/* -*- 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 "ActorsParent.h"

#include "mozilla/Unused.h"
#include "mozilla/dom/PBackgroundSDBConnectionParent.h"
#include "mozilla/dom/PBackgroundSDBRequestParent.h"
#include "mozilla/dom/quota/Client.h"
#include "mozilla/dom/quota/FileStreams.h"
#include "mozilla/dom/quota/MemoryOutputStream.h"
#include "mozilla/dom/quota/QuotaManager.h"
#include "mozilla/dom/quota/UsageInfo.h"
#include "mozilla/ipc/BackgroundParent.h"
#include "mozilla/ipc/PBackgroundParent.h"
#include "mozilla/ipc/PBackgroundSharedTypes.h"
#include "nsIFileStreams.h"
#include "nsIDirectoryEnumerator.h"
#include "nsStringStream.h"
#include "prio.h"
#include "SimpleDBCommon.h"

#define DISABLE_ASSERTS_FOR_FUZZING 0

#if DISABLE_ASSERTS_FOR_FUZZING
#define ASSERT_UNLESS_FUZZING(...) do { } while (0)
#else
#define ASSERT_UNLESS_FUZZING(...) MOZ_ASSERT(false, __VA_ARGS__)
#endif

namespace mozilla {
namespace dom {

using namespace mozilla::dom::quota;
using namespace mozilla::ipc;

namespace {

/*******************************************************************************
 * Constants
 ******************************************************************************/

const uint32_t kCopyBufferSize = 32768;

/*******************************************************************************
 * Actor class declarations
 ******************************************************************************/

class StreamHelper final
  : public Runnable
{
  nsCOMPtr<nsIEventTarget> mOwningEventTarget;
  nsCOMPtr<nsIFileStream> mFileStream;
  nsCOMPtr<nsIRunnable> mCallback;

public:
  StreamHelper(nsIFileStream* aFileStream,
               nsIRunnable* aCallback);

  void
  AsyncClose();

private:
  ~StreamHelper() override;

  void
  RunOnBackgroundThread();

  void
  RunOnIOThread();

  NS_DECL_NSIRUNNABLE
};

class Connection final
  : public PBackgroundSDBConnectionParent
{
  RefPtr<DirectoryLock> mDirectoryLock;
  nsCOMPtr<nsIFileStream> mFileStream;
  const PrincipalInfo mPrincipalInfo;
  nsCString mOrigin;
  nsString mName;

  bool mRunningRequest;
  bool mOpen;
  bool mAllowedToClose;
  bool mActorDestroyed;

public:
  explicit Connection(const PrincipalInfo& aPrincipalInfo);

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(mozilla::dom::Connection)

  nsIFileStream*
  GetFileStream() const
  {
    AssertIsOnIOThread();

    return mFileStream;
  }

  const PrincipalInfo&
  GetPrincipalInfo() const
  {
    MOZ_ASSERT(NS_IsMainThread());

    return mPrincipalInfo;
  }

  const nsCString&
  Origin() const
  {
    AssertIsOnBackgroundThread();
    MOZ_ASSERT(!mOrigin.IsEmpty());

    return mOrigin;
  }

  const nsString&
  Name() const
  {
    AssertIsOnBackgroundThread();
    MOZ_ASSERT(!mName.IsEmpty());

    return mName;
  }

  void
  OnNewRequest();

  void
  OnRequestFinished();

  void
  OnOpen(const nsACString& aOrigin,
         const nsAString& aName,
         already_AddRefed<DirectoryLock> aDirectoryLock,
         already_AddRefed<nsIFileStream> aFileStream);

  void
  OnClose();

  void
  AllowToClose();

private:
  ~Connection();

  void
  MaybeCloseStream();

  bool
  VerifyRequestParams(const SDBRequestParams& aParams) const;

  // IPDL methods.
  virtual void
  ActorDestroy(ActorDestroyReason aWhy) override;

  mozilla::ipc::IPCResult
  RecvDeleteMe() override;

  virtual PBackgroundSDBRequestParent*
  AllocPBackgroundSDBRequestParent(const SDBRequestParams& aParams) override;

  virtual mozilla::ipc::IPCResult
  RecvPBackgroundSDBRequestConstructor(PBackgroundSDBRequestParent* aActor,
                                       const SDBRequestParams& aParams)
                                       override;

  virtual bool
  DeallocPBackgroundSDBRequestParent(PBackgroundSDBRequestParent* aActor)
                                     override;
};

class ConnectionOperationBase
  : public Runnable
  , public PBackgroundSDBRequestParent
{
  nsCOMPtr<nsIEventTarget> mOwningEventTarget;
  RefPtr<Connection> mConnection;
  nsresult mResultCode;
  Atomic<bool> mOperationMayProceed;
  bool mActorDestroyed;

public:
  nsIEventTarget*
  OwningEventTarget() const
  {
    MOZ_ASSERT(mOwningEventTarget);

    return mOwningEventTarget;
  }

  bool
  IsOnOwningThread() const
  {
    MOZ_ASSERT(mOwningEventTarget);

    bool current;
    return
      NS_SUCCEEDED(mOwningEventTarget->IsOnCurrentThread(&current)) && current;
  }

  void
  AssertIsOnOwningThread() const
  {
    MOZ_ASSERT(IsOnBackgroundThread());
    MOZ_ASSERT(IsOnOwningThread());
  }

  Connection*
  GetConnection() const
  {
    MOZ_ASSERT(mConnection);

    return mConnection;
  }

  nsresult
  ResultCode() const
  {
    return mResultCode;
  }

  void
  MaybeSetFailureCode(nsresult aErrorCode)
  {
    MOZ_ASSERT(NS_FAILED(aErrorCode));

    if (NS_SUCCEEDED(mResultCode)) {
      mResultCode = aErrorCode;
    }
  }

  // May be called on any thread, but you should call IsActorDestroyed() if
  // you know you're on the background thread because it is slightly faster.
  bool
  OperationMayProceed() const
  {
    return mOperationMayProceed;
  }

  bool
  IsActorDestroyed() const
  {
    AssertIsOnOwningThread();

    return mActorDestroyed;
  }

  // May be overridden by subclasses if they need to perform work on the
  // background thread before being dispatched but must always call the base
  // class implementation. Returning false will kill the child actors and
  // prevent dispatch.
  virtual bool
  Init();

  virtual nsresult
  Dispatch();

  // This callback will be called on the background thread before releasing the
  // final reference to this request object. Subclasses may perform any
  // additional cleanup here but must always call the base class implementation.
  virtual void
  Cleanup();

protected:
  ConnectionOperationBase(Connection* aConnection)
    : Runnable("dom::ConnectionOperationBase")
    , mOwningEventTarget(GetCurrentThreadEventTarget())
    , mConnection(aConnection)
    , mResultCode(NS_OK)
    , mOperationMayProceed(true)
    , mActorDestroyed(false)
  {
    AssertIsOnOwningThread();
  }

  ~ConnectionOperationBase() override;

  void
  SendResults();

  void
  DatabaseWork();

  // Methods that subclasses must implement.
  virtual nsresult
  DoDatabaseWork(nsIFileStream* aFileStream) = 0;

  // Subclasses use this override to set the IPDL response value.
  virtual void
  GetResponse(SDBRequestResponse& aResponse) = 0;

  // A method that subclasses may implement.
  virtual void
  OnSuccess();

private:
  NS_IMETHOD
  Run() override;

  // IPDL methods.
  void
  ActorDestroy(ActorDestroyReason aWhy) override;
};

class OpenOp final
  : public ConnectionOperationBase
  , public OpenDirectoryListener
{
  enum class State
  {
    // Just created on the PBackground thread, dispatched to the main thread.
    // Next step is FinishOpen.
    Initial,

    // Opening directory or initializing quota manager on the PBackground
    // thread. Next step is either DirectoryOpenPending if quota manager is
    // already initialized or QuotaManagerPending if quota manager needs to be
    // initialized.
    FinishOpen,

    // Waiting for quota manager initialization to complete on the PBackground
    // thread. Next step is either SendingResults if initialization failed or
    // DirectoryOpenPending if initialization succeeded.
    QuotaManagerPending,

    // Waiting for directory open allowed on the PBackground thread. The next
    // step is either SendingResults if directory lock failed to acquire, or
    // DatabaseWorkOpen if directory lock is acquired.
    DirectoryOpenPending,

    // Waiting to do/doing work on the QuotaManager IO thread. Its next step is
    // SendingResults.
    DatabaseWorkOpen,

    // Waiting to send/sending results on the PBackground thread. Next step is
    // Completed.
    SendingResults,

    // All done.
    Completed
  };

  const SDBRequestOpenParams mParams;
  RefPtr<DirectoryLock> mDirectoryLock;
  nsCOMPtr<nsIFileStream> mFileStream;
  nsCString mSuffix;
  nsCString mGroup;
  nsCString mOrigin;
  State mState;
  bool mFileStreamOpen;

public:
  OpenOp(Connection* aConnection, const SDBRequestParams& aParams);

  nsresult
  Dispatch() override;

private:
  ~OpenOp() override;

  nsresult
  Open();

  nsresult
  FinishOpen();

  nsresult
  QuotaManagerOpen();

  nsresult
  OpenDirectory();

  nsresult
  SendToIOThread();

  nsresult
  DatabaseWork();

  void
  StreamClosedCallback();

  // ConnectionOperationBase overrides
  nsresult
  DoDatabaseWork(nsIFileStream* aFileStream) override;

  void
  GetResponse(SDBRequestResponse& aResponse) override;

  void
  OnSuccess() override;

  void
  Cleanup() override;

  NS_DECL_ISUPPORTS_INHERITED

  NS_IMETHOD
  Run() override;

  // OpenDirectoryListener overrides.
  void
  DirectoryLockAcquired(DirectoryLock* aLock) override;

  void
  DirectoryLockFailed() override;
};

class SeekOp final
  : public ConnectionOperationBase
{
  const SDBRequestSeekParams mParams;

public:
  SeekOp(Connection* aConnection,
         const SDBRequestParams& aParams);

private:
  ~SeekOp() override = default;

  nsresult
  DoDatabaseWork(nsIFileStream* aFileStream) override;

  void
  GetResponse(SDBRequestResponse& aResponse) override;
};

class ReadOp final
  : public ConnectionOperationBase
{
  const SDBRequestReadParams mParams;

  RefPtr<MemoryOutputStream> mOutputStream;

public:
  ReadOp(Connection* aConnection,
         const SDBRequestParams& aParams);

  bool
  Init() override;

private:
  ~ReadOp() override = default;

  nsresult
  DoDatabaseWork(nsIFileStream* aFileStream) override;

  void
  GetResponse(SDBRequestResponse& aResponse) override;
};

class WriteOp final
  : public ConnectionOperationBase
{
  const SDBRequestWriteParams mParams;

  nsCOMPtr<nsIInputStream> mInputStream;

  uint64_t mSize;

public:
  WriteOp(Connection* aConnection,
          const SDBRequestParams& aParams);

  bool
  Init() override;

private:
  ~WriteOp() override = default;

  nsresult
  DoDatabaseWork(nsIFileStream* aFileStream) override;

  void
  GetResponse(SDBRequestResponse& aResponse) override;
};

class CloseOp final
  : public ConnectionOperationBase
{
public:
  explicit CloseOp(Connection* aConnection);

private:
  ~CloseOp() override = default;

  nsresult
  DoDatabaseWork(nsIFileStream* aFileStream) override;

  void
  GetResponse(SDBRequestResponse& aResponse) override;

  void
  OnSuccess() override;
};

/*******************************************************************************
 * Other class declarations
 ******************************************************************************/

class QuotaClient final
  : public mozilla::dom::quota::Client
{
  static QuotaClient* sInstance;

  bool mShutdownRequested;

public:
  QuotaClient();

  static bool
  IsShuttingDownOnBackgroundThread()
  {
    AssertIsOnBackgroundThread();

    if (sInstance) {
      return sInstance->IsShuttingDown();
    }

    return QuotaManager::IsShuttingDown();
  }

  static bool
  IsShuttingDownOnNonBackgroundThread()
  {
    MOZ_ASSERT(!IsOnBackgroundThread());

    return QuotaManager::IsShuttingDown();
  }

  bool
  IsShuttingDown() const
  {
    AssertIsOnBackgroundThread();

    return mShutdownRequested;
  }

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(QuotaClient, override)

  Type
  GetType() override;

  nsresult
  InitOrigin(PersistenceType aPersistenceType,
             const nsACString& aGroup,
             const nsACString& aOrigin,
             const AtomicBool& aCanceled,
             UsageInfo* aUsageInfo) override;

  nsresult
  GetUsageForOrigin(PersistenceType aPersistenceType,
                    const nsACString& aGroup,
                    const nsACString& aOrigin,
                    const AtomicBool& aCanceled,
                    UsageInfo* aUsageInfo) override;

  void
  OnOriginClearCompleted(PersistenceType aPersistenceType,
                         const nsACString& aOrigin)
                         override;

  void
  ReleaseIOThreadObjects() override;

  void
  AbortOperations(const nsACString& aOrigin) override;

  void
  AbortOperationsForProcess(ContentParentId aContentParentId) override;

  void
  StartIdleMaintenance() override;

  void
  StopIdleMaintenance() override;

  void
  ShutdownWorkThreads() override;

private:
  ~QuotaClient() override;
};

/*******************************************************************************
 * Globals
 ******************************************************************************/

typedef nsTArray<RefPtr<Connection>> ConnectionArray;

StaticAutoPtr<ConnectionArray> gOpenConnections;

} // namespace

/*******************************************************************************
 * Exported functions
 ******************************************************************************/

PBackgroundSDBConnectionParent*
AllocPBackgroundSDBConnectionParent(const PrincipalInfo& aPrincipalInfo)
{
  AssertIsOnBackgroundThread();

  if (NS_WARN_IF(QuotaClient::IsShuttingDownOnBackgroundThread())) {
    return nullptr;
  }

  if (NS_WARN_IF(aPrincipalInfo.type() == PrincipalInfo::TNullPrincipalInfo)) {
    ASSERT_UNLESS_FUZZING();
    return nullptr;
  }

  RefPtr<Connection> actor = new Connection(aPrincipalInfo);

  return actor.forget().take();
}

bool
RecvPBackgroundSDBConnectionConstructor(PBackgroundSDBConnectionParent* aActor,
                                        const PrincipalInfo& aPrincipalInfo)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(aActor);
  MOZ_ASSERT(!QuotaClient::IsShuttingDownOnBackgroundThread());

  return true;
}

bool
DeallocPBackgroundSDBConnectionParent(PBackgroundSDBConnectionParent* aActor)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(aActor);

  RefPtr<Connection> actor = dont_AddRef(static_cast<Connection*>(aActor));
  return true;
}

namespace simpledb {

already_AddRefed<mozilla::dom::quota::Client>
CreateQuotaClient()
{
  AssertIsOnBackgroundThread();

  RefPtr<QuotaClient> client = new QuotaClient();
  return client.forget();
}

} // namespace simpledb

/*******************************************************************************
 * StreamHelper
 ******************************************************************************/

StreamHelper::StreamHelper(nsIFileStream* aFileStream,
                           nsIRunnable* aCallback)
  : Runnable("dom::StreamHelper")
  , mOwningEventTarget(GetCurrentThreadEventTarget())
  , mFileStream(aFileStream)
  , mCallback(aCallback)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(aFileStream);
  MOZ_ASSERT(aCallback);
}

StreamHelper::~StreamHelper()
{
  MOZ_ASSERT(!mFileStream);
  MOZ_ASSERT(!mCallback);
}

void
StreamHelper::AsyncClose()
{
  AssertIsOnBackgroundThread();

  QuotaManager* quotaManager = QuotaManager::Get();
  MOZ_ASSERT(quotaManager);

  MOZ_ALWAYS_SUCCEEDS(
    quotaManager->IOThread()->Dispatch(this, NS_DISPATCH_NORMAL));
}

void
StreamHelper::RunOnBackgroundThread()
{
  AssertIsOnBackgroundThread();

  nsCOMPtr<nsIFileStream> fileStream;
  mFileStream.swap(fileStream);

  nsCOMPtr<nsIRunnable> callback;
  mCallback.swap(callback);

  callback->Run();
}

void
StreamHelper::RunOnIOThread()
{
  AssertIsOnIOThread();
  MOZ_ASSERT(mFileStream);

  nsCOMPtr<nsIInputStream> inputStream = do_QueryInterface(mFileStream);
  MOZ_ASSERT(inputStream);

  nsresult rv = inputStream->Close();
  Unused << NS_WARN_IF(NS_FAILED(rv));

  MOZ_ALWAYS_SUCCEEDS(mOwningEventTarget->Dispatch(this, NS_DISPATCH_NORMAL));
}

NS_IMETHODIMP
StreamHelper::Run()
{
  MOZ_ASSERT(mCallback);

  if (IsOnBackgroundThread()) {
    RunOnBackgroundThread();
  } else {
    RunOnIOThread();
  }

  return NS_OK;
}

/*******************************************************************************
 * Connection
 ******************************************************************************/

Connection::Connection(const PrincipalInfo& aPrincipalInfo)
  : mPrincipalInfo(aPrincipalInfo)
  , mRunningRequest(false)
  , mOpen(false)
  , mAllowedToClose(false)
  , mActorDestroyed(false)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!QuotaClient::IsShuttingDownOnBackgroundThread());
}

Connection::~Connection()
{
  MOZ_ASSERT(!mRunningRequest);
  MOZ_ASSERT(!mOpen);
  MOZ_ASSERT(mActorDestroyed);
}

void
Connection::OnNewRequest()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!mRunningRequest);

  mRunningRequest = true;
}

void
Connection::OnRequestFinished()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(mRunningRequest);

  mRunningRequest = false;

  MaybeCloseStream();
}

void
Connection::OnOpen(const nsACString& aOrigin,
                   const nsAString& aName,
                   already_AddRefed<DirectoryLock> aDirectoryLock,
                   already_AddRefed<nsIFileStream> aFileStream)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!aOrigin.IsEmpty());
  MOZ_ASSERT(!aName.IsEmpty());
  MOZ_ASSERT(mOrigin.IsEmpty());
  MOZ_ASSERT(mName.IsEmpty());
  MOZ_ASSERT(!mDirectoryLock);
  MOZ_ASSERT(!mFileStream);
  MOZ_ASSERT(!mOpen);

  mOrigin = aOrigin;
  mName = aName;
  mDirectoryLock = aDirectoryLock;
  mFileStream = aFileStream;
  mOpen = true;

  if (!gOpenConnections) {
    gOpenConnections = new ConnectionArray();
  }

  gOpenConnections->AppendElement(this);
}

void
Connection::OnClose()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!mOrigin.IsEmpty());
  MOZ_ASSERT(mDirectoryLock);
  MOZ_ASSERT(mFileStream);
  MOZ_ASSERT(mOpen);

  mOrigin.Truncate();
  mName.Truncate();
  mDirectoryLock = nullptr;
  mFileStream = nullptr;
  mOpen = false;

  MOZ_ASSERT(gOpenConnections);
  gOpenConnections->RemoveElement(this);

  if (gOpenConnections->IsEmpty()) {
    gOpenConnections = nullptr;
  }

  if (mAllowedToClose && !mActorDestroyed) {
    Unused << SendClosed();
  }
}

void
Connection::AllowToClose()
{
  AssertIsOnBackgroundThread();

  if (mAllowedToClose) {
    return;
  }

  mAllowedToClose = true;

  if (!mActorDestroyed) {
    Unused << SendAllowToClose();
  }

  MaybeCloseStream();
}

void
Connection::MaybeCloseStream()
{
  AssertIsOnBackgroundThread();

  if (!mRunningRequest &&
      mOpen &&
      mAllowedToClose) {
    nsCOMPtr<nsIRunnable> callback =
      NewRunnableMethod("dom::Connection::OnClose",
                        this,
                        &Connection::OnClose);

    RefPtr<StreamHelper> helper = new StreamHelper(mFileStream, callback);
    helper->AsyncClose();
  }
}

bool
Connection::VerifyRequestParams(const SDBRequestParams& aParams) const
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(aParams.type() != SDBRequestParams::T__None);

  switch (aParams.type()) {
    case SDBRequestParams::TSDBRequestOpenParams: {
      if (NS_WARN_IF(mOpen)) {
        ASSERT_UNLESS_FUZZING();
        return false;
      }

      break;
    }

    case SDBRequestParams::TSDBRequestSeekParams:
    case SDBRequestParams::TSDBRequestReadParams:
    case SDBRequestParams::TSDBRequestWriteParams:
    case SDBRequestParams::TSDBRequestCloseParams: {
      if (NS_WARN_IF(!mOpen)) {
        ASSERT_UNLESS_FUZZING();
        return false;
      }

      break;
    }

    default:
      MOZ_CRASH("Should never get here!");
  }

  return true;
}

void
Connection::ActorDestroy(ActorDestroyReason aWhy)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!mActorDestroyed);

  mActorDestroyed = true;

  AllowToClose();
}

mozilla::ipc::IPCResult
Connection::RecvDeleteMe()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!mActorDestroyed);

  IProtocol* mgr = Manager();
  if (!PBackgroundSDBConnectionParent::Send__delete__(this)) {
    return IPC_FAIL_NO_REASON(mgr);
  }

  return IPC_OK();
}

PBackgroundSDBRequestParent*
Connection::AllocPBackgroundSDBRequestParent(const SDBRequestParams& aParams)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(aParams.type() != SDBRequestParams::T__None);

  if (aParams.type() == SDBRequestParams::TSDBRequestOpenParams &&
      NS_WARN_IF(QuotaClient::IsShuttingDownOnBackgroundThread())) {
    return nullptr;
  }

  if (mAllowedToClose) {
    return nullptr;
  }

#ifdef DEBUG
  // Always verify parameters in DEBUG builds!
  bool trustParams = false;
#else
  PBackgroundParent* backgroundActor = Manager();
  MOZ_ASSERT(backgroundActor);

  bool trustParams = !BackgroundParent::IsOtherProcessActor(backgroundActor);
#endif

  if (NS_WARN_IF(!trustParams && !VerifyRequestParams(aParams))) {
    ASSERT_UNLESS_FUZZING();
    return nullptr;
  }

  if (NS_WARN_IF(mRunningRequest)) {
    ASSERT_UNLESS_FUZZING();
    return nullptr;
  }

  RefPtr<ConnectionOperationBase> actor;

  switch (aParams.type()) {
    case SDBRequestParams::TSDBRequestOpenParams:
      actor = new OpenOp(this, aParams);
      break;

    case SDBRequestParams::TSDBRequestSeekParams:
      actor = new SeekOp(this, aParams);
      break;

    case SDBRequestParams::TSDBRequestReadParams:
      actor = new ReadOp(this, aParams);
      break;

    case SDBRequestParams::TSDBRequestWriteParams:
      actor = new WriteOp(this, aParams);
      break;

    case SDBRequestParams::TSDBRequestCloseParams:
      actor = new CloseOp(this);
      break;

    default:
      MOZ_CRASH("Should never get here!");
  }

  // Transfer ownership to IPDL.
  return actor.forget().take();
}

mozilla::ipc::IPCResult
Connection::RecvPBackgroundSDBRequestConstructor(
                                            PBackgroundSDBRequestParent* aActor,
                                            const SDBRequestParams& aParams)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(aActor);
  MOZ_ASSERT(aParams.type() != SDBRequestParams::T__None);
  MOZ_ASSERT_IF(aParams.type() == SDBRequestParams::TSDBRequestOpenParams,
                !QuotaClient::IsShuttingDownOnBackgroundThread());
  MOZ_ASSERT(!mAllowedToClose);
  MOZ_ASSERT(!mRunningRequest);

  auto* op = static_cast<ConnectionOperationBase*>(aActor);

  if (NS_WARN_IF(!op->Init())) {
    op->Cleanup();
    return IPC_FAIL_NO_REASON(this);
  }

  if (NS_WARN_IF(NS_FAILED(op->Dispatch()))) {
    op->Cleanup();
    return IPC_FAIL_NO_REASON(this);
  }

  return IPC_OK();
}

bool
Connection::DeallocPBackgroundSDBRequestParent(
                                            PBackgroundSDBRequestParent* aActor)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(aActor);

  // Transfer ownership back from IPDL.
  RefPtr<ConnectionOperationBase> actor =
    dont_AddRef(static_cast<ConnectionOperationBase*>(aActor));
  return true;
}

/*******************************************************************************
 * ConnectionOperationBase
 ******************************************************************************/

ConnectionOperationBase::~ConnectionOperationBase()
{
  MOZ_ASSERT(!mConnection,
             "ConnectionOperationBase::Cleanup() was not called by a subclass!");
  MOZ_ASSERT(mActorDestroyed);
}

bool
ConnectionOperationBase::Init()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(mConnection);

  mConnection->OnNewRequest();

  return true;
}

nsresult
ConnectionOperationBase::Dispatch()
{
  if (NS_WARN_IF(QuotaClient::IsShuttingDownOnBackgroundThread()) ||
      IsActorDestroyed()) {
    return NS_ERROR_FAILURE;
  }

  QuotaManager* quotaManager = QuotaManager::Get();
  MOZ_ASSERT(quotaManager);

  nsresult rv = quotaManager->IOThread()->Dispatch(this, NS_DISPATCH_NORMAL);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

void
ConnectionOperationBase::Cleanup()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(mConnection);

  mConnection->OnRequestFinished();

  mConnection = nullptr;
}

void
ConnectionOperationBase::SendResults()
{
  AssertIsOnOwningThread();

  if (IsActorDestroyed()) {
    MaybeSetFailureCode(NS_ERROR_FAILURE);
  } else {
    SDBRequestResponse response;

    if (NS_SUCCEEDED(mResultCode)) {
      GetResponse(response);

      MOZ_ASSERT(response.type() != SDBRequestResponse::T__None);
      MOZ_ASSERT(response.type() != SDBRequestResponse::Tnsresult);
    } else {
      response = mResultCode;
    }

    Unused <<
      PBackgroundSDBRequestParent::Send__delete__(this, response);

    if (NS_SUCCEEDED(mResultCode)) {
      OnSuccess();
    }
  }

  Cleanup();
}

void
ConnectionOperationBase::DatabaseWork()
{
  AssertIsOnIOThread();
  MOZ_ASSERT(NS_SUCCEEDED(mResultCode));

  if (!OperationMayProceed()) {
    // The operation was canceled in some way, likely because the child process
    // has crashed.
    mResultCode = NS_ERROR_FAILURE;
  } else {
    nsIFileStream* fileStream = mConnection->GetFileStream();
    MOZ_ASSERT(fileStream);

    nsresult rv = DoDatabaseWork(fileStream);
    if (NS_FAILED(rv)) {
      mResultCode = rv;
    }
  }

  MOZ_ALWAYS_SUCCEEDS(mOwningEventTarget->Dispatch(this, NS_DISPATCH_NORMAL));
}

void
ConnectionOperationBase::OnSuccess()
{
  AssertIsOnOwningThread();
}

NS_IMETHODIMP
ConnectionOperationBase::Run()
{
  if (IsOnBackgroundThread()) {
    SendResults();
  } else {
    DatabaseWork();
  }

  return NS_OK;
}

void
ConnectionOperationBase::ActorDestroy(ActorDestroyReason aWhy)
{
  AssertIsOnBackgroundThread();

  mOperationMayProceed = false;
  mActorDestroyed = true;
}

OpenOp::OpenOp(Connection* aConnection, const SDBRequestParams& aParams)
  : ConnectionOperationBase(aConnection)
  , mParams(aParams.get_SDBRequestOpenParams())
  , mState(State::Initial)
  , mFileStreamOpen(false)
{
  MOZ_ASSERT(aParams.type() == SDBRequestParams::TSDBRequestOpenParams);
}

OpenOp::~OpenOp()
{
  MOZ_ASSERT(!mDirectoryLock);
  MOZ_ASSERT(!mFileStream);
  MOZ_ASSERT(!mFileStreamOpen);
  MOZ_ASSERT_IF(OperationMayProceed(),
                mState == State::Initial || mState == State::Completed);
}

nsresult
OpenOp::Dispatch()
{
  MOZ_ALWAYS_SUCCEEDS(NS_DispatchToMainThread(this));

  return NS_OK;
}

nsresult
OpenOp::Open()
{
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(mState == State::Initial);

  if (NS_WARN_IF(QuotaClient::IsShuttingDownOnNonBackgroundThread()) ||
      !OperationMayProceed()) {
    return NS_ERROR_FAILURE;
  }

  if (NS_WARN_IF(!Preferences::GetBool(kPrefSimpleDBEnabled, false))) {
    return NS_ERROR_UNEXPECTED;
  }

  const PrincipalInfo& principalInfo = GetConnection()->GetPrincipalInfo();

  if (principalInfo.type() == PrincipalInfo::TSystemPrincipalInfo) {
    QuotaManager::GetInfoForChrome(&mSuffix, &mGroup, &mOrigin);
  } else {
    MOZ_ASSERT(principalInfo.type() == PrincipalInfo::TContentPrincipalInfo);

    nsresult rv;
    nsCOMPtr<nsIPrincipal> principal =
      PrincipalInfoToPrincipal(principalInfo, &rv);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    rv = QuotaManager::GetInfoFromPrincipal(principal,
                                            &mSuffix,
                                            &mGroup,
                                            &mOrigin);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  mState = State::FinishOpen;
  MOZ_ALWAYS_SUCCEEDS(OwningEventTarget()->Dispatch(this, NS_DISPATCH_NORMAL));

  return NS_OK;
}

nsresult
OpenOp::FinishOpen()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(mState == State::FinishOpen);

  if (gOpenConnections) {
    for (Connection* connection : *gOpenConnections) {
      if (connection->Origin() == mOrigin &&
          connection->Name() == mParams.name()) {
        return NS_ERROR_STORAGE_BUSY;
      }
    }
  }

  if (QuotaManager::Get()) {
    nsresult rv = OpenDirectory();
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    return NS_OK;
  }

  mState = State::QuotaManagerPending;
  QuotaManager::GetOrCreate(this);

  return NS_OK;
}

nsresult
OpenOp::QuotaManagerOpen()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(mState == State::QuotaManagerPending);

  if (NS_WARN_IF(!QuotaManager::Get())) {
    return NS_ERROR_FAILURE;
  }

  nsresult rv = OpenDirectory();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

nsresult
OpenOp::OpenDirectory()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(mState == State::FinishOpen ||
             mState == State::QuotaManagerPending);
  MOZ_ASSERT(!mOrigin.IsEmpty());
  MOZ_ASSERT(!mDirectoryLock);
  MOZ_ASSERT(!QuotaClient::IsShuttingDownOnBackgroundThread());
  MOZ_ASSERT(QuotaManager::Get());

  mState = State::DirectoryOpenPending;
  QuotaManager::Get()->OpenDirectory(PERSISTENCE_TYPE_DEFAULT,
                                     mGroup,
                                     mOrigin,
                                     mozilla::dom::quota::Client::SDB,
                                     /* aExclusive */ false,
                                     this);

  return NS_OK;
}

nsresult
OpenOp::SendToIOThread()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(mState == State::DirectoryOpenPending);

  if (NS_WARN_IF(QuotaClient::IsShuttingDownOnBackgroundThread()) ||
      IsActorDestroyed()) {
    return NS_ERROR_FAILURE;
  }

  mFileStream = new FileStream(PERSISTENCE_TYPE_DEFAULT, mGroup, mOrigin);

  QuotaManager* quotaManager = QuotaManager::Get();
  MOZ_ASSERT(quotaManager);

  // Must set this before dispatching otherwise we will race with the IO thread.
  mState = State::DatabaseWorkOpen;

  nsresult rv = quotaManager->IOThread()->Dispatch(this, NS_DISPATCH_NORMAL);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

nsresult
OpenOp::DatabaseWork()
{
  AssertIsOnIOThread();
  MOZ_ASSERT(mState == State::DatabaseWorkOpen);
  MOZ_ASSERT(mFileStream);
  MOZ_ASSERT(!mFileStreamOpen);

  if (NS_WARN_IF(QuotaClient::IsShuttingDownOnNonBackgroundThread()) ||
      !OperationMayProceed()) {
    return NS_ERROR_FAILURE;
  }

  QuotaManager* quotaManager = QuotaManager::Get();
  MOZ_ASSERT(quotaManager);

  nsCOMPtr<nsIFile> dbDirectory;
  nsresult rv =
    quotaManager->EnsureOriginIsInitialized(PERSISTENCE_TYPE_DEFAULT,
                                            mSuffix,
                                            mGroup,
                                            mOrigin,
                                            getter_AddRefs(dbDirectory));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  rv = dbDirectory->Append(NS_LITERAL_STRING(SDB_DIRECTORY_NAME));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  bool exists;
  rv = dbDirectory->Exists(&exists);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (!exists) {
    rv = dbDirectory->Create(nsIFile::DIRECTORY_TYPE, 0755);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }
#ifdef DEBUG
  else {
    bool isDirectory;
    MOZ_ASSERT(NS_SUCCEEDED(dbDirectory->IsDirectory(&isDirectory)));
    MOZ_ASSERT(isDirectory);
  }
#endif

  nsCOMPtr<nsIFile> dbFile;
  rv = dbDirectory->Clone(getter_AddRefs(dbFile));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  rv = dbFile->Append(mParams.name());
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsString databaseFilePath;
  rv = dbFile->GetPath(databaseFilePath);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  rv = mFileStream->Init(dbFile, PR_RDWR | PR_CREATE_FILE, 0644, 0);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  mFileStreamOpen = true;

  rv = DoDatabaseWork(mFileStream);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  // Must set mState before dispatching otherwise we will race with the owning
  // thread.
  mState = State::SendingResults;

  rv = OwningEventTarget()->Dispatch(this, NS_DISPATCH_NORMAL);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

void
OpenOp::StreamClosedCallback()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(NS_FAILED(ResultCode()));
  MOZ_ASSERT(mDirectoryLock);
  MOZ_ASSERT(mFileStream);
  MOZ_ASSERT(mFileStreamOpen);

  mDirectoryLock = nullptr;
  mFileStream = nullptr;
  mFileStreamOpen = false;
}

nsresult
OpenOp::DoDatabaseWork(nsIFileStream* aFileStream)
{
  AssertIsOnIOThread();

  return NS_OK;
}

void
OpenOp::GetResponse(SDBRequestResponse& aResponse)
{
  AssertIsOnOwningThread();

  aResponse = SDBRequestOpenResponse();
}

void
OpenOp::OnSuccess()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(NS_SUCCEEDED(ResultCode()));
  MOZ_ASSERT(!mOrigin.IsEmpty());
  MOZ_ASSERT(mDirectoryLock);
  MOZ_ASSERT(mFileStream);
  MOZ_ASSERT(mFileStreamOpen);

  RefPtr<DirectoryLock> directoryLock;
  nsCOMPtr<nsIFileStream> fileStream;

  mDirectoryLock.swap(directoryLock);
  mFileStream.swap(fileStream);
  mFileStreamOpen = false;

  GetConnection()->OnOpen(mOrigin,
                          mParams.name(),
                          directoryLock.forget(),
                          fileStream.forget());
}

void
OpenOp::Cleanup()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT_IF(mFileStreamOpen, mFileStream);

  if (mFileStream && mFileStreamOpen) {
    // If we have an initialized file stream then the operation must have failed
    // and there must be a directory lock too.
    MOZ_ASSERT(NS_FAILED(ResultCode()));
    MOZ_ASSERT(mDirectoryLock);

    // We must close the stream on the I/O thread before releasing it on this
    // thread. The directory lock can't be released either.
    nsCOMPtr<nsIRunnable> callback =
      NewRunnableMethod("dom::OpenOp::StreamClosedCallback",
                        this,
                        &OpenOp::StreamClosedCallback);

    RefPtr<StreamHelper> helper = new StreamHelper(mFileStream, callback);
    helper->AsyncClose();
  } else {
    MOZ_ASSERT(!mFileStreamOpen);

    mDirectoryLock = nullptr;
    mFileStream = nullptr;
  }

  ConnectionOperationBase::Cleanup();
}

NS_IMPL_ISUPPORTS_INHERITED0(OpenOp, ConnectionOperationBase)

NS_IMETHODIMP
OpenOp::Run()
{
  nsresult rv;

  switch (mState) {
    case State::Initial:
      rv = Open();
      break;

    case State::FinishOpen:
      rv = FinishOpen();
      break;

    case State::QuotaManagerPending:
      rv = QuotaManagerOpen();
      break;

    case State::DatabaseWorkOpen:
      rv = DatabaseWork();
      break;

    case State::SendingResults:
      SendResults();
      return NS_OK;

    default:
      MOZ_CRASH("Bad state!");
  }

  if (NS_WARN_IF(NS_FAILED(rv)) && mState != State::SendingResults) {
    MaybeSetFailureCode(rv);

    // Must set mState before dispatching otherwise we will race with the owning
    // thread.
    mState = State::SendingResults;

    if (IsOnOwningThread()) {
      SendResults();
    } else {
      MOZ_ALWAYS_SUCCEEDS(
        OwningEventTarget()->Dispatch(this, NS_DISPATCH_NORMAL));
    }
  }

  return NS_OK;
}

void
OpenOp::DirectoryLockAcquired(DirectoryLock* aLock)
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(mState == State::DirectoryOpenPending);
  MOZ_ASSERT(!mDirectoryLock);

  mDirectoryLock = aLock;

  nsresult rv = SendToIOThread();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    MaybeSetFailureCode(rv);

    // The caller holds a strong reference to us, no need for a self reference
    // before calling Run().

    mState = State::SendingResults;
    MOZ_ALWAYS_SUCCEEDS(Run());

    return;
  }
}

void
OpenOp::DirectoryLockFailed()
{
  AssertIsOnOwningThread();
  MOZ_ASSERT(mState == State::DirectoryOpenPending);
  MOZ_ASSERT(!mDirectoryLock);

  MaybeSetFailureCode(NS_ERROR_FAILURE);

  // The caller holds a strong reference to us, no need for a self reference
  // before calling Run().

  mState = State::SendingResults;
  MOZ_ALWAYS_SUCCEEDS(Run());
}

SeekOp::SeekOp(Connection* aConnection,
               const SDBRequestParams& aParams)
  : ConnectionOperationBase(aConnection)
  , mParams(aParams.get_SDBRequestSeekParams())
{
  MOZ_ASSERT(aParams.type() == SDBRequestParams::TSDBRequestSeekParams);
}

nsresult
SeekOp::DoDatabaseWork(nsIFileStream* aFileStream)
{
  AssertIsOnIOThread();
  MOZ_ASSERT(aFileStream);

  nsCOMPtr<nsISeekableStream> seekableStream = do_QueryInterface(aFileStream);
  MOZ_ASSERT(seekableStream);

  nsresult rv = seekableStream->Seek(nsISeekableStream::NS_SEEK_SET,
                                     mParams.offset());

  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

void
SeekOp::GetResponse(SDBRequestResponse& aResponse)
{
  aResponse = SDBRequestSeekResponse();
}

ReadOp::ReadOp(Connection* aConnection,
               const SDBRequestParams& aParams)
  : ConnectionOperationBase(aConnection)
  , mParams(aParams.get_SDBRequestReadParams())
{
  MOZ_ASSERT(aParams.type() == SDBRequestParams::TSDBRequestReadParams);
}

bool
ReadOp::Init()
{
  AssertIsOnOwningThread();

  if (NS_WARN_IF(!ConnectionOperationBase::Init())) {
    return false;
  }

  mOutputStream = MemoryOutputStream::Create(mParams.size());
  if (NS_WARN_IF(!mOutputStream)) {
    return false;
  }

  return true;
}

nsresult
ReadOp::DoDatabaseWork(nsIFileStream* aFileStream)
{
  AssertIsOnIOThread();
  MOZ_ASSERT(aFileStream);

  nsCOMPtr<nsIInputStream> inputStream = do_QueryInterface(aFileStream);
  MOZ_ASSERT(inputStream);

  nsresult rv;

  uint64_t offset = 0;

  do {
    char copyBuffer[kCopyBufferSize];

    uint64_t max = mParams.size() - offset;
    if (max == 0) {
      break;
    }

    uint32_t count = sizeof(copyBuffer);
    if (count > max) {
      count = max;
    }

    uint32_t numRead;
    rv = inputStream->Read(copyBuffer, count, &numRead);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    if (!numRead) {
      break;
    }

    uint32_t numWrite;
    rv = mOutputStream->Write(copyBuffer, numRead, &numWrite);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    if (NS_WARN_IF(numWrite != numRead)) {
      return NS_ERROR_FAILURE;
    }

    offset += numWrite;
  } while (true);

  MOZ_ASSERT(offset == mParams.size());

  MOZ_ALWAYS_SUCCEEDS(mOutputStream->Close());

  return NS_OK;
}

void
ReadOp::GetResponse(SDBRequestResponse& aResponse)
{
  aResponse = SDBRequestReadResponse(mOutputStream->Data());
}

WriteOp::WriteOp(Connection* aConnection,
                 const SDBRequestParams& aParams)
  : ConnectionOperationBase(aConnection)
  , mParams(aParams.get_SDBRequestWriteParams())
  , mSize(0)
{
  MOZ_ASSERT(aParams.type() == SDBRequestParams::TSDBRequestWriteParams);
}

bool
WriteOp::Init()
{
  AssertIsOnOwningThread();

  if (NS_WARN_IF(!ConnectionOperationBase::Init())) {
    return false;
  }

  const nsCString& string = mParams.data();

  nsCOMPtr<nsIInputStream> inputStream;
  nsresult rv =
    NS_NewCStringInputStream(getter_AddRefs(inputStream), string);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return false;
  }

  mInputStream = std::move(inputStream);
  mSize = string.Length();

  return true;
}

nsresult
WriteOp::DoDatabaseWork(nsIFileStream* aFileStream)
{
  AssertIsOnIOThread();
  MOZ_ASSERT(aFileStream);

  nsCOMPtr<nsIOutputStream> outputStream = do_QueryInterface(aFileStream);
  MOZ_ASSERT(outputStream);

  nsresult rv;

  do {
    char copyBuffer[kCopyBufferSize];

    uint32_t numRead;
    rv = mInputStream->Read(copyBuffer, sizeof(copyBuffer), &numRead);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      break;
    }

    if (!numRead) {
      break;
    }

    uint32_t numWrite;
    rv = outputStream->Write(copyBuffer, numRead, &numWrite);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    if (NS_WARN_IF(numWrite != numRead)) {
      return NS_ERROR_FAILURE;
    }
  } while (true);

  MOZ_ALWAYS_SUCCEEDS(mInputStream->Close());

  return NS_OK;
}

void
WriteOp::GetResponse(SDBRequestResponse& aResponse)
{
  aResponse = SDBRequestWriteResponse();
}

CloseOp::CloseOp(Connection* aConnection)
  : ConnectionOperationBase(aConnection)
{ }

nsresult
CloseOp::DoDatabaseWork(nsIFileStream* aFileStream)
{
  AssertIsOnIOThread();
  MOZ_ASSERT(aFileStream);

  nsCOMPtr<nsIInputStream> inputStream = do_QueryInterface(aFileStream);
  MOZ_ASSERT(inputStream);

  nsresult rv = inputStream->Close();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

void
CloseOp::GetResponse(SDBRequestResponse& aResponse)
{
  aResponse = SDBRequestCloseResponse();
}

void
CloseOp::OnSuccess()
{
  AssertIsOnOwningThread();

  GetConnection()->OnClose();
}

/*******************************************************************************
 * QuotaClient
 ******************************************************************************/

QuotaClient* QuotaClient::sInstance = nullptr;

QuotaClient::QuotaClient()
  : mShutdownRequested(false)
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!sInstance, "We expect this to be a singleton!");

  sInstance = this;
}

QuotaClient::~QuotaClient()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(sInstance == this, "We expect this to be a singleton!");

  sInstance = nullptr;
}

mozilla::dom::quota::Client::Type
QuotaClient::GetType()
{
  return QuotaClient::SDB;
}

nsresult
QuotaClient::InitOrigin(PersistenceType aPersistenceType,
                        const nsACString& aGroup,
                        const nsACString& aOrigin,
                        const AtomicBool& aCanceled,
                        UsageInfo* aUsageInfo)
{
  AssertIsOnIOThread();

  if (!aUsageInfo) {
    return NS_OK;
  }

  return GetUsageForOrigin(aPersistenceType,
                           aGroup,
                           aOrigin,
                           aCanceled,
                           aUsageInfo);
}

nsresult
QuotaClient::GetUsageForOrigin(PersistenceType aPersistenceType,
                               const nsACString& aGroup,
                               const nsACString& aOrigin,
                               const AtomicBool& aCanceled,
                               UsageInfo* aUsageInfo)
{
  AssertIsOnIOThread();
  MOZ_ASSERT(aUsageInfo);

  QuotaManager* quotaManager = QuotaManager::Get();
  MOZ_ASSERT(quotaManager);

  nsCOMPtr<nsIFile> directory;
  nsresult rv = quotaManager->GetDirectoryForOrigin(aPersistenceType, aOrigin,
                                                    getter_AddRefs(directory));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  MOZ_ASSERT(directory);

  rv = directory->Append(NS_LITERAL_STRING(SDB_DIRECTORY_NAME));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  DebugOnly<bool> exists;
  MOZ_ASSERT(NS_SUCCEEDED(directory->Exists(&exists)) && exists);

  nsCOMPtr<nsIDirectoryEnumerator> entries;
  rv = directory->GetDirectoryEntries(getter_AddRefs(entries));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  bool hasMore;
  while (NS_SUCCEEDED((rv = entries->HasMoreElements(&hasMore))) &&
         hasMore && !aCanceled) {
    nsCOMPtr<nsISupports> entry;
    rv = entries->GetNext(getter_AddRefs(entry));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    nsCOMPtr<nsIFile> file = do_QueryInterface(entry);
    MOZ_ASSERT(file);

    int64_t fileSize;
    rv = file->GetFileSize(&fileSize);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    MOZ_ASSERT(fileSize >= 0);

    aUsageInfo->AppendToDatabaseUsage(uint64_t(fileSize));
  }
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

void
QuotaClient::OnOriginClearCompleted(PersistenceType aPersistenceType,
                                    const nsACString& aOrigin)
{
  AssertIsOnIOThread();
}

void
QuotaClient::ReleaseIOThreadObjects()
{
  AssertIsOnIOThread();
}

void
QuotaClient::AbortOperations(const nsACString& aOrigin)
{
  AssertIsOnBackgroundThread();

  if (gOpenConnections) {
    for (Connection* connection : *gOpenConnections) {
      if (aOrigin.IsVoid() || connection->Origin() == aOrigin) {
        connection->AllowToClose();
      }
    }
  }
}

void
QuotaClient::AbortOperationsForProcess(ContentParentId aContentParentId)
{
  AssertIsOnBackgroundThread();
}

void
QuotaClient::StartIdleMaintenance()
{
  AssertIsOnBackgroundThread();
}

void
QuotaClient::StopIdleMaintenance()
{
  AssertIsOnBackgroundThread();
}

void
QuotaClient::ShutdownWorkThreads()
{
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!mShutdownRequested);

  mShutdownRequested = true;

  if (gOpenConnections) {
    for (Connection* connection : *gOpenConnections) {
      connection->AllowToClose();
    }

    MOZ_ALWAYS_TRUE(SpinEventLoopUntil([&]() { return !gOpenConnections; }));
  }
}

} // namespace dom
} // namespace mozilla