1 files changed, 68 insertions, 0 deletions
diff --git a/extensions/universalchardet/src/base/nsSJISProber.cpp b/extensions/universalchardet/src/base/nsSJISProber.cpp
new file mode 100644
index 000000000..73d615bd9
--- /dev/null
+++ b/extensions/universalchardet/src/base/nsSJISProber.cpp
@@ -0,0 +1,68 @@
+/* -*- 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/. */
+
+// for S-JIS encoding, obeserve characteristic:
+// 1, kana character (or hankaku?) often have hight frequency of appereance
+// 2, kana character often exist in group
+// 3, certain combination of kana is never used in japanese language
+
+#include "nsSJISProber.h"
+#include "nsDebug.h"
+
+void  nsSJISProber::Reset(void)
+{
+  mCodingSM->Reset(); 
+  mState = eDetecting;
+  mContextAnalyser.Reset();
+  mDistributionAnalyser.Reset();
+}
+
+nsProbingState nsSJISProber::HandleData(const char* aBuf, uint32_t aLen)
+{
+  NS_ASSERTION(aLen, "HandleData called with empty buffer");
+  nsSMState codingState;
+
+  for (uint32_t i = 0; i < aLen; i++)
+  {
+    codingState = mCodingSM->NextState(aBuf[i]);
+    if (codingState == eItsMe)
+    {
+      mState = eFoundIt;
+      break;
+    }
+    if (codingState == eStart)
+    {
+      uint32_t charLen = mCodingSM->GetCurrentCharLen();
+      if (i == 0)
+      {
+        mLastChar[1] = aBuf[0];
+        mContextAnalyser.HandleOneChar(mLastChar+2-charLen, charLen);
+        mDistributionAnalyser.HandleOneChar(mLastChar, charLen);
+      }
+      else
+      {
+        mContextAnalyser.HandleOneChar(aBuf+i+1-charLen, charLen);
+        mDistributionAnalyser.HandleOneChar(aBuf+i-1, charLen);
+      }
+    }
+  }
+
+  mLastChar[0] = aBuf[aLen-1];
+
+  if (mState == eDetecting)
+    if (mContextAnalyser.GotEnoughData() && GetConfidence() > SHORTCUT_THRESHOLD)
+      mState = eFoundIt;
+
+  return mState;
+}
+
+float nsSJISProber::GetConfidence(void)
+{
+  float contxtCf = mContextAnalyser.GetConfidence();
+  float distribCf = mDistributionAnalyser.GetConfidence();
+
+  return (contxtCf > distribCf ? contxtCf : distribCf);
+}
+