1 files changed, 107 insertions, 0 deletions
diff --git a/extensions/universalchardet/src/base/JpCntx.h b/extensions/universalchardet/src/base/JpCntx.h
new file mode 100644
index 000000000..88e096432
--- /dev/null
+++ b/extensions/universalchardet/src/base/JpCntx.h
@@ -0,0 +1,107 @@
+/* -*- Mode: C++; tab-width: 2; 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/. */
+
+#ifndef __JPCNTX_H__
+#define __JPCNTX_H__
+
+#define NUM_OF_CATEGORY 6
+
+#include "nscore.h" 
+
+#define ENOUGH_REL_THRESHOLD  100
+#define MAX_REL_THRESHOLD     1000
+
+//hiragana frequency category table
+extern const uint8_t jp2CharContext[83][83];
+
+class JapaneseContextAnalysis
+{
+public:
+  JapaneseContextAnalysis() {Reset();}
+
+  void HandleData(const char* aBuf, uint32_t aLen);
+
+  void HandleOneChar(const char* aStr, uint32_t aCharLen)
+  {
+    int32_t order;
+
+    //if we received enough data, stop here   
+    if (mTotalRel > MAX_REL_THRESHOLD)   mDone = true;
+    if (mDone)       return;
+     
+    //Only 2-bytes characters are of our interest
+    order = (aCharLen == 2) ? GetOrder(aStr) : -1;
+    if (order != -1 && mLastCharOrder != -1)
+    {
+      mTotalRel++;
+      //count this sequence to its category counter
+      mRelSample[jp2CharContext[mLastCharOrder][order]]++;
+    }
+    mLastCharOrder = order;
+  }
+
+  float GetConfidence(void);
+  void      Reset();
+  bool GotEnoughData() {return mTotalRel > ENOUGH_REL_THRESHOLD;}
+
+protected:
+  virtual int32_t GetOrder(const char* str, uint32_t *charLen) = 0;
+  virtual int32_t GetOrder(const char* str) = 0;
+
+  //category counters, each integer counts sequences in its category
+  uint32_t mRelSample[NUM_OF_CATEGORY];
+
+  //total sequence received
+  uint32_t mTotalRel;
+
+  //Number of sequences needed to trigger detection
+  uint32_t mDataThreshold;
+  
+  //The order of previous char
+  int32_t  mLastCharOrder;
+
+  //if last byte in current buffer is not the last byte of a character, we
+  //need to know how many byte to skip in next buffer.
+  uint32_t mNeedToSkipCharNum;
+
+  //If this flag is set to true, detection is done and conclusion has been made
+  bool     mDone;
+};
+
+
+class SJISContextAnalysis : public JapaneseContextAnalysis
+{
+  //SJISContextAnalysis(){};
+protected:
+  int32_t GetOrder(const char* str, uint32_t *charLen);
+
+  int32_t GetOrder(const char* str)
+  {
+    //We only interested in Hiragana, so first byte is '\202'
+    if (*str == '\202' && 
+          (unsigned char)*(str+1) >= (unsigned char)0x9f && 
+          (unsigned char)*(str+1) <= (unsigned char)0xf1)
+      return (unsigned char)*(str+1) - (unsigned char)0x9f;
+    return -1;
+  }
+};
+
+class EUCJPContextAnalysis : public JapaneseContextAnalysis
+{
+protected:
+  int32_t GetOrder(const char* str, uint32_t *charLen);
+  int32_t GetOrder(const char* str)
+    //We only interested in Hiragana, so first byte is '\244'
+  {
+    if (*str == '\244' &&
+          (unsigned char)*(str+1) >= (unsigned char)0xa1 &&
+          (unsigned char)*(str+1) <= (unsigned char)0xf3)
+      return (unsigned char)*(str+1) - (unsigned char)0xa1;
+    return -1;
+  }
+};
+
+#endif /* __JPCNTX_H__ */
+