summaryrefslogtreecommitdiffstats
path: root/dom/media/MediaCache.cpp
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--dom/media/MediaCache.cpp2816
1 files changed, 2816 insertions, 0 deletions
diff --git a/dom/media/MediaCache.cpp b/dom/media/MediaCache.cpp
new file mode 100644
index 0000000000..41d51a49cc
--- /dev/null
+++ b/dom/media/MediaCache.cpp
@@ -0,0 +1,2816 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MediaCache.h"
+
+#include "ChannelMediaResource.h"
+#include "FileBlockCache.h"
+#include "MediaBlockCacheBase.h"
+#include "MediaResource.h"
+#include "MemoryBlockCache.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/ErrorNames.h"
+#include "mozilla/Logging.h"
+#include "mozilla/Monitor.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Services.h"
+#include "mozilla/StaticPtr.h"
+#include "mozilla/StaticPrefs_browser.h"
+#include "mozilla/StaticPrefs_media.h"
+#include "mozilla/Telemetry.h"
+#include "nsContentUtils.h"
+#include "nsINetworkLinkService.h"
+#include "nsIObserverService.h"
+#include "nsPrintfCString.h"
+#include "nsProxyRelease.h"
+#include "nsTHashSet.h"
+#include "nsThreadUtils.h"
+#include "prio.h"
+#include "VideoUtils.h"
+#include <algorithm>
+
+namespace mozilla {
+
+#undef LOG
+#undef LOGI
+#undef LOGE
+LazyLogModule gMediaCacheLog("MediaCache");
+#define LOG(...) MOZ_LOG(gMediaCacheLog, LogLevel::Debug, (__VA_ARGS__))
+#define LOGI(...) MOZ_LOG(gMediaCacheLog, LogLevel::Info, (__VA_ARGS__))
+#define LOGE(...) \
+ NS_DebugBreak(NS_DEBUG_WARNING, nsPrintfCString(__VA_ARGS__).get(), nullptr, \
+ __FILE__, __LINE__)
+
+// For HTTP seeking, if number of bytes needing to be
+// seeked forward is less than this value then a read is
+// done rather than a byte range request.
+//
+// If we assume a 100Mbit connection, and assume reissuing an HTTP seek causes
+// a delay of 200ms, then in that 200ms we could have simply read ahead 2MB. So
+// setting SEEK_VS_READ_THRESHOLD to 1MB sounds reasonable.
+static const int64_t SEEK_VS_READ_THRESHOLD = 1 * 1024 * 1024;
+
+// Readahead blocks for non-seekable streams will be limited to this
+// fraction of the cache space. We don't normally evict such blocks
+// because replacing them requires a seek, but we need to make sure
+// they don't monopolize the cache.
+static const double NONSEEKABLE_READAHEAD_MAX = 0.5;
+
+// Data N seconds before the current playback position is given the same
+// priority as data REPLAY_PENALTY_FACTOR*N seconds ahead of the current
+// playback position. REPLAY_PENALTY_FACTOR is greater than 1 to reflect that
+// data in the past is less likely to be played again than data in the future.
+// We want to give data just behind the current playback position reasonably
+// high priority in case codecs need to retrieve that data (e.g. because
+// tracks haven't been muxed well or are being decoded at uneven rates).
+// 1/REPLAY_PENALTY_FACTOR as much data will be kept behind the
+// current playback position as will be kept ahead of the current playback
+// position.
+static const uint32_t REPLAY_PENALTY_FACTOR = 3;
+
+// When looking for a reusable block, scan forward this many blocks
+// from the desired "best" block location to look for free blocks,
+// before we resort to scanning the whole cache. The idea is to try to
+// store runs of stream blocks close-to-consecutively in the cache if we
+// can.
+static const uint32_t FREE_BLOCK_SCAN_LIMIT = 16;
+
+#ifdef DEBUG
+// Turn this on to do very expensive cache state validation
+// #define DEBUG_VERIFY_CACHE
+#endif
+
+class MediaCacheFlusher final : public nsIObserver,
+ public nsSupportsWeakReference {
+ public:
+ NS_DECL_ISUPPORTS
+ NS_DECL_NSIOBSERVER
+
+ static void RegisterMediaCache(MediaCache* aMediaCache);
+ static void UnregisterMediaCache(MediaCache* aMediaCache);
+
+ private:
+ MediaCacheFlusher() = default;
+ ~MediaCacheFlusher() = default;
+
+ // Singleton instance created when a first MediaCache is registered, and
+ // released when the last MediaCache is unregistered.
+ // The observer service will keep a weak reference to it, for notifications.
+ static StaticRefPtr<MediaCacheFlusher> gMediaCacheFlusher;
+
+ nsTArray<MediaCache*> mMediaCaches;
+};
+
+/* static */
+StaticRefPtr<MediaCacheFlusher> MediaCacheFlusher::gMediaCacheFlusher;
+
+NS_IMPL_ISUPPORTS(MediaCacheFlusher, nsIObserver, nsISupportsWeakReference)
+
+/* static */
+void MediaCacheFlusher::RegisterMediaCache(MediaCache* aMediaCache) {
+ NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
+
+ if (!gMediaCacheFlusher) {
+ gMediaCacheFlusher = new MediaCacheFlusher();
+ nsCOMPtr<nsIObserverService> observerService =
+ mozilla::services::GetObserverService();
+ if (observerService) {
+ observerService->AddObserver(gMediaCacheFlusher, "last-pb-context-exited",
+ true);
+ observerService->AddObserver(gMediaCacheFlusher,
+ "cacheservice:empty-cache", true);
+ observerService->AddObserver(
+ gMediaCacheFlusher, "contentchild:network-link-type-changed", true);
+ observerService->AddObserver(gMediaCacheFlusher,
+ NS_NETWORK_LINK_TYPE_TOPIC, true);
+ }
+ }
+
+ gMediaCacheFlusher->mMediaCaches.AppendElement(aMediaCache);
+}
+
+/* static */
+void MediaCacheFlusher::UnregisterMediaCache(MediaCache* aMediaCache) {
+ NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
+
+ gMediaCacheFlusher->mMediaCaches.RemoveElement(aMediaCache);
+
+ if (gMediaCacheFlusher->mMediaCaches.Length() == 0) {
+ gMediaCacheFlusher = nullptr;
+ }
+}
+
+class MediaCache {
+ using AutoLock = MonitorAutoLock;
+
+ public:
+ NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaCache)
+
+ friend class MediaCacheStream::BlockList;
+ typedef MediaCacheStream::BlockList BlockList;
+ static const int64_t BLOCK_SIZE = MediaCacheStream::BLOCK_SIZE;
+
+ // Get an instance of a MediaCache (or nullptr if initialization failed).
+ // aContentLength is the content length if known already, otherwise -1.
+ // If the length is known and considered small enough, a discrete MediaCache
+ // with memory backing will be given. Otherwise the one MediaCache with
+ // file backing will be provided.
+ // If aIsPrivateBrowsing is true, only initialization of a memory backed
+ // MediaCache will be attempted, returning nullptr if that fails.
+ static RefPtr<MediaCache> GetMediaCache(int64_t aContentLength,
+ bool aIsPrivateBrowsing);
+
+ nsISerialEventTarget* OwnerThread() const { return sThread; }
+
+ // Brutally flush the cache contents. Main thread only.
+ void Flush();
+
+ // Close all streams associated with private browsing windows. This will
+ // also remove the blocks from the cache since we don't want to leave any
+ // traces when PB is done.
+ void CloseStreamsForPrivateBrowsing();
+
+ // Cache-file access methods. These are the lowest-level cache methods.
+ // mMonitor must be held; these can be called on any thread.
+ // This can return partial reads.
+ // Note mMonitor will be dropped while doing IO. The caller need
+ // to handle changes happening when the monitor is not held.
+ nsresult ReadCacheFile(AutoLock&, int64_t aOffset, void* aData,
+ int32_t aLength, int32_t* aBytes);
+
+ // The generated IDs are always positive.
+ int64_t AllocateResourceID(AutoLock&) { return ++mNextResourceID; }
+
+ // mMonitor must be held, called on main thread.
+ // These methods are used by the stream to set up and tear down streams,
+ // and to handle reads and writes.
+ // Add aStream to the list of streams.
+ void OpenStream(AutoLock&, MediaCacheStream* aStream, bool aIsClone = false);
+ // Remove aStream from the list of streams.
+ void ReleaseStream(AutoLock&, MediaCacheStream* aStream);
+ // Free all blocks belonging to aStream.
+ void ReleaseStreamBlocks(AutoLock&, MediaCacheStream* aStream);
+ // Find a cache entry for this data, and write the data into it
+ void AllocateAndWriteBlock(
+ AutoLock&, MediaCacheStream* aStream, int32_t aStreamBlockIndex,
+ Span<const uint8_t> aData1,
+ Span<const uint8_t> aData2 = Span<const uint8_t>());
+
+ // mMonitor must be held; can be called on any thread
+ // Notify the cache that a seek has been requested. Some blocks may
+ // need to change their class between PLAYED_BLOCK and READAHEAD_BLOCK.
+ // This does not trigger channel seeks directly, the next Update()
+ // will do that if necessary. The caller will call QueueUpdate().
+ void NoteSeek(AutoLock&, MediaCacheStream* aStream, int64_t aOldOffset);
+ // Notify the cache that a block has been read from. This is used
+ // to update last-use times. The block may not actually have a
+ // cache entry yet since Read can read data from a stream's
+ // in-memory mPartialBlockBuffer while the block is only partly full,
+ // and thus hasn't yet been committed to the cache. The caller will
+ // call QueueUpdate().
+ void NoteBlockUsage(AutoLock&, MediaCacheStream* aStream, int32_t aBlockIndex,
+ int64_t aStreamOffset, MediaCacheStream::ReadMode aMode,
+ TimeStamp aNow);
+ // Mark aStream as having the block, adding it as an owner.
+ void AddBlockOwnerAsReadahead(AutoLock&, int32_t aBlockIndex,
+ MediaCacheStream* aStream,
+ int32_t aStreamBlockIndex);
+
+ // This queues a call to Update() on the media cache thread.
+ void QueueUpdate(AutoLock&);
+
+ // Notify all streams for the resource ID that the suspended status changed
+ // at the end of MediaCache::Update.
+ void QueueSuspendedStatusUpdate(AutoLock&, int64_t aResourceID);
+
+ // Updates the cache state asynchronously on the media cache thread:
+ // -- try to trim the cache back to its desired size, if necessary
+ // -- suspend channels that are going to read data that's lower priority
+ // than anything currently cached
+ // -- resume channels that are going to read data that's higher priority
+ // than something currently cached
+ // -- seek channels that need to seek to a new location
+ void Update();
+
+#ifdef DEBUG_VERIFY_CACHE
+ // Verify invariants, especially block list invariants
+ void Verify(AutoLock&);
+#else
+ void Verify(AutoLock&) {}
+#endif
+
+ mozilla::Monitor& Monitor() {
+ // This method should only be called outside the main thread.
+ // The MOZ_DIAGNOSTIC_ASSERT(!NS_IsMainThread()) assertion should be
+ // re-added as part of bug 1464045
+ return mMonitor;
+ }
+
+ // Polls whether we're on a cellular network connection, and posts a task
+ // to the MediaCache thread to set the value of MediaCache::sOnCellular.
+ // Call on main thread only.
+ static void UpdateOnCellular();
+
+ /**
+ * An iterator that makes it easy to iterate through all streams that
+ * have a given resource ID and are not closed.
+ * Must be used while holding the media cache lock.
+ */
+ class ResourceStreamIterator {
+ public:
+ ResourceStreamIterator(MediaCache* aMediaCache, int64_t aResourceID)
+ : mMediaCache(aMediaCache), mResourceID(aResourceID), mNext(0) {
+ aMediaCache->mMonitor.AssertCurrentThreadOwns();
+ }
+ MediaCacheStream* Next(AutoLock& aLock) {
+ while (mNext < mMediaCache->mStreams.Length()) {
+ MediaCacheStream* stream = mMediaCache->mStreams[mNext];
+ ++mNext;
+ if (stream->GetResourceID() == mResourceID && !stream->IsClosed(aLock))
+ return stream;
+ }
+ return nullptr;
+ }
+
+ private:
+ MediaCache* mMediaCache;
+ int64_t mResourceID;
+ uint32_t mNext;
+ };
+
+ protected:
+ explicit MediaCache(MediaBlockCacheBase* aCache)
+ : mMonitor("MediaCache.mMonitor"),
+ mBlockCache(aCache),
+ mUpdateQueued(false)
+#ifdef DEBUG
+ ,
+ mInUpdate(false)
+#endif
+ {
+ NS_ASSERTION(NS_IsMainThread(), "Only construct MediaCache on main thread");
+ MOZ_COUNT_CTOR(MediaCache);
+ MediaCacheFlusher::RegisterMediaCache(this);
+ UpdateOnCellular();
+ }
+
+ ~MediaCache() {
+ NS_ASSERTION(NS_IsMainThread(), "Only destroy MediaCache on main thread");
+ if (this == gMediaCache) {
+ LOG("~MediaCache(Global file-backed MediaCache)");
+ // This is the file-backed MediaCache, reset the global pointer.
+ gMediaCache = nullptr;
+ } else {
+ LOG("~MediaCache(Memory-backed MediaCache %p)", this);
+ }
+ MediaCacheFlusher::UnregisterMediaCache(this);
+ NS_ASSERTION(mStreams.IsEmpty(), "Stream(s) still open!");
+ Truncate();
+ NS_ASSERTION(mIndex.Length() == 0, "Blocks leaked?");
+
+ MOZ_COUNT_DTOR(MediaCache);
+ }
+
+ static size_t CacheSize() {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+ return sOnCellular ? StaticPrefs::media_cache_size_cellular()
+ : StaticPrefs::media_cache_size();
+ }
+
+ static size_t ReadaheadLimit() {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+ return sOnCellular ? StaticPrefs::media_cache_readahead_limit_cellular()
+ : StaticPrefs::media_cache_readahead_limit();
+ }
+
+ static size_t ResumeThreshold() {
+ return sOnCellular ? StaticPrefs::media_cache_resume_threshold_cellular()
+ : StaticPrefs::media_cache_resume_threshold();
+ }
+
+ // Find a free or reusable block and return its index. If there are no
+ // free blocks and no reusable blocks, add a new block to the cache
+ // and return it. Can return -1 on OOM.
+ int32_t FindBlockForIncomingData(AutoLock&, TimeStamp aNow,
+ MediaCacheStream* aStream,
+ int32_t aStreamBlockIndex);
+ // Find a reusable block --- a free block, if there is one, otherwise
+ // the reusable block with the latest predicted-next-use, or -1 if
+ // there aren't any freeable blocks. Only block indices less than
+ // aMaxSearchBlockIndex are considered. If aForStream is non-null,
+ // then aForStream and aForStreamBlock indicate what media data will
+ // be placed; FindReusableBlock will favour returning free blocks
+ // near other blocks for that point in the stream.
+ int32_t FindReusableBlock(AutoLock&, TimeStamp aNow,
+ MediaCacheStream* aForStream,
+ int32_t aForStreamBlock,
+ int32_t aMaxSearchBlockIndex);
+ bool BlockIsReusable(AutoLock&, int32_t aBlockIndex);
+ // Given a list of blocks sorted with the most reusable blocks at the
+ // end, find the last block whose stream is not pinned (if any)
+ // and whose cache entry index is less than aBlockIndexLimit
+ // and append it to aResult.
+ void AppendMostReusableBlock(AutoLock&, BlockList* aBlockList,
+ nsTArray<uint32_t>* aResult,
+ int32_t aBlockIndexLimit);
+
+ enum BlockClass {
+ // block belongs to mMetadataBlockList because data has been consumed
+ // from it in "metadata mode" --- in particular blocks read during
+ // Ogg seeks go into this class. These blocks may have played data
+ // in them too.
+ METADATA_BLOCK,
+ // block belongs to mPlayedBlockList because its offset is
+ // less than the stream's current reader position
+ PLAYED_BLOCK,
+ // block belongs to the stream's mReadaheadBlockList because its
+ // offset is greater than or equal to the stream's current
+ // reader position
+ READAHEAD_BLOCK
+ };
+
+ struct BlockOwner {
+ constexpr BlockOwner() = default;
+
+ // The stream that owns this block, or null if the block is free.
+ MediaCacheStream* mStream = nullptr;
+ // The block index in the stream. Valid only if mStream is non-null.
+ // Initialized to an insane value to highlight misuse.
+ uint32_t mStreamBlock = UINT32_MAX;
+ // Time at which this block was last used. Valid only if
+ // mClass is METADATA_BLOCK or PLAYED_BLOCK.
+ TimeStamp mLastUseTime;
+ BlockClass mClass = READAHEAD_BLOCK;
+ };
+
+ struct Block {
+ // Free blocks have an empty mOwners array
+ nsTArray<BlockOwner> mOwners;
+ };
+
+ // Get the BlockList that the block should belong to given its
+ // current owner
+ BlockList* GetListForBlock(AutoLock&, BlockOwner* aBlock);
+ // Get the BlockOwner for the given block index and owning stream
+ // (returns null if the stream does not own the block)
+ BlockOwner* GetBlockOwner(AutoLock&, int32_t aBlockIndex,
+ MediaCacheStream* aStream);
+ // Returns true iff the block is free
+ bool IsBlockFree(int32_t aBlockIndex) {
+ return mIndex[aBlockIndex].mOwners.IsEmpty();
+ }
+ // Add the block to the free list and mark its streams as not having
+ // the block in cache
+ void FreeBlock(AutoLock&, int32_t aBlock);
+ // Mark aStream as not having the block, removing it as an owner. If
+ // the block has no more owners it's added to the free list.
+ void RemoveBlockOwner(AutoLock&, int32_t aBlockIndex,
+ MediaCacheStream* aStream);
+ // Swap all metadata associated with the two blocks. The caller
+ // is responsible for swapping up any cache file state.
+ void SwapBlocks(AutoLock&, int32_t aBlockIndex1, int32_t aBlockIndex2);
+ // Insert the block into the readahead block list for the stream
+ // at the right point in the list.
+ void InsertReadaheadBlock(AutoLock&, BlockOwner* aBlockOwner,
+ int32_t aBlockIndex);
+
+ // Guess the duration until block aBlock will be next used
+ TimeDuration PredictNextUse(AutoLock&, TimeStamp aNow, int32_t aBlock);
+ // Guess the duration until the next incoming data on aStream will be used
+ TimeDuration PredictNextUseForIncomingData(AutoLock&,
+ MediaCacheStream* aStream);
+
+ // Truncate the file and index array if there are free blocks at the
+ // end
+ void Truncate();
+
+ void FlushInternal(AutoLock&);
+
+ // There is at most one file-backed media cache.
+ // It is owned by all MediaCacheStreams that use it.
+ // This is a raw pointer set by GetMediaCache(), and reset by ~MediaCache(),
+ // both on the main thread; and is not accessed anywhere else.
+ static inline MediaCache* gMediaCache = nullptr;
+
+ // This member is main-thread only. It's used to allocate unique
+ // resource IDs to streams.
+ int64_t mNextResourceID = 0;
+
+ // The monitor protects all the data members here. Also, off-main-thread
+ // readers that need to block will Wait() on this monitor. When new
+ // data becomes available in the cache, we NotifyAll() on this monitor.
+ mozilla::Monitor mMonitor MOZ_UNANNOTATED;
+ // This must always be accessed when the monitor is held.
+ nsTArray<MediaCacheStream*> mStreams;
+ // The Blocks describing the cache entries.
+ nsTArray<Block> mIndex;
+
+ RefPtr<MediaBlockCacheBase> mBlockCache;
+ // The list of free blocks; they are not ordered.
+ BlockList mFreeBlocks;
+ // True if an event to run Update() has been queued but not processed
+ bool mUpdateQueued;
+#ifdef DEBUG
+ bool mInUpdate;
+#endif
+ // A list of resource IDs to notify about the change in suspended status.
+ nsTArray<int64_t> mSuspendedStatusToNotify;
+ // The thread on which we will run data callbacks from the channels.
+ // Note this thread is shared among all MediaCache instances.
+ static inline StaticRefPtr<nsIThread> sThread;
+ // True if we've tried to init sThread. Note we try once only so it is safe
+ // to access sThread on all threads.
+ static inline bool sThreadInit = false;
+
+ private:
+ // MediaCache thread only. True if we're on a cellular network connection.
+ static inline bool sOnCellular = false;
+
+ // Try to trim the cache back to its desired size, if necessary. Return the
+ // amount of free block counts after trimming.
+ int32_t TrimCacheIfNeeded(AutoLock& aLock, const TimeStamp& aNow);
+
+ struct StreamAction {
+ enum { NONE, SEEK, RESUME, SUSPEND } mTag = NONE;
+ // Members for 'SEEK' only.
+ bool mResume = false;
+ int64_t mSeekTarget = -1;
+ };
+ // In each update, media cache would determine an action for each stream,
+ // possible actions are: keeping the stream unchanged, seeking to the new
+ // position, resuming its channel or suspending its channel. The action would
+ // be determined by considering a lot of different factors, eg. stream's data
+ // offset and length, how many free or reusable blocks are avaliable, the
+ // predicted time for the next block...e.t.c. This function will write the
+ // corresponding action for each stream in `mStreams` into `aActions`.
+ void DetermineActionsForStreams(AutoLock& aLock, const TimeStamp& aNow,
+ nsTArray<StreamAction>& aActions,
+ int32_t aFreeBlockCount);
+
+ // Used by MediaCacheStream::GetDebugInfo() only for debugging.
+ // Don't add new callers to this function.
+ friend void MediaCacheStream::GetDebugInfo(
+ dom::MediaCacheStreamDebugInfo& aInfo);
+ mozilla::Monitor& GetMonitorOnTheMainThread() {
+ MOZ_DIAGNOSTIC_ASSERT(NS_IsMainThread());
+ return mMonitor;
+ }
+};
+
+void MediaCache::UpdateOnCellular() {
+ NS_ASSERTION(NS_IsMainThread(),
+ "Only call on main thread"); // JNI required on Android...
+ bool onCellular = OnCellularConnection();
+ LOG("MediaCache::UpdateOnCellular() onCellular=%d", onCellular);
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCache::UpdateOnCellular", [=]() { sOnCellular = onCellular; });
+ sThread->Dispatch(r.forget());
+}
+
+NS_IMETHODIMP
+MediaCacheFlusher::Observe(nsISupports* aSubject, char const* aTopic,
+ char16_t const* aData) {
+ NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
+
+ if (strcmp(aTopic, "last-pb-context-exited") == 0) {
+ for (MediaCache* mc : mMediaCaches) {
+ mc->CloseStreamsForPrivateBrowsing();
+ }
+ return NS_OK;
+ }
+ if (strcmp(aTopic, "cacheservice:empty-cache") == 0) {
+ for (MediaCache* mc : mMediaCaches) {
+ mc->Flush();
+ }
+ return NS_OK;
+ }
+ if (strcmp(aTopic, "contentchild:network-link-type-changed") == 0 ||
+ strcmp(aTopic, NS_NETWORK_LINK_TYPE_TOPIC) == 0) {
+ MediaCache::UpdateOnCellular();
+ }
+ return NS_OK;
+}
+
+MediaCacheStream::MediaCacheStream(ChannelMediaResource* aClient,
+ bool aIsPrivateBrowsing)
+ : mMediaCache(nullptr),
+ mClient(aClient),
+ mIsTransportSeekable(false),
+ mCacheSuspended(false),
+ mChannelEnded(false),
+ mStreamOffset(0),
+ mPlaybackBytesPerSecond(10000),
+ mPinCount(0),
+ mNotifyDataEndedStatus(NS_ERROR_NOT_INITIALIZED),
+ mIsPrivateBrowsing(aIsPrivateBrowsing) {}
+
+size_t MediaCacheStream::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+ AutoLock lock(mMediaCache->Monitor());
+
+ // Looks like these are not owned:
+ // - mClient
+ size_t size = mBlocks.ShallowSizeOfExcludingThis(aMallocSizeOf);
+ size += mReadaheadBlocks.SizeOfExcludingThis(aMallocSizeOf);
+ size += mMetadataBlocks.SizeOfExcludingThis(aMallocSizeOf);
+ size += mPlayedBlocks.SizeOfExcludingThis(aMallocSizeOf);
+ size += aMallocSizeOf(mPartialBlockBuffer.get());
+
+ return size;
+}
+
+size_t MediaCacheStream::BlockList::SizeOfExcludingThis(
+ MallocSizeOf aMallocSizeOf) const {
+ return mEntries.ShallowSizeOfExcludingThis(aMallocSizeOf);
+}
+
+void MediaCacheStream::BlockList::AddFirstBlock(int32_t aBlock) {
+ NS_ASSERTION(!mEntries.GetEntry(aBlock), "Block already in list");
+ Entry* entry = mEntries.PutEntry(aBlock);
+
+ if (mFirstBlock < 0) {
+ entry->mNextBlock = entry->mPrevBlock = aBlock;
+ } else {
+ entry->mNextBlock = mFirstBlock;
+ entry->mPrevBlock = mEntries.GetEntry(mFirstBlock)->mPrevBlock;
+ mEntries.GetEntry(entry->mNextBlock)->mPrevBlock = aBlock;
+ mEntries.GetEntry(entry->mPrevBlock)->mNextBlock = aBlock;
+ }
+ mFirstBlock = aBlock;
+ ++mCount;
+}
+
+void MediaCacheStream::BlockList::AddAfter(int32_t aBlock, int32_t aBefore) {
+ NS_ASSERTION(!mEntries.GetEntry(aBlock), "Block already in list");
+ Entry* entry = mEntries.PutEntry(aBlock);
+
+ Entry* addAfter = mEntries.GetEntry(aBefore);
+ NS_ASSERTION(addAfter, "aBefore not in list");
+
+ entry->mNextBlock = addAfter->mNextBlock;
+ entry->mPrevBlock = aBefore;
+ mEntries.GetEntry(entry->mNextBlock)->mPrevBlock = aBlock;
+ mEntries.GetEntry(entry->mPrevBlock)->mNextBlock = aBlock;
+ ++mCount;
+}
+
+void MediaCacheStream::BlockList::RemoveBlock(int32_t aBlock) {
+ Entry* entry = mEntries.GetEntry(aBlock);
+ MOZ_DIAGNOSTIC_ASSERT(entry, "Block not in list");
+
+ if (entry->mNextBlock == aBlock) {
+ MOZ_DIAGNOSTIC_ASSERT(entry->mPrevBlock == aBlock,
+ "Linked list inconsistency");
+ MOZ_DIAGNOSTIC_ASSERT(mFirstBlock == aBlock, "Linked list inconsistency");
+ mFirstBlock = -1;
+ } else {
+ if (mFirstBlock == aBlock) {
+ mFirstBlock = entry->mNextBlock;
+ }
+ mEntries.GetEntry(entry->mNextBlock)->mPrevBlock = entry->mPrevBlock;
+ mEntries.GetEntry(entry->mPrevBlock)->mNextBlock = entry->mNextBlock;
+ }
+ mEntries.RemoveEntry(entry);
+ --mCount;
+}
+
+int32_t MediaCacheStream::BlockList::GetLastBlock() const {
+ if (mFirstBlock < 0) return -1;
+ return mEntries.GetEntry(mFirstBlock)->mPrevBlock;
+}
+
+int32_t MediaCacheStream::BlockList::GetNextBlock(int32_t aBlock) const {
+ int32_t block = mEntries.GetEntry(aBlock)->mNextBlock;
+ if (block == mFirstBlock) return -1;
+ return block;
+}
+
+int32_t MediaCacheStream::BlockList::GetPrevBlock(int32_t aBlock) const {
+ if (aBlock == mFirstBlock) return -1;
+ return mEntries.GetEntry(aBlock)->mPrevBlock;
+}
+
+#ifdef DEBUG
+void MediaCacheStream::BlockList::Verify() {
+ int32_t count = 0;
+ if (mFirstBlock >= 0) {
+ int32_t block = mFirstBlock;
+ do {
+ Entry* entry = mEntries.GetEntry(block);
+ NS_ASSERTION(mEntries.GetEntry(entry->mNextBlock)->mPrevBlock == block,
+ "Bad prev link");
+ NS_ASSERTION(mEntries.GetEntry(entry->mPrevBlock)->mNextBlock == block,
+ "Bad next link");
+ block = entry->mNextBlock;
+ ++count;
+ } while (block != mFirstBlock);
+ }
+ NS_ASSERTION(count == mCount, "Bad count");
+}
+#endif
+
+static void UpdateSwappedBlockIndex(int32_t* aBlockIndex, int32_t aBlock1Index,
+ int32_t aBlock2Index) {
+ int32_t index = *aBlockIndex;
+ if (index == aBlock1Index) {
+ *aBlockIndex = aBlock2Index;
+ } else if (index == aBlock2Index) {
+ *aBlockIndex = aBlock1Index;
+ }
+}
+
+void MediaCacheStream::BlockList::NotifyBlockSwapped(int32_t aBlockIndex1,
+ int32_t aBlockIndex2) {
+ Entry* e1 = mEntries.GetEntry(aBlockIndex1);
+ Entry* e2 = mEntries.GetEntry(aBlockIndex2);
+ int32_t e1Prev = -1, e1Next = -1, e2Prev = -1, e2Next = -1;
+
+ // Fix mFirstBlock
+ UpdateSwappedBlockIndex(&mFirstBlock, aBlockIndex1, aBlockIndex2);
+
+ // Fix mNextBlock/mPrevBlock links. First capture previous/next links
+ // so we don't get confused due to aliasing.
+ if (e1) {
+ e1Prev = e1->mPrevBlock;
+ e1Next = e1->mNextBlock;
+ }
+ if (e2) {
+ e2Prev = e2->mPrevBlock;
+ e2Next = e2->mNextBlock;
+ }
+ // Update the entries.
+ if (e1) {
+ mEntries.GetEntry(e1Prev)->mNextBlock = aBlockIndex2;
+ mEntries.GetEntry(e1Next)->mPrevBlock = aBlockIndex2;
+ }
+ if (e2) {
+ mEntries.GetEntry(e2Prev)->mNextBlock = aBlockIndex1;
+ mEntries.GetEntry(e2Next)->mPrevBlock = aBlockIndex1;
+ }
+
+ // Fix hashtable keys. First remove stale entries.
+ if (e1) {
+ e1Prev = e1->mPrevBlock;
+ e1Next = e1->mNextBlock;
+ mEntries.RemoveEntry(e1);
+ // Refresh pointer after hashtable mutation.
+ e2 = mEntries.GetEntry(aBlockIndex2);
+ }
+ if (e2) {
+ e2Prev = e2->mPrevBlock;
+ e2Next = e2->mNextBlock;
+ mEntries.RemoveEntry(e2);
+ }
+ // Put new entries back.
+ if (e1) {
+ e1 = mEntries.PutEntry(aBlockIndex2);
+ e1->mNextBlock = e1Next;
+ e1->mPrevBlock = e1Prev;
+ }
+ if (e2) {
+ e2 = mEntries.PutEntry(aBlockIndex1);
+ e2->mNextBlock = e2Next;
+ e2->mPrevBlock = e2Prev;
+ }
+}
+
+void MediaCache::FlushInternal(AutoLock& aLock) {
+ for (uint32_t blockIndex = 0; blockIndex < mIndex.Length(); ++blockIndex) {
+ FreeBlock(aLock, blockIndex);
+ }
+
+ // Truncate index array.
+ Truncate();
+ NS_ASSERTION(mIndex.Length() == 0, "Blocks leaked?");
+ // Reset block cache to its pristine state.
+ mBlockCache->Flush();
+}
+
+void MediaCache::Flush() {
+ MOZ_ASSERT(NS_IsMainThread());
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCache::Flush", [self = RefPtr<MediaCache>(this)]() mutable {
+ AutoLock lock(self->mMonitor);
+ self->FlushInternal(lock);
+ // Ensure MediaCache is deleted on the main thread.
+ NS_ReleaseOnMainThread("MediaCache::Flush", self.forget());
+ });
+ sThread->Dispatch(r.forget());
+}
+
+void MediaCache::CloseStreamsForPrivateBrowsing() {
+ MOZ_ASSERT(NS_IsMainThread());
+ sThread->Dispatch(NS_NewRunnableFunction(
+ "MediaCache::CloseStreamsForPrivateBrowsing",
+ [self = RefPtr<MediaCache>(this)]() mutable {
+ AutoLock lock(self->mMonitor);
+ // Copy mStreams since CloseInternal() will change the array.
+ for (MediaCacheStream* s : self->mStreams.Clone()) {
+ if (s->mIsPrivateBrowsing) {
+ s->CloseInternal(lock);
+ }
+ }
+ // Ensure MediaCache is deleted on the main thread.
+ NS_ReleaseOnMainThread("MediaCache::CloseStreamsForPrivateBrowsing",
+ self.forget());
+ }));
+}
+
+/* static */
+RefPtr<MediaCache> MediaCache::GetMediaCache(int64_t aContentLength,
+ bool aIsPrivateBrowsing) {
+ NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
+
+ if (!sThreadInit) {
+ sThreadInit = true;
+ nsCOMPtr<nsIThread> thread;
+ nsresult rv = NS_NewNamedThread("MediaCache", getter_AddRefs(thread));
+ if (NS_FAILED(rv)) {
+ NS_WARNING("Failed to create a thread for MediaCache.");
+ return nullptr;
+ }
+ sThread = ToRefPtr(std::move(thread));
+
+ static struct ClearThread {
+ // Called during shutdown to clear sThread.
+ void operator=(std::nullptr_t) {
+ MOZ_ASSERT(sThread, "We should only clear sThread once.");
+ sThread->Shutdown();
+ sThread = nullptr;
+ }
+ } sClearThread;
+ ClearOnShutdown(&sClearThread, ShutdownPhase::XPCOMShutdownThreads);
+ }
+
+ if (!sThread) {
+ return nullptr;
+ }
+
+ const int64_t mediaMemoryCacheMaxSize =
+ static_cast<int64_t>(StaticPrefs::media_memory_cache_max_size()) * 1024;
+
+ // Force usage of in-memory cache if we are in private browsing mode
+ // and the forceMediaMemoryCache pref is set
+ // We will not attempt to create an on-disk cache if this is the case
+ const bool forceMediaMemoryCache =
+ aIsPrivateBrowsing &&
+ StaticPrefs::browser_privatebrowsing_forceMediaMemoryCache();
+
+ // Alternatively, use an in-memory cache if the media will fit entirely
+ // in memory
+ // aContentLength < 0 indicates we do not know content's actual size
+ const bool contentFitsInMediaMemoryCache =
+ (aContentLength > 0) && (aContentLength <= mediaMemoryCacheMaxSize);
+
+ // Try to allocate a memory cache for our content
+ if (contentFitsInMediaMemoryCache || forceMediaMemoryCache) {
+ // Figure out how large our cache should be
+ int64_t cacheSize = 0;
+ if (contentFitsInMediaMemoryCache) {
+ cacheSize = aContentLength;
+ } else if (forceMediaMemoryCache) {
+ // Unknown content length, we'll give the maximum allowed cache size
+ // just to be sure.
+ if (aContentLength < 0) {
+ cacheSize = mediaMemoryCacheMaxSize;
+ } else {
+ // If the content length is less than the maximum allowed cache size,
+ // use that, otherwise we cap it to max size.
+ cacheSize = std::min(aContentLength, mediaMemoryCacheMaxSize);
+ }
+ }
+
+ RefPtr<MediaBlockCacheBase> bc = new MemoryBlockCache(cacheSize);
+ nsresult rv = bc->Init();
+ if (NS_SUCCEEDED(rv)) {
+ RefPtr<MediaCache> mc = new MediaCache(bc);
+ LOG("GetMediaCache(%" PRIi64 ") -> Memory MediaCache %p", aContentLength,
+ mc.get());
+ return mc;
+ }
+
+ // MemoryBlockCache initialization failed.
+ // If we require use of a memory media cache, we will bail here.
+ // Otherwise use a file-backed MediaCache below.
+ if (forceMediaMemoryCache) {
+ return nullptr;
+ }
+ }
+
+ if (gMediaCache) {
+ LOG("GetMediaCache(%" PRIi64 ") -> Existing file-backed MediaCache",
+ aContentLength);
+ return gMediaCache;
+ }
+
+ RefPtr<MediaBlockCacheBase> bc = new FileBlockCache();
+ nsresult rv = bc->Init();
+ if (NS_SUCCEEDED(rv)) {
+ gMediaCache = new MediaCache(bc);
+ LOG("GetMediaCache(%" PRIi64 ") -> Created file-backed MediaCache",
+ aContentLength);
+ } else {
+ LOG("GetMediaCache(%" PRIi64 ") -> Failed to create file-backed MediaCache",
+ aContentLength);
+ }
+
+ return gMediaCache;
+}
+
+nsresult MediaCache::ReadCacheFile(AutoLock&, int64_t aOffset, void* aData,
+ int32_t aLength, int32_t* aBytes) {
+ if (!mBlockCache) {
+ return NS_ERROR_FAILURE;
+ }
+ return mBlockCache->Read(aOffset, reinterpret_cast<uint8_t*>(aData), aLength,
+ aBytes);
+}
+
+// Allowed range is whatever can be accessed with an int32_t block index.
+static bool IsOffsetAllowed(int64_t aOffset) {
+ return aOffset < (int64_t(INT32_MAX) + 1) * MediaCache::BLOCK_SIZE &&
+ aOffset >= 0;
+}
+
+// Convert 64-bit offset to 32-bit block index.
+// Assumes offset range-check was already done.
+static int32_t OffsetToBlockIndexUnchecked(int64_t aOffset) {
+ // Still check for allowed range in debug builds, to catch out-of-range
+ // issues early during development.
+ MOZ_ASSERT(IsOffsetAllowed(aOffset));
+ return int32_t(aOffset / MediaCache::BLOCK_SIZE);
+}
+
+// Convert 64-bit offset to 32-bit block index. -1 if out of allowed range.
+static int32_t OffsetToBlockIndex(int64_t aOffset) {
+ return IsOffsetAllowed(aOffset) ? OffsetToBlockIndexUnchecked(aOffset) : -1;
+}
+
+// Convert 64-bit offset to 32-bit offset inside a block.
+// Will not fail (even if offset is outside allowed range), so there is no
+// need to check for errors.
+static int32_t OffsetInBlock(int64_t aOffset) {
+ // Still check for allowed range in debug builds, to catch out-of-range
+ // issues early during development.
+ MOZ_ASSERT(IsOffsetAllowed(aOffset));
+ return int32_t(aOffset % MediaCache::BLOCK_SIZE);
+}
+
+int32_t MediaCache::FindBlockForIncomingData(AutoLock& aLock, TimeStamp aNow,
+ MediaCacheStream* aStream,
+ int32_t aStreamBlockIndex) {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+
+ int32_t blockIndex =
+ FindReusableBlock(aLock, aNow, aStream, aStreamBlockIndex, INT32_MAX);
+
+ if (blockIndex < 0 || !IsBlockFree(blockIndex)) {
+ // The block returned is already allocated.
+ // Don't reuse it if a) there's room to expand the cache or
+ // b) the data we're going to store in the free block is not higher
+ // priority than the data already stored in the free block.
+ // The latter can lead us to go over the cache limit a bit.
+ if ((mIndex.Length() <
+ uint32_t(mBlockCache->GetMaxBlocks(MediaCache::CacheSize())) ||
+ blockIndex < 0 ||
+ PredictNextUseForIncomingData(aLock, aStream) >=
+ PredictNextUse(aLock, aNow, blockIndex))) {
+ blockIndex = mIndex.Length();
+ // XXX(Bug 1631371) Check if this should use a fallible operation as it
+ // pretended earlier.
+ mIndex.AppendElement();
+ mFreeBlocks.AddFirstBlock(blockIndex);
+ return blockIndex;
+ }
+ }
+
+ return blockIndex;
+}
+
+bool MediaCache::BlockIsReusable(AutoLock&, int32_t aBlockIndex) {
+ Block* block = &mIndex[aBlockIndex];
+ for (uint32_t i = 0; i < block->mOwners.Length(); ++i) {
+ MediaCacheStream* stream = block->mOwners[i].mStream;
+ if (stream->mPinCount > 0 ||
+ uint32_t(OffsetToBlockIndex(stream->mStreamOffset)) ==
+ block->mOwners[i].mStreamBlock) {
+ return false;
+ }
+ }
+ return true;
+}
+
+void MediaCache::AppendMostReusableBlock(AutoLock& aLock, BlockList* aBlockList,
+ nsTArray<uint32_t>* aResult,
+ int32_t aBlockIndexLimit) {
+ int32_t blockIndex = aBlockList->GetLastBlock();
+ if (blockIndex < 0) return;
+ do {
+ // Don't consider blocks for pinned streams, or blocks that are
+ // beyond the specified limit, or a block that contains a stream's
+ // current read position (such a block contains both played data
+ // and readahead data)
+ if (blockIndex < aBlockIndexLimit && BlockIsReusable(aLock, blockIndex)) {
+ aResult->AppendElement(blockIndex);
+ return;
+ }
+ blockIndex = aBlockList->GetPrevBlock(blockIndex);
+ } while (blockIndex >= 0);
+}
+
+int32_t MediaCache::FindReusableBlock(AutoLock& aLock, TimeStamp aNow,
+ MediaCacheStream* aForStream,
+ int32_t aForStreamBlock,
+ int32_t aMaxSearchBlockIndex) {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+
+ uint32_t length =
+ std::min(uint32_t(aMaxSearchBlockIndex), uint32_t(mIndex.Length()));
+
+ if (aForStream && aForStreamBlock > 0 &&
+ uint32_t(aForStreamBlock) <= aForStream->mBlocks.Length()) {
+ int32_t prevCacheBlock = aForStream->mBlocks[aForStreamBlock - 1];
+ if (prevCacheBlock >= 0) {
+ uint32_t freeBlockScanEnd =
+ std::min(length, prevCacheBlock + FREE_BLOCK_SCAN_LIMIT);
+ for (uint32_t i = prevCacheBlock; i < freeBlockScanEnd; ++i) {
+ if (IsBlockFree(i)) return i;
+ }
+ }
+ }
+
+ if (!mFreeBlocks.IsEmpty()) {
+ int32_t blockIndex = mFreeBlocks.GetFirstBlock();
+ do {
+ if (blockIndex < aMaxSearchBlockIndex) return blockIndex;
+ blockIndex = mFreeBlocks.GetNextBlock(blockIndex);
+ } while (blockIndex >= 0);
+ }
+
+ // Build a list of the blocks we should consider for the "latest
+ // predicted time of next use". We can exploit the fact that the block
+ // linked lists are ordered by increasing time of next use. This is
+ // actually the whole point of having the linked lists.
+ AutoTArray<uint32_t, 8> candidates;
+ for (uint32_t i = 0; i < mStreams.Length(); ++i) {
+ MediaCacheStream* stream = mStreams[i];
+ if (stream->mPinCount > 0) {
+ // No point in even looking at this stream's blocks
+ continue;
+ }
+
+ AppendMostReusableBlock(aLock, &stream->mMetadataBlocks, &candidates,
+ length);
+ AppendMostReusableBlock(aLock, &stream->mPlayedBlocks, &candidates, length);
+
+ // Don't consider readahead blocks in non-seekable streams. If we
+ // remove the block we won't be able to seek back to read it later.
+ if (stream->mIsTransportSeekable) {
+ AppendMostReusableBlock(aLock, &stream->mReadaheadBlocks, &candidates,
+ length);
+ }
+ }
+
+ TimeDuration latestUse;
+ int32_t latestUseBlock = -1;
+ for (uint32_t i = 0; i < candidates.Length(); ++i) {
+ TimeDuration nextUse = PredictNextUse(aLock, aNow, candidates[i]);
+ if (nextUse > latestUse) {
+ latestUse = nextUse;
+ latestUseBlock = candidates[i];
+ }
+ }
+
+ return latestUseBlock;
+}
+
+MediaCache::BlockList* MediaCache::GetListForBlock(AutoLock&,
+ BlockOwner* aBlock) {
+ switch (aBlock->mClass) {
+ case METADATA_BLOCK:
+ NS_ASSERTION(aBlock->mStream, "Metadata block has no stream?");
+ return &aBlock->mStream->mMetadataBlocks;
+ case PLAYED_BLOCK:
+ NS_ASSERTION(aBlock->mStream, "Metadata block has no stream?");
+ return &aBlock->mStream->mPlayedBlocks;
+ case READAHEAD_BLOCK:
+ NS_ASSERTION(aBlock->mStream, "Readahead block has no stream?");
+ return &aBlock->mStream->mReadaheadBlocks;
+ default:
+ NS_ERROR("Invalid block class");
+ return nullptr;
+ }
+}
+
+MediaCache::BlockOwner* MediaCache::GetBlockOwner(AutoLock&,
+ int32_t aBlockIndex,
+ MediaCacheStream* aStream) {
+ Block* block = &mIndex[aBlockIndex];
+ for (uint32_t i = 0; i < block->mOwners.Length(); ++i) {
+ if (block->mOwners[i].mStream == aStream) return &block->mOwners[i];
+ }
+ return nullptr;
+}
+
+void MediaCache::SwapBlocks(AutoLock& aLock, int32_t aBlockIndex1,
+ int32_t aBlockIndex2) {
+ Block* block1 = &mIndex[aBlockIndex1];
+ Block* block2 = &mIndex[aBlockIndex2];
+
+ block1->mOwners.SwapElements(block2->mOwners);
+
+ // Now all references to block1 have to be replaced with block2 and
+ // vice versa.
+ // First update stream references to blocks via mBlocks.
+ const Block* blocks[] = {block1, block2};
+ int32_t blockIndices[] = {aBlockIndex1, aBlockIndex2};
+ for (int32_t i = 0; i < 2; ++i) {
+ for (uint32_t j = 0; j < blocks[i]->mOwners.Length(); ++j) {
+ const BlockOwner* b = &blocks[i]->mOwners[j];
+ b->mStream->mBlocks[b->mStreamBlock] = blockIndices[i];
+ }
+ }
+
+ // Now update references to blocks in block lists.
+ mFreeBlocks.NotifyBlockSwapped(aBlockIndex1, aBlockIndex2);
+
+ nsTHashSet<MediaCacheStream*> visitedStreams;
+
+ for (int32_t i = 0; i < 2; ++i) {
+ for (uint32_t j = 0; j < blocks[i]->mOwners.Length(); ++j) {
+ MediaCacheStream* stream = blocks[i]->mOwners[j].mStream;
+ // Make sure that we don't update the same stream twice --- that
+ // would result in swapping the block references back again!
+ if (!visitedStreams.EnsureInserted(stream)) continue;
+ stream->mReadaheadBlocks.NotifyBlockSwapped(aBlockIndex1, aBlockIndex2);
+ stream->mPlayedBlocks.NotifyBlockSwapped(aBlockIndex1, aBlockIndex2);
+ stream->mMetadataBlocks.NotifyBlockSwapped(aBlockIndex1, aBlockIndex2);
+ }
+ }
+
+ Verify(aLock);
+}
+
+void MediaCache::RemoveBlockOwner(AutoLock& aLock, int32_t aBlockIndex,
+ MediaCacheStream* aStream) {
+ Block* block = &mIndex[aBlockIndex];
+ for (uint32_t i = 0; i < block->mOwners.Length(); ++i) {
+ BlockOwner* bo = &block->mOwners[i];
+ if (bo->mStream == aStream) {
+ GetListForBlock(aLock, bo)->RemoveBlock(aBlockIndex);
+ bo->mStream->mBlocks[bo->mStreamBlock] = -1;
+ block->mOwners.RemoveElementAt(i);
+ if (block->mOwners.IsEmpty()) {
+ mFreeBlocks.AddFirstBlock(aBlockIndex);
+ }
+ return;
+ }
+ }
+}
+
+void MediaCache::AddBlockOwnerAsReadahead(AutoLock& aLock, int32_t aBlockIndex,
+ MediaCacheStream* aStream,
+ int32_t aStreamBlockIndex) {
+ Block* block = &mIndex[aBlockIndex];
+ if (block->mOwners.IsEmpty()) {
+ mFreeBlocks.RemoveBlock(aBlockIndex);
+ }
+ BlockOwner* bo = block->mOwners.AppendElement();
+ bo->mStream = aStream;
+ bo->mStreamBlock = aStreamBlockIndex;
+ aStream->mBlocks[aStreamBlockIndex] = aBlockIndex;
+ bo->mClass = READAHEAD_BLOCK;
+ InsertReadaheadBlock(aLock, bo, aBlockIndex);
+}
+
+void MediaCache::FreeBlock(AutoLock& aLock, int32_t aBlock) {
+ Block* block = &mIndex[aBlock];
+ if (block->mOwners.IsEmpty()) {
+ // already free
+ return;
+ }
+
+ LOG("Released block %d", aBlock);
+
+ for (uint32_t i = 0; i < block->mOwners.Length(); ++i) {
+ BlockOwner* bo = &block->mOwners[i];
+ GetListForBlock(aLock, bo)->RemoveBlock(aBlock);
+ bo->mStream->mBlocks[bo->mStreamBlock] = -1;
+ }
+ block->mOwners.Clear();
+ mFreeBlocks.AddFirstBlock(aBlock);
+ Verify(aLock);
+}
+
+TimeDuration MediaCache::PredictNextUse(AutoLock&, TimeStamp aNow,
+ int32_t aBlock) {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+ NS_ASSERTION(!IsBlockFree(aBlock), "aBlock is free");
+
+ Block* block = &mIndex[aBlock];
+ // Blocks can be belong to multiple streams. The predicted next use
+ // time is the earliest time predicted by any of the streams.
+ TimeDuration result;
+ for (uint32_t i = 0; i < block->mOwners.Length(); ++i) {
+ BlockOwner* bo = &block->mOwners[i];
+ TimeDuration prediction;
+ switch (bo->mClass) {
+ case METADATA_BLOCK:
+ // This block should be managed in LRU mode. For metadata we predict
+ // that the time until the next use is the time since the last use.
+ prediction = aNow - bo->mLastUseTime;
+ break;
+ case PLAYED_BLOCK: {
+ // This block should be managed in LRU mode, and we should impose
+ // a "replay delay" to reflect the likelihood of replay happening
+ NS_ASSERTION(static_cast<int64_t>(bo->mStreamBlock) * BLOCK_SIZE <
+ bo->mStream->mStreamOffset,
+ "Played block after the current stream position?");
+ int64_t bytesBehind =
+ bo->mStream->mStreamOffset -
+ static_cast<int64_t>(bo->mStreamBlock) * BLOCK_SIZE;
+ int64_t millisecondsBehind =
+ bytesBehind * 1000 / bo->mStream->mPlaybackBytesPerSecond;
+ prediction = TimeDuration::FromMilliseconds(std::min<int64_t>(
+ millisecondsBehind * REPLAY_PENALTY_FACTOR, INT32_MAX));
+ break;
+ }
+ case READAHEAD_BLOCK: {
+ int64_t bytesAhead =
+ static_cast<int64_t>(bo->mStreamBlock) * BLOCK_SIZE -
+ bo->mStream->mStreamOffset;
+ NS_ASSERTION(bytesAhead >= 0,
+ "Readahead block before the current stream position?");
+ int64_t millisecondsAhead =
+ bytesAhead * 1000 / bo->mStream->mPlaybackBytesPerSecond;
+ prediction = TimeDuration::FromMilliseconds(
+ std::min<int64_t>(millisecondsAhead, INT32_MAX));
+ break;
+ }
+ default:
+ NS_ERROR("Invalid class for predicting next use");
+ return TimeDuration(0);
+ }
+ if (i == 0 || prediction < result) {
+ result = prediction;
+ }
+ }
+ return result;
+}
+
+TimeDuration MediaCache::PredictNextUseForIncomingData(
+ AutoLock&, MediaCacheStream* aStream) {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+
+ int64_t bytesAhead = aStream->mChannelOffset - aStream->mStreamOffset;
+ if (bytesAhead <= -BLOCK_SIZE) {
+ // Hmm, no idea when data behind us will be used. Guess 24 hours.
+ return TimeDuration::FromSeconds(24 * 60 * 60);
+ }
+ if (bytesAhead <= 0) return TimeDuration(0);
+ int64_t millisecondsAhead =
+ bytesAhead * 1000 / aStream->mPlaybackBytesPerSecond;
+ return TimeDuration::FromMilliseconds(
+ std::min<int64_t>(millisecondsAhead, INT32_MAX));
+}
+
+void MediaCache::Update() {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+
+ AutoLock lock(mMonitor);
+
+ mUpdateQueued = false;
+#ifdef DEBUG
+ mInUpdate = true;
+#endif
+ const TimeStamp now = TimeStamp::Now();
+ const int32_t freeBlockCount = TrimCacheIfNeeded(lock, now);
+
+ // The action to use for each stream. We store these so we can make
+ // decisions while holding the cache lock but implement those decisions
+ // without holding the cache lock, since we need to call out to
+ // stream, decoder and element code.
+ AutoTArray<StreamAction, 10> actions;
+ DetermineActionsForStreams(lock, now, actions, freeBlockCount);
+
+#ifdef DEBUG
+ mInUpdate = false;
+#endif
+
+ // First, update the mCacheSuspended/mCacheEnded flags so that they're all
+ // correct when we fire our CacheClient commands below. Those commands can
+ // rely on these flags being set correctly for all streams.
+ for (uint32_t i = 0; i < mStreams.Length(); ++i) {
+ MediaCacheStream* stream = mStreams[i];
+ switch (actions[i].mTag) {
+ case StreamAction::SEEK:
+ stream->mCacheSuspended = false;
+ stream->mChannelEnded = false;
+ break;
+ case StreamAction::RESUME:
+ stream->mCacheSuspended = false;
+ break;
+ case StreamAction::SUSPEND:
+ stream->mCacheSuspended = true;
+ break;
+ default:
+ break;
+ }
+ }
+
+ for (uint32_t i = 0; i < mStreams.Length(); ++i) {
+ MediaCacheStream* stream = mStreams[i];
+ switch (actions[i].mTag) {
+ case StreamAction::SEEK:
+ LOG("Stream %p CacheSeek to %" PRId64 " (resume=%d)", stream,
+ actions[i].mSeekTarget, actions[i].mResume);
+ stream->mClient->CacheClientSeek(actions[i].mSeekTarget,
+ actions[i].mResume);
+ break;
+ case StreamAction::RESUME:
+ LOG("Stream %p Resumed", stream);
+ stream->mClient->CacheClientResume();
+ QueueSuspendedStatusUpdate(lock, stream->mResourceID);
+ break;
+ case StreamAction::SUSPEND:
+ LOG("Stream %p Suspended", stream);
+ stream->mClient->CacheClientSuspend();
+ QueueSuspendedStatusUpdate(lock, stream->mResourceID);
+ break;
+ default:
+ break;
+ }
+ }
+
+ // Notify streams about the suspended status changes.
+ for (uint32_t i = 0; i < mSuspendedStatusToNotify.Length(); ++i) {
+ MediaCache::ResourceStreamIterator iter(this, mSuspendedStatusToNotify[i]);
+ while (MediaCacheStream* stream = iter.Next(lock)) {
+ stream->mClient->CacheClientNotifySuspendedStatusChanged(
+ stream->AreAllStreamsForResourceSuspended(lock));
+ }
+ }
+ mSuspendedStatusToNotify.Clear();
+}
+
+int32_t MediaCache::TrimCacheIfNeeded(AutoLock& aLock, const TimeStamp& aNow) {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+
+ const int32_t maxBlocks = mBlockCache->GetMaxBlocks(MediaCache::CacheSize());
+
+ int32_t freeBlockCount = mFreeBlocks.GetCount();
+ TimeDuration latestPredictedUseForOverflow = 0;
+ if (mIndex.Length() > uint32_t(maxBlocks)) {
+ // Try to trim back the cache to its desired maximum size. The cache may
+ // have overflowed simply due to data being received when we have
+ // no blocks in the main part of the cache that are free or lower
+ // priority than the new data. The cache can also be overflowing because
+ // the media.cache_size preference was reduced.
+ // First, figure out what the least valuable block in the cache overflow
+ // is. We don't want to replace any blocks in the main part of the
+ // cache whose expected time of next use is earlier or equal to that.
+ // If we allow that, we can effectively end up discarding overflowing
+ // blocks (by moving an overflowing block to the main part of the cache,
+ // and then overwriting it with another overflowing block), and we try
+ // to avoid that since it requires HTTP seeks.
+ // We also use this loop to eliminate overflowing blocks from
+ // freeBlockCount.
+ for (int32_t blockIndex = mIndex.Length() - 1; blockIndex >= maxBlocks;
+ --blockIndex) {
+ if (IsBlockFree(blockIndex)) {
+ // Don't count overflowing free blocks in our free block count
+ --freeBlockCount;
+ continue;
+ }
+ TimeDuration predictedUse = PredictNextUse(aLock, aNow, blockIndex);
+ latestPredictedUseForOverflow =
+ std::max(latestPredictedUseForOverflow, predictedUse);
+ }
+ } else {
+ freeBlockCount += maxBlocks - mIndex.Length();
+ }
+
+ // Now try to move overflowing blocks to the main part of the cache.
+ for (int32_t blockIndex = mIndex.Length() - 1; blockIndex >= maxBlocks;
+ --blockIndex) {
+ if (IsBlockFree(blockIndex)) continue;
+
+ Block* block = &mIndex[blockIndex];
+ // Try to relocate the block close to other blocks for the first stream.
+ // There is no point in trying to make it close to other blocks in
+ // *all* the streams it might belong to.
+ int32_t destinationBlockIndex =
+ FindReusableBlock(aLock, aNow, block->mOwners[0].mStream,
+ block->mOwners[0].mStreamBlock, maxBlocks);
+ if (destinationBlockIndex < 0) {
+ // Nowhere to place this overflow block. We won't be able to
+ // place any more overflow blocks.
+ break;
+ }
+
+ // Don't evict |destinationBlockIndex| if it is within [cur, end) otherwise
+ // a new channel will be opened to download this block again which is bad.
+ bool inCurrentCachedRange = false;
+ for (BlockOwner& owner : mIndex[destinationBlockIndex].mOwners) {
+ MediaCacheStream* stream = owner.mStream;
+ int64_t end = OffsetToBlockIndexUnchecked(
+ stream->GetCachedDataEndInternal(aLock, stream->mStreamOffset));
+ int64_t cur = OffsetToBlockIndexUnchecked(stream->mStreamOffset);
+ if (cur <= owner.mStreamBlock && owner.mStreamBlock < end) {
+ inCurrentCachedRange = true;
+ break;
+ }
+ }
+ if (inCurrentCachedRange) {
+ continue;
+ }
+
+ if (IsBlockFree(destinationBlockIndex) ||
+ PredictNextUse(aLock, aNow, destinationBlockIndex) >
+ latestPredictedUseForOverflow) {
+ // Reuse blocks in the main part of the cache that are less useful than
+ // the least useful overflow blocks
+
+ nsresult rv = mBlockCache->MoveBlock(blockIndex, destinationBlockIndex);
+
+ if (NS_SUCCEEDED(rv)) {
+ // We successfully copied the file data.
+ LOG("Swapping blocks %d and %d (trimming cache)", blockIndex,
+ destinationBlockIndex);
+ // Swapping the block metadata here lets us maintain the
+ // correct positions in the linked lists
+ SwapBlocks(aLock, blockIndex, destinationBlockIndex);
+ // Free the overflowing block even if the copy failed.
+ LOG("Released block %d (trimming cache)", blockIndex);
+ FreeBlock(aLock, blockIndex);
+ }
+ } else {
+ LOG("Could not trim cache block %d (destination %d, "
+ "predicted next use %f, latest predicted use for overflow %f",
+ blockIndex, destinationBlockIndex,
+ PredictNextUse(aLock, aNow, destinationBlockIndex).ToSeconds(),
+ latestPredictedUseForOverflow.ToSeconds());
+ }
+ }
+ // Try chopping back the array of cache entries and the cache file.
+ Truncate();
+ return freeBlockCount;
+}
+
+void MediaCache::DetermineActionsForStreams(AutoLock& aLock,
+ const TimeStamp& aNow,
+ nsTArray<StreamAction>& aActions,
+ int32_t aFreeBlockCount) {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+
+ // Count the blocks allocated for readahead of non-seekable streams
+ // (these blocks can't be freed but we don't want them to monopolize the
+ // cache)
+ int32_t nonSeekableReadaheadBlockCount = 0;
+ for (uint32_t i = 0; i < mStreams.Length(); ++i) {
+ MediaCacheStream* stream = mStreams[i];
+ if (!stream->mIsTransportSeekable) {
+ nonSeekableReadaheadBlockCount += stream->mReadaheadBlocks.GetCount();
+ }
+ }
+
+ // If freeBlockCount is zero, then compute the latest of
+ // the predicted next-uses for all blocks
+ TimeDuration latestNextUse;
+ const int32_t maxBlocks = mBlockCache->GetMaxBlocks(MediaCache::CacheSize());
+ if (aFreeBlockCount == 0) {
+ const int32_t reusableBlock =
+ FindReusableBlock(aLock, aNow, nullptr, 0, maxBlocks);
+ if (reusableBlock >= 0) {
+ latestNextUse = PredictNextUse(aLock, aNow, reusableBlock);
+ }
+ }
+
+ for (uint32_t i = 0; i < mStreams.Length(); ++i) {
+ aActions.AppendElement(StreamAction{});
+
+ MediaCacheStream* stream = mStreams[i];
+ if (stream->mClosed) {
+ LOG("Stream %p closed", stream);
+ continue;
+ }
+
+ // We make decisions based on mSeekTarget when there is a pending seek.
+ // Otherwise we will keep issuing seek requests until mChannelOffset
+ // is changed by NotifyDataStarted() which is bad.
+ const int64_t channelOffset = stream->mSeekTarget != -1
+ ? stream->mSeekTarget
+ : stream->mChannelOffset;
+
+ // Figure out where we should be reading from. It's the first
+ // uncached byte after the current mStreamOffset.
+ const int64_t dataOffset =
+ stream->GetCachedDataEndInternal(aLock, stream->mStreamOffset);
+ MOZ_ASSERT(dataOffset >= 0);
+
+ // Compute where we'd actually seek to to read at readOffset
+ int64_t desiredOffset = dataOffset;
+ if (stream->mIsTransportSeekable) {
+ if (desiredOffset > channelOffset &&
+ desiredOffset <= channelOffset + SEEK_VS_READ_THRESHOLD) {
+ // Assume it's more efficient to just keep reading up to the
+ // desired position instead of trying to seek
+ desiredOffset = channelOffset;
+ }
+ } else {
+ // We can't seek directly to the desired offset...
+ if (channelOffset > desiredOffset) {
+ // Reading forward won't get us anywhere, we need to go backwards.
+ // Seek back to 0 (the client will reopen the stream) and then
+ // read forward.
+ NS_WARNING("Can't seek backwards, so seeking to 0");
+ desiredOffset = 0;
+ // Flush cached blocks out, since if this is a live stream
+ // the cached data may be completely different next time we
+ // read it. We have to assume that live streams don't
+ // advertise themselves as being seekable...
+ ReleaseStreamBlocks(aLock, stream);
+ } else {
+ // otherwise reading forward is looking good, so just stay where we
+ // are and don't trigger a channel seek!
+ desiredOffset = channelOffset;
+ }
+ }
+
+ // Figure out if we should be reading data now or not. It's amazing
+ // how complex this is, but each decision is simple enough.
+ bool enableReading;
+ if (stream->mStreamLength >= 0 && dataOffset >= stream->mStreamLength) {
+ // We want data at the end of the stream, where there's nothing to
+ // read. We don't want to try to read if we're suspended, because that
+ // might create a new channel and seek unnecessarily (and incorrectly,
+ // since HTTP doesn't allow seeking to the actual EOF), and we don't want
+ // to suspend if we're not suspended and already reading at the end of
+ // the stream, since there just might be more data than the server
+ // advertised with Content-Length, and we may as well keep reading.
+ // But we don't want to seek to the end of the stream if we're not
+ // already there.
+ LOG("Stream %p at end of stream", stream);
+ enableReading =
+ !stream->mCacheSuspended && stream->mStreamLength == channelOffset;
+ } else if (desiredOffset < stream->mStreamOffset) {
+ // We're reading to try to catch up to where the current stream
+ // reader wants to be. Better not stop.
+ LOG("Stream %p catching up", stream);
+ enableReading = true;
+ } else if (desiredOffset < stream->mStreamOffset + BLOCK_SIZE) {
+ // The stream reader is waiting for us, or nearly so. Better feed it.
+ LOG("Stream %p feeding reader", stream);
+ enableReading = true;
+ } else if (!stream->mIsTransportSeekable &&
+ nonSeekableReadaheadBlockCount >=
+ maxBlocks * NONSEEKABLE_READAHEAD_MAX) {
+ // This stream is not seekable and there are already too many blocks
+ // being cached for readahead for nonseekable streams (which we can't
+ // free). So stop reading ahead now.
+ LOG("Stream %p throttling non-seekable readahead", stream);
+ enableReading = false;
+ } else if (mIndex.Length() > uint32_t(maxBlocks)) {
+ // We're in the process of bringing the cache size back to the
+ // desired limit, so don't bring in more data yet
+ LOG("Stream %p throttling to reduce cache size", stream);
+ enableReading = false;
+ } else {
+ TimeDuration predictedNewDataUse =
+ PredictNextUseForIncomingData(aLock, stream);
+
+ if (stream->mThrottleReadahead && stream->mCacheSuspended &&
+ predictedNewDataUse.ToSeconds() > MediaCache::ResumeThreshold()) {
+ // Don't need data for a while, so don't bother waking up the stream
+ LOG("Stream %p avoiding wakeup since more data is not needed", stream);
+ enableReading = false;
+ } else if (stream->mThrottleReadahead &&
+ predictedNewDataUse.ToSeconds() >
+ MediaCache::ReadaheadLimit()) {
+ // Don't read ahead more than this much
+ LOG("Stream %p throttling to avoid reading ahead too far", stream);
+ enableReading = false;
+ } else if (aFreeBlockCount > 0) {
+ // Free blocks in the cache, so keep reading
+ LOG("Stream %p reading since there are free blocks", stream);
+ enableReading = true;
+ } else if (latestNextUse <= TimeDuration(0)) {
+ // No reusable blocks, so can't read anything
+ LOG("Stream %p throttling due to no reusable blocks", stream);
+ enableReading = false;
+ } else {
+ // Read ahead if the data we expect to read is more valuable than
+ // the least valuable block in the main part of the cache
+ LOG("Stream %p predict next data in %f, current worst block is %f",
+ stream, predictedNewDataUse.ToSeconds(), latestNextUse.ToSeconds());
+ enableReading = predictedNewDataUse < latestNextUse;
+ }
+ }
+
+ if (enableReading) {
+ for (uint32_t j = 0; j < i; ++j) {
+ MediaCacheStream* other = mStreams[j];
+ if (other->mResourceID == stream->mResourceID && !other->mClosed &&
+ !other->mClientSuspended && !other->mChannelEnded &&
+ OffsetToBlockIndexUnchecked(other->mSeekTarget != -1
+ ? other->mSeekTarget
+ : other->mChannelOffset) ==
+ OffsetToBlockIndexUnchecked(desiredOffset)) {
+ // This block is already going to be read by the other stream.
+ // So don't try to read it from this stream as well.
+ enableReading = false;
+ LOG("Stream %p waiting on same block (%" PRId32 ") from stream %p",
+ stream, OffsetToBlockIndexUnchecked(desiredOffset), other);
+ break;
+ }
+ }
+ }
+
+ if (channelOffset != desiredOffset && enableReading) {
+ // We need to seek now.
+ NS_ASSERTION(stream->mIsTransportSeekable || desiredOffset == 0,
+ "Trying to seek in a non-seekable stream!");
+ // Round seek offset down to the start of the block. This is essential
+ // because we don't want to think we have part of a block already
+ // in mPartialBlockBuffer.
+ stream->mSeekTarget =
+ OffsetToBlockIndexUnchecked(desiredOffset) * BLOCK_SIZE;
+ aActions[i].mTag = StreamAction::SEEK;
+ aActions[i].mResume = stream->mCacheSuspended;
+ aActions[i].mSeekTarget = stream->mSeekTarget;
+ } else if (enableReading && stream->mCacheSuspended) {
+ aActions[i].mTag = StreamAction::RESUME;
+ } else if (!enableReading && !stream->mCacheSuspended) {
+ aActions[i].mTag = StreamAction::SUSPEND;
+ }
+ LOG("Stream %p, mCacheSuspended=%d, enableReading=%d, action=%s", stream,
+ stream->mCacheSuspended, enableReading,
+ aActions[i].mTag == StreamAction::SEEK ? "SEEK"
+ : aActions[i].mTag == StreamAction::RESUME ? "RESUME"
+ : aActions[i].mTag == StreamAction::SUSPEND ? "SUSPEND"
+ : "NONE");
+ }
+}
+
+void MediaCache::QueueUpdate(AutoLock&) {
+ // Queuing an update while we're in an update raises a high risk of
+ // triggering endless events
+ NS_ASSERTION(!mInUpdate, "Queuing an update while we're in an update");
+ if (mUpdateQueued) {
+ return;
+ }
+ mUpdateQueued = true;
+ sThread->Dispatch(NS_NewRunnableFunction(
+ "MediaCache::QueueUpdate", [self = RefPtr<MediaCache>(this)]() mutable {
+ self->Update();
+ // Ensure MediaCache is deleted on the main thread.
+ NS_ReleaseOnMainThread("UpdateEvent::mMediaCache", self.forget());
+ }));
+}
+
+void MediaCache::QueueSuspendedStatusUpdate(AutoLock&, int64_t aResourceID) {
+ if (!mSuspendedStatusToNotify.Contains(aResourceID)) {
+ mSuspendedStatusToNotify.AppendElement(aResourceID);
+ }
+}
+
+#ifdef DEBUG_VERIFY_CACHE
+void MediaCache::Verify(AutoLock&) {
+ mFreeBlocks.Verify();
+ for (uint32_t i = 0; i < mStreams.Length(); ++i) {
+ MediaCacheStream* stream = mStreams[i];
+ stream->mReadaheadBlocks.Verify();
+ stream->mPlayedBlocks.Verify();
+ stream->mMetadataBlocks.Verify();
+
+ // Verify that the readahead blocks are listed in stream block order
+ int32_t block = stream->mReadaheadBlocks.GetFirstBlock();
+ int32_t lastStreamBlock = -1;
+ while (block >= 0) {
+ uint32_t j = 0;
+ while (mIndex[block].mOwners[j].mStream != stream) {
+ ++j;
+ }
+ int32_t nextStreamBlock = int32_t(mIndex[block].mOwners[j].mStreamBlock);
+ NS_ASSERTION(lastStreamBlock < nextStreamBlock,
+ "Blocks not increasing in readahead stream");
+ lastStreamBlock = nextStreamBlock;
+ block = stream->mReadaheadBlocks.GetNextBlock(block);
+ }
+ }
+}
+#endif
+
+void MediaCache::InsertReadaheadBlock(AutoLock& aLock, BlockOwner* aBlockOwner,
+ int32_t aBlockIndex) {
+ // Find the last block whose stream block is before aBlockIndex's
+ // stream block, and insert after it
+ MediaCacheStream* stream = aBlockOwner->mStream;
+ int32_t readaheadIndex = stream->mReadaheadBlocks.GetLastBlock();
+ while (readaheadIndex >= 0) {
+ BlockOwner* bo = GetBlockOwner(aLock, readaheadIndex, stream);
+ NS_ASSERTION(bo, "stream must own its blocks");
+ if (bo->mStreamBlock < aBlockOwner->mStreamBlock) {
+ stream->mReadaheadBlocks.AddAfter(aBlockIndex, readaheadIndex);
+ return;
+ }
+ NS_ASSERTION(bo->mStreamBlock > aBlockOwner->mStreamBlock,
+ "Duplicated blocks??");
+ readaheadIndex = stream->mReadaheadBlocks.GetPrevBlock(readaheadIndex);
+ }
+
+ stream->mReadaheadBlocks.AddFirstBlock(aBlockIndex);
+ Verify(aLock);
+}
+
+void MediaCache::AllocateAndWriteBlock(AutoLock& aLock,
+ MediaCacheStream* aStream,
+ int32_t aStreamBlockIndex,
+ Span<const uint8_t> aData1,
+ Span<const uint8_t> aData2) {
+ MOZ_ASSERT(sThread->IsOnCurrentThread());
+
+ // Remove all cached copies of this block
+ ResourceStreamIterator iter(this, aStream->mResourceID);
+ while (MediaCacheStream* stream = iter.Next(aLock)) {
+ while (aStreamBlockIndex >= int32_t(stream->mBlocks.Length())) {
+ stream->mBlocks.AppendElement(-1);
+ }
+ if (stream->mBlocks[aStreamBlockIndex] >= 0) {
+ // We no longer want to own this block
+ int32_t globalBlockIndex = stream->mBlocks[aStreamBlockIndex];
+ LOG("Released block %d from stream %p block %d(%" PRId64 ")",
+ globalBlockIndex, stream, aStreamBlockIndex,
+ aStreamBlockIndex * BLOCK_SIZE);
+ RemoveBlockOwner(aLock, globalBlockIndex, stream);
+ }
+ }
+
+ // Extend the mBlocks array as necessary
+
+ TimeStamp now = TimeStamp::Now();
+ int32_t blockIndex =
+ FindBlockForIncomingData(aLock, now, aStream, aStreamBlockIndex);
+ if (blockIndex >= 0) {
+ FreeBlock(aLock, blockIndex);
+
+ Block* block = &mIndex[blockIndex];
+ LOG("Allocated block %d to stream %p block %d(%" PRId64 ")", blockIndex,
+ aStream, aStreamBlockIndex, aStreamBlockIndex * BLOCK_SIZE);
+
+ ResourceStreamIterator iter(this, aStream->mResourceID);
+ while (MediaCacheStream* stream = iter.Next(aLock)) {
+ BlockOwner* bo = block->mOwners.AppendElement();
+ if (!bo) {
+ // Roll back mOwners if any allocation fails.
+ block->mOwners.Clear();
+ return;
+ }
+ bo->mStream = stream;
+ }
+
+ if (block->mOwners.IsEmpty()) {
+ // This happens when all streams with the resource id are closed. We can
+ // just return here now and discard the data.
+ return;
+ }
+
+ // Tell each stream using this resource about the new block.
+ for (auto& bo : block->mOwners) {
+ bo.mStreamBlock = aStreamBlockIndex;
+ bo.mLastUseTime = now;
+ bo.mStream->mBlocks[aStreamBlockIndex] = blockIndex;
+ if (aStreamBlockIndex * BLOCK_SIZE < bo.mStream->mStreamOffset) {
+ bo.mClass = PLAYED_BLOCK;
+ // This must be the most-recently-used block, since we
+ // marked it as used now (which may be slightly bogus, but we'll
+ // treat it as used for simplicity).
+ GetListForBlock(aLock, &bo)->AddFirstBlock(blockIndex);
+ Verify(aLock);
+ } else {
+ // This may not be the latest readahead block, although it usually
+ // will be. We may have to scan for the right place to insert
+ // the block in the list.
+ bo.mClass = READAHEAD_BLOCK;
+ InsertReadaheadBlock(aLock, &bo, blockIndex);
+ }
+ }
+
+ // Invariant: block->mOwners.IsEmpty() iff we can find an entry
+ // in mFreeBlocks for a given blockIndex.
+ MOZ_DIAGNOSTIC_ASSERT(!block->mOwners.IsEmpty());
+ mFreeBlocks.RemoveBlock(blockIndex);
+
+ nsresult rv = mBlockCache->WriteBlock(blockIndex, aData1, aData2);
+ if (NS_FAILED(rv)) {
+ LOG("Released block %d from stream %p block %d(%" PRId64 ")", blockIndex,
+ aStream, aStreamBlockIndex, aStreamBlockIndex * BLOCK_SIZE);
+ FreeBlock(aLock, blockIndex);
+ }
+ }
+
+ // Queue an Update since the cache state has changed (for example
+ // we might want to stop loading because the cache is full)
+ QueueUpdate(aLock);
+}
+
+void MediaCache::OpenStream(AutoLock& aLock, MediaCacheStream* aStream,
+ bool aIsClone) {
+ LOG("Stream %p opened, aIsClone=%d, mCacheSuspended=%d, "
+ "mDidNotifyDataEnded=%d",
+ aStream, aIsClone, aStream->mCacheSuspended,
+ aStream->mDidNotifyDataEnded);
+ mStreams.AppendElement(aStream);
+
+ // A cloned stream should've got the ID from its original.
+ if (!aIsClone) {
+ MOZ_ASSERT(aStream->mResourceID == 0, "mResourceID has been initialized.");
+ aStream->mResourceID = AllocateResourceID(aLock);
+ }
+
+ // We should have a valid ID now no matter it is cloned or not.
+ MOZ_ASSERT(aStream->mResourceID > 0, "mResourceID is invalid");
+
+ // Queue an update since a new stream has been opened.
+ QueueUpdate(aLock);
+}
+
+void MediaCache::ReleaseStream(AutoLock&, MediaCacheStream* aStream) {
+ MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
+ LOG("Stream %p closed", aStream);
+ mStreams.RemoveElement(aStream);
+ // The caller needs to call QueueUpdate() to re-run Update().
+}
+
+void MediaCache::ReleaseStreamBlocks(AutoLock& aLock,
+ MediaCacheStream* aStream) {
+ // XXX scanning the entire stream doesn't seem great, if not much of it
+ // is cached, but the only easy alternative is to scan the entire cache
+ // which isn't better
+ uint32_t length = aStream->mBlocks.Length();
+ for (uint32_t i = 0; i < length; ++i) {
+ int32_t blockIndex = aStream->mBlocks[i];
+ if (blockIndex >= 0) {
+ LOG("Released block %d from stream %p block %d(%" PRId64 ")", blockIndex,
+ aStream, i, i * BLOCK_SIZE);
+ RemoveBlockOwner(aLock, blockIndex, aStream);
+ }
+ }
+}
+
+void MediaCache::Truncate() {
+ uint32_t end;
+ for (end = mIndex.Length(); end > 0; --end) {
+ if (!IsBlockFree(end - 1)) break;
+ mFreeBlocks.RemoveBlock(end - 1);
+ }
+
+ if (end < mIndex.Length()) {
+ mIndex.TruncateLength(end);
+ // XXX We could truncate the cache file here, but we don't seem
+ // to have a cross-platform API for doing that. At least when all
+ // streams are closed we shut down the cache, which erases the
+ // file at that point.
+ }
+}
+
+void MediaCache::NoteBlockUsage(AutoLock& aLock, MediaCacheStream* aStream,
+ int32_t aBlockIndex, int64_t aStreamOffset,
+ MediaCacheStream::ReadMode aMode,
+ TimeStamp aNow) {
+ if (aBlockIndex < 0) {
+ // this block is not in the cache yet
+ return;
+ }
+
+ BlockOwner* bo = GetBlockOwner(aLock, aBlockIndex, aStream);
+ if (!bo) {
+ // this block is not in the cache yet
+ return;
+ }
+
+ // The following check has to be <= because the stream offset has
+ // not yet been updated for the data read from this block
+ NS_ASSERTION(bo->mStreamBlock * BLOCK_SIZE <= aStreamOffset,
+ "Using a block that's behind the read position?");
+
+ GetListForBlock(aLock, bo)->RemoveBlock(aBlockIndex);
+ bo->mClass =
+ (aMode == MediaCacheStream::MODE_METADATA || bo->mClass == METADATA_BLOCK)
+ ? METADATA_BLOCK
+ : PLAYED_BLOCK;
+ // Since this is just being used now, it can definitely be at the front
+ // of mMetadataBlocks or mPlayedBlocks
+ GetListForBlock(aLock, bo)->AddFirstBlock(aBlockIndex);
+ bo->mLastUseTime = aNow;
+ Verify(aLock);
+}
+
+void MediaCache::NoteSeek(AutoLock& aLock, MediaCacheStream* aStream,
+ int64_t aOldOffset) {
+ if (aOldOffset < aStream->mStreamOffset) {
+ // We seeked forward. Convert blocks from readahead to played.
+ // Any readahead block that intersects the seeked-over range must
+ // be converted.
+ int32_t blockIndex = OffsetToBlockIndex(aOldOffset);
+ if (blockIndex < 0) {
+ return;
+ }
+ int32_t endIndex =
+ std::min(OffsetToBlockIndex(aStream->mStreamOffset + (BLOCK_SIZE - 1)),
+ int32_t(aStream->mBlocks.Length()));
+ if (endIndex < 0) {
+ return;
+ }
+ TimeStamp now = TimeStamp::Now();
+ while (blockIndex < endIndex) {
+ int32_t cacheBlockIndex = aStream->mBlocks[blockIndex];
+ if (cacheBlockIndex >= 0) {
+ // Marking the block used may not be exactly what we want but
+ // it's simple
+ NoteBlockUsage(aLock, aStream, cacheBlockIndex, aStream->mStreamOffset,
+ MediaCacheStream::MODE_PLAYBACK, now);
+ }
+ ++blockIndex;
+ }
+ } else {
+ // We seeked backward. Convert from played to readahead.
+ // Any played block that is entirely after the start of the seeked-over
+ // range must be converted.
+ int32_t blockIndex =
+ OffsetToBlockIndex(aStream->mStreamOffset + (BLOCK_SIZE - 1));
+ if (blockIndex < 0) {
+ return;
+ }
+ int32_t endIndex =
+ std::min(OffsetToBlockIndex(aOldOffset + (BLOCK_SIZE - 1)),
+ int32_t(aStream->mBlocks.Length()));
+ if (endIndex < 0) {
+ return;
+ }
+ while (blockIndex < endIndex) {
+ MOZ_ASSERT(endIndex > 0);
+ int32_t cacheBlockIndex = aStream->mBlocks[endIndex - 1];
+ if (cacheBlockIndex >= 0) {
+ BlockOwner* bo = GetBlockOwner(aLock, cacheBlockIndex, aStream);
+ NS_ASSERTION(bo, "Stream doesn't own its blocks?");
+ if (bo->mClass == PLAYED_BLOCK) {
+ aStream->mPlayedBlocks.RemoveBlock(cacheBlockIndex);
+ bo->mClass = READAHEAD_BLOCK;
+ // Adding this as the first block is sure to be OK since
+ // this must currently be the earliest readahead block
+ // (that's why we're proceeding backwards from the end of
+ // the seeked range to the start)
+ aStream->mReadaheadBlocks.AddFirstBlock(cacheBlockIndex);
+ Verify(aLock);
+ }
+ }
+ --endIndex;
+ }
+ }
+}
+
+void MediaCacheStream::NotifyLoadID(uint32_t aLoadID) {
+ MOZ_ASSERT(aLoadID > 0);
+
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCacheStream::NotifyLoadID",
+ [client = RefPtr<ChannelMediaResource>(mClient), this, aLoadID]() {
+ AutoLock lock(mMediaCache->Monitor());
+ mLoadID = aLoadID;
+ });
+ OwnerThread()->Dispatch(r.forget());
+}
+
+void MediaCacheStream::NotifyDataStartedInternal(uint32_t aLoadID,
+ int64_t aOffset,
+ bool aSeekable,
+ int64_t aLength) {
+ MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
+ MOZ_ASSERT(aLoadID > 0);
+ LOG("Stream %p DataStarted: %" PRId64 " aLoadID=%u aLength=%" PRId64, this,
+ aOffset, aLoadID, aLength);
+
+ AutoLock lock(mMediaCache->Monitor());
+ NS_WARNING_ASSERTION(aOffset == mSeekTarget || aOffset == mChannelOffset,
+ "Server is giving us unexpected offset");
+ MOZ_ASSERT(aOffset >= 0);
+ if (aLength >= 0) {
+ mStreamLength = aLength;
+ }
+ mChannelOffset = aOffset;
+ if (mStreamLength >= 0) {
+ // If we started reading at a certain offset, then for sure
+ // the stream is at least that long.
+ mStreamLength = std::max(mStreamLength, mChannelOffset);
+ }
+ mLoadID = aLoadID;
+
+ MOZ_ASSERT(aOffset == 0 || aSeekable,
+ "channel offset must be zero when we become non-seekable");
+ mIsTransportSeekable = aSeekable;
+ // Queue an Update since we may change our strategy for dealing
+ // with this stream
+ mMediaCache->QueueUpdate(lock);
+
+ // Reset mSeekTarget since the seek is completed so MediaCache::Update() will
+ // make decisions based on mChannelOffset instead of mSeekTarget.
+ mSeekTarget = -1;
+
+ // Reset these flags since a new load has begun.
+ mChannelEnded = false;
+ mDidNotifyDataEnded = false;
+
+ UpdateDownloadStatistics(lock);
+}
+
+void MediaCacheStream::NotifyDataStarted(uint32_t aLoadID, int64_t aOffset,
+ bool aSeekable, int64_t aLength) {
+ MOZ_ASSERT(NS_IsMainThread());
+ MOZ_ASSERT(aLoadID > 0);
+
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCacheStream::NotifyDataStarted",
+ [=, client = RefPtr<ChannelMediaResource>(mClient)]() {
+ NotifyDataStartedInternal(aLoadID, aOffset, aSeekable, aLength);
+ });
+ OwnerThread()->Dispatch(r.forget());
+}
+
+void MediaCacheStream::NotifyDataReceived(uint32_t aLoadID, uint32_t aCount,
+ const uint8_t* aData) {
+ MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
+ MOZ_ASSERT(aLoadID > 0);
+
+ AutoLock lock(mMediaCache->Monitor());
+ if (mClosed) {
+ // Nothing to do if the stream is closed.
+ return;
+ }
+
+ LOG("Stream %p DataReceived at %" PRId64 " count=%u aLoadID=%u", this,
+ mChannelOffset, aCount, aLoadID);
+
+ if (mLoadID != aLoadID) {
+ // mChannelOffset is updated to a new position when loading a new channel.
+ // We should discard the data coming from the old channel so it won't be
+ // stored to the wrong positoin.
+ return;
+ }
+
+ mDownloadStatistics.AddBytes(aCount);
+
+ // True if we commit any blocks to the cache.
+ bool cacheUpdated = false;
+
+ auto source = Span<const uint8_t>(aData, aCount);
+
+ // We process the data one block (or part of a block) at a time
+ while (!source.IsEmpty()) {
+ // The data we've collected so far in the partial block.
+ auto partial = Span<const uint8_t>(mPartialBlockBuffer.get(),
+ OffsetInBlock(mChannelOffset));
+
+ // The number of bytes needed to complete the partial block.
+ size_t remaining = BLOCK_SIZE - partial.Length();
+
+ if (source.Length() >= remaining) {
+ // We have a whole block now to write it out.
+ mMediaCache->AllocateAndWriteBlock(
+ lock, this, OffsetToBlockIndexUnchecked(mChannelOffset), partial,
+ source.First(remaining));
+ source = source.From(remaining);
+ mChannelOffset += remaining;
+ cacheUpdated = true;
+ } else {
+ // The buffer to be filled in the partial block.
+ auto buf = Span<uint8_t>(mPartialBlockBuffer.get() + partial.Length(),
+ remaining);
+ memcpy(buf.Elements(), source.Elements(), source.Length());
+ mChannelOffset += source.Length();
+ break;
+ }
+ }
+
+ MediaCache::ResourceStreamIterator iter(mMediaCache, mResourceID);
+ while (MediaCacheStream* stream = iter.Next(lock)) {
+ if (stream->mStreamLength >= 0) {
+ // The stream is at least as long as what we've read
+ stream->mStreamLength = std::max(stream->mStreamLength, mChannelOffset);
+ }
+ stream->mClient->CacheClientNotifyDataReceived();
+ }
+
+ // XXX it would be fairly easy to optimize things a lot more to
+ // avoid waking up reader threads unnecessarily
+ if (cacheUpdated) {
+ // Wake up the reader who is waiting for the committed blocks.
+ lock.NotifyAll();
+ }
+}
+
+void MediaCacheStream::FlushPartialBlockInternal(AutoLock& aLock,
+ bool aNotifyAll) {
+ MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
+
+ int32_t blockIndex = OffsetToBlockIndexUnchecked(mChannelOffset);
+ int32_t blockOffset = OffsetInBlock(mChannelOffset);
+ if (blockOffset > 0) {
+ LOG("Stream %p writing partial block: [%d] bytes; "
+ "mStreamOffset [%" PRId64 "] mChannelOffset[%" PRId64
+ "] mStreamLength [%" PRId64 "] notifying: [%s]",
+ this, blockOffset, mStreamOffset, mChannelOffset, mStreamLength,
+ aNotifyAll ? "yes" : "no");
+
+ // Write back the partial block
+ memset(mPartialBlockBuffer.get() + blockOffset, 0,
+ BLOCK_SIZE - blockOffset);
+ auto data = Span<const uint8_t>(mPartialBlockBuffer.get(), BLOCK_SIZE);
+ mMediaCache->AllocateAndWriteBlock(aLock, this, blockIndex, data);
+ }
+
+ // |mChannelOffset == 0| means download ends with no bytes received.
+ // We should also wake up those readers who are waiting for data
+ // that will never come.
+ if ((blockOffset > 0 || mChannelOffset == 0) && aNotifyAll) {
+ // Wake up readers who may be waiting for this data
+ aLock.NotifyAll();
+ }
+}
+
+void MediaCacheStream::UpdateDownloadStatistics(AutoLock&) {
+ if (mChannelEnded || mClientSuspended) {
+ mDownloadStatistics.Stop();
+ } else {
+ mDownloadStatistics.Start();
+ }
+}
+
+void MediaCacheStream::NotifyDataEndedInternal(uint32_t aLoadID,
+ nsresult aStatus) {
+ MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
+ AutoLock lock(mMediaCache->Monitor());
+
+ if (mClosed || aLoadID != mLoadID) {
+ // Nothing to do if the stream is closed or a new load has begun.
+ return;
+ }
+
+ // It is prudent to update channel/cache status before calling
+ // CacheClientNotifyDataEnded() which will read |mChannelEnded|.
+ mChannelEnded = true;
+ mMediaCache->QueueUpdate(lock);
+
+ UpdateDownloadStatistics(lock);
+
+ if (NS_FAILED(aStatus)) {
+ // Notify the client about this network error.
+ mDidNotifyDataEnded = true;
+ mNotifyDataEndedStatus = aStatus;
+ mClient->CacheClientNotifyDataEnded(aStatus);
+ // Wake up the readers so they can fail gracefully.
+ lock.NotifyAll();
+ return;
+ }
+
+ // Note we don't flush the partial block when download ends abnormally for
+ // the padding zeros will give wrong data to other streams.
+ FlushPartialBlockInternal(lock, true);
+
+ MediaCache::ResourceStreamIterator iter(mMediaCache, mResourceID);
+ while (MediaCacheStream* stream = iter.Next(lock)) {
+ // We read the whole stream, so remember the true length
+ stream->mStreamLength = mChannelOffset;
+ if (!stream->mDidNotifyDataEnded) {
+ stream->mDidNotifyDataEnded = true;
+ stream->mNotifyDataEndedStatus = aStatus;
+ stream->mClient->CacheClientNotifyDataEnded(aStatus);
+ }
+ }
+}
+
+void MediaCacheStream::NotifyDataEnded(uint32_t aLoadID, nsresult aStatus) {
+ MOZ_ASSERT(NS_IsMainThread());
+ MOZ_ASSERT(aLoadID > 0);
+
+ RefPtr<ChannelMediaResource> client = mClient;
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCacheStream::NotifyDataEnded", [client, this, aLoadID, aStatus]() {
+ NotifyDataEndedInternal(aLoadID, aStatus);
+ });
+ OwnerThread()->Dispatch(r.forget());
+}
+
+void MediaCacheStream::NotifyClientSuspended(bool aSuspended) {
+ MOZ_ASSERT(NS_IsMainThread());
+
+ RefPtr<ChannelMediaResource> client = mClient;
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCacheStream::NotifyClientSuspended", [client, this, aSuspended]() {
+ AutoLock lock(mMediaCache->Monitor());
+ if (!mClosed && mClientSuspended != aSuspended) {
+ mClientSuspended = aSuspended;
+ // mClientSuspended changes the decision of reading streams.
+ mMediaCache->QueueUpdate(lock);
+ UpdateDownloadStatistics(lock);
+ if (mClientSuspended) {
+ // Download is suspended. Wake up the readers that might be able to
+ // get data from the partial block.
+ lock.NotifyAll();
+ }
+ }
+ });
+ OwnerThread()->Dispatch(r.forget());
+}
+
+void MediaCacheStream::NotifyResume() {
+ MOZ_ASSERT(NS_IsMainThread());
+
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCacheStream::NotifyResume",
+ [this, client = RefPtr<ChannelMediaResource>(mClient)]() {
+ AutoLock lock(mMediaCache->Monitor());
+ if (mClosed) {
+ return;
+ }
+ // Don't resume download if we are already at the end of the stream for
+ // seek will fail and be wasted anyway.
+ int64_t offset = mSeekTarget != -1 ? mSeekTarget : mChannelOffset;
+ if (mStreamLength < 0 || offset < mStreamLength) {
+ mClient->CacheClientSeek(offset, false);
+ // DownloadResumed() will be notified when a new channel is opened.
+ }
+ // The channel remains dead. If we want to read some other data in the
+ // future, CacheClientSeek() will be called to reopen the channel.
+ });
+ OwnerThread()->Dispatch(r.forget());
+}
+
+MediaCacheStream::~MediaCacheStream() {
+ MOZ_ASSERT(NS_IsMainThread(), "Only call on main thread");
+ MOZ_ASSERT(!mPinCount, "Unbalanced Pin");
+ MOZ_ASSERT(!mMediaCache || mClosed);
+
+ uint32_t lengthKb = uint32_t(std::min(
+ std::max(mStreamLength, int64_t(0)) / 1024, int64_t(UINT32_MAX)));
+ LOG("MediaCacheStream::~MediaCacheStream(this=%p) "
+ "MEDIACACHESTREAM_LENGTH_KB=%" PRIu32,
+ this, lengthKb);
+}
+
+bool MediaCacheStream::AreAllStreamsForResourceSuspended(AutoLock& aLock) {
+ MOZ_ASSERT(!NS_IsMainThread());
+
+ MediaCache::ResourceStreamIterator iter(mMediaCache, mResourceID);
+ // Look for a stream that's able to read the data we need
+ int64_t dataOffset = -1;
+ while (MediaCacheStream* stream = iter.Next(aLock)) {
+ if (stream->mCacheSuspended || stream->mChannelEnded || stream->mClosed) {
+ continue;
+ }
+ if (dataOffset < 0) {
+ dataOffset = GetCachedDataEndInternal(aLock, mStreamOffset);
+ }
+ // Ignore streams that are reading beyond the data we need
+ if (stream->mChannelOffset > dataOffset) {
+ continue;
+ }
+ return false;
+ }
+
+ return true;
+}
+
+RefPtr<GenericPromise> MediaCacheStream::Close() {
+ MOZ_ASSERT(NS_IsMainThread());
+ if (!mMediaCache) {
+ return GenericPromise::CreateAndResolve(true, __func__);
+ }
+
+ return InvokeAsync(OwnerThread(), "MediaCacheStream::Close",
+ [this, client = RefPtr<ChannelMediaResource>(mClient)] {
+ AutoLock lock(mMediaCache->Monitor());
+ CloseInternal(lock);
+ return GenericPromise::CreateAndResolve(true, __func__);
+ });
+}
+
+void MediaCacheStream::CloseInternal(AutoLock& aLock) {
+ MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
+
+ if (mClosed) {
+ return;
+ }
+
+ // Closing a stream will change the return value of
+ // MediaCacheStream::AreAllStreamsForResourceSuspended as well as
+ // ChannelMediaResource::IsSuspendedByCache. Let's notify it.
+ mMediaCache->QueueSuspendedStatusUpdate(aLock, mResourceID);
+
+ mClosed = true;
+ mMediaCache->ReleaseStreamBlocks(aLock, this);
+ mMediaCache->ReleaseStream(aLock, this);
+ // Wake up any blocked readers
+ aLock.NotifyAll();
+
+ // Queue an Update since we may have created more free space.
+ mMediaCache->QueueUpdate(aLock);
+}
+
+void MediaCacheStream::Pin() {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ ++mPinCount;
+ // Queue an Update since we may no longer want to read more into the
+ // cache, if this stream's block have become non-evictable
+ mMediaCache->QueueUpdate(lock);
+}
+
+void MediaCacheStream::Unpin() {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ NS_ASSERTION(mPinCount > 0, "Unbalanced Unpin");
+ --mPinCount;
+ // Queue an Update since we may be able to read more into the
+ // cache, if this stream's block have become evictable
+ mMediaCache->QueueUpdate(lock);
+}
+
+int64_t MediaCacheStream::GetLength() const {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ return mStreamLength;
+}
+
+MediaCacheStream::LengthAndOffset MediaCacheStream::GetLengthAndOffset() const {
+ MOZ_ASSERT(NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ return {mStreamLength, mChannelOffset};
+}
+
+int64_t MediaCacheStream::GetNextCachedData(int64_t aOffset) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ return GetNextCachedDataInternal(lock, aOffset);
+}
+
+int64_t MediaCacheStream::GetCachedDataEnd(int64_t aOffset) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ return GetCachedDataEndInternal(lock, aOffset);
+}
+
+bool MediaCacheStream::IsDataCachedToEndOfStream(int64_t aOffset) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ if (mStreamLength < 0) return false;
+ return GetCachedDataEndInternal(lock, aOffset) >= mStreamLength;
+}
+
+int64_t MediaCacheStream::GetCachedDataEndInternal(AutoLock&, int64_t aOffset) {
+ int32_t blockIndex = OffsetToBlockIndex(aOffset);
+ if (blockIndex < 0) {
+ return aOffset;
+ }
+ while (size_t(blockIndex) < mBlocks.Length() && mBlocks[blockIndex] != -1) {
+ ++blockIndex;
+ }
+ int64_t result = blockIndex * BLOCK_SIZE;
+ if (blockIndex == OffsetToBlockIndexUnchecked(mChannelOffset)) {
+ // The block containing mChannelOffset may be partially read but not
+ // yet committed to the main cache
+ result = mChannelOffset;
+ }
+ if (mStreamLength >= 0) {
+ // The last block in the cache may only be partially valid, so limit
+ // the cached range to the stream length
+ result = std::min(result, mStreamLength);
+ }
+ return std::max(result, aOffset);
+}
+
+int64_t MediaCacheStream::GetNextCachedDataInternal(AutoLock&,
+ int64_t aOffset) {
+ if (aOffset == mStreamLength) return -1;
+
+ int32_t startBlockIndex = OffsetToBlockIndex(aOffset);
+ if (startBlockIndex < 0) {
+ return -1;
+ }
+ int32_t channelBlockIndex = OffsetToBlockIndexUnchecked(mChannelOffset);
+
+ if (startBlockIndex == channelBlockIndex && aOffset < mChannelOffset) {
+ // The block containing mChannelOffset is partially read, but not
+ // yet committed to the main cache. aOffset lies in the partially
+ // read portion, thus it is effectively cached.
+ return aOffset;
+ }
+
+ if (size_t(startBlockIndex) >= mBlocks.Length()) return -1;
+
+ // Is the current block cached?
+ if (mBlocks[startBlockIndex] != -1) return aOffset;
+
+ // Count the number of uncached blocks
+ bool hasPartialBlock = OffsetInBlock(mChannelOffset) != 0;
+ int32_t blockIndex = startBlockIndex + 1;
+ while (true) {
+ if ((hasPartialBlock && blockIndex == channelBlockIndex) ||
+ (size_t(blockIndex) < mBlocks.Length() && mBlocks[blockIndex] != -1)) {
+ // We at the incoming channel block, which has has data in it,
+ // or are we at a cached block. Return index of block start.
+ return blockIndex * BLOCK_SIZE;
+ }
+
+ // No more cached blocks?
+ if (size_t(blockIndex) >= mBlocks.Length()) return -1;
+
+ ++blockIndex;
+ }
+
+ MOZ_ASSERT_UNREACHABLE("Should return in loop");
+ return -1;
+}
+
+void MediaCacheStream::SetReadMode(ReadMode aMode) {
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCacheStream::SetReadMode",
+ [this, client = RefPtr<ChannelMediaResource>(mClient), aMode]() {
+ AutoLock lock(mMediaCache->Monitor());
+ if (!mClosed && mCurrentMode != aMode) {
+ mCurrentMode = aMode;
+ mMediaCache->QueueUpdate(lock);
+ }
+ });
+ OwnerThread()->Dispatch(r.forget());
+}
+
+void MediaCacheStream::SetPlaybackRate(uint32_t aBytesPerSecond) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ MOZ_ASSERT(aBytesPerSecond > 0, "Zero playback rate not allowed");
+
+ AutoLock lock(mMediaCache->Monitor());
+ if (!mClosed && mPlaybackBytesPerSecond != aBytesPerSecond) {
+ mPlaybackBytesPerSecond = aBytesPerSecond;
+ mMediaCache->QueueUpdate(lock);
+ }
+}
+
+nsresult MediaCacheStream::Seek(AutoLock& aLock, int64_t aOffset) {
+ MOZ_ASSERT(!NS_IsMainThread());
+
+ if (!IsOffsetAllowed(aOffset)) {
+ return NS_ERROR_ILLEGAL_VALUE;
+ }
+ if (mClosed) {
+ return NS_ERROR_ABORT;
+ }
+
+ int64_t oldOffset = mStreamOffset;
+ mStreamOffset = aOffset;
+ LOG("Stream %p Seek to %" PRId64, this, mStreamOffset);
+ mMediaCache->NoteSeek(aLock, this, oldOffset);
+ mMediaCache->QueueUpdate(aLock);
+ return NS_OK;
+}
+
+void MediaCacheStream::ThrottleReadahead(bool bThrottle) {
+ MOZ_ASSERT(NS_IsMainThread());
+
+ nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
+ "MediaCacheStream::ThrottleReadahead",
+ [client = RefPtr<ChannelMediaResource>(mClient), this, bThrottle]() {
+ AutoLock lock(mMediaCache->Monitor());
+ if (!mClosed && mThrottleReadahead != bThrottle) {
+ LOGI("Stream %p ThrottleReadahead %d", this, bThrottle);
+ mThrottleReadahead = bThrottle;
+ mMediaCache->QueueUpdate(lock);
+ }
+ });
+ OwnerThread()->Dispatch(r.forget());
+}
+
+uint32_t MediaCacheStream::ReadPartialBlock(AutoLock&, int64_t aOffset,
+ Span<char> aBuffer) {
+ MOZ_ASSERT(IsOffsetAllowed(aOffset));
+
+ if (OffsetToBlockIndexUnchecked(mChannelOffset) !=
+ OffsetToBlockIndexUnchecked(aOffset) ||
+ aOffset >= mChannelOffset) {
+ // Not in the partial block or no data to read.
+ return 0;
+ }
+
+ auto source = Span<const uint8_t>(
+ mPartialBlockBuffer.get() + OffsetInBlock(aOffset),
+ OffsetInBlock(mChannelOffset) - OffsetInBlock(aOffset));
+ // We have |source.Length() <= BLOCK_SIZE < INT32_MAX| to guarantee
+ // that |bytesToRead| can fit into a uint32_t.
+ uint32_t bytesToRead = std::min(aBuffer.Length(), source.Length());
+ memcpy(aBuffer.Elements(), source.Elements(), bytesToRead);
+ return bytesToRead;
+}
+
+Result<uint32_t, nsresult> MediaCacheStream::ReadBlockFromCache(
+ AutoLock& aLock, int64_t aOffset, Span<char> aBuffer,
+ bool aNoteBlockUsage) {
+ MOZ_ASSERT(IsOffsetAllowed(aOffset));
+
+ // OffsetToBlockIndexUnchecked() is always non-negative.
+ uint32_t index = OffsetToBlockIndexUnchecked(aOffset);
+ int32_t cacheBlock = index < mBlocks.Length() ? mBlocks[index] : -1;
+ if (cacheBlock < 0 || (mStreamLength >= 0 && aOffset >= mStreamLength)) {
+ // Not in the cache.
+ return 0;
+ }
+
+ if (aBuffer.Length() > size_t(BLOCK_SIZE)) {
+ // Clamp the buffer to avoid overflow below since we will read at most
+ // BLOCK_SIZE bytes.
+ aBuffer = aBuffer.First(BLOCK_SIZE);
+ }
+
+ if (mStreamLength >= 0 &&
+ int64_t(aBuffer.Length()) > mStreamLength - aOffset) {
+ // Clamp reads to stream's length
+ aBuffer = aBuffer.First(mStreamLength - aOffset);
+ }
+
+ // |BLOCK_SIZE - OffsetInBlock(aOffset)| <= BLOCK_SIZE
+ int32_t bytesToRead =
+ std::min<int32_t>(BLOCK_SIZE - OffsetInBlock(aOffset), aBuffer.Length());
+ int32_t bytesRead = 0;
+ nsresult rv = mMediaCache->ReadCacheFile(
+ aLock, cacheBlock * BLOCK_SIZE + OffsetInBlock(aOffset),
+ aBuffer.Elements(), bytesToRead, &bytesRead);
+
+ // Ensure |cacheBlock * BLOCK_SIZE + OffsetInBlock(aOffset)| won't overflow.
+ static_assert(INT64_MAX >= BLOCK_SIZE * (uint32_t(INT32_MAX) + 1),
+ "BLOCK_SIZE too large!");
+
+ if (NS_FAILED(rv)) {
+ nsCString name;
+ GetErrorName(rv, name);
+ LOGE("Stream %p ReadCacheFile failed, rv=%s", this, name.Data());
+ return mozilla::Err(rv);
+ }
+
+ if (aNoteBlockUsage) {
+ mMediaCache->NoteBlockUsage(aLock, this, cacheBlock, aOffset, mCurrentMode,
+ TimeStamp::Now());
+ }
+
+ return bytesRead;
+}
+
+nsresult MediaCacheStream::Read(AutoLock& aLock, char* aBuffer, uint32_t aCount,
+ uint32_t* aBytes) {
+ MOZ_ASSERT(!NS_IsMainThread());
+
+ // Cache the offset in case it is changed again when we are waiting for the
+ // monitor to be notified to avoid reading at the wrong position.
+ auto streamOffset = mStreamOffset;
+
+ // The buffer we are about to fill.
+ auto buffer = Span<char>(aBuffer, aCount);
+
+ // Read one block (or part of a block) at a time
+ while (!buffer.IsEmpty()) {
+ if (mClosed) {
+ return NS_ERROR_ABORT;
+ }
+
+ if (!IsOffsetAllowed(streamOffset)) {
+ LOGE("Stream %p invalid offset=%" PRId64, this, streamOffset);
+ return NS_ERROR_ILLEGAL_VALUE;
+ }
+
+ if (mStreamLength >= 0 && streamOffset >= mStreamLength) {
+ // Don't try to read beyond the end of the stream
+ break;
+ }
+
+ Result<uint32_t, nsresult> rv = ReadBlockFromCache(
+ aLock, streamOffset, buffer, true /* aNoteBlockUsage */);
+ if (rv.isErr()) {
+ return rv.unwrapErr();
+ }
+
+ uint32_t bytes = rv.unwrap();
+ if (bytes > 0) {
+ // Got data from the cache successfully. Read next block.
+ streamOffset += bytes;
+ buffer = buffer.From(bytes);
+ continue;
+ }
+
+ // See if we can use the data in the partial block of any stream reading
+ // this resource. Note we use the partial block only when it is completed,
+ // that is reaching EOS.
+ bool foundDataInPartialBlock = false;
+ MediaCache::ResourceStreamIterator iter(mMediaCache, mResourceID);
+ while (MediaCacheStream* stream = iter.Next(aLock)) {
+ if (OffsetToBlockIndexUnchecked(stream->mChannelOffset) ==
+ OffsetToBlockIndexUnchecked(streamOffset) &&
+ stream->mChannelOffset == stream->mStreamLength) {
+ uint32_t bytes = stream->ReadPartialBlock(aLock, streamOffset, buffer);
+ streamOffset += bytes;
+ buffer = buffer.From(bytes);
+ foundDataInPartialBlock = true;
+ break;
+ }
+ }
+ if (foundDataInPartialBlock) {
+ // Break for we've reached EOS.
+ break;
+ }
+
+ if (mDidNotifyDataEnded && NS_FAILED(mNotifyDataEndedStatus)) {
+ // Since download ends abnormally, there is no point in waiting for new
+ // data to come. We will check the partial block to read as many bytes as
+ // possible before exiting this function.
+ bytes = ReadPartialBlock(aLock, streamOffset, buffer);
+ streamOffset += bytes;
+ buffer = buffer.From(bytes);
+ break;
+ }
+
+ if (mStreamOffset != streamOffset) {
+ // Update mStreamOffset before we drop the lock. We need to run
+ // Update() again since stream reading strategy might have changed.
+ mStreamOffset = streamOffset;
+ mMediaCache->QueueUpdate(aLock);
+ }
+
+ // No data to read, so block
+ aLock.Wait();
+ }
+
+ uint32_t count = buffer.Elements() - aBuffer;
+ *aBytes = count;
+ if (count == 0) {
+ return NS_OK;
+ }
+
+ // Some data was read, so queue an update since block priorities may
+ // have changed
+ mMediaCache->QueueUpdate(aLock);
+
+ LOG("Stream %p Read at %" PRId64 " count=%d", this, streamOffset - count,
+ count);
+ mStreamOffset = streamOffset;
+ return NS_OK;
+}
+
+nsresult MediaCacheStream::ReadAt(int64_t aOffset, char* aBuffer,
+ uint32_t aCount, uint32_t* aBytes) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ nsresult rv = Seek(lock, aOffset);
+ if (NS_FAILED(rv)) return rv;
+ return Read(lock, aBuffer, aCount, aBytes);
+}
+
+nsresult MediaCacheStream::ReadFromCache(char* aBuffer, int64_t aOffset,
+ uint32_t aCount) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+
+ // The buffer we are about to fill.
+ auto buffer = Span<char>(aBuffer, aCount);
+
+ // Read one block (or part of a block) at a time
+ int64_t streamOffset = aOffset;
+ while (!buffer.IsEmpty()) {
+ if (mClosed) {
+ // We need to check |mClosed| in each iteration which might be changed
+ // after calling |mMediaCache->ReadCacheFile|.
+ return NS_ERROR_FAILURE;
+ }
+
+ if (!IsOffsetAllowed(streamOffset)) {
+ LOGE("Stream %p invalid offset=%" PRId64, this, streamOffset);
+ return NS_ERROR_ILLEGAL_VALUE;
+ }
+
+ Result<uint32_t, nsresult> rv =
+ ReadBlockFromCache(lock, streamOffset, buffer);
+ if (rv.isErr()) {
+ return rv.unwrapErr();
+ }
+
+ uint32_t bytes = rv.unwrap();
+ if (bytes > 0) {
+ // Read data from the cache successfully. Let's try next block.
+ streamOffset += bytes;
+ buffer = buffer.From(bytes);
+ continue;
+ }
+
+ // The partial block is our last chance to get data.
+ bytes = ReadPartialBlock(lock, streamOffset, buffer);
+ if (bytes < buffer.Length()) {
+ // Not enough data to read.
+ return NS_ERROR_FAILURE;
+ }
+
+ // Return for we've got all the requested bytes.
+ return NS_OK;
+ }
+
+ return NS_OK;
+}
+
+nsresult MediaCacheStream::Init(int64_t aContentLength) {
+ NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
+ MOZ_ASSERT(!mMediaCache, "Has been initialized.");
+
+ if (aContentLength > 0) {
+ uint32_t length = uint32_t(std::min(aContentLength, int64_t(UINT32_MAX)));
+ LOG("MediaCacheStream::Init(this=%p) "
+ "MEDIACACHESTREAM_NOTIFIED_LENGTH=%" PRIu32,
+ this, length);
+
+ mStreamLength = aContentLength;
+ }
+
+ mMediaCache = MediaCache::GetMediaCache(aContentLength, mIsPrivateBrowsing);
+ if (!mMediaCache) {
+ return NS_ERROR_FAILURE;
+ }
+
+ OwnerThread()->Dispatch(NS_NewRunnableFunction(
+ "MediaCacheStream::Init",
+ [this, res = RefPtr<ChannelMediaResource>(mClient)]() {
+ AutoLock lock(mMediaCache->Monitor());
+ mMediaCache->OpenStream(lock, this);
+ }));
+
+ return NS_OK;
+}
+
+void MediaCacheStream::InitAsClone(MediaCacheStream* aOriginal) {
+ MOZ_ASSERT(!mMediaCache, "Has been initialized.");
+ MOZ_ASSERT(aOriginal->mMediaCache, "Don't clone an uninitialized stream.");
+
+ // Use the same MediaCache as our clone.
+ mMediaCache = aOriginal->mMediaCache;
+ OwnerThread()->Dispatch(NS_NewRunnableFunction(
+ "MediaCacheStream::InitAsClone",
+ [this, aOriginal, r1 = RefPtr<ChannelMediaResource>(mClient),
+ r2 = RefPtr<ChannelMediaResource>(aOriginal->mClient)]() {
+ InitAsCloneInternal(aOriginal);
+ }));
+}
+
+void MediaCacheStream::InitAsCloneInternal(MediaCacheStream* aOriginal) {
+ MOZ_ASSERT(OwnerThread()->IsOnCurrentThread());
+ AutoLock lock(mMediaCache->Monitor());
+ LOG("MediaCacheStream::InitAsCloneInternal(this=%p, original=%p)", this,
+ aOriginal);
+
+ // Download data and notify events if necessary. Note the order is important
+ // in order to mimic the behavior of data being downloaded from the channel.
+
+ // Step 1: copy/download data from the original stream.
+ mResourceID = aOriginal->mResourceID;
+ mStreamLength = aOriginal->mStreamLength;
+ mIsTransportSeekable = aOriginal->mIsTransportSeekable;
+ mDownloadStatistics = aOriginal->mDownloadStatistics;
+ mDownloadStatistics.Stop();
+
+ // Grab cache blocks from aOriginal as readahead blocks for our stream
+ for (uint32_t i = 0; i < aOriginal->mBlocks.Length(); ++i) {
+ int32_t cacheBlockIndex = aOriginal->mBlocks[i];
+ if (cacheBlockIndex < 0) continue;
+
+ while (i >= mBlocks.Length()) {
+ mBlocks.AppendElement(-1);
+ }
+ // Every block is a readahead block for the clone because the clone's
+ // initial stream offset is zero
+ mMediaCache->AddBlockOwnerAsReadahead(lock, cacheBlockIndex, this, i);
+ }
+
+ // Copy the partial block.
+ mChannelOffset = aOriginal->mChannelOffset;
+ memcpy(mPartialBlockBuffer.get(), aOriginal->mPartialBlockBuffer.get(),
+ BLOCK_SIZE);
+
+ // Step 2: notify the client that we have new data so the decoder has a chance
+ // to compute 'canplaythrough' and buffer ranges.
+ mClient->CacheClientNotifyDataReceived();
+
+ // Step 3: notify download ended if necessary.
+ if (aOriginal->mDidNotifyDataEnded &&
+ NS_SUCCEEDED(aOriginal->mNotifyDataEndedStatus)) {
+ mNotifyDataEndedStatus = aOriginal->mNotifyDataEndedStatus;
+ mDidNotifyDataEnded = true;
+ mClient->CacheClientNotifyDataEnded(mNotifyDataEndedStatus);
+ }
+
+ // Step 4: notify download is suspended by the cache.
+ mClientSuspended = true;
+ mCacheSuspended = true;
+ mChannelEnded = true;
+ mClient->CacheClientSuspend();
+ mMediaCache->QueueSuspendedStatusUpdate(lock, mResourceID);
+
+ // Step 5: add the stream to be managed by the cache.
+ mMediaCache->OpenStream(lock, this, true /* aIsClone */);
+ // Wake up the reader which is waiting for the cloned data.
+ lock.NotifyAll();
+}
+
+nsISerialEventTarget* MediaCacheStream::OwnerThread() const {
+ return mMediaCache->OwnerThread();
+}
+
+nsresult MediaCacheStream::GetCachedRanges(MediaByteRangeSet& aRanges) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ // Take the monitor, so that the cached data ranges can't grow while we're
+ // trying to loop over them.
+ AutoLock lock(mMediaCache->Monitor());
+
+ // We must be pinned while running this, otherwise the cached data ranges may
+ // shrink while we're trying to loop over them.
+ NS_ASSERTION(mPinCount > 0, "Must be pinned");
+
+ int64_t startOffset = GetNextCachedDataInternal(lock, 0);
+ while (startOffset >= 0) {
+ int64_t endOffset = GetCachedDataEndInternal(lock, startOffset);
+ NS_ASSERTION(startOffset < endOffset,
+ "Buffered range must end after its start");
+ // Bytes [startOffset..endOffset] are cached.
+ aRanges += MediaByteRange(startOffset, endOffset);
+ startOffset = GetNextCachedDataInternal(lock, endOffset);
+ NS_ASSERTION(
+ startOffset == -1 || startOffset > endOffset,
+ "Must have advanced to start of next range, or hit end of stream");
+ }
+ return NS_OK;
+}
+
+double MediaCacheStream::GetDownloadRate(bool* aIsReliable) {
+ MOZ_ASSERT(!NS_IsMainThread());
+ AutoLock lock(mMediaCache->Monitor());
+ return mDownloadStatistics.GetRate(aIsReliable);
+}
+
+void MediaCacheStream::GetDebugInfo(dom::MediaCacheStreamDebugInfo& aInfo) {
+ AutoLock lock(mMediaCache->GetMonitorOnTheMainThread());
+ aInfo.mStreamLength = mStreamLength;
+ aInfo.mChannelOffset = mChannelOffset;
+ aInfo.mCacheSuspended = mCacheSuspended;
+ aInfo.mChannelEnded = mChannelEnded;
+ aInfo.mLoadID = mLoadID;
+}
+
+} // namespace mozilla
+
+// avoid redefined macro in unified build
+#undef LOG
+#undef LOGI