Bug 1216460 - [1.1] Refactor data types, fix logs and prevent harmful type promotions in SourceBuffer eviction handling. r=jya

dom/media/mediasource/SourceBufferContentManager.h

@@ -70,7 +70,7 @@ public:
   // eviction.
   virtual EvictDataResult
   EvictData(media::TimeUnit aPlaybackTime,
-            uint32_t aThreshold,
+            int64_t aThreshold,
             media::TimeUnit* aBufferStartTime) = 0;
 
   // Evicts data up to aTime.

dom/media/mediasource/SourceBufferResource.cpp

@@ -134,7 +134,7 @@ SourceBufferResource::ReadFromCache(char* aBuffer, int64_t aOffset, uint32_t aCo
 }
 
 uint32_t
-SourceBufferResource::EvictData(uint64_t aPlaybackOffset, uint32_t aThreshold,
+SourceBufferResource::EvictData(uint64_t aPlaybackOffset, int64_t aThreshold,
                                 ErrorResult& aRv)
 {
   SBR_DEBUG("EvictData(aPlaybackOffset=%llu,"

dom/media/mediasource/SourceBufferResource.h

@@ -113,7 +113,7 @@ public:
   }
   // Remove data from resource if it holds more than the threshold
   // number of bytes. Returns amount evicted.
-  uint32_t EvictData(uint64_t aPlaybackOffset, uint32_t aThreshold,
+  uint32_t EvictData(uint64_t aPlaybackOffset, int64_t aThreshold,
                      ErrorResult& aRv);
 
   // Remove data from resource before the given offset.

dom/media/mediasource/TrackBuffersManager.cpp

@@ -198,7 +198,7 @@ TrackBuffersManager::RangeRemoval(TimeUnit aStart, TimeUnit aEnd)
 
 TrackBuffersManager::EvictDataResult
 TrackBuffersManager::EvictData(TimeUnit aPlaybackTime,
-                               uint32_t aThreshold,
+                               int64_t aThresholdReduct,
                                TimeUnit* aBufferStartTime)
 {
   MOZ_ASSERT(NS_IsMainThread());
@@ -353,7 +353,7 @@ TrackBuffersManager::CompleteResetParserState()
 
 void
 TrackBuffersManager::DoEvictData(const TimeUnit& aPlaybackTime,
-                                 uint32_t aSizeToEvict)
+                                 int64_t aSizeToEvict)
 {
   MOZ_ASSERT(OnTaskQueue());
 
@@ -365,7 +365,7 @@ TrackBuffersManager::DoEvictData(const TimeUnit& aPlaybackTime,
   TimeUnit lowerLimit = std::min(track.mNextSampleTime, aPlaybackTime);
   uint32_t lastKeyFrameIndex = 0;
   int64_t toEvict = aSizeToEvict;
-  uint32_t partialEvict = 0;
+  int64_t partialEvict = 0;
   for (uint32_t i = 0; i < buffer.Length(); i++) {
     const auto& frame = buffer[i];
     if (frame->mKeyframe) {
@@ -382,17 +382,16 @@ TrackBuffersManager::DoEvictData(const TimeUnit& aPlaybackTime,
     partialEvict += frame->ComputedSizeOfIncludingThis();
   }
 
-  int64_t finalSize = mSizeSourceBuffer - aSizeToEvict;
-
   if (lastKeyFrameIndex > 0) {
-    MSE_DEBUG("Step1. Evicting %u bytes prior currentTime",
+    MSE_DEBUG("Step1. Evicting %lld bytes prior currentTime",
               aSizeToEvict - toEvict);
     CodedFrameRemoval(
       TimeInterval(TimeUnit::FromMicroseconds(0),
                    TimeUnit::FromMicroseconds(buffer[lastKeyFrameIndex]->mTime - 1)));
   }
 
-  if (mSizeSourceBuffer <= finalSize) {
+  const int64_t finalSize = mSizeSourceBuffer - aSizeToEvict;
+  if (mSizeSourceBuffer <= finalSize || !buffer.Length()) {
     return;
   }
 
@@ -415,8 +414,8 @@ TrackBuffersManager::DoEvictData(const TimeUnit& aPlaybackTime,
     toEvict -= frame->ComputedSizeOfIncludingThis();
   }
   if (evictedFramesStartIndex < buffer.Length()) {
-    MSE_DEBUG("Step2. Evicting %u bytes from trailing data",
-              mSizeSourceBuffer - finalSize);
+    MSE_DEBUG("Step2. Evicting %lld bytes from trailing data",
+              mSizeSourceBuffer - finalSize - toEvict);
     CodedFrameRemoval(
       TimeInterval(TimeUnit::FromMicroseconds(buffer[evictedFramesStartIndex]->mTime),
                    TimeUnit::FromInfinity()));
@@ -1630,7 +1629,7 @@ TrackBuffersManager::RemoveFrames(const TimeIntervals& aIntervals,
 {
   TrackBuffer& data = aTrackData.mBuffers.LastElement();
   Maybe<uint32_t> firstRemovedIndex;
-  uint32_t lastRemovedIndex;
+  uint32_t lastRemovedIndex = 0;
 
   // We loop from aStartIndex to avoid removing frames that we inserted earlier
   // and part of the current coded frame group. This is allows to handle step

dom/media/mediasource/TrackBuffersManager.h

@@ -56,7 +56,7 @@ public:
 
   EvictDataResult
   EvictData(media::TimeUnit aPlaybackTime,
-            uint32_t aThreshold,
+            int64_t aThresholdReduct,
             media::TimeUnit* aBufferStartTime) override;
 
   void EvictBefore(media::TimeUnit aTime) override;
@@ -200,7 +200,7 @@ private:
     OnDemuxFailed(TrackType::kAudioTrack, aFailure);
   }
 
-  void DoEvictData(const media::TimeUnit& aPlaybackTime, uint32_t aThreshold);
+  void DoEvictData(const media::TimeUnit& aPlaybackTime, int64_t aThreshold);
 
   struct TrackData {
     TrackData()