Bug 1000264 - Make AudioContext.decodeAudioData return a promise. r=ehsan,bz

--HG--
extra : rebase_source : 570014ee470ca5493073113ab3bc4bb0933c390a

dom/media/webaudio/AudioContext.cpp

@@ -36,6 +36,7 @@
 #include "OscillatorNode.h"
 #include "nsNetUtil.h"
 #include "AudioStream.h"
+#include "mozilla/dom/Promise.h"
 
 namespace mozilla {
 namespace dom {
@@ -438,16 +439,24 @@ AudioContext::Listener()
   return mListener;
 }
 
-void
+already_AddRefed<Promise>
 AudioContext::DecodeAudioData(const ArrayBuffer& aBuffer,
-                              DecodeSuccessCallback& aSuccessCallback,
+                              const Optional<OwningNonNull<DecodeSuccessCallback> >& aSuccessCallback,
                               const Optional<OwningNonNull<DecodeErrorCallback> >& aFailureCallback)
 {
+  ErrorResult rv;
+  nsCOMPtr<nsIGlobalObject> parentObject = do_QueryInterface(GetParentObject());
+  nsRefPtr<Promise> promise;
   AutoJSAPI jsapi;
   jsapi.Init();
   JSContext* cx = jsapi.cx();
   JSAutoCompartment ac(cx, aBuffer.Obj());
 
+  promise = Promise::Create(parentObject, rv);
+  if (rv.Failed()) {
+    return nullptr;
+  }
+
   aBuffer.ComputeLengthAndData();
 
   // Neuter the array buffer
@@ -462,15 +471,21 @@ AudioContext::DecodeAudioData(const ArrayBuffer& aBuffer,
   NS_SniffContent(NS_DATA_SNIFFER_CATEGORY, nullptr, data, length, contentType);
 
   nsRefPtr<DecodeErrorCallback> failureCallback;
+  nsRefPtr<DecodeSuccessCallback> successCallback;
   if (aFailureCallback.WasPassed()) {
     failureCallback = &aFailureCallback.Value();
   }
+  if (aSuccessCallback.WasPassed()) {
+    successCallback = &aSuccessCallback.Value();
+  }
   nsRefPtr<WebAudioDecodeJob> job(
     new WebAudioDecodeJob(contentType, this,
-                          &aSuccessCallback, failureCallback));
+                          promise, successCallback, failureCallback));
   mDecoder.AsyncDecodeMedia(contentType.get(), data, length, *job);
   // Transfer the ownership to mDecodeJobs
   mDecodeJobs.AppendElement(job.forget());
+
+  return promise.forget();
 }
 
 void

dom/media/webaudio/AudioContext.h

@@ -61,6 +61,7 @@ class PannerNode;
 class ScriptProcessorNode;
 class WaveShaperNode;
 class PeriodicWave;
+class Promise;
 
 class AudioContext MOZ_FINAL : public DOMEventTargetHelper,
                                public nsIMemoryReporter
@@ -184,9 +185,10 @@ public:
   CreatePeriodicWave(const Float32Array& aRealData, const Float32Array& aImagData,
                      ErrorResult& aRv);
 
-  void DecodeAudioData(const ArrayBuffer& aBuffer,
-                       DecodeSuccessCallback& aSuccessCallback,
-                       const Optional<OwningNonNull<DecodeErrorCallback> >& aFailureCallback);
+  already_AddRefed<Promise>
+  DecodeAudioData(const ArrayBuffer& aBuffer,
+                  const Optional<OwningNonNull<DecodeSuccessCallback> >& aSuccessCallback,
+                  const Optional<OwningNonNull<DecodeErrorCallback> >& aFailureCallback);
 
   // OfflineAudioContext methods
   void StartRendering(ErrorResult& aRv);

dom/media/webaudio/MediaBufferDecoder.cpp

@@ -21,6 +21,7 @@
 #include "nsIScriptError.h"
 #include "nsMimeTypes.h"
 #include "WebAudioUtils.h"
+#include "mozilla/dom/Promise.h"
 #ifdef XP_WIN
 #include "ThreadPoolCOMListener.h"
 #endif
@@ -512,16 +513,17 @@ MediaBufferDecoder::Shutdown() {
 
 WebAudioDecodeJob::WebAudioDecodeJob(const nsACString& aContentType,
                                      AudioContext* aContext,
+                                     Promise* aPromise,
                                      DecodeSuccessCallback* aSuccessCallback,
                                      DecodeErrorCallback* aFailureCallback)
   : mContentType(aContentType)
   , mWriteIndex(0)
   , mContext(aContext)
+  , mPromise(aPromise)
   , mSuccessCallback(aSuccessCallback)
   , mFailureCallback(aFailureCallback)
 {
   MOZ_ASSERT(aContext);
-  MOZ_ASSERT(aSuccessCallback);
   MOZ_ASSERT(NS_IsMainThread());
   MOZ_COUNT_CTOR(WebAudioDecodeJob);
 }
@@ -541,7 +543,10 @@ WebAudioDecodeJob::OnSuccess(ErrorCode aErrorCode)
   // Ignore errors in calling the callback, since there is not much that we can
   // do about it here.
   ErrorResult rv;
-  mSuccessCallback->Call(*mOutput, rv);
+  if (mSuccessCallback) {
+    mSuccessCallback->Call(*mOutput, rv);
+  }
+  mPromise->MaybeResolve(mOutput);
 
   mContext->RemoveFromDecodeQueue(this);
 }
@@ -589,6 +594,8 @@ WebAudioDecodeJob::OnFailure(ErrorCode aErrorCode)
     mFailureCallback->Call(rv);
   }
 
+  mPromise->MaybeReject(NS_ERROR_DOM_ENCODING_NOT_SUPPORTED_ERR);
+
   mContext->RemoveFromDecodeQueue(this);
 }
 

dom/media/webaudio/MediaBufferDecoder.h

@@ -22,6 +22,7 @@ class AudioBuffer;
 class AudioContext;
 class DecodeErrorCallback;
 class DecodeSuccessCallback;
+class Promise;
 }
 
 struct WebAudioDecodeJob MOZ_FINAL
@@ -30,6 +31,7 @@ struct WebAudioDecodeJob MOZ_FINAL
   // The callbacks are only necessary for asynchronous operation.
   WebAudioDecodeJob(const nsACString& aContentType,
                     dom::AudioContext* aContext,
+                    dom::Promise* aPromise,
                     dom::DecodeSuccessCallback* aSuccessCallback = nullptr,
                     dom::DecodeErrorCallback* aFailureCallback = nullptr);
 
@@ -58,6 +60,7 @@ struct WebAudioDecodeJob MOZ_FINAL
   nsCString mContentType;
   uint32_t mWriteIndex;
   nsRefPtr<dom::AudioContext> mContext;
+  nsRefPtr<dom::Promise> mPromise;
   nsRefPtr<dom::DecodeSuccessCallback> mSuccessCallback;
   nsRefPtr<dom::DecodeErrorCallback> mFailureCallback; // can be null
   nsRefPtr<dom::AudioBuffer> mOutput;

dom/webidl/AudioContext.webidl

@@ -25,9 +25,9 @@ interface AudioContext : EventTarget {
     [NewObject, Throws]
     AudioBuffer createBuffer(unsigned long numberOfChannels, unsigned long length, float sampleRate);
 
-    void decodeAudioData(ArrayBuffer audioData,
-                         DecodeSuccessCallback successCallback,
-                         optional DecodeErrorCallback errorCallback);
+    Promise<AudioBuffer> decodeAudioData(ArrayBuffer audioData,
+                                         optional DecodeSuccessCallback successCallback,
+                                         optional DecodeErrorCallback errorCallback);
 
     // AudioNode creation
     [NewObject]