Add Promises for EME (Chromium side)

content/renderer/media/webcontentdecryptionmodulesession_impl.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/webcontentdecryptionmodulesession_impl.h"
 
+#include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/renderer/media/cdm_session_adapter.h"
+#include "media/base/media_keys.h"

[ddorwin, 2014/05/05 18:35:42]

duplicate with .h

[jrummell, 2014/05/08 23:37:45]

Done.

+#include "media/base/media_keys_session_promise.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 
 namespace content {
 
 WebContentDecryptionModuleSessionImpl::WebContentDecryptionModuleSessionImpl(
-    uint32 session_id,
     Client* client,
     const scoped_refptr<CdmSessionAdapter>& adapter)
     : adapter_(adapter),
       client_(client),
-      session_id_(session_id) {
+      weak_ptr_factory_(this) {
 }
 
 WebContentDecryptionModuleSessionImpl::
     ~WebContentDecryptionModuleSessionImpl() {
-  adapter_->RemoveSession(session_id_);
+  if (!web_session_id_.empty())
+    adapter_->RemoveSession(web_session_id_);
 }
 
 blink::WebString WebContentDecryptionModuleSessionImpl::sessionId() const {
-  return web_session_id_;
+  return blink::WebString::fromUTF8(web_session_id_);
 }
 
 void WebContentDecryptionModuleSessionImpl::initializeNewSession(

[ddorwin, 2014/05/05 18:35:42]

I wonder if we'll eventually want to move session creation to webcdm_impl.

-    const blink::WebString& mime_type,
-    const uint8* init_data, size_t init_data_length) {
+    const blink::WebString& init_data_type,

[ddorwin, 2014/05/05 18:35:42]

We might want to DLOG(WARNING) if this includes a '/', which would likely be a
MIME type.

[jrummell, 2014/05/08 23:37:45]

Done.

+    const uint8* init_data,
+    size_t init_data_length) {
   // TODO(ddorwin): Guard against this in supported types check and remove this.
   // Chromium only supports ASCII MIME types.
-  if (!IsStringASCII(mime_type)) {
+  if (!IsStringASCII(init_data_type)) {
     NOTREACHED();
-    OnSessionError(media::MediaKeys::kUnknownError, 0);
+    OnSessionError("InvalidCharacterError",

[ddorwin, 2014/05/05 18:35:42]

This is a Chromium choice, not a spec issue, so we should just report
NotSupportedError.

Ditto with the text - use what's in the spec.

[jrummell, 2014/05/08 23:37:45]

Done.

+                   0,
+                   "init_data_type contains non-ASCII characters.");
     return;
   }
 
-  adapter_->InitializeNewSession(
-      session_id_, base::UTF16ToASCII(mime_type), init_data, init_data_length);
+  scoped_ptr<media::MediaKeysSessionPromise> promise(
+      new media::MediaKeysSessionPromise(
+          media::PromiseResolvedCB(),

[ddorwin, 2014/05/05 18:35:42]

This is weird. As noted in the promise header, we shouldn't have two resolve
promises.

[jrummell, 2014/05/08 23:37:45]

Done.

+          base::Bind(&WebContentDecryptionModuleSessionImpl::setSessionId,

[ddorwin, 2014/05/05 18:35:42]

I think we're going to need to do more than set the session ID - we'll need to
tell Blink to create the session. The name should reflect this.

[jrummell, 2014/05/08 23:37:45]

Done.

+                     weak_ptr_factory_.GetWeakPtr()),
+          base::Bind(&WebContentDecryptionModuleSessionImpl::OnSessionError,

[ddorwin, 2014/05/05 18:35:42]

Even if we rely on the same code in the interim, the types of errors are
different and this CB should reflect that.

[jrummell, 2014/05/08 23:37:45]

Done.

+                     weak_ptr_factory_.GetWeakPtr())));
+  adapter_->InitializeNewSession(base::UTF16ToASCII(init_data_type),
+                                 init_data,
+                                 init_data_length,
+                                 media::MediaKeys::SessionType::kTemporary,
+                                 promise.Pass());
 }
 
 void WebContentDecryptionModuleSessionImpl::update(const uint8* response,
                                                    size_t response_length) {
   DCHECK(response);
-  adapter_->UpdateSession(session_id_, response, response_length);
+  scoped_ptr<media::MediaKeysSessionPromise> promise(

[ddorwin, 2014/05/05 18:35:42]

You might consider helper functions for creating the sessions. It will make this
code cleaner.

[jrummell, 2014/05/08 23:37:45]

Done as a macro. If everybody is OK with it, I'll repeat it in the other classes
that create promises.

+      new media::MediaKeysSessionPromise(
+          base::Bind(&WebContentDecryptionModuleSessionImpl::OnSessionReady,
+                     weak_ptr_factory_.GetWeakPtr()),
+          media::PromiseResolvedWithSessionCB(),
+          base::Bind(&WebContentDecryptionModuleSessionImpl::OnSessionError,
+                     weak_ptr_factory_.GetWeakPtr())));
+  adapter_->UpdateSession(
+      web_session_id_, response, response_length, promise.Pass());
 }
 
 void WebContentDecryptionModuleSessionImpl::release() {
-  adapter_->ReleaseSession(session_id_);
-}
-
-void WebContentDecryptionModuleSessionImpl::OnSessionCreated(
-    const std::string& web_session_id) {
-  // Due to heartbeat messages, OnSessionCreated() can get called multiple
-  // times.
-  // TODO(jrummell): Once all CDMs are updated to support reference ids,
-  // OnSessionCreated() should only be called once, and the second check can be
-  // removed.
-  blink::WebString id = blink::WebString::fromUTF8(web_session_id);
-  DCHECK(web_session_id_.isEmpty() || web_session_id_ == id)
-      << "Session ID may not be changed once set.";
-  web_session_id_ = id;
+  scoped_ptr<media::MediaKeysSessionPromise> promise(
+      new media::MediaKeysSessionPromise(
+          base::Bind(&WebContentDecryptionModuleSessionImpl::OnSessionClosed,
+                     weak_ptr_factory_.GetWeakPtr()),
+          media::PromiseResolvedWithSessionCB(),
+          base::Bind(&WebContentDecryptionModuleSessionImpl::OnSessionError,
+                     weak_ptr_factory_.GetWeakPtr())));
+  adapter_->ReleaseSession(web_session_id_, promise.Pass());
 }
 
 void WebContentDecryptionModuleSessionImpl::OnSessionMessage(
     const std::vector<uint8>& message,
     const std::string& destination_url) {
   client_->message(message.empty() ? NULL : &message[0],
                    message.size(),
                    GURL(destination_url));
 }
 
 void WebContentDecryptionModuleSessionImpl::OnSessionReady() {
   client_->ready();
 }
 
 void WebContentDecryptionModuleSessionImpl::OnSessionClosed() {
   client_->close();
 }
 
 void WebContentDecryptionModuleSessionImpl::OnSessionError(
-    media::MediaKeys::KeyError error_code,
-    uint32 system_code) {
-  client_->error(static_cast<Client::MediaKeyErrorCode>(error_code),
-                 system_code);
+    const std::string& error_name,
+    uint32 system_code,
+    const std::string& error_message) {
+  // Convert |error_name| back to MediaKeyErrorCode if possible.
+  // TODO(jrummell): Remove this conversion when promises flow
+  // back into blink:: (as the code there will handle the names).

[ddorwin, 2014/05/05 18:35:42]

Not if it is "CDM4ClientError"

[jrummell, 2014/05/08 23:37:45]

True. Changes with exception_code.

+  if (error_name == "CDM4ClientError") {

[ddorwin, 2014/05/05 18:35:42]

What about output error?

[jrummell, 2014/05/08 23:37:45]

Client doesn't have a output error. Only unknown and client.

+    client_->error(Client::MediaKeyErrorCode::MediaKeyErrorCodeClient,
+                   system_code);
+  } else {
+    // This will include all other CDM4 errors and any error generated
+    // by CDM5 or later.
+    client_->error(Client::MediaKeyErrorCode::MediaKeyErrorCodeUnknown,
+                   system_code);
+  }
+}
+
+void WebContentDecryptionModuleSessionImpl::setSessionId(
+    const std::string& web_session_id) {
+  DCHECK(web_session_id_.empty()) << "Session ID may not be changed once set.";
+  web_session_id_ = web_session_id;
+  adapter_->RegisterSession(web_session_id_, weak_ptr_factory_.GetWeakPtr());
 }
 
 }  // namespace content