intl/chardet/nsCyrillicDetector.cpp

   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>
   8
   9 #include "nsCOMPtr.h"
  10 #include "nsISupports.h"
  11 #include "nsICharsetDetector.h"
  12 #include "nsICharsetDetectionObserver.h"
  13 #include "nsIStringCharsetDetector.h"
  14 #include "nsCyrillicDetector.h"
  15
  16 //----------------------------------------------------------------------
  17 // Interface nsISupports [implementation]
  18 NS_IMPL_ISUPPORTS(nsCyrXPCOMDetector, nsICharsetDetector)
  19 NS_IMPL_ISUPPORTS(nsCyrXPCOMStringDetector, nsIStringCharsetDetector)
  20
  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 }
  44
  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    }
  61
  62    if( 0 == max ) // if we didn't get any 8 bits data
  63      return;
  64
  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 }
  72
  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 }
  81
  82 //---------------------------------------------------------------------
  83 nsCyrXPCOMDetector::~nsCyrXPCOMDetector()
  84 {
  85 }
  86
  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;
  94
  95   mObserver = aObserver;
  96   return NS_OK;
  97 }
  98
  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");
 104
 105   if((nullptr == aBuf) || (nullptr == oDontFeedMe))
 106      return NS_ERROR_ILLEGAL_VALUE;
 107
 108   this->HandleData(aBuf, aLen);
 109   *oDontFeedMe = false;
 110   return NS_OK;
 111 }
 112
 113 //----------------------------------------------------------
 114 NS_IMETHODIMP nsCyrXPCOMDetector::Done()
 115 {
 116   NS_ASSERTION(mObserver != nullptr , "have not init yet");
 117   this->DataEnd();
 118   return NS_OK;
 119 }
 120
 121 //----------------------------------------------------------
 122 void nsCyrXPCOMDetector::Report(const char* aCharset)
 123 {
 124   NS_ASSERTION(mObserver != nullptr , "have not init yet");
 125   mObserver->Notify(aCharset, eBestAnswer);
 126 }
 127
 128 //---------------------------------------------------------------------
 129 nsCyrXPCOMStringDetector:: nsCyrXPCOMStringDetector(uint8_t aItems,
 130                       const uint8_t ** aCyrillicClass,
 131                       const char **aCharsets)
 132              : nsCyrillicDetector(aItems, aCyrillicClass, aCharsets)
 133 {
 134 }
 135
 136 //---------------------------------------------------------------------
 137 nsCyrXPCOMStringDetector::~nsCyrXPCOMStringDetector()
 138 {
 139 }
 140
 141 //---------------------------------------------------------------------
 142 void nsCyrXPCOMStringDetector::Report(const char *aCharset)
 143 {
 144    mResult = aCharset;
 145 }
 146
 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 }
 159
 160