//* -*- 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 "nsHashKeys.h"

#include "nsIMemoryReporter.h"

#include "nsString.h"

#include "nsCOMPtr.h"

#include "mozilla/Attributes.h"

#include "mozilla/Dafsa.h"

#include "mozilla/MemoryReporting.h"

#include "mozilla/MruCache.h"

class nsIIDNService;

class nsEffectiveTLDService final

  : public nsIEffectiveTLDService

  , public nsIMemoryReporter

{

public:

  NS_DECL_ISUPPORTS

  NS_DECL_NSIEFFECTIVETLDSERVICE

  NS_DECL_NSIMEMORYREPORTER

  nsEffectiveTLDService();

  nsresult Init();

  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);

private:

  nsresult GetBaseDomainInternal(nsCString &aHostname, int32_t aAdditionalParts, nsACString &aBaseDomain);

  nsresult NormalizeHostname(nsCString &aHostname);

  ~nsEffectiveTLDService();

  nsCOMPtr<nsIIDNService>     mIDNService;

  // The DAFSA provides a compact encoding of the rather large eTLD list.

  mozilla::Dafsa mGraph;

  struct TLDCacheEntry

  {

    nsCString mHost;

    nsCString mBaseDomain;

  };

  // 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;

    }

  };

  TldCache mMruTable;

};

#endif // EffectiveTLDService_h