1 files changed, 643 insertions, 0 deletions
diff --git a/dom/base/MutableBlobStorage.cpp b/dom/base/MutableBlobStorage.cpp
new file mode 100644
index 000000000..54ca4fe39
--- /dev/null
+++ b/dom/base/MutableBlobStorage.cpp
@@ -0,0 +1,643 @@
+/* -*- 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/MutableBlobStorage.h"
+#include "mozilla/CheckedInt.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/TaskQueue.h"
+#include "nsAnonymousTemporaryFile.h"
+#include "nsNetCID.h"
+#include "WorkerPrivate.h"
+
+#define BLOB_MEMORY_TEMPORARY_FILE 1048576
+
+namespace mozilla {
+namespace dom {
+
+namespace {
+
+// This class uses the callback to inform when the Blob is created or when the
+// error must be propagated.
+class BlobCreationDoneRunnable final : public Runnable
+{
+public:
+  BlobCreationDoneRunnable(MutableBlobStorage* aBlobStorage,
+                           MutableBlobStorageCallback* aCallback,
+                           Blob* aBlob,
+                           nsresult aRv)
+    : mBlobStorage(aBlobStorage)
+    , mCallback(aCallback)
+    , mBlob(aBlob)
+    , mRv(aRv)
+  {
+    MOZ_ASSERT(aBlobStorage);
+    MOZ_ASSERT(aCallback);
+    MOZ_ASSERT((NS_FAILED(aRv) && !aBlob) ||
+               (NS_SUCCEEDED(aRv) && aBlob));
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    mCallback->BlobStoreCompleted(mBlobStorage, mBlob, mRv);
+    mCallback = nullptr;
+    mBlob = nullptr;
+    return NS_OK;
+  }
+
+private:
+  ~BlobCreationDoneRunnable()
+  {
+    // If something when wrong, we still have to release these objects in the
+    // correct thread.
+    NS_ReleaseOnMainThread(mCallback.forget());
+    NS_ReleaseOnMainThread(mBlob.forget());
+  }
+
+  RefPtr<MutableBlobStorage> mBlobStorage;
+  RefPtr<MutableBlobStorageCallback> mCallback;
+  RefPtr<Blob> mBlob;
+  nsresult mRv;
+};
+
+// This runnable goes back to the main-thread and informs the BlobStorage about
+// the temporary file.
+class FileCreatedRunnable final : public Runnable
+{
+public:
+  FileCreatedRunnable(MutableBlobStorage* aBlobStorage, PRFileDesc* aFD)
+    : mBlobStorage(aBlobStorage)
+    , mFD(aFD)
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+    MOZ_ASSERT(aBlobStorage);
+    MOZ_ASSERT(aFD);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    mBlobStorage->TemporaryFileCreated(mFD);
+    mFD = nullptr;
+    return NS_OK;
+  }
+
+private:
+  ~FileCreatedRunnable()
+  {
+    // If something when wrong, we still have to close the FileDescriptor.
+    if (mFD) {
+      PR_Close(mFD);
+    }
+  }
+
+  RefPtr<MutableBlobStorage> mBlobStorage;
+  PRFileDesc* mFD;
+};
+
+// This runnable creates the temporary file. When done, FileCreatedRunnable is
+// dispatched back to the main-thread.
+class CreateTemporaryFileRunnable final : public Runnable
+{
+public:
+  explicit CreateTemporaryFileRunnable(MutableBlobStorage* aBlobStorage)
+    : mBlobStorage(aBlobStorage)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(aBlobStorage);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+
+    PRFileDesc* tempFD = nullptr;
+    nsresult rv = NS_OpenAnonymousTemporaryFile(&tempFD);
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      // In sandboxed context we are not allowed to create temporary files, but
+      // this doesn't mean that BlobStorage should fail. We can continue to
+      // store data in memory.  We don't change the storageType so that we don't
+      // try to create a temporary file again.
+      return NS_OK;
+    }
+
+    // The ownership of the tempFD is moved to the FileCreatedRunnable.
+    return NS_DispatchToMainThread(new FileCreatedRunnable(mBlobStorage, tempFD));
+  }
+
+private:
+  RefPtr<MutableBlobStorage> mBlobStorage;
+};
+
+// Simple runnable to propagate the error to the BlobStorage.
+class ErrorPropagationRunnable final : public Runnable
+{
+public:
+  ErrorPropagationRunnable(MutableBlobStorage* aBlobStorage, nsresult aRv)
+    : mBlobStorage(aBlobStorage)
+    , mRv(aRv)
+  {}
+
+  NS_IMETHOD
+  Run() override
+  {
+    mBlobStorage->ErrorPropagated(mRv);
+    return NS_OK;
+  }
+
+private:
+  RefPtr<MutableBlobStorage> mBlobStorage;
+  nsresult mRv;
+};
+
+// This runnable moves a buffer to the IO thread and there, it writes it into
+// the temporary file.
+class WriteRunnable final : public Runnable
+{
+public:
+  static WriteRunnable*
+  CopyBuffer(MutableBlobStorage* aBlobStorage, PRFileDesc* aFD,
+             const void* aData, uint32_t aLength)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(aBlobStorage);
+    MOZ_ASSERT(aFD);
+    MOZ_ASSERT(aData);
+
+    // We have to take a copy of this buffer.
+    void* data = malloc(aLength);
+    if (!data) {
+      return nullptr;
+    }
+
+    memcpy((char*)data, aData, aLength);
+    return new WriteRunnable(aBlobStorage, aFD, data, aLength);
+  }
+
+  static WriteRunnable*
+  AdoptBuffer(MutableBlobStorage* aBlobStorage, PRFileDesc* aFD,
+              void* aData, uint32_t aLength)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(aBlobStorage);
+    MOZ_ASSERT(aFD);
+    MOZ_ASSERT(aData);
+
+    return new WriteRunnable(aBlobStorage, aFD, aData, aLength);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+
+    int32_t written = PR_Write(mFD, mData, mLength);
+    if (NS_WARN_IF(written < 0 || uint32_t(written) != mLength)) {
+      return NS_DispatchToMainThread(
+        new ErrorPropagationRunnable(mBlobStorage, NS_ERROR_FAILURE));
+    }
+
+    return NS_OK;
+  }
+
+private:
+  WriteRunnable(MutableBlobStorage* aBlobStorage, PRFileDesc* aFD,
+                void* aData, uint32_t aLength)
+    : mBlobStorage(aBlobStorage)
+    , mFD(aFD)
+    , mData(aData)
+    , mLength(aLength)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(mBlobStorage);
+    MOZ_ASSERT(aFD);
+    MOZ_ASSERT(aData);
+  }
+
+  ~WriteRunnable()
+  {
+    free(mData);
+  }
+
+  RefPtr<MutableBlobStorage> mBlobStorage;
+  PRFileDesc* mFD;
+  void* mData;
+  uint32_t mLength;
+};
+
+// This runnable closes the FD in case something goes wrong or the temporary
+// file is not needed anymore.
+class CloseFileRunnable final : public Runnable
+{
+public:
+  explicit CloseFileRunnable(PRFileDesc* aFD)
+    : mFD(aFD)
+  {}
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+    PR_Close(mFD);
+    mFD = nullptr;
+    return NS_OK;
+  }
+
+private:
+  ~CloseFileRunnable()
+  {
+    if (mFD) {
+      PR_Close(mFD);
+    }
+  }
+
+  PRFileDesc* mFD;
+};
+
+// This runnable is dispatched to the main-thread from the IO thread and its
+// task is to create the blob and inform the callback.
+class CreateBlobRunnable final : public Runnable
+{
+public:
+  CreateBlobRunnable(MutableBlobStorage* aBlobStorage,
+                     already_AddRefed<nsISupports> aParent,
+                     const nsACString& aContentType,
+                     already_AddRefed<MutableBlobStorageCallback> aCallback)
+    : mBlobStorage(aBlobStorage)
+    , mParent(aParent)
+    , mContentType(aContentType)
+    , mCallback(aCallback)
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    mBlobStorage->CreateBlobAndRespond(mParent.forget(), mContentType,
+                                       mCallback.forget());
+    return NS_OK;
+  }
+
+private:
+  ~CreateBlobRunnable()
+  {
+    // If something when wrong, we still have to release data in the correct
+    // thread.
+    NS_ReleaseOnMainThread(mParent.forget());
+    NS_ReleaseOnMainThread(mCallback.forget());
+  }
+
+  RefPtr<MutableBlobStorage> mBlobStorage;
+  nsCOMPtr<nsISupports> mParent;
+  nsCString mContentType;
+  RefPtr<MutableBlobStorageCallback> mCallback;
+};
+
+// This task is used to know when the writing is completed. From the IO thread
+// it dispatches a CreateBlobRunnable to the main-thread.
+class LastRunnable final : public Runnable
+{
+public:
+  LastRunnable(MutableBlobStorage* aBlobStorage,
+               nsISupports* aParent,
+               const nsACString& aContentType,
+               MutableBlobStorageCallback* aCallback)
+    : mBlobStorage(aBlobStorage)
+    , mParent(aParent)
+    , mContentType(aContentType)
+    , mCallback(aCallback)
+  {
+    MOZ_ASSERT(NS_IsMainThread());
+    MOZ_ASSERT(mBlobStorage);
+    MOZ_ASSERT(aCallback);
+  }
+
+  NS_IMETHOD
+  Run() override
+  {
+    MOZ_ASSERT(!NS_IsMainThread());
+    RefPtr<Runnable> runnable =
+      new CreateBlobRunnable(mBlobStorage, mParent.forget(),
+                             mContentType, mCallback.forget());
+    return NS_DispatchToMainThread(runnable);
+  }
+
+private:
+  ~LastRunnable()
+  {
+    // If something when wrong, we still have to release data in the correct
+    // thread.
+    NS_ReleaseOnMainThread(mParent.forget());
+    NS_ReleaseOnMainThread(mCallback.forget());
+  }
+
+  RefPtr<MutableBlobStorage> mBlobStorage;
+  nsCOMPtr<nsISupports> mParent;
+  nsCString mContentType;
+  RefPtr<MutableBlobStorageCallback> mCallback;
+};
+
+} // anonymous namespace
+
+MutableBlobStorage::MutableBlobStorage(MutableBlobStorageType aType)
+  : mData(nullptr)
+  , mDataLen(0)
+  , mDataBufferLen(0)
+  , mStorageState(aType == eOnlyInMemory ? eKeepInMemory : eInMemory)
+  , mFD(nullptr)
+  , mErrorResult(NS_OK)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+}
+
+MutableBlobStorage::~MutableBlobStorage()
+{
+  free(mData);
+
+  if (mFD) {
+    RefPtr<Runnable> runnable = new CloseFileRunnable(mFD);
+    DispatchToIOThread(runnable.forget());
+  }
+
+  if (mTaskQueue) {
+    mTaskQueue->BeginShutdown();
+  }
+}
+
+uint64_t
+MutableBlobStorage::GetBlobWhenReady(nsISupports* aParent,
+                                     const nsACString& aContentType,
+                                     MutableBlobStorageCallback* aCallback)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(aCallback);
+
+  // GetBlob can be called just once.
+  MOZ_ASSERT(mStorageState != eClosed);
+  StorageState previousState = mStorageState;
+  mStorageState = eClosed;
+
+  if (previousState == eInTemporaryFile) {
+    MOZ_ASSERT(mFD);
+
+    if (NS_FAILED(mErrorResult)) {
+      RefPtr<Runnable> runnable =
+        new BlobCreationDoneRunnable(this, aCallback, nullptr, mErrorResult);
+      NS_DispatchToMainThread(runnable.forget());
+      return 0;
+    }
+
+    // We want to wait until all the WriteRunnable are completed. The way we do
+    // this is to go to the I/O thread and then we come back: the runnables are
+    // executed in order and this LastRunnable will be... the last one.
+    RefPtr<Runnable> runnable =
+      new LastRunnable(this, aParent, aContentType, aCallback);
+    DispatchToIOThread(runnable.forget());
+    return mDataLen;
+  }
+
+  // If we are waiting for the temporary file, it's better to wait...
+  if (previousState == eWaitingForTemporaryFile) {
+    mPendingParent = aParent;
+    mPendingContentType = aContentType;
+    mPendingCallback = aCallback;
+    return mDataLen;
+  }
+
+  RefPtr<BlobImpl> blobImpl;
+
+  if (mData) {
+    blobImpl = new BlobImplMemory(mData, mDataLen,
+                                  NS_ConvertUTF8toUTF16(aContentType));
+
+    mData = nullptr; // The BlobImplMemory takes ownership of the buffer
+    mDataLen = 0;
+    mDataBufferLen = 0;
+  } else {
+    blobImpl = new EmptyBlobImpl(NS_ConvertUTF8toUTF16(aContentType));
+  }
+
+  RefPtr<Blob> blob = Blob::Create(aParent, blobImpl);
+  RefPtr<BlobCreationDoneRunnable> runnable =
+    new BlobCreationDoneRunnable(this, aCallback, blob, NS_OK);
+
+  nsresult error = NS_DispatchToMainThread(runnable);
+  if (NS_WARN_IF(NS_FAILED(error))) {
+    return 0;
+  }
+
+  return mDataLen;
+}
+
+nsresult
+MutableBlobStorage::Append(const void* aData, uint32_t aLength)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mStorageState != eClosed);
+  NS_ENSURE_ARG_POINTER(aData);
+
+  if (!aLength) {
+    return NS_OK;
+  }
+
+  // If eInMemory is the current Storage state, we could maybe migrate to
+  // a temporary file.
+  if (mStorageState == eInMemory && ShouldBeTemporaryStorage(aLength)) {
+    nsresult rv = MaybeCreateTemporaryFile();
+    if (NS_WARN_IF(NS_FAILED(rv))) {
+      return rv;
+    }
+  }
+
+  // If we are already in the temporaryFile mode, we have to dispatch a
+  // runnable.
+  if (mStorageState == eInTemporaryFile) {
+    MOZ_ASSERT(mFD);
+
+    RefPtr<WriteRunnable> runnable =
+      WriteRunnable::CopyBuffer(this, mFD, aData, aLength);
+    if (NS_WARN_IF(!runnable)) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+
+    DispatchToIOThread(runnable.forget());
+
+    mDataLen += aLength;
+    return NS_OK;
+  }
+
+  // By default, we store in memory.
+
+  uint64_t offset = mDataLen;
+
+  if (!ExpandBufferSize(aLength)) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  memcpy((char*)mData + offset, aData, aLength);
+  return NS_OK;
+}
+
+bool
+MutableBlobStorage::ExpandBufferSize(uint64_t aSize)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mStorageState < eInTemporaryFile);
+
+  if (mDataBufferLen >= mDataLen + aSize) {
+    mDataLen += aSize;
+    return true;
+  }
+
+  // Start at 1 or we'll loop forever.
+  CheckedUint32 bufferLen =
+    std::max<uint32_t>(static_cast<uint32_t>(mDataBufferLen), 1);
+  while (bufferLen.isValid() && bufferLen.value() < mDataLen + aSize) {
+    bufferLen *= 2;
+  }
+
+  if (!bufferLen.isValid()) {
+    return false;
+  }
+
+  void* data = realloc(mData, bufferLen.value());
+  if (!data) {
+    return false;
+  }
+
+  mData = data;
+  mDataBufferLen = bufferLen.value();
+  mDataLen += aSize;
+  return true;
+}
+
+bool
+MutableBlobStorage::ShouldBeTemporaryStorage(uint64_t aSize) const
+{
+  MOZ_ASSERT(mStorageState == eInMemory);
+
+  CheckedUint32 bufferSize = mDataLen;
+  bufferSize += aSize;
+
+  if (!bufferSize.isValid()) {
+    return false;
+  }
+
+  return bufferSize.value() >= Preferences::GetUint("dom.blob.memoryToTemporaryFile",
+                                                    BLOB_MEMORY_TEMPORARY_FILE);
+}
+
+nsresult
+MutableBlobStorage::MaybeCreateTemporaryFile()
+{
+  RefPtr<Runnable> runnable = new CreateTemporaryFileRunnable(this);
+  DispatchToIOThread(runnable.forget());
+
+  mStorageState = eWaitingForTemporaryFile;
+  return NS_OK;
+}
+
+void
+MutableBlobStorage::TemporaryFileCreated(PRFileDesc* aFD)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mStorageState == eWaitingForTemporaryFile ||
+             mStorageState == eClosed);
+  MOZ_ASSERT_IF(mPendingCallback, mStorageState == eClosed);
+
+  // If the object has been already closed and we don't need to execute a
+  // callback, we need just to close the file descriptor in the correct thread.
+  if (mStorageState == eClosed && !mPendingCallback) {
+    RefPtr<Runnable> runnable = new CloseFileRunnable(aFD);
+    DispatchToIOThread(runnable.forget());
+    return;
+  }
+
+  // If we still receiving data, we can proceed in temporary-file mode.
+  if (mStorageState == eWaitingForTemporaryFile) {
+    mStorageState = eInTemporaryFile;
+  }
+
+  mFD = aFD;
+
+  // This runnable takes the ownership of mData and it will write this buffer
+  // into the temporary file.
+  RefPtr<WriteRunnable> runnable =
+    WriteRunnable::AdoptBuffer(this, mFD, mData, mDataLen);
+  MOZ_ASSERT(runnable);
+
+  mData = nullptr;
+
+  DispatchToIOThread(runnable.forget());
+
+  // If we are closed, it means that GetBlobWhenReady() has been called when we
+  // were already waiting for a temporary file-descriptor. Finally we are here,
+  // AdoptBuffer runnable is going to write the current buffer into this file.
+  // After that, there is nothing else to write, and we dispatch LastRunnable
+  // which ends up calling mPendingCallback via CreateBlobRunnable.
+  if (mStorageState == eClosed) {
+    MOZ_ASSERT(mPendingCallback);
+
+    RefPtr<Runnable> runnable =
+      new LastRunnable(this, mPendingParent, mPendingContentType,
+                       mPendingCallback);
+    DispatchToIOThread(runnable.forget());
+
+    mPendingParent = nullptr;
+    mPendingCallback = nullptr;
+  }
+}
+
+void
+MutableBlobStorage::CreateBlobAndRespond(already_AddRefed<nsISupports> aParent,
+                                         const nsACString& aContentType,
+                                         already_AddRefed<MutableBlobStorageCallback> aCallback)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(mStorageState == eClosed);
+  MOZ_ASSERT(mFD);
+
+  nsCOMPtr<nsISupports> parent(aParent);
+  RefPtr<MutableBlobStorageCallback> callback(aCallback);
+
+  RefPtr<Blob> blob =
+    File::CreateTemporaryBlob(parent, mFD, 0, mDataLen,
+                              NS_ConvertUTF8toUTF16(aContentType));
+  callback->BlobStoreCompleted(this, blob, NS_OK);
+
+  // ownership of this FD is moved to the BlobImpl.
+  mFD = nullptr;
+}
+
+void
+MutableBlobStorage::ErrorPropagated(nsresult aRv)
+{
+  MOZ_ASSERT(NS_IsMainThread());
+  mErrorResult = aRv;
+}
+
+void
+MutableBlobStorage::DispatchToIOThread(already_AddRefed<nsIRunnable> aRunnable)
+{
+  if (!mTaskQueue) {
+    nsCOMPtr<nsIEventTarget> target
+      = do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
+    MOZ_ASSERT(target);
+
+    mTaskQueue = new TaskQueue(target.forget());
+  }
+
+  nsCOMPtr<nsIRunnable> runnable(aRunnable);
+  mTaskQueue->Dispatch(runnable.forget());
+}
+
+} // dom namespace
+} // mozilla namespace