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Diffstat (limited to 'libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsSBCharSetProber.cpp')
-rw-r--r--libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsSBCharSetProber.cpp126
1 files changed, 126 insertions, 0 deletions
diff --git a/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsSBCharSetProber.cpp b/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsSBCharSetProber.cpp
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+++ b/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsSBCharSetProber.cpp
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+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla Universal charset detector code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2001
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ * Shy Shalom <shooshX@gmail.com>
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+#include <stdio.h>
+#include "nsSBCharSetProber.h"
+
+nsProbingState nsSingleByteCharSetProber::HandleData(const char* aBuf, PRUint32 aLen)
+{
+ unsigned char order;
+
+ for (PRUint32 i = 0; i < aLen; i++)
+ {
+ order = mModel->charToOrderMap[(unsigned char)aBuf[i]];
+
+ if (order < SYMBOL_CAT_ORDER)
+ mTotalChar++;
+ if (order < SAMPLE_SIZE)
+ {
+ mFreqChar++;
+
+ if (mLastOrder < SAMPLE_SIZE)
+ {
+ mTotalSeqs++;
+ if (!mReversed)
+ ++(mSeqCounters[mModel->precedenceMatrix[mLastOrder*SAMPLE_SIZE+order]]);
+ else // reverse the order of the letters in the lookup
+ ++(mSeqCounters[mModel->precedenceMatrix[order*SAMPLE_SIZE+mLastOrder]]);
+ }
+ }
+ mLastOrder = order;
+ }
+
+ if (mState == eDetecting)
+ if (mTotalSeqs > SB_ENOUGH_REL_THRESHOLD)
+ {
+ float cf = GetConfidence();
+ if (cf > POSITIVE_SHORTCUT_THRESHOLD)
+ mState = eFoundIt;
+ else if (cf < NEGATIVE_SHORTCUT_THRESHOLD)
+ mState = eNotMe;
+ }
+
+ return mState;
+}
+
+void nsSingleByteCharSetProber::Reset(void)
+{
+ mState = eDetecting;
+ mLastOrder = 255;
+ for (PRUint32 i = 0; i < NUMBER_OF_SEQ_CAT; i++)
+ mSeqCounters[i] = 0;
+ mTotalSeqs = 0;
+ mTotalChar = 0;
+ mFreqChar = 0;
+}
+
+//#define NEGATIVE_APPROACH 1
+
+float nsSingleByteCharSetProber::GetConfidence(void)
+{
+#ifdef NEGATIVE_APPROACH
+ if (mTotalSeqs > 0)
+ if (mTotalSeqs > mSeqCounters[NEGATIVE_CAT]*10 )
+ return ((float)(mTotalSeqs - mSeqCounters[NEGATIVE_CAT]*10))/mTotalSeqs * mFreqChar / mTotalChar;
+ return (float)0.01;
+#else //POSITIVE_APPROACH
+ float r;
+
+ if (mTotalSeqs > 0) {
+ r = ((float)1.0) * mSeqCounters[POSITIVE_CAT] / mTotalSeqs / mModel->mTypicalPositiveRatio;
+ r = r*mFreqChar/mTotalChar;
+ if (r >= (float)1.00)
+ r = (float)0.99;
+ return r;
+ }
+ return (float)0.01;
+#endif
+}
+
+const char* nsSingleByteCharSetProber::GetCharSetName()
+{
+ if (!mNameProber)
+ return mModel->charsetName;
+ return mNameProber->GetCharSetName();
+}
+
+#ifdef DEBUG_chardet
+void nsSingleByteCharSetProber::DumpStatus()
+{
+ printf(" SBCS: %1.3f [%s]\r\n", GetConfidence(), GetCharSetName());
+}
+#endif