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37
38 // for japanese encoding, obeserve characteristic:
39 // 1, kana character (or hankaku?) often have hight frequency of appereance
40 // 2, kana character often exist in group
41 // 3, certain combination of kana is never used in japanese language
42
43 #include "nsEUCJPProber.h"
44
Reset(void)45 void nsEUCJPProber::Reset(void)
46 {
47 mCodingSM->Reset();
48 mState = eDetecting;
49 mContextAnalyser.Reset(mIsPreferredLanguage);
50 mDistributionAnalyser.Reset(mIsPreferredLanguage);
51 }
52
HandleData(const char * aBuf,PRUint32 aLen)53 nsProbingState nsEUCJPProber::HandleData(const char* aBuf, PRUint32 aLen)
54 {
55 nsSMState codingState;
56
57 for (PRUint32 i = 0; i < aLen; i++)
58 {
59 codingState = mCodingSM->NextState(aBuf[i]);
60 if (codingState == eItsMe)
61 {
62 mState = eFoundIt;
63 break;
64 }
65 if (codingState == eStart)
66 {
67 PRUint32 charLen = mCodingSM->GetCurrentCharLen();
68
69 if (i == 0)
70 {
71 mLastChar[1] = aBuf[0];
72 mContextAnalyser.HandleOneChar(mLastChar, charLen);
73 mDistributionAnalyser.HandleOneChar(mLastChar, charLen);
74 }
75 else
76 {
77 mContextAnalyser.HandleOneChar(aBuf+i-1, charLen);
78 mDistributionAnalyser.HandleOneChar(aBuf+i-1, charLen);
79 }
80 }
81 }
82
83 mLastChar[0] = aBuf[aLen-1];
84
85 if (mState == eDetecting)
86 if (mContextAnalyser.GotEnoughData() && GetConfidence() > SHORTCUT_THRESHOLD)
87 mState = eFoundIt;
88
89 return mState;
90 }
91
GetConfidence(void)92 float nsEUCJPProber::GetConfidence(void)
93 {
94 float contxtCf = mContextAnalyser.GetConfidence();
95 float distribCf = mDistributionAnalyser.GetConfidence();
96
97 return (contxtCf > distribCf ? contxtCf : distribCf);
98 }
99
100