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-rw-r--r--dom/cache/ReadStream.cpp620
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diff --git a/dom/cache/ReadStream.cpp b/dom/cache/ReadStream.cpp
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+++ b/dom/cache/ReadStream.cpp
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+/* -*- 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 "nsIThread.h"
+#include "nsStringStream.h"
+#include "nsTArray.h"
+
+namespace mozilla::dom::cache {
+
+using mozilla::Unused;
+
+// ----------------------------------------------------------------------------
+
+// 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(Maybe<CacheReadStream>* aReadStreamOut, ErrorResult& aRv);
+
+ void Serialize(CacheReadStream* aReadStreamOut, ErrorResult& aRv);
+
+ // ReadStream::Controllable methods
+ virtual void CloseStream() override;
+
+ virtual void CloseStreamWithoutReporting() 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 StreamStatus();
+
+ 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);
+
+ NS_DECL_OWNINGTHREAD;
+
+ ~Inner();
+
+ private:
+ class NoteClosedRunnable;
+ class ForgetRunnable;
+
+ void NoteClosed();
+
+ void Forget();
+
+ void NoteClosedOnOwningThread();
+
+ void ForgetOnOwningThread();
+
+ nsIInputStream* EnsureStream();
+
+ void AsyncOpenStreamOnOwningThread();
+
+ void MaybeAbortAsyncOpenStream();
+
+ void OpenStreamFailed();
+
+ inline SafeRefPtr<Inner> SafeRefPtrFromThis() {
+ return Controllable::SafeRefPtrFromThis().downcast<Inner>();
+ }
+
+ // 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<nsISerialEventTarget> mOwningEventTarget;
+
+ enum State { Open, Closed, NumStates };
+ Atomic<State> mState;
+ Atomic<bool> mHasEverBeenRead;
+ bool mAsyncOpenStarted;
+
+ // 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 MOZ_UNANNOTATED;
+ CondVar mCondVar;
+ nsCOMPtr<nsIInputStream> mStream;
+ nsCOMPtr<nsIInputStream> mSnappyStream;
+};
+
+// ----------------------------------------------------------------------------
+
+// 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(SafeRefPtr<ReadStream::Inner> aStream)
+ : CancelableRunnable("dom::cache::ReadStream::Inner::NoteClosedRunnable"),
+ mStream(std::move(aStream)) {}
+
+ NS_IMETHOD Run() override {
+ mStream->NoteClosedOnOwningThread();
+ 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() = default;
+
+ const SafeRefPtr<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(SafeRefPtr<ReadStream::Inner> aStream)
+ : CancelableRunnable("dom::cache::ReadStream::Inner::ForgetRunnable"),
+ mStream(std::move(aStream)) {}
+
+ NS_IMETHOD Run() override {
+ mStream->ForgetOnOwningThread();
+ 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() = default;
+
+ const SafeRefPtr<ReadStream::Inner> mStream;
+};
+
+// ----------------------------------------------------------------------------
+
+ReadStream::Inner::Inner(StreamControl* aControl, const nsID& aId,
+ nsIInputStream* aStream)
+ : mControl(aControl),
+ mId(aId),
+ mOwningEventTarget(GetCurrentSerialEventTarget()),
+ mState(Open),
+ mHasEverBeenRead(false),
+ mAsyncOpenStarted(false),
+ mMutex("dom::cache::ReadStream"),
+ mCondVar(mMutex, "dom::cache::ReadStream"),
+ mStream(aStream),
+ mSnappyStream(aStream ? new SnappyUncompressInputStream(aStream)
+ : nullptr) {
+ MOZ_DIAGNOSTIC_ASSERT(mControl);
+ mControl->AddReadStream(SafeRefPtrFromThis());
+}
+
+void ReadStream::Inner::Serialize(Maybe<CacheReadStream>* aReadStreamOut,
+ ErrorResult& aRv) {
+ MOZ_ASSERT(mOwningEventTarget->IsOnCurrentThread());
+ MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut);
+ aReadStreamOut->emplace(CacheReadStream());
+ Serialize(&aReadStreamOut->ref(), aRv);
+}
+
+void ReadStream::Inner::Serialize(CacheReadStream* aReadStreamOut,
+ ErrorResult& aRv) {
+ MOZ_ASSERT(mOwningEventTarget->IsOnCurrentThread());
+ MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut);
+
+ if (mState != Open) {
+ aRv.ThrowTypeError(
+ "Response body is a cache file stream that has already been closed.");
+ return;
+ }
+
+ MOZ_DIAGNOSTIC_ASSERT(mControl);
+
+ aReadStreamOut->id() = mId;
+ mControl->SerializeControl(aReadStreamOut);
+
+ {
+ MutexAutoLock lock(mMutex);
+ mControl->SerializeStream(aReadStreamOut, mStream);
+ }
+
+ MOZ_DIAGNOSTIC_ASSERT(aReadStreamOut->stream().isNothing() ||
+ aReadStreamOut->stream().ref().stream().type() !=
+ mozilla::ipc::InputStreamParams::T__None);
+
+ // 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(mOwningEventTarget->IsOnCurrentThread());
+ MOZ_ALWAYS_SUCCEEDS(Close());
+}
+
+void ReadStream::Inner::CloseStreamWithoutReporting() {
+ MOZ_ASSERT(mOwningEventTarget->IsOnCurrentThread());
+ Forget();
+}
+
+bool ReadStream::Inner::HasEverBeenRead() const {
+ MOZ_ASSERT(mOwningEventTarget->IsOnCurrentThread());
+ return mHasEverBeenRead;
+}
+
+nsresult ReadStream::Inner::Close() {
+ // stream ops can happen on any thread
+ nsresult rv = NS_OK;
+ {
+ MutexAutoLock lock(mMutex);
+ if (mSnappyStream) {
+ 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 = EnsureStream()->Available(aNumAvailableOut);
+ }
+
+ if (NS_FAILED(rv)) {
+ Close();
+ }
+
+ return rv;
+}
+
+nsresult ReadStream::Inner::StreamStatus() {
+ // stream ops can happen on any thread
+ nsresult rv = NS_OK;
+ {
+ MutexAutoLock lock(mMutex);
+ rv = EnsureStream()->StreamStatus();
+ }
+
+ 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 = EnsureStream()->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 = EnsureStream()->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);
+ if (mSnappyStream) {
+ return mSnappyStream->IsNonBlocking(aNonBlockingOut);
+ }
+ *aNonBlockingOut = false;
+ return NS_OK;
+}
+
+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 (mOwningEventTarget->IsOnCurrentThread()) {
+ NoteClosedOnOwningThread();
+ return;
+ }
+
+ nsCOMPtr<nsIRunnable> runnable = new NoteClosedRunnable(SafeRefPtrFromThis());
+ MOZ_ALWAYS_SUCCEEDS(mOwningEventTarget->Dispatch(runnable.forget(),
+ nsIThread::DISPATCH_NORMAL));
+}
+
+void ReadStream::Inner::Forget() {
+ // Any thread
+ if (mState == Closed) {
+ return;
+ }
+
+ if (mOwningEventTarget->IsOnCurrentThread()) {
+ ForgetOnOwningThread();
+ return;
+ }
+
+ nsCOMPtr<nsIRunnable> runnable = new ForgetRunnable(SafeRefPtrFromThis());
+ MOZ_ALWAYS_SUCCEEDS(mOwningEventTarget->Dispatch(runnable.forget(),
+ nsIThread::DISPATCH_NORMAL));
+}
+
+void ReadStream::Inner::NoteClosedOnOwningThread() {
+ MOZ_ASSERT(mOwningEventTarget->IsOnCurrentThread());
+
+ // Mark closed and do nothing if we were already closed
+ if (!mState.compareExchange(Open, Closed)) {
+ return;
+ }
+
+ MaybeAbortAsyncOpenStream();
+
+ MOZ_DIAGNOSTIC_ASSERT(mControl);
+ mControl->NoteClosed(SafeRefPtrFromThis(), mId);
+ mControl = nullptr;
+}
+
+void ReadStream::Inner::ForgetOnOwningThread() {
+ MOZ_ASSERT(mOwningEventTarget->IsOnCurrentThread());
+
+ // Mark closed and do nothing if we were already closed
+ if (!mState.compareExchange(Open, Closed)) {
+ return;
+ }
+
+ MaybeAbortAsyncOpenStream();
+
+ MOZ_DIAGNOSTIC_ASSERT(mControl);
+ mControl->ForgetReadStream(SafeRefPtrFromThis());
+ mControl = nullptr;
+}
+
+nsIInputStream* ReadStream::Inner::EnsureStream() {
+ mMutex.AssertCurrentThreadOwns();
+
+ // We need to block the current thread while we open the stream. We
+ // cannot do this safely from the main owning thread since it would
+ // trigger deadlock. This should be ok, though, since a blocking
+ // stream like this should never be read on the owning thread anyway.
+ if (mOwningEventTarget->IsOnCurrentThread()) {
+ MOZ_CRASH("Blocking read on the js/ipc owning thread!");
+ }
+
+ if (mSnappyStream) {
+ return mSnappyStream;
+ }
+
+ nsCOMPtr<nsIRunnable> r = NewCancelableRunnableMethod(
+ "ReadStream::Inner::AsyncOpenStreamOnOwningThread", this,
+ &ReadStream::Inner::AsyncOpenStreamOnOwningThread);
+ nsresult rv =
+ mOwningEventTarget->Dispatch(r.forget(), nsIThread::DISPATCH_NORMAL);
+ if (NS_WARN_IF(NS_FAILED(rv))) {
+ OpenStreamFailed();
+ return mSnappyStream;
+ }
+
+ mCondVar.Wait();
+ MOZ_DIAGNOSTIC_ASSERT(mSnappyStream);
+
+ return mSnappyStream;
+}
+
+void ReadStream::Inner::AsyncOpenStreamOnOwningThread() {
+ MOZ_ASSERT(mOwningEventTarget->IsOnCurrentThread());
+
+ if (mSnappyStream) {
+ // Different threads might request opening the stream at the same time. If
+ // the earlier request succeeded, then use the result.
+ mCondVar.NotifyAll();
+ return;
+ }
+
+ if (!mControl || mState == Closed) {
+ MutexAutoLock lock(mMutex);
+ OpenStreamFailed();
+ mCondVar.NotifyAll();
+ return;
+ }
+
+ if (mAsyncOpenStarted) {
+ return;
+ }
+ mAsyncOpenStarted = true;
+
+ RefPtr<ReadStream::Inner> self = this;
+ mControl->OpenStream(mId, [self](nsCOMPtr<nsIInputStream>&& aStream) {
+ MutexAutoLock lock(self->mMutex);
+ self->mAsyncOpenStarted = false;
+ if (!self->mStream) {
+ if (!aStream) {
+ self->OpenStreamFailed();
+ } else {
+ self->mStream = std::move(aStream);
+ self->mSnappyStream = new SnappyUncompressInputStream(self->mStream);
+ }
+ }
+ self->mCondVar.NotifyAll();
+ });
+}
+
+void ReadStream::Inner::MaybeAbortAsyncOpenStream() {
+ if (!mAsyncOpenStarted) {
+ return;
+ }
+
+ MutexAutoLock lock(mMutex);
+ OpenStreamFailed();
+ mCondVar.NotifyAll();
+}
+
+void ReadStream::Inner::OpenStreamFailed() {
+ MOZ_DIAGNOSTIC_ASSERT(!mStream);
+ MOZ_DIAGNOSTIC_ASSERT(!mSnappyStream);
+ mMutex.AssertCurrentThreadOwns();
+ Unused << NS_NewCStringInputStream(getter_AddRefs(mStream), ""_ns);
+ mSnappyStream = mStream;
+ mStream->Close();
+ NoteClosed();
+}
+
+// ----------------------------------------------------------------------------
+
+NS_IMPL_ISUPPORTS(cache::ReadStream, nsIInputStream, ReadStream);
+
+// static
+already_AddRefed<ReadStream> ReadStream::Create(
+ const Maybe<CacheReadStream>& aMaybeReadStream) {
+ if (aMaybeReadStream.isNothing()) {
+ return nullptr;
+ }
+
+ return Create(aMaybeReadStream.ref());
+}
+
+// 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.control()) {
+ return nullptr;
+ }
+
+ MOZ_DIAGNOSTIC_ASSERT(aReadStream.stream().isNothing() ||
+ aReadStream.stream().ref().stream().type() !=
+ mozilla::ipc::InputStreamParams::T__None);
+
+ // Control is guaranteed to survive this method as ActorDestroy() cannot
+ // run on this thread until we complete.
+ StreamControl* control;
+ if (aReadStream.control().IsChild()) {
+ auto actor =
+ static_cast<CacheStreamControlChild*>(aReadStream.control().AsChild());
+ control = actor;
+ } else {
+ auto actor = static_cast<CacheStreamControlParent*>(
+ aReadStream.control().AsParent());
+ control = actor;
+ }
+ MOZ_DIAGNOSTIC_ASSERT(control);
+
+ nsCOMPtr<nsIInputStream> stream = DeserializeIPCStream(aReadStream.stream());
+
+ // Currently we expect all cache read streams to be blocking file streams.
+#if defined(MOZ_DIAGNOSTIC_ASSERT_ENABLED)
+ if (stream) {
+ nsCOMPtr<nsIAsyncInputStream> asyncStream = do_QueryInterface(stream);
+ MOZ_DIAGNOSTIC_ASSERT(!asyncStream);
+ }
+#endif
+
+ return MakeAndAddRef<ReadStream>(MakeSafeRefPtr<ReadStream::Inner>(
+ std::move(control), aReadStream.id(), stream));
+}
+
+// static
+already_AddRefed<ReadStream> ReadStream::Create(
+ PCacheStreamControlParent* aControl, const nsID& aId,
+ nsIInputStream* aStream) {
+ MOZ_DIAGNOSTIC_ASSERT(aControl);
+
+ return MakeAndAddRef<ReadStream>(MakeSafeRefPtr<ReadStream::Inner>(
+ static_cast<CacheStreamControlParent*>(aControl), aId, aStream));
+}
+
+void ReadStream::Serialize(Maybe<CacheReadStream>* aReadStreamOut,
+ ErrorResult& aRv) {
+ mInner->Serialize(aReadStreamOut, aRv);
+}
+
+void ReadStream::Serialize(CacheReadStream* aReadStreamOut, ErrorResult& aRv) {
+ mInner->Serialize(aReadStreamOut, aRv);
+}
+
+ReadStream::ReadStream(SafeRefPtr<ReadStream::Inner> aInner)
+ : mInner(std::move(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::StreamStatus() { return mInner->StreamStatus(); }
+
+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 mozilla::dom::cache