Encrypted Media: Replace DecryptorClient with key event callbacks.

webkit/media/crypto/proxy_decryptor.cc

 // Copyright (c) 2012 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 "webkit/media/crypto/proxy_decryptor.h"
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 45 matching lines @@
   DCHECK(encrypted);
   DCHECK(encrypted->GetDecryptConfig());
   std::string key_id = encrypted->GetDecryptConfig()->key_id();
   scoped_array<uint8> key_id_array(new uint8[key_id.size()]);
   memcpy(key_id_array.get(), key_id.data(), key_id.size());
   client->NeedKey("", "", key_id_array.Pass(), key_id.size());
 }
 
 ProxyDecryptor::ProxyDecryptor(
     const scoped_refptr<base::MessageLoopProxy>& message_loop,
-    media::DecryptorClient* decryptor_client,
+    const KeyAddedCB& key_added_cb,
+    const KeyErrorCB& key_error_cb,
+    const KeyMessageCB& key_message_cb,
+    const NeedKeyCB& need_key_cb,
     WebKit::WebMediaPlayerClient* web_media_player_client,
     WebKit::WebFrame* web_frame)
     : decryption_message_loop_(message_loop),
-      client_(decryptor_client),
+      key_added_cb_(key_added_cb),
+      key_error_cb_(key_error_cb),
+      key_message_cb_(key_message_cb),
+      need_key_cb_(need_key_cb),
       web_media_player_client_(web_media_player_client),
       web_frame_(web_frame),
       is_waiting_for_decryptor_(false),
       is_canceling_decrypt_(false),
       has_new_key_added_(false) {
 }
 
 ProxyDecryptor::~ProxyDecryptor() {
 }
 
@@ skipping 24 matching lines @@
                                         int init_data_length) {
   // We do not support run-time switching of decryptors. GenerateKeyRequest()
   // only creates a new decryptor when |decryptor_| is not initialized.
   DVLOG(1) << "GenerateKeyRequest: key_system = " << key_system;
 
   base::AutoLock auto_lock(lock_);
 
   if (!decryptor_) {
     decryptor_ = CreateDecryptor(key_system);
     if (!decryptor_) {
-      client_->KeyError(key_system, "", media::Decryptor::kUnknownError, 0);
+      KeyError(key_system, "", media::Decryptor::kUnknownError, 0);
       return false;
     }
   }
 
   if (!decryptor_->GenerateKeyRequest(key_system,
                                       init_data, init_data_length)) {
     decryptor_.reset();
     return false;
   }
 
@@ skipping 46 matching lines @@
   {
     base::AutoLock auto_lock(lock_);
     decryptor = decryptor_.get();
   }
   if (!decryptor) {
     DVLOG(1) << "Decrypt(): decryptor not initialized.";
 
     // TODO(xhwang): The same NeedKey may be fired here and multiple times in
     // OnBufferDecrypted(). While the spec says only one NeedKey should be
     // fired. Leave them as is since the spec about this may change.
-    FireNeedKey(client_, encrypted);
+    FireNeedKey(this, encrypted);
     return;
   }
 
   DecryptPendingBuffer();
 }
 
 void ProxyDecryptor::CancelDecrypt(StreamType stream_type) {
   DVLOG(1) << "CancelDecrypt()";
   DCHECK(decryption_message_loop_->BelongsToCurrentThread());
   DCHECK_EQ(stream_type, kVideo);  // Only support video decrypt-only for now.
@@ skipping 42 matching lines @@
 }
 
 void ProxyDecryptor::ResetDecoder(StreamType stream_type) {
   NOTREACHED() << "ProxyDecryptor does not support audio/video decoding";
 }
 
 void ProxyDecryptor::DeinitializeDecoder(StreamType stream_type) {
   NOTREACHED() << "ProxyDecryptor does not support audio/video decoding";
 }
 
+void ProxyDecryptor::KeyAdded(const std::string& key_system,
+                              const std::string& session_id) {
+  key_added_cb_.Run(key_system, session_id);
+}
+
+void ProxyDecryptor::KeyError(const std::string& key_system,
+                              const std::string& session_id,
+                              Decryptor::KeyError error_code,
+                              int system_code) {
+  key_error_cb_.Run(key_system, session_id, error_code, system_code);
+}
+
+void ProxyDecryptor::KeyMessage(const std::string& key_system,
+                                const std::string& session_id,
+                                scoped_array<uint8> message,
+                                int message_length,
+                                const std::string& default_url) {
+  key_message_cb_.Run(
+      key_system, session_id, message.Pass(), message_length, default_url);
+}
+
+void ProxyDecryptor::NeedKey(const std::string& key_system,
+                             const std::string& session_id,
+                             scoped_array<uint8> init_data,
+                             int init_data_length) {
+  need_key_cb_.Run(key_system, session_id, init_data.Pass(), init_data_length);
+}

[Ami GONE FROM CHROMIUM, 2012/10/23 06:52:22]

This collection of functions is a pretty strong smell that something's
suboptimal :)

[xhwang, 2012/10/23 07:32:13]

If we remove DecryptorClient and use callbacks exclusively, should
ProxyDecryptor implements the callbacks and pass those to Aes/PpapiDecryptor to
avoid jumping-layers? e.g. to avoid AesDecryptor/PpapiDecryptor to call WMPI
directly? 

[Ami GONE FROM CHROMIUM, 2012/10/23 07:42:54]

I /think/ so...
But it's late and I'm not as familiar with this code as I could be.

+
 scoped_ptr<media::Decryptor> ProxyDecryptor::CreatePpapiDecryptor(
     const std::string& key_system) {
-  DCHECK(client_);
   DCHECK(web_media_player_client_);
   DCHECK(web_frame_);
 
   std::string plugin_type = GetPluginType(key_system);
   DCHECK(!plugin_type.empty());
   const scoped_refptr<webkit::ppapi::PluginInstance>& plugin_instance =
     CreatePluginInstance(plugin_type, web_media_player_client_, web_frame_);
   if (!plugin_instance) {
     DVLOG(1) << "PpapiDecryptor: plugin instance creation failed.";
     return scoped_ptr<media::Decryptor>();
   }
 
-  return scoped_ptr<media::Decryptor>(new PpapiDecryptor(client_,
+  return scoped_ptr<media::Decryptor>(new PpapiDecryptor(this,
                                                          plugin_instance));
 }
 
 scoped_ptr<media::Decryptor> ProxyDecryptor::CreateDecryptor(
     const std::string& key_system) {
-  DCHECK(client_);
-
   if (CanUseAesDecryptor(key_system))
-    return scoped_ptr<media::Decryptor>(new media::AesDecryptor(client_));
+    return scoped_ptr<media::Decryptor>(new media::AesDecryptor(this));
 
   // We only support AesDecryptor and PpapiDecryptor. So if we cannot
   // use the AesDecryptor, then we'll try to create a PpapiDecryptor for given
   // |key_system|.
   return CreatePpapiDecryptor(key_system);
 }
 
 void ProxyDecryptor::OnNewKeyAdded() {
   if (!decryption_message_loop_->BelongsToCurrentThread()) {
     // TODO(xhwang): Using base::Unretained may cause race during destruction
@@ skipping 68 matching lines @@
   DCHECK_EQ(status, media::Decryptor::kNoKey);
   DVLOG(1) << "OnBufferDecrypted(): kNoKey fired";
   if (need_to_try_again_if_nokey_is_returned) {
     DecryptPendingBuffer();
     return;
   }
 
   // TODO(xhwang): The same NeedKey may be fired multiple times here and also
   // in Decrypt(). While the spec says only one NeedKey should be fired. Leave
   // them as is since the spec about this may change.
-  FireNeedKey(client_, pending_buffer_to_decrypt_);
+  FireNeedKey(this, pending_buffer_to_decrypt_);
 }
 
 }  // namespace webkit_media