1 files changed, 75 insertions, 0 deletions
diff --git a/dom/quota/ScopedLogExtraInfo.h b/dom/quota/ScopedLogExtraInfo.h
new file mode 100644
index 0000000000..d8412ae5b1
--- /dev/null
+++ b/dom/quota/ScopedLogExtraInfo.h
@@ -0,0 +1,75 @@
+/* -*- 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/. */
+
+#ifndef DOM_QUOTA_SCOPEDLOGEXTRAINFO_H_
+#define DOM_QUOTA_SCOPEDLOGEXTRAINFO_H_
+
+#include "mozilla/dom/quota/Config.h"
+
+#include <map>
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/ThreadLocal.h"
+#include "nsString.h"
+#include "nsXULAppAPI.h"
+
+namespace mozilla::dom::quota {
+
+struct MOZ_STACK_CLASS ScopedLogExtraInfo {
+  static constexpr const char kTagQuery[] = "query";
+  static constexpr const char kTagContext[] = "context";
+
+#ifdef QM_SCOPED_LOG_EXTRA_INFO_ENABLED
+ private:
+  static auto FindSlot(const char* aTag);
+
+ public:
+  template <size_t N>
+  ScopedLogExtraInfo(const char (&aTag)[N], const nsACString& aExtraInfo)
+      : mTag{aTag}, mCurrentValue{aExtraInfo} {
+    // Initialize is currently only called in the parent process, we could call
+    // it directly from nsLayoutStatics::Initialize in the content process to
+    // allow use of ScopedLogExtraInfo in that too. The check in GetExtraInfoMap
+    // must be removed then.
+    MOZ_ASSERT(XRE_IsParentProcess());
+
+    AddInfo();
+  }
+
+  ~ScopedLogExtraInfo();
+
+  ScopedLogExtraInfo(ScopedLogExtraInfo&& aOther);
+  ScopedLogExtraInfo& operator=(ScopedLogExtraInfo&& aOther) = delete;
+
+  ScopedLogExtraInfo(const ScopedLogExtraInfo&) = delete;
+  ScopedLogExtraInfo& operator=(const ScopedLogExtraInfo&) = delete;
+
+  using ScopedLogExtraInfoMap = std::map<const char*, const nsACString*>;
+  static ScopedLogExtraInfoMap GetExtraInfoMap();
+
+  static void Initialize();
+
+ private:
+  const char* mTag;
+  const nsACString* mPreviousValue;
+  nsCString mCurrentValue;
+
+  static MOZ_THREAD_LOCAL(const nsACString*) sQueryValue;
+  static MOZ_THREAD_LOCAL(const nsACString*) sContextValue;
+
+  void AddInfo();
+#else
+  template <size_t N>
+  ScopedLogExtraInfo(const char (&aTag)[N], const nsACString& aExtraInfo) {}
+
+  // user-defined to silence unused variable warnings
+  ~ScopedLogExtraInfo() {}
+#endif
+};
+
+}  // namespace mozilla::dom::quota
+
+#endif  // DOM_QUOTA_SCOPEDLOGEXTRAINFO_H_