The Tor Browser: intl/chardet/src/nsCyrillicDetector.cpp@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

     2 /* This Source Code Form is subject to the terms of the Mozilla Public

     3  * License, v. 2.0. If a copy of the MPL was not distributed with this

     4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     5 #include "nscore.h"

     6 #include "nsCyrillicProb.h"

     7 #include <stdio.h>

     9 #include "nsCOMPtr.h"

    10 #include "nsISupports.h"

    11 #include "nsICharsetDetector.h"

    12 #include "nsICharsetDetectionObserver.h"

    13 #include "nsIStringCharsetDetector.h"

    14 #include "nsCyrillicDetector.h"

    16 //----------------------------------------------------------------------

    17 // Interface nsISupports [implementation]

    18 NS_IMPL_ISUPPORTS(nsCyrXPCOMDetector, nsICharsetDetector)

    19 NS_IMPL_ISUPPORTS(nsCyrXPCOMStringDetector, nsIStringCharsetDetector)

    21 void nsCyrillicDetector::HandleData(const char* aBuf, uint32_t aLen)

    22 {

    23    uint8_t cls;

    24    const char* b;

    25    uint32_t i;

    26    if(mDone)

    27       return;

    28    for(i=0, b=aBuf;i<aLen;i++,b++)

    29    {

    30      for(unsigned j=0;j<mItems;j++)

    31      {

    32         if( 0x80 & *b)

    33            cls = mCyrillicClass[j][(*b) & 0x7F];

    34         else

    35            cls = 0;

    36         NS_ASSERTION( cls <= 32 , "illegal character class");

    37         mProb[j] += gCyrillicProb[mLastCls[j]][cls];

    38         mLastCls[j] = cls;

    39      }

    40    }

    41    // We now only based on the first block we receive

    42    DataEnd();

    43 }

    45 //---------------------------------------------------------------------

    46 #define THRESHOLD_RATIO 1.5f

    47 void nsCyrillicDetector::DataEnd()

    48 {

    49    uint32_t max=0;

    50    uint8_t  maxIdx=0;

    51    uint8_t j;

    52    if(mDone)

    53       return;

    54    for(j=0;j<mItems;j++) {

    55       if(mProb[j] > max)

    56       {

    57            max = mProb[j];

    58            maxIdx= j;

    59       }

    60    }

    62    if( 0 == max ) // if we didn't get any 8 bits data

    63      return;

    65 #ifdef DEBUG

    66    for(j=0;j<mItems;j++)

    67       printf("Charset %s->\t%d\n", mCharsets[j], mProb[j]);

    68 #endif

    69    this->Report(mCharsets[maxIdx]);

    70    mDone = true;

    71 }

    73 //---------------------------------------------------------------------

    74 nsCyrXPCOMDetector:: nsCyrXPCOMDetector(uint8_t aItems,

    75                       const uint8_t ** aCyrillicClass,

    76                       const char **aCharsets)

    77 	     : nsCyrillicDetector(aItems, aCyrillicClass, aCharsets)

    78 {

    79     mObserver = nullptr;

    80 }

    82 //---------------------------------------------------------------------

    83 nsCyrXPCOMDetector::~nsCyrXPCOMDetector()

    84 {

    85 }

    87 //---------------------------------------------------------------------

    88 NS_IMETHODIMP nsCyrXPCOMDetector::Init(

    89   nsICharsetDetectionObserver* aObserver)

    90 {

    91   NS_ASSERTION(mObserver == nullptr , "Init twice");

    92   if(nullptr == aObserver)

    93      return NS_ERROR_ILLEGAL_VALUE;

    95   mObserver = aObserver;

    96   return NS_OK;

    97 }

    99 //----------------------------------------------------------

   100 NS_IMETHODIMP nsCyrXPCOMDetector::DoIt(

   101   const char* aBuf, uint32_t aLen, bool* oDontFeedMe)

   102 {

   103   NS_ASSERTION(mObserver != nullptr , "have not init yet");

   105   if((nullptr == aBuf) || (nullptr == oDontFeedMe))

   106      return NS_ERROR_ILLEGAL_VALUE;

   108   this->HandleData(aBuf, aLen);

   109   *oDontFeedMe = false;

   110   return NS_OK;

   111 }

   113 //----------------------------------------------------------

   114 NS_IMETHODIMP nsCyrXPCOMDetector::Done()

   115 {

   116   NS_ASSERTION(mObserver != nullptr , "have not init yet");

   117   this->DataEnd();

   118   return NS_OK;

   119 }

   121 //----------------------------------------------------------

   122 void nsCyrXPCOMDetector::Report(const char* aCharset)

   123 {

   124   NS_ASSERTION(mObserver != nullptr , "have not init yet");

   125   mObserver->Notify(aCharset, eBestAnswer);

   126 }

   128 //---------------------------------------------------------------------

   129 nsCyrXPCOMStringDetector:: nsCyrXPCOMStringDetector(uint8_t aItems,

   130                       const uint8_t ** aCyrillicClass,

   131                       const char **aCharsets)

   132 	     : nsCyrillicDetector(aItems, aCyrillicClass, aCharsets)

   133 {

   134 }

   136 //---------------------------------------------------------------------

   137 nsCyrXPCOMStringDetector::~nsCyrXPCOMStringDetector()

   138 {

   139 }

   141 //---------------------------------------------------------------------

   142 void nsCyrXPCOMStringDetector::Report(const char *aCharset)

   143 {

   144    mResult = aCharset;

   145 }

   147 //---------------------------------------------------------------------

   148 NS_IMETHODIMP nsCyrXPCOMStringDetector::DoIt(const char* aBuf, uint32_t aLen,

   149                      const char** oCharset, nsDetectionConfident &oConf)

   150 {

   151    mResult = nullptr;

   152    mDone = false;

   153    this->HandleData(aBuf, aLen);

   154    this->DataEnd();

   155    *oCharset=mResult;

   156    oConf = eBestAnswer;

   157    return NS_OK;

   158 }

The Tor Browser / file revision

intl/chardet/src/nsCyrillicDetector.cpp@97036ab72558

intl/chardet/src/nsCyrillicDetector.cpp