),
+                                             web_session_id),
+                                  base::Bind(&ProxyDecryptor::OnSessionError,
+                                             weak_ptr_factory_.GetWeakPtr(),
+                                             web_session_id)));
+  media_keys_->ReleaseSession(web_session_id, promise.Pass());
 }
 
 scoped_ptr<media::MediaKeys> ProxyDecryptor::CreateMediaKeys(
     const std::string& key_system,
     const GURL& security_origin) {
   return ContentDecryptionModuleFactory::Create(
       key_system,
       security_origin,
 #if defined(ENABLE_PEPPER_CDMS)
       create_pepper_cdm_cb_,
 #elif defined(OS_ANDROID)
       manager_,
       &cdm_id_,
 #endif  // defined(ENABLE_PEPPER_CDMS)
-      base::Bind(&ProxyDecryptor::OnSessionCreated,
-                 weak_ptr_factory_.GetWeakPtr()),
       base::Bind(&ProxyDecryptor::OnSessionMessage,
                  weak_ptr_factory_.GetWeakPtr()),
       base::Bind(&ProxyDecryptor::OnSessionReady,
                  weak_ptr_factory_.GetWeakPtr()),
       base::Bind(&ProxyDecryptor::OnSessionClosed,
                  weak_ptr_factory_.GetWeakPtr()),
       base::Bind(&ProxyDecryptor::OnSessionError,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
-void ProxyDecryptor::OnSessionCreated(uint32 session_id,
-                                      const std::string& web_session_id) {
-  // Due to heartbeat messages, OnSessionCreated() can get called multiple
-  // times.
-  SessionIdMap::iterator it = sessions_.find(session_id);
-  DCHECK(it == sessions_.end() || it->second == web_session_id);
-  if (it == sessions_.end())
-    sessions_[session_id] = web_session_id;
+void ProxyDecryptor::OnSessionMessage(const std::string& web_session_id,
+                                      const std::vector<uint8>& message,
+                                      const std::string& destination_url) {
+  key_message_cb_.Run(web_session_id, message, destination_url);
 }
 
-void ProxyDecryptor::OnSessionMessage(uint32 session_id,
-                                      const std::vector<uint8>& message,
-                                      const std::string& destination_url) {
-  // Assumes that OnSessionCreated() has been called before this.
-  key_message_cb_.Run(LookupWebSessionId(session_id), message, destination_url);
+void ProxyDecryptor::OnSessionReady(const std::string& web_session_id) {
+  key_added_cb_.Run(web_session_id);
 }
 
-void ProxyDecryptor::OnSessionReady(uint32 session_id) {
-  // Assumes that OnSessionCreated() has been called before this.
-  key_added_cb_.Run(LookupWebSessionId(session_id));
+void ProxyDecryptor::OnSessionClosed(const std::string& web_session_id) {
+  std::set<std::string>::iterator it =
+      persistent_sessions_.find(web_session_id);
+  active_sessions_.erase(web_session_id);
+  if (it != persistent_sessions_.end()) {
+    persistent_sessions_.erase(it);
+    OnSessionError(web_session_id,
+                   media::MediaKeys::EXCEPTION_NOT_SUPPORTED_ERROR,
+                   kSessionClosedSystemCode,
+                   "Do not close persistent sessions.");
+  }
 }
 
-void ProxyDecryptor::OnSessionClosed(uint32 session_id) {
-  std::set<uint32>::iterator it = persistent_sessions_.find(session_id);
-  if (it != persistent_sessions_.end()) {
-    persistent_sessions_.erase(it);
-    OnSessionError(
-        session_id, media::MediaKeys::kUnknownError, kSessionClosedSystemCode);
+void ProxyDecryptor::OnSessionError(const std::string& web_session_id,
+                                    media::MediaKeys::Exception exception_code,
+                                    uint32 system_code,
+                                    const std::string& error_message) {
+  // Convert |error_name| back to MediaKeys::KeyError if possible. Prefixed
+  // EME has different error message, so all the specific error events will
+  // get lost.
+  media::MediaKeys::KeyError error_code;
+  switch (exception_code) {
+    case media::MediaKeys::EXCEPTION_CLIENT_ERROR:
+      error_code = media::MediaKeys::kClientError;
+      break;
+    case media::MediaKeys::EXCEPTION_OUTPUT_ERROR:
+      error_code = media::MediaKeys::kOutputError;
+      break;
+    default:
+      // This will include all other CDM4 errors and any error generated
+      // by CDM5 or later.
+      error_code = media::MediaKeys::kUnknownError;
+      break;
   }
-
-  sessions_.erase(session_id);
+  key_error_cb_.Run(web_session_id, error_code, system_code);
 }
 
-void ProxyDecryptor::OnSessionError(uint32 session_id,
-                                    media::MediaKeys::KeyError error_code,
-                                    uint32 system_code) {
-  // Assumes that OnSessionCreated() has been called before this.
-  key_error_cb_.Run(LookupWebSessionId(session_id), error_code, system_code);
-}
-
-uint32 ProxyDecryptor::LookupSessionId(const std::string& session_id) const {
-  for (SessionIdMap::const_iterator it = sessions_.begin();
-       it != sessions_.end();
-       ++it) {
-    if (it->second == session_id)
-      return it->first;
+void ProxyDecryptor::SetSessionId(bool persistent,
+                                  const std::string& web_session_id) {
+  active_sessions_.insert(web_session_id);
+  if (persistent) {
+    persistent_sessions_.insert(web_session_id);
   }
-
-  // If |session_id| is null, then use the single reference id.
-  if (session_id.empty() && sessions_.size() == 1)
-    return sessions_.begin()->first;
-
-  return kInvalidSessionId;
-}
-
-const std::string& ProxyDecryptor::LookupWebSessionId(uint32 session_id) const {
-  DCHECK_NE(session_id, kInvalidSessionId);
-
-  // Session may not exist if error happens during GenerateKeyRequest().
-  SessionIdMap::const_iterator it = sessions_.find(session_id);
-  return (it != sessions_.end()) ? it->second : base::EmptyString();
 }
 
 }  // namespace content