1 files changed, 149 insertions, 0 deletions
diff --git a/extensions/universalchardet/src/base/nsLatin1Prober.cpp b/extensions/universalchardet/src/base/nsLatin1Prober.cpp
new file mode 100644
index 000000000..e2769486e
--- /dev/null
+++ b/extensions/universalchardet/src/base/nsLatin1Prober.cpp
@@ -0,0 +1,149 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsLatin1Prober.h"
+#include "prmem.h"
+#include <stdio.h>
+
+#define UDF    0        // undefined
+#define OTH    1        //other
+#define ASC    2        // ascii capital letter
+#define ASS    3        // ascii small letter
+#define ACV    4        // accent capital vowel
+#define ACO    5        // accent capital other
+#define ASV    6        // accent small vowel
+#define ASO    7        // accent small other
+#define CLASS_NUM   8    // total classes
+
+static const unsigned char Latin1_CharToClass[] = 
+{
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 00 - 07
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 08 - 0F
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 10 - 17
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 18 - 1F
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 20 - 27
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 28 - 2F
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 30 - 37
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 38 - 3F
+  OTH, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   // 40 - 47
+  ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   // 48 - 4F
+  ASC, ASC, ASC, ASC, ASC, ASC, ASC, ASC,   // 50 - 57
+  ASC, ASC, ASC, OTH, OTH, OTH, OTH, OTH,   // 58 - 5F
+  OTH, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   // 60 - 67
+  ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   // 68 - 6F
+  ASS, ASS, ASS, ASS, ASS, ASS, ASS, ASS,   // 70 - 77
+  ASS, ASS, ASS, OTH, OTH, OTH, OTH, OTH,   // 78 - 7F
+  OTH, UDF, OTH, ASO, OTH, OTH, OTH, OTH,   // 80 - 87
+  OTH, OTH, ACO, OTH, ACO, UDF, ACO, UDF,   // 88 - 8F
+  UDF, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // 90 - 97
+  OTH, OTH, ASO, OTH, ASO, UDF, ASO, ACO,   // 98 - 9F
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // A0 - A7
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // A8 - AF
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // B0 - B7
+  OTH, OTH, OTH, OTH, OTH, OTH, OTH, OTH,   // B8 - BF
+  ACV, ACV, ACV, ACV, ACV, ACV, ACO, ACO,   // C0 - C7
+  ACV, ACV, ACV, ACV, ACV, ACV, ACV, ACV,   // C8 - CF
+  ACO, ACO, ACV, ACV, ACV, ACV, ACV, OTH,   // D0 - D7
+  ACV, ACV, ACV, ACV, ACV, ACO, ACO, ACO,   // D8 - DF
+  ASV, ASV, ASV, ASV, ASV, ASV, ASO, ASO,   // E0 - E7
+  ASV, ASV, ASV, ASV, ASV, ASV, ASV, ASV,   // E8 - EF
+  ASO, ASO, ASV, ASV, ASV, ASV, ASV, OTH,   // F0 - F7
+  ASV, ASV, ASV, ASV, ASV, ASO, ASO, ASO,   // F8 - FF
+};
+
+
+/* 0 : illegal 
+   1 : very unlikely 
+   2 : normal 
+   3 : very likely
+*/
+static const unsigned char Latin1ClassModel[] = 
+{
+/*      UDF OTH ASC ASS ACV ACO ASV ASO  */
+/*UDF*/  0,  0,  0,  0,  0,  0,  0,  0,
+/*OTH*/  0,  3,  3,  3,  3,  3,  3,  3,
+/*ASC*/  0,  3,  3,  3,  3,  3,  3,  3, 
+/*ASS*/  0,  3,  3,  3,  1,  1,  3,  3,
+/*ACV*/  0,  3,  3,  3,  1,  2,  1,  2,
+/*ACO*/  0,  3,  3,  3,  3,  3,  3,  3, 
+/*ASV*/  0,  3,  1,  3,  1,  1,  1,  3, 
+/*ASO*/  0,  3,  1,  3,  1,  1,  3,  3,
+};
+
+void  nsLatin1Prober::Reset(void)
+{
+  mState = eDetecting;
+  mLastCharClass = OTH;
+  for (int i = 0; i < FREQ_CAT_NUM; i++)
+    mFreqCounter[i] = 0;
+}
+
+
+nsProbingState nsLatin1Prober::HandleData(const char* aBuf, uint32_t aLen)
+{
+  char *newBuf1 = 0;
+  uint32_t newLen1 = 0;
+
+  if (!FilterWithEnglishLetters(aBuf, aLen, &newBuf1, newLen1)) {
+    newBuf1 = (char*)aBuf;
+    newLen1 = aLen;
+  }
+  
+  unsigned char charClass;
+  unsigned char freq;
+  for (uint32_t i = 0; i < newLen1; i++)
+  {
+    charClass = Latin1_CharToClass[(unsigned char)newBuf1[i]];
+    freq = Latin1ClassModel[mLastCharClass*CLASS_NUM + charClass];
+    if (freq == 0) {
+      mState = eNotMe;
+      break;
+    }
+    mFreqCounter[freq]++;
+    mLastCharClass = charClass;
+  }
+
+  if (newBuf1 != aBuf)
+    PR_FREEIF(newBuf1);
+
+  return mState;
+}
+
+float nsLatin1Prober::GetConfidence(void)
+{
+  if (mState == eNotMe)
+    return 0.01f;
+  
+  float confidence;
+  uint32_t total = 0;
+  for (int32_t i = 0; i < FREQ_CAT_NUM; i++)
+    total += mFreqCounter[i];
+
+  if(!total)
+    confidence = 0.0f;
+  else
+  {
+    confidence = mFreqCounter[3]*1.0f / total;
+    confidence -= mFreqCounter[1]*20.0f/total;
+  }
+
+  if (confidence < 0.0f)
+    confidence = 0.0f;
+  
+  // lower the confidence of latin1 so that other more accurate detector 
+  // can take priority.
+  confidence *= 0.50f;
+
+  return confidence;
+}
+
+#ifdef DEBUG_chardet
+void  nsLatin1Prober::DumpStatus()
+{
+  printf(" Latin1Prober: %1.3f [%s]\r\n", GetConfidence(), GetCharSetName());
+}
+#endif
+
+