gecko-dev/netwerk/dns/nsEffectiveTLDService.h
2020-03-12 15:17:56 +00:00

93 lines
3.0 KiB
C++

//* -*- 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_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();
nsCOMPtr<nsIIDNService> mIDNService;
// The DAFSA provides a compact encoding of the rather large eTLD list.
mozilla::Maybe<mozilla::Dafsa> mGraph;
// Memory map used for a new updated dafsa
mozilla::loader::AutoMemMap mDafsaMap;
// 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;
}
};
TldCache mMruTable;
};
#endif // EffectiveTLDService_h