Bug 1081755 - Implement MediaKeySession keyschange event. r=edwin,bz

content/base/src/nsGkAtomList.h

@@ -496,6 +496,7 @@ GK_ATOM(keepcurrentinview, "keepcurrentinview")
 GK_ATOM(keepobjectsalive, "keepobjectsalive")
 GK_ATOM(key, "key")
 GK_ATOM(keycode, "keycode")
+GK_ATOM(keyschange, "keyschange")
 GK_ATOM(keydown, "keydown")
 GK_ATOM(keygen, "keygen")
 GK_ATOM(keypress, "keypress")

content/media/eme/CDMCallbackProxy.cpp

@@ -272,8 +272,18 @@ CDMCallbackProxy::KeyIdUsable(const nsCString& aSessionId,
 {
   MOZ_ASSERT(mProxy->IsOnGMPThread());
 
-  CDMCaps::AutoLock caps(mProxy->Capabilites());
-  caps.SetKeyUsable(aKeyId, NS_ConvertUTF8toUTF16(aSessionId));
+  bool keysChange = false;
+  {
+    CDMCaps::AutoLock caps(mProxy->Capabilites());
+    keysChange = caps.SetKeyUsable(aKeyId, NS_ConvertUTF8toUTF16(aSessionId));
+  }
+  if (keysChange) {
+    nsRefPtr<nsIRunnable> task;
+    task = NS_NewRunnableMethodWithArg<nsString>(mProxy,
+                                                 &CDMProxy::OnKeysChange,
+                                                 NS_ConvertUTF8toUTF16(aSessionId));
+    NS_DispatchToMainThread(task);
+  }
 }
 
 void
@@ -282,8 +292,18 @@ CDMCallbackProxy::KeyIdNotUsable(const nsCString& aSessionId,
 {
   MOZ_ASSERT(mProxy->IsOnGMPThread());
 
-  CDMCaps::AutoLock caps(mProxy->Capabilites());
-  caps.SetKeyUnusable(aKeyId, NS_ConvertUTF8toUTF16(aSessionId));
+  bool keysChange = false;
+  {
+    CDMCaps::AutoLock caps(mProxy->Capabilites());
+    keysChange = caps.SetKeyUnusable(aKeyId, NS_ConvertUTF8toUTF16(aSessionId));
+  }
+  if (keysChange) {
+    nsRefPtr<nsIRunnable> task;
+    task = NS_NewRunnableMethodWithArg<nsString>(mProxy,
+                                                 &CDMProxy::OnKeysChange,
+                                                 NS_ConvertUTF8toUTF16(aSessionId));
+    NS_DispatchToMainThread(task);
+  }
 }
 
 void

content/media/eme/CDMCaps.cpp

@@ -88,12 +88,16 @@ CDMCaps::AutoLock::IsKeyUsable(const CencKeyId& aKeyId)
   return false;
 }
 
-void
+bool
 CDMCaps::AutoLock::SetKeyUsable(const CencKeyId& aKeyId,
                                 const nsString& aSessionId)
 {
   mData.mMonitor.AssertCurrentThreadOwns();
-  mData.mUsableKeyIds.AppendElement(UsableKey(aKeyId, aSessionId));
+  UsableKey key(aKeyId, aSessionId);
+  if (mData.mUsableKeyIds.Contains(key)) {
+    return false;
+  }
+  mData.mUsableKeyIds.AppendElement(key);
   auto& waiters = mData.mWaitForKeys;
   size_t i = 0;
   while (i < waiters.Length()) {
@@ -110,13 +114,18 @@ CDMCaps::AutoLock::SetKeyUsable(const CencKeyId& aKeyId,
       i++;
     }
   }
+  return true;
 }
 
-void
+bool
 CDMCaps::AutoLock::SetKeyUnusable(const CencKeyId& aKeyId,
                                   const nsString& aSessionId)
 {
   mData.mMonitor.AssertCurrentThreadOwns();
+  UsableKey key(aKeyId, aSessionId);
+  if (!mData.mUsableKeyIds.Contains(key)) {
+    return false;
+  }
   auto& keys = mData.mUsableKeyIds;
   for (size_t i = 0; i < keys.Length(); i++) {
     if (keys[i].mId == aKeyId &&
@@ -125,6 +134,7 @@ CDMCaps::AutoLock::SetKeyUnusable(const CencKeyId& aKeyId,
       break;
     }
   }
+  return true;
 }
 
 void

content/media/eme/CDMCaps.h

@@ -38,8 +38,13 @@ public:
 
     bool IsKeyUsable(const CencKeyId& aKeyId);
 
-    void SetKeyUsable(const CencKeyId& aKeyId, const nsString& aSessionId);
-    void SetKeyUnusable(const CencKeyId& aKeyId, const nsString& aSessionId);
+    // Returns true if setting this key usable results in the usable keys
+    // changing for this session, i.e. the key was not previously marked usable.
+    bool SetKeyUsable(const CencKeyId& aKeyId, const nsString& aSessionId);
+
+    // Returns true if setting this key unusable results in the usable keys
+    // changing for this session, i.e. the key was previously marked usable.
+    bool SetKeyUnusable(const CencKeyId& aKeyId, const nsString& aSessionId);
 
     void DropKeysForSession(const nsAString& aSessionId);
     void GetUsableKeysForSession(const nsAString& aSessionId,
@@ -99,6 +104,11 @@ private:
       : mId(aOther.mId)
       , mSessionId(aOther.mSessionId)
     {}
+    bool operator==(const UsableKey& aOther) const {
+      return mId == aOther.mId &&
+             mSessionId == aOther.mSessionId;
+    };
+
     CencKeyId mId;
     nsString mSessionId;
   };

content/media/eme/CDMProxy.cpp

@@ -425,6 +425,19 @@ CDMProxy::OnSessionMessage(const nsAString& aSessionId,
   }
 }
 
+void
+CDMProxy::OnKeysChange(const nsAString& aSessionId)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
+  nsRefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
+  if (session) {
+    session->DispatchKeysChange();
+  }
+}
+
 void
 CDMProxy::OnExpirationChange(const nsAString& aSessionId,
                              GMPTimestamp aExpiryTime)

content/media/eme/CDMProxy.h

@@ -162,6 +162,9 @@ public:
 
   CDMCaps& Capabilites();
 
+  // Main thread only.
+  void OnKeysChange(const nsAString& aSessionId);
+
 #ifdef DEBUG
   bool IsOnGMPThread();
 #endif

content/media/eme/MediaKeySession.cpp

@@ -13,6 +13,7 @@
 #include "mozilla/CDMProxy.h"
 #include "mozilla/AsyncEventDispatcher.h"
 #include "mozilla/Move.h"
+#include "nsContentUtils.h"
 
 namespace mozilla {
 namespace dom {
@@ -284,5 +285,24 @@ MediaKeySession::DispatchKeyError(uint32_t aSystemCode)
   asyncDispatcher->PostDOMEvent();
 }
 
+void
+MediaKeySession::DispatchKeysChange()
+{
+  if (IsClosed()) {
+    return;
+  }
+  DebugOnly<nsresult> rv =
+    nsContentUtils::DispatchTrustedEvent(mKeys->GetOwnerDoc(),
+                                         this,
+                                         NS_LITERAL_STRING("keyschange"),
+                                         false,
+                                         false);
+#ifdef DEBUG
+  if (NS_FAILED(rv)) {
+    NS_WARNING("Failed to dispatch keyschange event");
+  }
+#endif
+}
+
 } // namespace dom
 } // namespace mozilla

content/media/eme/MediaKeySession.h

@@ -84,6 +84,8 @@ public:
 
   void DispatchKeyError(uint32_t system_code);
 
+  void DispatchKeysChange();
+
   void OnClosed();
 
   bool IsClosed() const;

content/media/eme/MediaKeys.cpp

@@ -591,5 +591,11 @@ CopyArrayBufferViewOrArrayBufferData(const ArrayBufferViewOrArrayBuffer& aBuffer
   return true;
 }
 
+nsIDocument*
+MediaKeys::GetOwnerDoc() const
+{
+  return mElement ? mElement->OwnerDoc() : nullptr;
+}
+
 } // namespace dom
 } // namespace mozilla

content/media/eme/MediaKeys.h

@@ -122,6 +122,10 @@ public:
   // was created, failure otherwise.
   nsresult CheckPrincipals();
 
+  // Returns a pointer to the bound media element's owner doc.
+  // If we're not bound, this returns null.
+  nsIDocument* GetOwnerDoc() const;
+
 private:
 
   static bool IsTypeSupported(const nsAString& aKeySystem,

content/media/test/test_encryptedMediaExtensions.html

@@ -153,6 +153,25 @@ function PlayTest(test, elem)
   elem.play();
 }
 
+function KeysChangeFunc(session, keys) {
+  session.keyIdsReceived = [];
+  for (var keyid in keys) {
+    info("Set " + keyid + " to false in session.keyIdsReceived");
+    session.keyIdsReceived[keyid] = false;
+  }
+  return function(ev) {
+    var session = ev.target;
+    session.gotKeysChanged = true;
+    session.getUsableKeyIds().then(function(keyIds) {
+      for (var k = 0; k < keyIds.length; k++) {
+        var kid = Base64ToHex(window.btoa(ArrayBufferToString(keyIds[k])));
+        ok(kid in session.keyIdsReceived, "session.keyIdsReceived contained " + kid + " as expected.");
+        session.keyIdsReceived[kid] = true;
+      }
+    }, bail("Failed to get keyIds"));
+  }
+}
+
 function startTest(test, token)
 {
   manager.started(test._token);
@@ -170,6 +189,7 @@ function startTest(test, token)
 
     MediaKeys.create(KEYSYSTEM_TYPE).then(function(mediaKeys) {
       info(token + " created MediaKeys object ok");
+      mediaKeys.sessions = [];
       return v.setMediaKeys(mediaKeys);
     }, bail("failed to create MediaKeys object")).then(function() {
       info(token + " set MediaKeys on <video> element ok");
@@ -178,6 +198,8 @@ function startTest(test, token)
          "MediaKeys should still support keysystem after CDM created...");
 
       var session = v.mediaKeys.createSession(test.sessionType);
+      v.mediaKeys.sessions.push(session);
+      session.addEventListener("keyschange", KeysChangeFunc(session, test.keys), false);
       session.addEventListener("message", UpdateSessionFunc(test));
       session.generateRequest(ev.initDataType, ev.initData).then(function() {
       }, bail(token + " Failed to initialise MediaKeySession"));
@@ -198,6 +220,17 @@ function startTest(test, token)
        token + " Duration of video should be corrrect");
     ok(Math.abs(test.duration - v.currentTime) < 0.1,
        token + " Current time should be same as duration");
+    // Verify all sessions had all keys went sent the to the CDM usable, and thus
+    // that we received keyschange event(s).
+    var sessions = v.mediaKeys.sessions;
+    is(sessions.length, 1, "should have 1 session");
+    for (var i = 0; i < sessions.length; i++) {
+      var session = sessions[i];
+      ok(session.gotKeysChanged, "Should have received at least one keychange event");
+      for (var kid in session.keyIdsReceived) {
+        ok(session.keyIdsReceived[kid], "key with id " + kid + " was usable as expected");
+      }
+    }
   });
 
   v.addEventListener("error", bail(token + " got error event"));