gecko-dev/dom/quota/ScopedLogExtraInfo.cpp

/* -*- 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 "ScopedLogExtraInfo.h"

namespace mozilla::dom::quota {

#ifdef QM_SCOPED_LOG_EXTRA_INFO_ENABLED
MOZ_THREAD_LOCAL(const Tainted<nsCString>*)
ScopedLogExtraInfo::sQueryValueTainted;
MOZ_THREAD_LOCAL(const Tainted<nsCString>*)
ScopedLogExtraInfo::sContextValueTainted;
MOZ_THREAD_LOCAL(const Tainted<nsCString>*)
ScopedLogExtraInfo::sStorageOriginValueTainted;

/* static */
auto ScopedLogExtraInfo::FindSlot(const char* aTag) {
  // XXX For now, don't use a real map but just allow the known tag values.

  if (aTag == kTagQueryTainted) {
    return &sQueryValueTainted;
  }

  if (aTag == kTagContextTainted) {
    return &sContextValueTainted;
  }

  if (aTag == kTagStorageOriginTainted) {
    return &sStorageOriginValueTainted;
  }

  MOZ_CRASH("Unknown tag!");
}

ScopedLogExtraInfo::~ScopedLogExtraInfo() {
  if (mTag) {
    MOZ_ASSERT(&mCurrentValue == FindSlot(mTag)->get(),
               "Bad scoping of ScopedLogExtraInfo, must not be interleaved!");

    FindSlot(mTag)->set(mPreviousValue);
  }
}

ScopedLogExtraInfo::ScopedLogExtraInfo(ScopedLogExtraInfo&& aOther) noexcept
    : mTag(aOther.mTag),
      mPreviousValue(aOther.mPreviousValue),
      mCurrentValue(std::move(aOther.mCurrentValue)) {
  aOther.mTag = nullptr;
  FindSlot(mTag)->set(&mCurrentValue);
}

/* static */ ScopedLogExtraInfo::ScopedLogExtraInfoMap
ScopedLogExtraInfo::GetExtraInfoMap() {
  // This could be done in a cheaper way, but this is never called on a hot
  // path, so we anticipate using a real map inside here to make use simpler for
  // the caller(s).

  ScopedLogExtraInfoMap map;
  if (sQueryValueTainted.get()) {
    map.emplace(kTagQueryTainted, sQueryValueTainted.get());
  }

  if (sContextValueTainted.get()) {
    map.emplace(kTagContextTainted, sContextValueTainted.get());
  }

  if (sStorageOriginValueTainted.get()) {
    map.emplace(kTagStorageOriginTainted, sStorageOriginValueTainted.get());
  }

  return map;
}

/* static */ void ScopedLogExtraInfo::Initialize() {
  MOZ_ALWAYS_TRUE(sQueryValueTainted.init());
  MOZ_ALWAYS_TRUE(sContextValueTainted.init());
  MOZ_ALWAYS_TRUE(sStorageOriginValueTainted.init());
}

void ScopedLogExtraInfo::AddInfo() {
  auto* slot = FindSlot(mTag);
  MOZ_ASSERT(slot);
  mPreviousValue = slot->get();

  slot->set(&mCurrentValue);
}
#endif

}  // namespace mozilla::dom::quota