dom/serviceworkers/ServiceWorkerRegistrar.cpp
author Dimi Lee <dlee@mozilla.com>
Sat, 08 Aug 2020 06:00:00 +0000
changeset 543991 fa0dbdf15f291e814b4854d515d7ef3e4548b7fb
parent 538159 3d7ffaefcd5a6c10988a1ecc3b75c3d55e1cd9e2
permissions -rw-r--r--
Bug 1658010 - Add null pointer check before notifying content block event r=xeonchen Differential Revision: https://phabricator.services.mozilla.com/D86421

/* -*- 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 "ServiceWorkerRegistrar.h"
#include "mozilla/dom/ServiceWorkerRegistrarTypes.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/net/MozURL.h"

#include "nsIEventTarget.h"
#include "nsIInputStream.h"
#include "nsILineInputStream.h"
#include "nsIObserverService.h"
#include "nsIOutputStream.h"
#include "nsISafeOutputStream.h"
#include "nsIServiceWorkerManager.h"
#include "nsIWritablePropertyBag2.h"

#include "MainThreadUtils.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/dom/StorageActivityService.h"
#include "mozilla/ErrorNames.h"
#include "mozilla/ipc/BackgroundChild.h"
#include "mozilla/ipc/BackgroundParent.h"
#include "mozilla/ipc/PBackgroundChild.h"
#include "mozilla/ModuleUtils.h"
#include "mozilla/Result.h"
#include "mozilla/ResultExtensions.h"
#include "mozilla/Services.h"
#include "mozilla/StaticPtr.h"
#include "mozJSComponentLoader.h"
#include "nsAppDirectoryServiceDefs.h"
#include "nsContentUtils.h"
#include "nsDirectoryServiceUtils.h"
#include "nsNetCID.h"
#include "nsNetUtil.h"
#include "nsServiceManagerUtils.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
#include "ServiceWorkerUtils.h"

using namespace mozilla::ipc;

namespace mozilla {
namespace dom {

namespace {

static const char* gSupportedRegistrarVersions[] = {
    SERVICEWORKERREGISTRAR_VERSION, "7", "6", "5", "4", "3", "2"};

static const uint32_t kInvalidGeneration = static_cast<uint32_t>(-1);

StaticRefPtr<ServiceWorkerRegistrar> gServiceWorkerRegistrar;

nsresult GetOriginAndBaseDomain(const nsACString& aURL, nsACString& aOrigin,
                                nsACString& aBaseDomain) {
  RefPtr<net::MozURL> url;
  nsresult rv = net::MozURL::Init(getter_AddRefs(url), aURL);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  url->Origin(aOrigin);

  rv = url->BaseDomain(aBaseDomain);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

nsresult ReadLine(nsILineInputStream* aStream, nsACString& aValue) {
  bool hasMoreLines;
  nsresult rv = aStream->ReadLine(aValue, &hasMoreLines);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (NS_WARN_IF(!hasMoreLines)) {
    return NS_ERROR_FAILURE;
  }

  return NS_OK;
}

nsresult CreatePrincipalInfo(nsILineInputStream* aStream,
                             ServiceWorkerRegistrationData* aEntry,
                             bool aSkipSpec = false) {
  nsAutoCString suffix;
  nsresult rv = ReadLine(aStream, suffix);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  OriginAttributes attrs;
  if (!attrs.PopulateFromSuffix(suffix)) {
    return NS_ERROR_INVALID_ARG;
  }

  if (aSkipSpec) {
    nsAutoCString unused;
    nsresult rv = ReadLine(aStream, unused);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  rv = ReadLine(aStream, aEntry->scope());
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsCString origin;
  nsCString baseDomain;
  rv = GetOriginAndBaseDomain(aEntry->scope(), origin, baseDomain);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  aEntry->principal() = mozilla::ipc::ContentPrincipalInfo(
      attrs, origin, aEntry->scope(), Nothing(), baseDomain);

  return NS_OK;
}

}  // namespace

NS_IMPL_ISUPPORTS(ServiceWorkerRegistrar, nsIObserver, nsIAsyncShutdownBlocker)

void ServiceWorkerRegistrar::Initialize() {
  MOZ_ASSERT(!gServiceWorkerRegistrar);

  if (!XRE_IsParentProcess()) {
    return;
  }

  gServiceWorkerRegistrar = new ServiceWorkerRegistrar();
  ClearOnShutdown(&gServiceWorkerRegistrar);

  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
  if (obs) {
    DebugOnly<nsresult> rv = obs->AddObserver(gServiceWorkerRegistrar,
                                              "profile-after-change", false);
    MOZ_ASSERT(NS_SUCCEEDED(rv));
  }
}

/* static */
already_AddRefed<ServiceWorkerRegistrar> ServiceWorkerRegistrar::Get() {
  MOZ_ASSERT(XRE_IsParentProcess());

  MOZ_ASSERT(gServiceWorkerRegistrar);
  RefPtr<ServiceWorkerRegistrar> service = gServiceWorkerRegistrar.get();
  return service.forget();
}

ServiceWorkerRegistrar::ServiceWorkerRegistrar()
    : mMonitor("ServiceWorkerRegistrar.mMonitor"),
      mDataLoaded(false),
      mDataGeneration(kInvalidGeneration),
      mFileGeneration(kInvalidGeneration),
      mRetryCount(0),
      mShuttingDown(false),
      mRunnableDispatched(false) {
  MOZ_ASSERT(NS_IsMainThread());
}

ServiceWorkerRegistrar::~ServiceWorkerRegistrar() {
  MOZ_ASSERT(!mRunnableDispatched);
}

void ServiceWorkerRegistrar::GetRegistrations(
    nsTArray<ServiceWorkerRegistrationData>& aValues) {
  MOZ_ASSERT(NS_IsMainThread());
  MOZ_ASSERT(aValues.IsEmpty());

  MonitorAutoLock lock(mMonitor);

  // If we don't have the profile directory, profile is not started yet (and
  // probably we are in a utest).
  if (!mProfileDir) {
    return;
  }

  // We care just about the first execution because this can be blocked by
  // loading data from disk.
  static bool firstTime = true;
  TimeStamp startTime;

  if (firstTime) {
    startTime = TimeStamp::NowLoRes();
  }

  // Waiting for data loaded.
  mMonitor.AssertCurrentThreadOwns();
  while (!mDataLoaded) {
    mMonitor.Wait();
  }

  aValues.AppendElements(mData);

  MaybeResetGeneration();
  MOZ_DIAGNOSTIC_ASSERT(mDataGeneration != kInvalidGeneration);
  MOZ_DIAGNOSTIC_ASSERT(mFileGeneration != kInvalidGeneration);

  if (firstTime) {
    firstTime = false;
    Telemetry::AccumulateTimeDelta(
        Telemetry::SERVICE_WORKER_REGISTRATION_LOADING, startTime);
  }
}

namespace {

bool Equivalent(const ServiceWorkerRegistrationData& aLeft,
                const ServiceWorkerRegistrationData& aRight) {
  MOZ_ASSERT(aLeft.principal().type() ==
             mozilla::ipc::PrincipalInfo::TContentPrincipalInfo);
  MOZ_ASSERT(aRight.principal().type() ==
             mozilla::ipc::PrincipalInfo::TContentPrincipalInfo);

  const auto& leftPrincipal = aLeft.principal().get_ContentPrincipalInfo();
  const auto& rightPrincipal = aRight.principal().get_ContentPrincipalInfo();

  // Only compare the attributes, not the spec part of the principal.
  // The scope comparison above already covers the origin and codebase
  // principals include the full path in their spec which is not what
  // we want here.
  return aLeft.scope() == aRight.scope() &&
         leftPrincipal.attrs() == rightPrincipal.attrs();
}

}  // anonymous namespace

void ServiceWorkerRegistrar::RegisterServiceWorker(
    const ServiceWorkerRegistrationData& aData) {
  AssertIsOnBackgroundThread();

  if (mShuttingDown) {
    NS_WARNING("Failed to register a serviceWorker during shutting down.");
    return;
  }

  {
    MonitorAutoLock lock(mMonitor);
    MOZ_ASSERT(mDataLoaded);
    RegisterServiceWorkerInternal(aData);
  }

  MaybeScheduleSaveData();
  StorageActivityService::SendActivity(aData.principal());
}

void ServiceWorkerRegistrar::UnregisterServiceWorker(
    const PrincipalInfo& aPrincipalInfo, const nsACString& aScope) {
  AssertIsOnBackgroundThread();

  if (mShuttingDown) {
    NS_WARNING("Failed to unregister a serviceWorker during shutting down.");
    return;
  }

  bool deleted = false;

  {
    MonitorAutoLock lock(mMonitor);
    MOZ_ASSERT(mDataLoaded);

    ServiceWorkerRegistrationData tmp;
    tmp.principal() = aPrincipalInfo;
    tmp.scope() = aScope;

    for (uint32_t i = 0; i < mData.Length(); ++i) {
      if (Equivalent(tmp, mData[i])) {
        mData.RemoveElementAt(i);
        mDataGeneration = GetNextGeneration();
        deleted = true;
        break;
      }
    }
  }

  if (deleted) {
    MaybeScheduleSaveData();
    StorageActivityService::SendActivity(aPrincipalInfo);
  }
}

void ServiceWorkerRegistrar::RemoveAll() {
  AssertIsOnBackgroundThread();

  if (mShuttingDown) {
    NS_WARNING("Failed to remove all the serviceWorkers during shutting down.");
    return;
  }

  bool deleted = false;

  nsTArray<ServiceWorkerRegistrationData> data;
  {
    MonitorAutoLock lock(mMonitor);
    MOZ_ASSERT(mDataLoaded);

    // Let's take a copy in order to inform StorageActivityService.
    data = mData.Clone();

    deleted = !mData.IsEmpty();
    mData.Clear();

    mDataGeneration = GetNextGeneration();
  }

  if (!deleted) {
    return;
  }

  MaybeScheduleSaveData();

  for (uint32_t i = 0, len = data.Length(); i < len; ++i) {
    StorageActivityService::SendActivity(data[i].principal());
  }
}

void ServiceWorkerRegistrar::LoadData() {
  MOZ_ASSERT(!NS_IsMainThread());
  MOZ_ASSERT(!mDataLoaded);

  nsresult rv = ReadData();

  if (NS_WARN_IF(NS_FAILED(rv))) {
    DeleteData();
    // Also if the reading failed we have to notify what is waiting for data.
  }

  MonitorAutoLock lock(mMonitor);
  MOZ_ASSERT(!mDataLoaded);
  mDataLoaded = true;
  mMonitor.Notify();
}

nsresult ServiceWorkerRegistrar::ReadData() {
  // We cannot assert about the correct thread because normally this method
  // runs on a IO thread, but in gTests we call it from the main-thread.

  nsCOMPtr<nsIFile> file;

  {
    MonitorAutoLock lock(mMonitor);

    if (!mProfileDir) {
      return NS_ERROR_FAILURE;
    }

    nsresult rv = mProfileDir->Clone(getter_AddRefs(file));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  nsresult rv = file->Append(nsLiteralString(SERVICEWORKERREGISTRAR_FILE));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

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

  if (!exists) {
    return NS_OK;
  }

  nsCOMPtr<nsIInputStream> stream;
  rv = NS_NewLocalFileInputStream(getter_AddRefs(stream), file);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsCOMPtr<nsILineInputStream> lineInputStream = do_QueryInterface(stream);
  MOZ_ASSERT(lineInputStream);

  nsAutoCString version;
  bool hasMoreLines;
  rv = lineInputStream->ReadLine(version, &hasMoreLines);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (!IsSupportedVersion(version)) {
    nsContentUtils::LogMessageToConsole(
        nsPrintfCString("Unsupported service worker registrar version: %s",
                        version.get())
            .get());
    return NS_ERROR_FAILURE;
  }

  nsTArray<ServiceWorkerRegistrationData> tmpData;

  bool overwrite = false;
  bool dedupe = false;
  while (hasMoreLines) {
    ServiceWorkerRegistrationData* entry = tmpData.AppendElement();

#define GET_LINE(x)                                 \
  rv = lineInputStream->ReadLine(x, &hasMoreLines); \
  if (NS_WARN_IF(NS_FAILED(rv))) {                  \
    return rv;                                      \
  }                                                 \
  if (NS_WARN_IF(!hasMoreLines)) {                  \
    return NS_ERROR_FAILURE;                        \
  }

    nsAutoCString line;
    if (version.EqualsLiteral(SERVICEWORKERREGISTRAR_VERSION)) {
      rv = CreatePrincipalInfo(lineInputStream, entry);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      GET_LINE(entry->currentWorkerURL());

      nsAutoCString fetchFlag;
      GET_LINE(fetchFlag);
      if (!fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE) &&
          !fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_FALSE)) {
        return NS_ERROR_INVALID_ARG;
      }
      entry->currentWorkerHandlesFetch() =
          fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE);

      nsAutoCString cacheName;
      GET_LINE(cacheName);
      CopyUTF8toUTF16(cacheName, entry->cacheName());

      nsAutoCString updateViaCache;
      GET_LINE(updateViaCache);
      entry->updateViaCache() = updateViaCache.ToInteger(&rv, 16);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      } else if (entry->updateViaCache() >
                 nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_NONE) {
        return NS_ERROR_INVALID_ARG;
      }

      nsAutoCString installedTimeStr;
      GET_LINE(installedTimeStr);
      int64_t installedTime = installedTimeStr.ToInteger64(&rv);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      entry->currentWorkerInstalledTime() = installedTime;

      nsAutoCString activatedTimeStr;
      GET_LINE(activatedTimeStr);
      int64_t activatedTime = activatedTimeStr.ToInteger64(&rv);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      entry->currentWorkerActivatedTime() = activatedTime;

      nsAutoCString lastUpdateTimeStr;
      GET_LINE(lastUpdateTimeStr);
      int64_t lastUpdateTime = lastUpdateTimeStr.ToInteger64(&rv);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      entry->lastUpdateTime() = lastUpdateTime;
    } else if (version.EqualsLiteral("7")) {
      rv = CreatePrincipalInfo(lineInputStream, entry);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      GET_LINE(entry->currentWorkerURL());

      nsAutoCString fetchFlag;
      GET_LINE(fetchFlag);
      if (!fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE) &&
          !fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_FALSE)) {
        return NS_ERROR_INVALID_ARG;
      }
      entry->currentWorkerHandlesFetch() =
          fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE);

      nsAutoCString cacheName;
      GET_LINE(cacheName);
      CopyUTF8toUTF16(cacheName, entry->cacheName());

      nsAutoCString loadFlags;
      GET_LINE(loadFlags);
      entry->updateViaCache() =
          loadFlags.ToInteger(&rv, 16) == nsIRequest::LOAD_NORMAL
              ? nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_ALL
              : nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_IMPORTS;

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

      nsAutoCString installedTimeStr;
      GET_LINE(installedTimeStr);
      int64_t installedTime = installedTimeStr.ToInteger64(&rv);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      entry->currentWorkerInstalledTime() = installedTime;

      nsAutoCString activatedTimeStr;
      GET_LINE(activatedTimeStr);
      int64_t activatedTime = activatedTimeStr.ToInteger64(&rv);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      entry->currentWorkerActivatedTime() = activatedTime;

      nsAutoCString lastUpdateTimeStr;
      GET_LINE(lastUpdateTimeStr);
      int64_t lastUpdateTime = lastUpdateTimeStr.ToInteger64(&rv);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }
      entry->lastUpdateTime() = lastUpdateTime;
    } else if (version.EqualsLiteral("6")) {
      rv = CreatePrincipalInfo(lineInputStream, entry);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      GET_LINE(entry->currentWorkerURL());

      nsAutoCString fetchFlag;
      GET_LINE(fetchFlag);
      if (!fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE) &&
          !fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_FALSE)) {
        return NS_ERROR_INVALID_ARG;
      }
      entry->currentWorkerHandlesFetch() =
          fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE);

      nsAutoCString cacheName;
      GET_LINE(cacheName);
      CopyUTF8toUTF16(cacheName, entry->cacheName());

      nsAutoCString loadFlags;
      GET_LINE(loadFlags);
      entry->updateViaCache() =
          loadFlags.ToInteger(&rv, 16) == nsIRequest::LOAD_NORMAL
              ? nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_ALL
              : nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_IMPORTS;

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

      entry->currentWorkerInstalledTime() = 0;
      entry->currentWorkerActivatedTime() = 0;
      entry->lastUpdateTime() = 0;
    } else if (version.EqualsLiteral("5")) {
      overwrite = true;
      dedupe = true;

      rv = CreatePrincipalInfo(lineInputStream, entry);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      GET_LINE(entry->currentWorkerURL());

      nsAutoCString fetchFlag;
      GET_LINE(fetchFlag);
      if (!fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE) &&
          !fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_FALSE)) {
        return NS_ERROR_INVALID_ARG;
      }
      entry->currentWorkerHandlesFetch() =
          fetchFlag.EqualsLiteral(SERVICEWORKERREGISTRAR_TRUE);

      nsAutoCString cacheName;
      GET_LINE(cacheName);
      CopyUTF8toUTF16(cacheName, entry->cacheName());

      entry->updateViaCache() =
          nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_IMPORTS;

      entry->currentWorkerInstalledTime() = 0;
      entry->currentWorkerActivatedTime() = 0;
      entry->lastUpdateTime() = 0;
    } else if (version.EqualsLiteral("4")) {
      overwrite = true;
      dedupe = true;

      rv = CreatePrincipalInfo(lineInputStream, entry);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      GET_LINE(entry->currentWorkerURL());

      // default handlesFetch flag to Enabled
      entry->currentWorkerHandlesFetch() = true;

      nsAutoCString cacheName;
      GET_LINE(cacheName);
      CopyUTF8toUTF16(cacheName, entry->cacheName());

      entry->updateViaCache() =
          nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_IMPORTS;

      entry->currentWorkerInstalledTime() = 0;
      entry->currentWorkerActivatedTime() = 0;
      entry->lastUpdateTime() = 0;
    } else if (version.EqualsLiteral("3")) {
      overwrite = true;
      dedupe = true;

      rv = CreatePrincipalInfo(lineInputStream, entry, true);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      GET_LINE(entry->currentWorkerURL());

      // default handlesFetch flag to Enabled
      entry->currentWorkerHandlesFetch() = true;

      nsAutoCString cacheName;
      GET_LINE(cacheName);
      CopyUTF8toUTF16(cacheName, entry->cacheName());

      entry->updateViaCache() =
          nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_IMPORTS;

      entry->currentWorkerInstalledTime() = 0;
      entry->currentWorkerActivatedTime() = 0;
      entry->lastUpdateTime() = 0;
    } else if (version.EqualsLiteral("2")) {
      overwrite = true;
      dedupe = true;

      rv = CreatePrincipalInfo(lineInputStream, entry, true);
      if (NS_WARN_IF(NS_FAILED(rv))) {
        return rv;
      }

      // scriptSpec is no more used in latest version.
      nsAutoCString unused;
      GET_LINE(unused);

      GET_LINE(entry->currentWorkerURL());

      // default handlesFetch flag to Enabled
      entry->currentWorkerHandlesFetch() = true;

      nsAutoCString cacheName;
      GET_LINE(cacheName);
      CopyUTF8toUTF16(cacheName, entry->cacheName());

      // waitingCacheName is no more used in latest version.
      GET_LINE(unused);

      entry->updateViaCache() =
          nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_IMPORTS;

      entry->currentWorkerInstalledTime() = 0;
      entry->currentWorkerActivatedTime() = 0;
      entry->lastUpdateTime() = 0;
    } else {
      MOZ_ASSERT_UNREACHABLE("Should never get here!");
    }

#undef GET_LINE

    rv = lineInputStream->ReadLine(line, &hasMoreLines);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    if (!line.EqualsLiteral(SERVICEWORKERREGISTRAR_TERMINATOR)) {
      return NS_ERROR_FAILURE;
    }
  }

  stream->Close();

  // XXX: The following code is writing to mData without holding a
  //      monitor lock.  This might be ok since this is currently
  //      only called at startup where we block the main thread
  //      preventing further operation until it completes.  We should
  //      consider better locking here in the future.

  // Copy data over to mData.
  for (uint32_t i = 0; i < tmpData.Length(); ++i) {
    // Older versions could sometimes write out empty, useless entries.
    // Prune those here.
    if (!ServiceWorkerRegistrationDataIsValid(tmpData[i])) {
      continue;
    }

    bool match = false;
    if (dedupe) {
      MOZ_ASSERT(overwrite);
      // If this is an old profile, then we might need to deduplicate.  In
      // theory this can be removed in the future (Bug 1248449)
      for (uint32_t j = 0; j < mData.Length(); ++j) {
        // Use same comparison as RegisterServiceWorker. Scope contains
        // basic origin information.  Combine with any principal attributes.
        if (Equivalent(tmpData[i], mData[j])) {
          // Last match wins, just like legacy loading used to do in
          // the ServiceWorkerManager.
          mData[j] = tmpData[i];
          // Dupe found, so overwrite file with reduced list.
          match = true;
          break;
        }
      }
    } else {
#ifdef DEBUG
      // Otherwise assert no duplications in debug builds.
      for (uint32_t j = 0; j < mData.Length(); ++j) {
        MOZ_ASSERT(!Equivalent(tmpData[i], mData[j]));
      }
#endif
    }
    if (!match) {
      mData.AppendElement(tmpData[i]);
    }
  }

  // Overwrite previous version.
  // Cannot call SaveData directly because gtest uses main-thread.
  if (overwrite && NS_FAILED(WriteData(mData))) {
    NS_WARNING("Failed to write data for the ServiceWorker Registations.");
    DeleteData();
  }

  return NS_OK;
}

void ServiceWorkerRegistrar::DeleteData() {
  // We cannot assert about the correct thread because normally this method
  // runs on a IO thread, but in gTests we call it from the main-thread.

  nsCOMPtr<nsIFile> file;

  {
    MonitorAutoLock lock(mMonitor);
    mData.Clear();

    if (!mProfileDir) {
      return;
    }

    nsresult rv = mProfileDir->Clone(getter_AddRefs(file));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return;
    }
  }

  nsresult rv = file->Append(nsLiteralString(SERVICEWORKERREGISTRAR_FILE));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return;
  }

  rv = file->Remove(false);
  if (rv == NS_ERROR_FILE_NOT_FOUND) {
    return;
  }

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

void ServiceWorkerRegistrar::RegisterServiceWorkerInternal(
    const ServiceWorkerRegistrationData& aData) {
  bool found = false;
  for (uint32_t i = 0, len = mData.Length(); i < len; ++i) {
    if (Equivalent(aData, mData[i])) {
      mData[i] = aData;
      found = true;
      break;
    }
  }

  if (!found) {
    MOZ_ASSERT(ServiceWorkerRegistrationDataIsValid(aData));
    mData.AppendElement(aData);
  }

  mDataGeneration = GetNextGeneration();
}

class ServiceWorkerRegistrarSaveDataRunnable final : public Runnable {
  nsCOMPtr<nsIEventTarget> mEventTarget;
  const nsTArray<ServiceWorkerRegistrationData> mData;
  const uint32_t mGeneration;

 public:
  ServiceWorkerRegistrarSaveDataRunnable(
      nsTArray<ServiceWorkerRegistrationData>&& aData, uint32_t aGeneration)
      : Runnable("dom::ServiceWorkerRegistrarSaveDataRunnable"),
        mEventTarget(GetCurrentEventTarget()),
        mData(std::move(aData)),
        mGeneration(aGeneration) {
    AssertIsOnBackgroundThread();
    MOZ_DIAGNOSTIC_ASSERT(mGeneration != kInvalidGeneration);
  }

  NS_IMETHOD
  Run() override {
    RefPtr<ServiceWorkerRegistrar> service = ServiceWorkerRegistrar::Get();
    MOZ_ASSERT(service);

    uint32_t fileGeneration = kInvalidGeneration;

    if (NS_SUCCEEDED(service->SaveData(mData))) {
      fileGeneration = mGeneration;
    }

    RefPtr<Runnable> runnable = NewRunnableMethod<uint32_t>(
        "ServiceWorkerRegistrar::DataSaved", service,
        &ServiceWorkerRegistrar::DataSaved, fileGeneration);
    MOZ_ALWAYS_SUCCEEDS(
        mEventTarget->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL));

    return NS_OK;
  }
};

void ServiceWorkerRegistrar::MaybeScheduleSaveData() {
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!mShuttingDown);

  if (mShuttingDown || mRunnableDispatched ||
      mDataGeneration <= mFileGeneration) {
    return;
  }

  nsCOMPtr<nsIEventTarget> target =
      do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
  MOZ_ASSERT(target, "Must have stream transport service");

  uint32_t generation = kInvalidGeneration;
  nsTArray<ServiceWorkerRegistrationData> data;

  {
    MonitorAutoLock lock(mMonitor);
    generation = mDataGeneration;
    data.AppendElements(mData);
  }

  RefPtr<Runnable> runnable =
      new ServiceWorkerRegistrarSaveDataRunnable(std::move(data), generation);
  nsresult rv = target->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL);
  NS_ENSURE_SUCCESS_VOID(rv);

  mRunnableDispatched = true;
}

void ServiceWorkerRegistrar::ShutdownCompleted() {
  MOZ_ASSERT(NS_IsMainThread());

  DebugOnly<nsresult> rv = GetShutdownPhase()->RemoveBlocker(this);
  MOZ_ASSERT(NS_SUCCEEDED(rv));
}

nsresult ServiceWorkerRegistrar::SaveData(
    const nsTArray<ServiceWorkerRegistrationData>& aData) {
  MOZ_ASSERT(!NS_IsMainThread());

  nsresult rv = WriteData(aData);
  if (NS_FAILED(rv)) {
    NS_WARNING("Failed to write data for the ServiceWorker Registations.");
    // Don't touch the file or in-memory state.  Writing files can
    // sometimes fail due to virus scanning, etc.  We should just leave
    // things as is so the next save operation can pick up any changes
    // without losing data.
  }
  return rv;
}

void ServiceWorkerRegistrar::DataSaved(uint32_t aFileGeneration) {
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(mRunnableDispatched);

  mRunnableDispatched = false;

  // Check for shutdown before possibly triggering any more saves
  // runnables.
  MaybeScheduleShutdownCompleted();
  if (mShuttingDown) {
    return;
  }

  // If we got a valid generation, then the save was successful.
  if (aFileGeneration != kInvalidGeneration) {
    // Update the file generation.  We also check to see if we
    // can reset the generation back to zero if the file and data
    // are now in sync.  This allows us to avoid dealing with wrap
    // around of the generation count.
    mFileGeneration = aFileGeneration;
    MaybeResetGeneration();

    // Successful write resets the retry count.
    mRetryCount = 0;

    // Possibly schedule another save operation if more data
    // has come in while processing this one.
    MaybeScheduleSaveData();

    return;
  }

  // Otherwise, the save failed since the generation is invalid.  We
  // want to retry the save, but only a limited number of times.
  static const uint32_t kMaxRetryCount = 2;
  if (mRetryCount >= kMaxRetryCount) {
    return;
  }

  mRetryCount += 1;
  MaybeScheduleSaveData();
}

void ServiceWorkerRegistrar::MaybeScheduleShutdownCompleted() {
  AssertIsOnBackgroundThread();

  if (mRunnableDispatched || !mShuttingDown) {
    return;
  }

  RefPtr<Runnable> runnable =
      NewRunnableMethod("dom::ServiceWorkerRegistrar::ShutdownCompleted", this,
                        &ServiceWorkerRegistrar::ShutdownCompleted);
  MOZ_ALWAYS_SUCCEEDS(NS_DispatchToMainThread(runnable.forget()));
}

uint32_t ServiceWorkerRegistrar::GetNextGeneration() {
  uint32_t ret = mDataGeneration + 1;
  if (ret == kInvalidGeneration) {
    ret += 1;
  }
  return ret;
}

void ServiceWorkerRegistrar::MaybeResetGeneration() {
  if (mDataGeneration != mFileGeneration) {
    return;
  }
  mDataGeneration = mFileGeneration = 0;
}

bool ServiceWorkerRegistrar::IsSupportedVersion(
    const nsACString& aVersion) const {
  uint32_t numVersions = ArrayLength(gSupportedRegistrarVersions);
  for (uint32_t i = 0; i < numVersions; i++) {
    if (aVersion.EqualsASCII(gSupportedRegistrarVersions[i])) {
      return true;
    }
  }
  return false;
}

nsresult ServiceWorkerRegistrar::WriteData(
    const nsTArray<ServiceWorkerRegistrationData>& aData) {
  // We cannot assert about the correct thread because normally this method
  // runs on a IO thread, but in gTests we call it from the main-thread.

  nsCOMPtr<nsIFile> file;

  {
    MonitorAutoLock lock(mMonitor);

    if (!mProfileDir) {
      return NS_ERROR_FAILURE;
    }

    nsresult rv = mProfileDir->Clone(getter_AddRefs(file));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }

  nsresult rv = file->Append(nsLiteralString(SERVICEWORKERREGISTRAR_FILE));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsCOMPtr<nsIOutputStream> stream;
  rv = NS_NewSafeLocalFileOutputStream(getter_AddRefs(stream), file);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  nsAutoCString buffer;
  buffer.AppendLiteral(SERVICEWORKERREGISTRAR_VERSION);
  buffer.Append('\n');

  uint32_t count;
  rv = stream->Write(buffer.Data(), buffer.Length(), &count);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  if (count != buffer.Length()) {
    return NS_ERROR_UNEXPECTED;
  }

  for (uint32_t i = 0, len = aData.Length(); i < len; ++i) {
    // We have an assertion further up the stack, but as a last
    // resort avoid writing out broken entries here.
    if (!ServiceWorkerRegistrationDataIsValid(aData[i])) {
      continue;
    }

    const mozilla::ipc::PrincipalInfo& info = aData[i].principal();

    MOZ_ASSERT(info.type() ==
               mozilla::ipc::PrincipalInfo::TContentPrincipalInfo);

    const mozilla::ipc::ContentPrincipalInfo& cInfo =
        info.get_ContentPrincipalInfo();

    nsAutoCString suffix;
    cInfo.attrs().CreateSuffix(suffix);

    buffer.Truncate();
    buffer.Append(suffix.get());
    buffer.Append('\n');

    buffer.Append(aData[i].scope());
    buffer.Append('\n');

    buffer.Append(aData[i].currentWorkerURL());
    buffer.Append('\n');

    buffer.Append(aData[i].currentWorkerHandlesFetch()
                      ? SERVICEWORKERREGISTRAR_TRUE
                      : SERVICEWORKERREGISTRAR_FALSE);
    buffer.Append('\n');

    buffer.Append(NS_ConvertUTF16toUTF8(aData[i].cacheName()));
    buffer.Append('\n');

    buffer.AppendInt(aData[i].updateViaCache(), 16);
    buffer.Append('\n');
    MOZ_DIAGNOSTIC_ASSERT(
        aData[i].updateViaCache() ==
            nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_IMPORTS ||
        aData[i].updateViaCache() ==
            nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_ALL ||
        aData[i].updateViaCache() ==
            nsIServiceWorkerRegistrationInfo::UPDATE_VIA_CACHE_NONE);

    static_assert(nsIRequest::LOAD_NORMAL == 0,
                  "LOAD_NORMAL matches serialized value.");
    static_assert(nsIRequest::VALIDATE_ALWAYS == (1 << 11),
                  "VALIDATE_ALWAYS matches serialized value");

    buffer.AppendInt(aData[i].currentWorkerInstalledTime());
    buffer.Append('\n');

    buffer.AppendInt(aData[i].currentWorkerActivatedTime());
    buffer.Append('\n');

    buffer.AppendInt(aData[i].lastUpdateTime());
    buffer.Append('\n');

    buffer.AppendLiteral(SERVICEWORKERREGISTRAR_TERMINATOR);
    buffer.Append('\n');

    rv = stream->Write(buffer.Data(), buffer.Length(), &count);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    if (count != buffer.Length()) {
      return NS_ERROR_UNEXPECTED;
    }
  }

  nsCOMPtr<nsISafeOutputStream> safeStream = do_QueryInterface(stream);
  MOZ_ASSERT(safeStream);

  rv = safeStream->Finish();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  return NS_OK;
}

void ServiceWorkerRegistrar::ProfileStarted() {
  MOZ_ASSERT(NS_IsMainThread());

  MonitorAutoLock lock(mMonitor);
  MOZ_DIAGNOSTIC_ASSERT(!mProfileDir);

  nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
                                       getter_AddRefs(mProfileDir));
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return;
  }

  nsAutoString blockerName;
  MOZ_ALWAYS_SUCCEEDS(GetName(blockerName));

  rv = GetShutdownPhase()->AddBlocker(
      this, NS_LITERAL_STRING_FROM_CSTRING(__FILE__), __LINE__, blockerName);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return;
  }

  nsCOMPtr<nsIEventTarget> target =
      do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
  MOZ_ASSERT(target, "Must have stream transport service");

  nsCOMPtr<nsIRunnable> runnable =
      NewRunnableMethod("dom::ServiceWorkerRegistrar::LoadData", this,
                        &ServiceWorkerRegistrar::LoadData);
  rv = target->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL);
  if (NS_FAILED(rv)) {
    NS_WARNING("Failed to dispatch the LoadDataRunnable.");
  }
}

void ServiceWorkerRegistrar::ProfileStopped() {
  MOZ_ASSERT(NS_IsMainThread());

  MonitorAutoLock lock(mMonitor);

  if (!mProfileDir) {
    nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
                                         getter_AddRefs(mProfileDir));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return;
    }
  }

  PBackgroundChild* child = BackgroundChild::GetForCurrentThread();
  if (!child) {
    // Mutations to the ServiceWorkerRegistrar happen on the PBackground thread,
    // issued by the ServiceWorkerManagerService, so the appropriate place to
    // trigger shutdown is on that thread.
    //
    // However, it's quite possible that the PBackground thread was not brought
    // into existence for xpcshell tests.  We don't cause it to be created
    // ourselves for any reason, for example.
    //
    // In this scenario, we know that:
    // - We will receive exactly one call to ourself from BlockShutdown() and
    //   BlockShutdown() will be called (at most) once.
    // - The only way our Shutdown() method gets called is via
    //   BackgroundParentImpl::RecvShutdownServiceWorkerRegistrar() being
    //   invoked, which only happens if we get to that send below here that we
    //   can't get to.
    // - All Shutdown() does is set mShuttingDown=true (essential for
    //   invariants) and invoke MaybeScheduleShutdownCompleted().
    // - Since there is no PBackground thread, mRunnableDispatched must be false
    //   because only MaybeScheduleSaveData() set it and it only runs on the
    //   background thread, so it cannot have run.  And so we would expect
    //   MaybeScheduleShutdownCompleted() to schedule an invocation of
    //   ShutdownCompleted on the main thread.
    //
    // So it's appropriate for us to set mShuttingDown=true (as Shutdown would
    // do) and directly invoke ShutdownCompleted() (as Shutdown would indirectly
    // do via MaybeScheduleShutdownCompleted).
    mShuttingDown = true;
    ShutdownCompleted();
    return;
  }

  child->SendShutdownServiceWorkerRegistrar();
}

// Async shutdown blocker methods

NS_IMETHODIMP
ServiceWorkerRegistrar::BlockShutdown(nsIAsyncShutdownClient* aClient) {
  ProfileStopped();
  return NS_OK;
}

NS_IMETHODIMP
ServiceWorkerRegistrar::GetName(nsAString& aName) {
  aName = u"ServiceWorkerRegistrar: Flushing data"_ns;
  return NS_OK;
}

NS_IMETHODIMP
ServiceWorkerRegistrar::GetState(nsIPropertyBag** aBagOut) {
  nsCOMPtr<nsIWritablePropertyBag2> propertyBag =
      do_CreateInstance("@mozilla.org/hash-property-bag;1");

  MOZ_TRY(propertyBag->SetPropertyAsBool(u"shuttingDown"_ns, mShuttingDown));

  MOZ_TRY(propertyBag->SetPropertyAsBool(u"saveDataRunnableDispatched"_ns,
                                         mRunnableDispatched));

  propertyBag.forget(aBagOut);

  return NS_OK;
}

#define RELEASE_ASSERT_SUCCEEDED(rv, name)                                    \
  do {                                                                        \
    if (NS_FAILED(rv)) {                                                      \
      mozJSComponentLoader::Get()->AnnotateCrashReport();                     \
      if (rv == NS_ERROR_XPC_JAVASCRIPT_ERROR_WITH_DETAILS) {                 \
        if (auto* context = CycleCollectedJSContext::Get()) {                 \
          if (RefPtr<Exception> exn = context->GetPendingException()) {       \
            MOZ_CRASH_UNSAFE_PRINTF("Failed to get " name ": %s",             \
                                    exn->GetMessageMoz().get());              \
          }                                                                   \
        }                                                                     \
      }                                                                       \
                                                                              \
      nsAutoCString errorName;                                                \
      GetErrorName(rv, errorName);                                            \
      MOZ_CRASH_UNSAFE_PRINTF("Failed to get " name ": %s", errorName.get()); \
    }                                                                         \
  } while (0)

nsCOMPtr<nsIAsyncShutdownClient> ServiceWorkerRegistrar::GetShutdownPhase()
    const {
  nsresult rv;
  nsCOMPtr<nsIAsyncShutdownService> svc =
      do_GetService("@mozilla.org/async-shutdown-service;1", &rv);
  // If this fails, something is very wrong on the JS side (or we're out of
  // memory), and there's no point in continuing startup. Include as much
  // information as possible in the crash report.
  RELEASE_ASSERT_SUCCEEDED(rv, "async shutdown service");

  nsCOMPtr<nsIAsyncShutdownClient> client;
  rv = svc->GetProfileBeforeChange(getter_AddRefs(client));
  RELEASE_ASSERT_SUCCEEDED(rv, "profileBeforeChange shutdown blocker");
  return client;
}

#undef RELEASE_ASSERT_SUCCEEDED

void ServiceWorkerRegistrar::Shutdown() {
  AssertIsOnBackgroundThread();
  MOZ_ASSERT(!mShuttingDown);

  mShuttingDown = true;
  MaybeScheduleShutdownCompleted();
}

NS_IMETHODIMP
ServiceWorkerRegistrar::Observe(nsISupports* aSubject, const char* aTopic,
                                const char16_t* aData) {
  MOZ_ASSERT(NS_IsMainThread());

  if (!strcmp(aTopic, "profile-after-change")) {
    nsCOMPtr<nsIObserverService> observerService =
        services::GetObserverService();
    observerService->RemoveObserver(this, "profile-after-change");

    // The profile is fully loaded, now we can proceed with the loading of data
    // from disk.
    ProfileStarted();

    return NS_OK;
  }

  MOZ_ASSERT(false, "ServiceWorkerRegistrar got unexpected topic!");
  return NS_ERROR_UNEXPECTED;
}

}  // namespace dom
}  // namespace mozilla