nsUrlClassifierPrefixSet.h

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//* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=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 nsUrlClassifierPrefixSet_h_

#define nsUrlClassifierPrefixSet_h_

#include "nsIUrlClassifierPrefixSet.h"

#include "nsISupports.h"

#include "nsToolkitCompsCID.h"

#include "nsString.h"

#include "nsTArray.h"

#include "mozilla/FileUtils.h"

#include "mozilla/Mutex.h"

#include "mozilla/Poison.h"

class nsIInputStream;

class nsIOutputStream;

namespace mozilla {

namespace safebrowsing {

class VariableLengthPrefixSet;

}  // namespace safebrowsing

}  // namespace mozilla

class nsUrlClassifierPrefixSet final : public nsIUrlClassifierPrefixSet {

 public:

  nsUrlClassifierPrefixSet();

  NS_IMETHOD Init(const nsACString& aName) override;

  NS_IMETHOD SetPrefixes(const uint32_t* aArray, uint32_t aLength) override;

  NS_IMETHOD GetPrefixes(uint32_t* aCount, uint32_t** aPrefixes) override;

  NS_IMETHOD Contains(uint32_t aPrefix, bool* aFound) override;

  NS_IMETHOD IsEmpty(bool* aEmpty) override;

  nsresult GetPrefixesNative(FallibleTArray<uint32_t>& aOutArray);

  nsresult GetPrefixByIndex(uint32_t aIndex, uint32_t* aOutPrefix) const;

  nsresult WritePrefixes(nsCOMPtr<nsIOutputStream>& out) const;

  nsresult LoadPrefixes(nsCOMPtr<nsIInputStream>& in);

  uint32_t CalculatePreallocateSize() const;

  uint32_t Length() const;

  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;

  NS_DECL_THREADSAFE_ISUPPORTS

  friend class mozilla::safebrowsing::VariableLengthPrefixSet;

 private:

  virtual ~nsUrlClassifierPrefixSet() MOZ_REQUIRES(mLock);

  static const uint32_t DELTAS_LIMIT = 120;

  static const uint32_t MAX_INDEX_DIFF = (1 << 16);

  static const uint32_t PREFIXSET_VERSION_MAGIC = 1;

  void Clear() MOZ_REQUIRES(mLock);

  nsresult MakePrefixSet(const uint32_t* aArray, uint32_t aLength)

      MOZ_REQUIRES(mLock);

  uint32_t BinSearch(uint32_t start, uint32_t end, uint32_t target) const

      MOZ_REQUIRES(mLock);

  bool IsEmptyInternal() const MOZ_REQUIRES(mLock);

  // Lock to prevent races between the url-classifier thread (which does most

  // of the operations) and the main thread (which does memory reporting).

  // It should be held for all operations between Init() and destruction that

  // touch this class's data members.

  mutable mozilla::Mutex mLock;

  // list of fully stored prefixes, that also form the

  // start of a run of deltas in mIndexDeltas.

  nsTArray<uint32_t> mIndexPrefixes MOZ_GUARDED_BY(mLock);

  // array containing arrays of deltas from indices.

  // Index to the place that matches the closest lower

  // prefix from mIndexPrefix. Then every "delta" corresponds

  // to a prefix in the PrefixSet.

  // This array could be empty when we decide to store all the prefixes

  // in mIndexPrefixes.

  nsTArray<nsTArray<uint16_t> > mIndexDeltas MOZ_GUARDED_BY(mLock);

  // how many prefixes we have.

  uint32_t mTotalPrefixes MOZ_GUARDED_BY(mLock);

  nsCString mName;  // Set in Init() only

  mozilla::CorruptionCanary mCanary;

};

#endif