The Tor Browser: extensions/universalchardet/src/base/CharDistribution.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* -*- Mode: C++; tab-width: 2; 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/. */

     6 #include "CharDistribution.h"

     8 #include "JISFreq.tab"

     9 #include "Big5Freq.tab"

    10 #include "EUCKRFreq.tab"

    11 #include "EUCTWFreq.tab"

    12 #include "GB2312Freq.tab"

    13 #include "mozilla/ArrayUtils.h"

    15 #define SURE_YES 0.99f

    16 #define SURE_NO  0.01f

    18 //return confidence base on received data

    19 float CharDistributionAnalysis::GetConfidence(void)

    20 {

    21   //if we didn't receive any character in our consideration range, or the

    22   // number of frequent characters is below the minimum threshold, return

    23   // negative answer

    24   if (mTotalChars <= 0 || mFreqChars <= mDataThreshold)

    25     return SURE_NO;

    27   if (mTotalChars != mFreqChars) {

    28     float r = mFreqChars / ((mTotalChars - mFreqChars) * mTypicalDistributionRatio);

    30     if (r < SURE_YES)

    31       return r;

    32   }

    33   //normalize confidence, (we don't want to be 100% sure)

    34   return SURE_YES;

    35 }

    37 EUCTWDistributionAnalysis::EUCTWDistributionAnalysis()

    38 {

    39   mCharToFreqOrder = EUCTWCharToFreqOrder;

    40   mTableSize = mozilla::ArrayLength(EUCTWCharToFreqOrder);

    41   mTypicalDistributionRatio = EUCTW_TYPICAL_DISTRIBUTION_RATIO;

    42 }

    44 EUCKRDistributionAnalysis::EUCKRDistributionAnalysis()

    45 {

    46   mCharToFreqOrder = EUCKRCharToFreqOrder;

    47   mTableSize = mozilla::ArrayLength(EUCKRCharToFreqOrder);

    48   mTypicalDistributionRatio = EUCKR_TYPICAL_DISTRIBUTION_RATIO;

    49 }

    51 GB2312DistributionAnalysis::GB2312DistributionAnalysis()

    52 {

    53   mCharToFreqOrder = GB2312CharToFreqOrder;

    54   mTableSize = mozilla::ArrayLength(GB2312CharToFreqOrder);

    55   mTypicalDistributionRatio = GB2312_TYPICAL_DISTRIBUTION_RATIO;

    56 }

    58 Big5DistributionAnalysis::Big5DistributionAnalysis()

    59 {

    60   mCharToFreqOrder = Big5CharToFreqOrder;

    61   mTableSize = mozilla::ArrayLength(Big5CharToFreqOrder);

    62   mTypicalDistributionRatio = BIG5_TYPICAL_DISTRIBUTION_RATIO;

    63 }

    65 SJISDistributionAnalysis::SJISDistributionAnalysis()

    66 {

    67   mCharToFreqOrder = JISCharToFreqOrder;

    68   mTableSize = mozilla::ArrayLength(JISCharToFreqOrder);

    69   mTypicalDistributionRatio = JIS_TYPICAL_DISTRIBUTION_RATIO;

    70 }

    72 EUCJPDistributionAnalysis::EUCJPDistributionAnalysis()

    73 {

    74   mCharToFreqOrder = JISCharToFreqOrder;

    75   mTableSize = mozilla::ArrayLength(JISCharToFreqOrder);

    76   mTypicalDistributionRatio = JIS_TYPICAL_DISTRIBUTION_RATIO;

    77 }

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