1 files changed, 94 insertions, 0 deletions
diff --git a/netwerk/dns/nsEffectiveTLDService.h b/netwerk/dns/nsEffectiveTLDService.h
new file mode 100644
index 0000000000..e68156582a
--- /dev/null
+++ b/netwerk/dns/nsEffectiveTLDService.h
@@ -0,0 +1,94 @@
+//* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 EffectiveTLDService_h
+#define EffectiveTLDService_h
+
+#include "nsIEffectiveTLDService.h"
+
+#include "mozilla/AutoMemMap.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Dafsa.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/MruCache.h"
+#include "mozilla/RWLock.h"
+
+#include "nsCOMPtr.h"
+#include "nsHashKeys.h"
+#include "nsIMemoryReporter.h"
+#include "nsIObserver.h"
+#include "nsString.h"
+
+class nsIIDNService;
+
+class nsEffectiveTLDService final : public nsIEffectiveTLDService,
+                                    public nsIObserver,
+                                    public nsIMemoryReporter {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIEFFECTIVETLDSERVICE
+  NS_DECL_NSIMEMORYREPORTER
+  NS_DECL_NSIOBSERVER
+
+  nsEffectiveTLDService();
+  nsresult Init();
+
+  static nsEffectiveTLDService* GetInstance();
+
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
+
+ private:
+  nsresult GetBaseDomainInternal(nsCString& aHostname, int32_t aAdditionalParts,
+                                 bool aOnlyKnownPublicSuffix,
+                                 nsACString& aBaseDomain);
+  nsresult NormalizeHostname(nsCString& aHostname);
+  ~nsEffectiveTLDService();
+
+  // Only set in `Init()` which is called during service construction.
+  nsCOMPtr<nsIIDNService> mIDNService;
+
+  // The DAFSA provides a compact encoding of the rather large eTLD list.
+  mozilla::Maybe<mozilla::Dafsa> mGraph MOZ_GUARDED_BY(mGraphLock);
+
+  // Memory map used for a new updated dafsa
+  mozilla::loader::AutoMemMap mDafsaMap MOZ_GUARDED_BY(mGraphLock);
+
+  // Lock for mGraph and mDafsaMap
+  mozilla::RWLock mGraphLock;
+
+  // Note that the cache entries here can record entries that were cached
+  // successfully or unsuccessfully.  mResult must be checked before using an
+  // entry.  If it's a success error code, the cache entry is valid and can be
+  // used.
+  struct TLDCacheEntry {
+    nsCString mHost;
+    nsCString mBaseDomain;
+    nsresult mResult;
+  };
+
+  // We use a small most recently used cache to compensate for DAFSA lookups
+  // being slightly slower than a binary search on a larger table of strings.
+  //
+  // We first check the cache for a matching result and avoid a DAFSA lookup
+  // if a match is found. Otherwise we lookup the domain in the DAFSA and then
+  // cache the result. During standard browsing the same domains are repeatedly
+  // fed into |GetBaseDomainInternal| so this ends up being an effective
+  // mitigation getting about a 99% hit rate with four tabs open.
+  struct TldCache
+      : public mozilla::MruCache<nsACString, TLDCacheEntry, TldCache> {
+    static mozilla::HashNumber Hash(const nsACString& aKey) {
+      return mozilla::HashString(aKey);
+    }
+    static bool Match(const nsACString& aKey, const TLDCacheEntry& aVal) {
+      return aKey == aVal.mHost;
+    }
+  };
+
+  // NOTE: Only used on the main thread, so not guarded by mGraphLock.
+  TldCache mMruTable;
+};
+
+#endif  // EffectiveTLDService_h