Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
       2             : /* vim: set ts=8 sts=2 et sw=2 tw=80: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #include "mozilla/dom/FallbackEncoding.h"
       8             : 
       9             : #include "mozilla/Encoding.h"
      10             : #include "mozilla/intl/LocaleService.h"
      11             : #include "mozilla/Preferences.h"
      12             : #include "mozilla/Services.h"
      13             : #include "nsIObserverService.h"
      14             : #include "nsUConvPropertySearch.h"
      15             : 
      16             : using mozilla::intl::LocaleService;
      17             : 
      18             : namespace mozilla {
      19             : namespace dom {
      20             : 
      21             : static constexpr nsUConvProp localesFallbacks[] = {
      22             : #include "localesfallbacks.properties.h"
      23             : };
      24             : 
      25             : static constexpr nsUConvProp domainsFallbacks[] = {
      26             : #include "domainsfallbacks.properties.h"
      27             : };
      28             : 
      29             : static constexpr nsUConvProp nonParticipatingDomains[] = {
      30             : #include "nonparticipatingdomains.properties.h"
      31             : };
      32             : 
      33           3 : NS_IMPL_ISUPPORTS(FallbackEncoding, nsIObserver)
      34             : 
      35             : FallbackEncoding* FallbackEncoding::sInstance = nullptr;
      36             : bool FallbackEncoding::sGuessFallbackFromTopLevelDomain = true;
      37             : 
      38           3 : FallbackEncoding::FallbackEncoding()
      39           3 :   : mFallback(nullptr)
      40             : {
      41           3 :   MOZ_ASSERT(!FallbackEncoding::sInstance,
      42             :              "Singleton already exists.");
      43           3 : }
      44             : 
      45             : NotNull<const Encoding*>
      46           2 : FallbackEncoding::Get()
      47             : {
      48           2 :   if (mFallback) {
      49           0 :     return WrapNotNull(mFallback);
      50             :   }
      51             : 
      52             :   const nsAdoptingCString& override =
      53           4 :     Preferences::GetCString("intl.charset.fallback.override");
      54             :   // Don't let the user break things by setting the override to unreasonable
      55             :   // values via about:config
      56           2 :   auto encoding = Encoding::ForLabel(override);
      57           2 :   if (!encoding || !encoding->IsAsciiCompatible() ||
      58           0 :       encoding == UTF_8_ENCODING) {
      59           2 :     mFallback = nullptr;
      60             :   } else {
      61           0 :     mFallback = encoding;
      62             :   }
      63             : 
      64           2 :   if (mFallback) {
      65           0 :     return WrapNotNull(mFallback);
      66             :   }
      67             : 
      68           4 :   nsAutoCString locale;
      69           2 :   LocaleService::GetInstance()->GetAppLocaleAsLangTag(locale);
      70             : 
      71             :   // Let's lower case the string just in case unofficial language packs
      72             :   // don't stick to conventions.
      73           2 :   ToLowerCase(locale); // ASCII lowercasing with CString input!
      74             : 
      75             :   // Special case Traditional Chinese before throwing away stuff after the
      76             :   // language itself. Today we only ship zh-TW, but be defensive about
      77             :   // possible future values.
      78           6 :   if (locale.EqualsLiteral("zh-tw") ||
      79           4 :       locale.EqualsLiteral("zh-hk") ||
      80           6 :       locale.EqualsLiteral("zh-mo") ||
      81           2 :       locale.EqualsLiteral("zh-hant")) {
      82           0 :     mFallback = BIG5_ENCODING;
      83           0 :     return WrapNotNull(mFallback);
      84             :   }
      85             : 
      86             :   // Throw away regions and other variants to accommodate weird stuff seen
      87             :   // in telemetry--apparently unofficial language packs.
      88           2 :   int32_t index = locale.FindChar('-');
      89           2 :   if (index >= 0) {
      90           2 :     locale.Truncate(index);
      91             :   }
      92             : 
      93           4 :   nsAutoCString fallback;
      94           2 :   if (NS_FAILED(nsUConvPropertySearch::SearchPropertyValue(
      95             :       localesFallbacks, ArrayLength(localesFallbacks), locale, fallback))) {
      96           2 :     mFallback = WINDOWS_1252_ENCODING;
      97             :   } else {
      98           0 :     mFallback = Encoding::ForName(fallback);
      99             :   }
     100             : 
     101           2 :   return WrapNotNull(mFallback);
     102             : }
     103             : 
     104             : NotNull<const Encoding*>
     105           2 : FallbackEncoding::FromLocale()
     106             : {
     107           2 :   MOZ_ASSERT(FallbackEncoding::sInstance,
     108             :              "Using uninitialized fallback cache.");
     109           2 :   return FallbackEncoding::sInstance->Get();
     110             : }
     111             : 
     112             : // PrefChangedFunc
     113             : void
     114           0 : FallbackEncoding::PrefChanged(const char*, void*)
     115             : {
     116           0 :   MOZ_ASSERT(FallbackEncoding::sInstance,
     117             :              "Pref callback called with null fallback cache.");
     118           0 :   FallbackEncoding::sInstance->Invalidate();
     119           0 : }
     120             : 
     121             : NS_IMETHODIMP
     122           0 : FallbackEncoding::Observe(nsISupports *aSubject, const char *aTopic,
     123             :                          const char16_t *aData)
     124             : {
     125           0 :   MOZ_ASSERT(FallbackEncoding::sInstance,
     126             :              "Observe callback called with null fallback cache.");
     127           0 :   FallbackEncoding::sInstance->Invalidate();
     128           0 :   return NS_OK;
     129             : }
     130             : 
     131             : void
     132           3 : FallbackEncoding::Initialize()
     133             : {
     134           3 :   MOZ_ASSERT(!FallbackEncoding::sInstance,
     135             :              "Initializing pre-existing fallback cache.");
     136           3 :   FallbackEncoding::sInstance = new FallbackEncoding;
     137             :   Preferences::RegisterCallback(FallbackEncoding::PrefChanged,
     138             :                                 "intl.charset.fallback.override",
     139           3 :                                 nullptr);
     140             :   Preferences::AddBoolVarCache(&sGuessFallbackFromTopLevelDomain,
     141           3 :                                "intl.charset.fallback.tld");
     142             : 
     143           6 :   nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
     144           3 :   if (obs) {
     145           3 :     obs->AddObserver(sInstance, "intl:requested-locales-changed", true);
     146             :   }
     147           3 : }
     148             : 
     149             : void
     150           0 : FallbackEncoding::Shutdown()
     151             : {
     152           0 :   MOZ_ASSERT(FallbackEncoding::sInstance,
     153             :              "Releasing non-existent fallback cache.");
     154           0 :   nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
     155           0 :   if (obs) {
     156           0 :     obs->RemoveObserver(sInstance, "intl:requested-locales-changed");
     157             :   }
     158           0 :   delete FallbackEncoding::sInstance;
     159           0 :   FallbackEncoding::sInstance = nullptr;
     160           0 : }
     161             : 
     162             : bool
     163           0 : FallbackEncoding::IsParticipatingTopLevelDomain(const nsACString& aTLD)
     164             : {
     165           0 :   nsAutoCString dummy;
     166           0 :   return NS_FAILED(nsUConvPropertySearch::SearchPropertyValue(
     167             :       nonParticipatingDomains,
     168             :       ArrayLength(nonParticipatingDomains),
     169             :       aTLD,
     170             :       dummy));
     171             : }
     172             : 
     173             : NotNull<const Encoding*>
     174           0 : FallbackEncoding::FromTopLevelDomain(const nsACString& aTLD)
     175             : {
     176           0 :   nsAutoCString fallback;
     177           0 :   if (NS_FAILED(nsUConvPropertySearch::SearchPropertyValue(
     178             :       domainsFallbacks, ArrayLength(domainsFallbacks), aTLD, fallback))) {
     179           0 :     return WINDOWS_1252_ENCODING;
     180             :   }
     181           0 :   return Encoding::ForName(fallback);
     182             : }
     183             : 
     184             : } // namespace dom
     185             : } // namespace mozilla