gecko-dev/toolkit/components/url-classifier/nsUrlClassifierPrefixSet.h
Francois Marier b81007a163 Bug 1362761 - Safer Clean() and IsEmpty() handling in PrefixSet. r=dimi
This simplifies the logic around clearing the prefix set and also adds
the clearing of the mIndexDeltasChecksum which should have been done
as part of 3a00711bb0e6.

Additionally, the checks for whether or not the prefix set is empty
include some sanity-checking asserts.

Finally, mTotalPrefixes could be out of sync with mIndexPrefixes
and mIndexDeltas if LoadPrefixes() or MakePrefixSet() fail so we
now only update it once all elements have been added successfully.

There is now a release assert to catch grossly out-of-sync (or
corrupt) values of mTotalPrefixes.

MozReview-Commit-ID: BSbyD2dGsUY

Differential Revision: https://phabricator.services.mozilla.com/D2062

--HG--
extra : moz-landing-system : lando
2018-07-11 12:40:34 +00:00

96 lines
3.1 KiB
C++

//* -*- 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 "nsISupportsUtils.h"
#include "nsID.h"
#include "nsIFile.h"
#include "nsIMemoryReporter.h"
#include "nsIMutableArray.h"
#include "nsIFileStreams.h"
#include "nsIUrlClassifierPrefixSet.h"
#include "nsTArray.h"
#include "nsToolkitCompsCID.h"
#include "mozilla/FileUtils.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Mutex.h"
#include "mozilla/Poison.h"
namespace mozilla {
namespace safebrowsing {
class VariableLengthPrefixSet;
} // namespace safebrowsing
} // namespace mozilla
class nsUrlClassifierPrefixSet final
: public nsIUrlClassifierPrefixSet
, public nsIMemoryReporter
{
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;
NS_IMETHOD LoadFromFile(nsIFile* aFile) override;
NS_IMETHOD StoreToFile(nsIFile* aFile) override;
nsresult GetPrefixesNative(FallibleTArray<uint32_t>& outArray);
size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIMEMORYREPORTER
friend class mozilla::safebrowsing::VariableLengthPrefixSet;
private:
virtual ~nsUrlClassifierPrefixSet();
static const uint32_t MAX_BUFFER_SIZE = 64 * 1024;
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();
nsresult MakePrefixSet(const uint32_t* aArray, uint32_t aLength);
uint32_t BinSearch(uint32_t start, uint32_t end, uint32_t target) const;
bool IsEmptyInternal() const;
uint32_t CalculatePreallocateSize() const;
nsresult WritePrefixes(nsCOMPtr<nsIOutputStream>& out) const;
nsresult LoadPrefixes(nsCOMPtr<nsIInputStream>& in);
// 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;
// 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.
nsTArray<nsTArray<uint16_t> > mIndexDeltas;
uint32_t mIndexDeltasChecksum;
// how many prefixes we have.
uint32_t mTotalPrefixes;
nsCString mName;
nsCString mMemoryReportPath;
mozilla::CorruptionCanary mCanary;
};
#endif