1 files changed, 578 insertions, 0 deletions
diff --git a/dom/cache/ReadStream.cpp b/dom/cache/ReadStream.cpp
new file mode 100644
index 000000000..efce027a1
--- /dev/null
+++ b/dom/cache/ReadStream.cpp
@@ -0,0 +1,578 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 "mozilla/dom/cache/ReadStream.h"
+
+#include "mozilla/Unused.h"
+#include "mozilla/dom/cache/CacheStreamControlChild.h"
+#include "mozilla/dom/cache/CacheStreamControlParent.h"
+#include "mozilla/dom/cache/CacheTypes.h"
+#include "mozilla/ipc/IPCStreamUtils.h"
+#include "mozilla/SnappyUncompressInputStream.h"
+#include "nsIAsyncInputStream.h"
+#include "nsTArray.h"
+
+namespace mozilla {
+namespace dom {
+namespace cache {
+
+using mozilla::Unused;
+using mozilla::ipc::AutoIPCStream;
+using mozilla::ipc::IPCStream;
+
+// ----------------------------------------------------------------------------
+
+// The inner stream class.  This is where all of the real work is done.  As
+// an invariant Inner::Close() must be called before ~Inner().  This is
+// guaranteed by our outer ReadStream class.
+class ReadStream::Inner final : public ReadStream::Controllable
+{
+public:
+  Inner(StreamControl* aControl, const nsID& aId,
+        nsIInputStream* aStream);
+
+  void
+  Serialize(CacheReadStreamOrVoid* aReadStreamOut,
+            nsTArray<UniquePtr<AutoIPCStream>>& aStreamCleanupList,
+            ErrorResult& aRv);
+
+  void
+  Serialize(CacheReadStream* aReadStreamOut,
+            nsTArray<UniquePtr<AutoIPCStream>>& aStreamCleanupList,
+            ErrorResult& aRv);
+
+  // ReadStream::Controllable methods
+  virtual void
+  CloseStream() override;
+
+  virtual void
+  CloseStreamWithoutReporting() override;
+
+  virtual bool
+  MatchId(const nsID& aId) const override;
+
+  virtual bool
+  HasEverBeenRead() const override;
+
+  // Simulate nsIInputStream methods, but we don't actually inherit from it
+  nsresult
+  Close();
+
+  nsresult
+  Available(uint64_t *aNumAvailableOut);
+
+  nsresult
+  Read(char *aBuf, uint32_t aCount, uint32_t *aNumReadOut);
+
+  nsresult
+  ReadSegments(nsWriteSegmentFun aWriter, void *aClosure, uint32_t aCount,
+               uint32_t *aNumReadOut);
+
+  nsresult
+  IsNonBlocking(bool *aNonBlockingOut);
+
+private:
+  class NoteClosedRunnable;
+  class ForgetRunnable;
+
+  ~Inner();
+
+  void
+  NoteClosed();
+
+  void
+  Forget();
+
+  void
+  NoteClosedOnOwningThread();
+
+  void
+  ForgetOnOwningThread();
+
+  // Weak ref to the stream control actor.  The actor will always call either
+  // CloseStream() or CloseStreamWithoutReporting() before it's destroyed.  The
+  // weak ref is cleared in the resulting NoteClosedOnOwningThread() or
+  // ForgetOnOwningThread() method call.
+  StreamControl* mControl;
+
+  const nsID mId;
+  nsCOMPtr<nsIThread> mOwningThread;
+
+  enum State
+  {
+    Open,
+    Closed,
+    NumStates
+  };
+  Atomic<State> mState;
+  Atomic<bool> mHasEverBeenRead;
+
+
+  // The wrapped stream objects may not be threadsafe.  We need to be able
+  // to close a stream on our owning thread while an IO thread is simultaneously
+  // reading the same stream.  Therefore, protect all access to these stream
+  // objects with a mutex.
+  Mutex mMutex;
+  nsCOMPtr<nsIInputStream> mStream;
+  nsCOMPtr<nsIInputStream> mSnappyStream;
+
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(cache::ReadStream::Inner, override)
+};
+
+// ----------------------------------------------------------------------------
+
+// Runnable to notify actors that the ReadStream has closed.  This must
+// be done on the thread associated with the PBackground actor.  Must be
+// cancelable to execute on Worker threads (which can occur when the
+// ReadStream is constructed on a child process Worker thread).
+class ReadStream::Inner::NoteClosedRunnable final : public CancelableRunnable
+{
+public:
+  explicit NoteClosedRunnable(ReadStream::Inner* aStream)
+    : mStream(aStream)
+  { }
+
+  NS_IMETHOD Run() override
+  {
+    mStream->NoteClosedOnOwningThread();
+    mStream = nullptr;
+    return NS_OK;
+  }
+
+  // Note, we must proceed with the Run() method since our actor will not
+  // clean itself up until we note that the stream is closed.
+  nsresult Cancel() override
+  {
+    Run();
+    return NS_OK;
+  }
+
+private:
+  ~NoteClosedRunnable() { }
+
+  RefPtr<ReadStream::Inner> mStream;
+};
+
+// ----------------------------------------------------------------------------
+
+// Runnable to clear actors without reporting that the ReadStream has
+// closed.  Since this can trigger actor destruction, we need to do
+// it on the thread associated with the PBackground actor.  Must be
+// cancelable to execute on Worker threads (which can occur when the
+// ReadStream is constructed on a child process Worker thread).
+class ReadStream::Inner::ForgetRunnable final : public CancelableRunnable
+{
+public:
+  explicit ForgetRunnable(ReadStream::Inner* aStream)
+    : mStream(aStream)
+  { }
+
+  NS_IMETHOD Run() override
+  {
+    mStream->ForgetOnOwningThread();
+    mStream = nullptr;
+    return NS_OK;
+  }
+
+  // Note, we must proceed with the Run() method so that we properly
+  // call RemoveListener on the actor.
+  nsresult Cancel() override
+  {
+    Run();
+    return NS_OK;
+  }
+
+private:
+  ~ForgetRunnable() { }
+
+  RefPtr<ReadStream::Inner> mStream;
+};
+
+// ----------------------------------------------------------------------------
+
+ReadStream::Inner::Inner(StreamControl* aControl, const nsID& aId,
+                         nsIInputStream* aStream)
+  : mControl(aControl)
+  , mId(aId)
+  , mOwningThread(NS_GetCurrentThread())
+  , mState(Open)
+  , mHasEverBeenRead(false)
+  , mMutex("dom::cache::ReadStream")
+  , mStream(aStream)
+  , mSnappyStream(new SnappyUncompressInputStream(aStream))
+{
+  MOZ_DIAGNOSTIC_ASSERT(mStream);
+  MOZ_DIAGNOSTIC_ASSERT(mControl);
+  mControl->AddReadStream(this);
+}
+
+void
+ReadStream::Inner::Serialize(CacheReadStreamOrVoid* aReadStreamOut,
+                             nsTArray<UniquePtr<AutoIPCStream>>& aStreamCleanupList,
+                             ErrorResult& aRv)
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+  MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut);
+  *aReadStreamOut = CacheReadStream();
+  Serialize(&aReadStreamOut->get_CacheReadStream(), aStreamCleanupList, aRv);
+}
+
+void
+ReadStream::Inner::Serialize(CacheReadStream* aReadStreamOut,
+                             nsTArray<UniquePtr<AutoIPCStream>>& aStreamCleanupList,
+                             ErrorResult& aRv)
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+  MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut);
+
+  if (mState != Open) {
+    aRv.ThrowTypeError<MSG_CACHE_STREAM_CLOSED>();
+    return;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(mControl);
+
+  aReadStreamOut->id() = mId;
+  mControl->SerializeControl(aReadStreamOut);
+
+  {
+    MutexAutoLock lock(mMutex);
+    mControl->SerializeStream(aReadStreamOut, mStream, aStreamCleanupList);
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut->stream().type() ==
+                        IPCStream::TInputStreamParamsWithFds);
+
+  // We're passing ownership across the IPC barrier with the control, so
+  // do not signal that the stream is closed here.
+  Forget();
+}
+
+void
+ReadStream::Inner::CloseStream()
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+  Close();
+}
+
+void
+ReadStream::Inner::CloseStreamWithoutReporting()
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+  Forget();
+}
+
+bool
+ReadStream::Inner::MatchId(const nsID& aId) const
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+  return mId.Equals(aId);
+}
+
+bool
+ReadStream::Inner::HasEverBeenRead() const
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+  return mHasEverBeenRead;
+}
+
+nsresult
+ReadStream::Inner::Close()
+{
+  // stream ops can happen on any thread
+  nsresult rv = NS_OK;
+  {
+    MutexAutoLock lock(mMutex);
+    rv = mSnappyStream->Close();
+  }
+  NoteClosed();
+  return rv;
+}
+
+nsresult
+ReadStream::Inner::Available(uint64_t* aNumAvailableOut)
+{
+  // stream ops can happen on any thread
+  nsresult rv = NS_OK;
+  {
+    MutexAutoLock lock(mMutex);
+    rv = mSnappyStream->Available(aNumAvailableOut);
+  }
+
+  if (NS_FAILED(rv)) {
+    Close();
+  }
+
+  return rv;
+}
+
+nsresult
+ReadStream::Inner::Read(char* aBuf, uint32_t aCount, uint32_t* aNumReadOut)
+{
+  // stream ops can happen on any thread
+  MOZ_DIAGNOSTIC_ASSERT(aNumReadOut);
+
+  nsresult rv = NS_OK;
+  {
+    MutexAutoLock lock(mMutex);
+    rv = mSnappyStream->Read(aBuf, aCount, aNumReadOut);
+  }
+
+  if ((NS_FAILED(rv) && rv != NS_BASE_STREAM_WOULD_BLOCK) ||
+      *aNumReadOut == 0) {
+    Close();
+  }
+
+  mHasEverBeenRead = true;
+
+  return rv;
+}
+
+nsresult
+ReadStream::Inner::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                                uint32_t aCount, uint32_t* aNumReadOut)
+{
+  // stream ops can happen on any thread
+  MOZ_DIAGNOSTIC_ASSERT(aNumReadOut);
+
+  if (aCount) {
+    mHasEverBeenRead = true;
+  }
+
+
+  nsresult rv = NS_OK;
+  {
+    MutexAutoLock lock(mMutex);
+    rv = mSnappyStream->ReadSegments(aWriter, aClosure, aCount, aNumReadOut);
+  }
+
+  if ((NS_FAILED(rv) && rv != NS_BASE_STREAM_WOULD_BLOCK &&
+                        rv != NS_ERROR_NOT_IMPLEMENTED) || *aNumReadOut == 0) {
+    Close();
+  }
+
+  // Verify bytes were actually read before marking as being ever read.  For
+  // example, code can test if the stream supports ReadSegments() by calling
+  // this method with a dummy callback which doesn't read anything.  We don't
+  // want to trigger on that.
+  if (*aNumReadOut) {
+    mHasEverBeenRead = true;
+  }
+
+  return rv;
+}
+
+nsresult
+ReadStream::Inner::IsNonBlocking(bool* aNonBlockingOut)
+{
+  // stream ops can happen on any thread
+  MutexAutoLock lock(mMutex);
+  return mSnappyStream->IsNonBlocking(aNonBlockingOut);
+}
+
+ReadStream::Inner::~Inner()
+{
+  // Any thread
+  MOZ_DIAGNOSTIC_ASSERT(mState == Closed);
+  MOZ_DIAGNOSTIC_ASSERT(!mControl);
+}
+
+void
+ReadStream::Inner::NoteClosed()
+{
+  // Any thread
+  if (mState == Closed) {
+    return;
+  }
+
+  if (NS_GetCurrentThread() == mOwningThread) {
+    NoteClosedOnOwningThread();
+    return;
+  }
+
+  nsCOMPtr<nsIRunnable> runnable = new NoteClosedRunnable(this);
+  MOZ_ALWAYS_SUCCEEDS(
+    mOwningThread->Dispatch(runnable, nsIThread::DISPATCH_NORMAL));
+}
+
+void
+ReadStream::Inner::Forget()
+{
+  // Any thread
+  if (mState == Closed) {
+    return;
+  }
+
+  if (NS_GetCurrentThread() == mOwningThread) {
+    ForgetOnOwningThread();
+    return;
+  }
+
+  nsCOMPtr<nsIRunnable> runnable = new ForgetRunnable(this);
+  MOZ_ALWAYS_SUCCEEDS(
+    mOwningThread->Dispatch(runnable, nsIThread::DISPATCH_NORMAL));
+}
+
+void
+ReadStream::Inner::NoteClosedOnOwningThread()
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+
+  // Mark closed and do nothing if we were already closed
+  if (!mState.compareExchange(Open, Closed)) {
+    return;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(mControl);
+  mControl->NoteClosed(this, mId);
+  mControl = nullptr;
+}
+
+void
+ReadStream::Inner::ForgetOnOwningThread()
+{
+  MOZ_ASSERT(NS_GetCurrentThread() == mOwningThread);
+
+  // Mark closed and do nothing if we were already closed
+  if (!mState.compareExchange(Open, Closed)) {
+    return;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(mControl);
+  mControl->ForgetReadStream(this);
+  mControl = nullptr;
+}
+
+// ----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(cache::ReadStream, nsIInputStream, ReadStream);
+
+// static
+already_AddRefed<ReadStream>
+ReadStream::Create(const CacheReadStreamOrVoid& aReadStreamOrVoid)
+{
+  if (aReadStreamOrVoid.type() == CacheReadStreamOrVoid::Tvoid_t) {
+    return nullptr;
+  }
+
+  return Create(aReadStreamOrVoid.get_CacheReadStream());
+}
+
+// static
+already_AddRefed<ReadStream>
+ReadStream::Create(const CacheReadStream& aReadStream)
+{
+  // The parameter may or may not be for a Cache created stream.  The way we
+  // tell is by looking at the stream control actor.  If the actor exists,
+  // then we know the Cache created it.
+  if (!aReadStream.controlChild() && !aReadStream.controlParent()) {
+    return nullptr;
+  }
+
+  MOZ_DIAGNOSTIC_ASSERT(aReadStream.stream().type() ==
+                        IPCStream::TInputStreamParamsWithFds);
+
+  // Control is guaranteed to survive this method as ActorDestroy() cannot
+  // run on this thread until we complete.
+  StreamControl* control;
+  if (aReadStream.controlChild()) {
+    auto actor = static_cast<CacheStreamControlChild*>(aReadStream.controlChild());
+    control = actor;
+  } else {
+    auto actor = static_cast<CacheStreamControlParent*>(aReadStream.controlParent());
+    control = actor;
+  }
+  MOZ_DIAGNOSTIC_ASSERT(control);
+
+  nsCOMPtr<nsIInputStream> stream = DeserializeIPCStream(aReadStream.stream());
+  MOZ_DIAGNOSTIC_ASSERT(stream);
+
+  // Currently we expect all cache read streams to be blocking file streams.
+#if !defined(RELEASE_OR_BETA)
+  nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(stream);
+  MOZ_DIAGNOSTIC_ASSERT(!asyncStream);
+#endif
+
+  RefPtr<Inner> inner = new Inner(control, aReadStream.id(), stream);
+  RefPtr<ReadStream> ref = new ReadStream(inner);
+  return ref.forget();
+}
+
+// static
+already_AddRefed<ReadStream>
+ReadStream::Create(PCacheStreamControlParent* aControl, const nsID& aId,
+                   nsIInputStream* aStream)
+{
+  MOZ_DIAGNOSTIC_ASSERT(aControl);
+  auto actor = static_cast<CacheStreamControlParent*>(aControl);
+  RefPtr<Inner> inner = new Inner(actor, aId, aStream);
+  RefPtr<ReadStream> ref = new ReadStream(inner);
+  return ref.forget();
+}
+
+void
+ReadStream::Serialize(CacheReadStreamOrVoid* aReadStreamOut,
+                      nsTArray<UniquePtr<AutoIPCStream>>& aStreamCleanupList,
+                      ErrorResult& aRv)
+{
+  mInner->Serialize(aReadStreamOut, aStreamCleanupList, aRv);
+}
+
+void
+ReadStream::Serialize(CacheReadStream* aReadStreamOut,
+                      nsTArray<UniquePtr<AutoIPCStream>>& aStreamCleanupList,
+                      ErrorResult& aRv)
+{
+  mInner->Serialize(aReadStreamOut, aStreamCleanupList, aRv);
+}
+
+ReadStream::ReadStream(ReadStream::Inner* aInner)
+  : mInner(aInner)
+{
+  MOZ_DIAGNOSTIC_ASSERT(mInner);
+}
+
+ReadStream::~ReadStream()
+{
+  // Explicitly close the inner stream so that it does not have to
+  // deal with implicitly closing at destruction time.
+  mInner->Close();
+}
+
+NS_IMETHODIMP
+ReadStream::Close()
+{
+  return mInner->Close();
+}
+
+NS_IMETHODIMP
+ReadStream::Available(uint64_t* aNumAvailableOut)
+{
+  return mInner->Available(aNumAvailableOut);
+}
+
+NS_IMETHODIMP
+ReadStream::Read(char* aBuf, uint32_t aCount, uint32_t* aNumReadOut)
+{
+  return mInner->Read(aBuf, aCount, aNumReadOut);
+}
+
+NS_IMETHODIMP
+ReadStream::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                         uint32_t aCount, uint32_t* aNumReadOut)
+{
+  return mInner->ReadSegments(aWriter, aClosure, aCount, aNumReadOut);
+}
+
+NS_IMETHODIMP
+ReadStream::IsNonBlocking(bool* aNonBlockingOut)
+{
+  return mInner->IsNonBlocking(aNonBlockingOut);
+}
+
+} // namespace cache
+} // namespace dom
+} // namespace mozilla