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Diffstat (limited to 'src/ext/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsUniversalDetector.cpp')
-rw-r--r-- | src/ext/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsUniversalDetector.cpp | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/src/ext/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsUniversalDetector.cpp b/src/ext/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsUniversalDetector.cpp new file mode 100644 index 0000000..8993aae --- /dev/null +++ b/src/ext/libcharsetdetect/mozilla/extensions/universalchardet/src/base/nsUniversalDetector.cpp @@ -0,0 +1,336 @@ +/* -*- Mode: C++; tab-width: 2; 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 "nscore.h" + +#include "nsUniversalDetector.h" + +#include "nsMBCSGroupProber.h" +#include "nsSBCSGroupProber.h" +#include "nsEscCharsetProber.h" +#include "nsLatin1Prober.h" + +#include <iostream> + +nsUniversalDetector::nsUniversalDetector(PRUint32 aLanguageFilter) +{ + mDone = PR_FALSE; + mBestGuess = -1; //illegal value as signal + mInTag = PR_FALSE; + mEscCharSetProber = nsnull; + + mStart = PR_TRUE; + mDetectedCharset = nsnull; + mGotData = PR_FALSE; + mInputState = ePureAscii; + mLastChar = '\0'; + mLanguageFilter = aLanguageFilter; + + PRUint32 i; + for (i = 0; i < NUM_OF_CHARSET_PROBERS; i++) + mCharSetProbers[i] = nsnull; +} + +nsUniversalDetector::~nsUniversalDetector() +{ + for (PRInt32 i = 0; i < NUM_OF_CHARSET_PROBERS; i++) + delete mCharSetProbers[i]; + + delete mEscCharSetProber; +} + +void +nsUniversalDetector::Reset() +{ + mDone = PR_FALSE; + mBestGuess = -1; //illegal value as signal + mInTag = PR_FALSE; + + mStart = PR_TRUE; + mDetectedCharset = nsnull; + mGotData = PR_FALSE; + mInputState = ePureAscii; + mLastChar = '\0'; + + if (mEscCharSetProber) + mEscCharSetProber->Reset(); + + PRUint32 i; + for (i = 0; i < NUM_OF_CHARSET_PROBERS; i++) + if (mCharSetProbers[i]) + mCharSetProbers[i]->Reset(); +} + +//--------------------------------------------------------------------- +#define SHORTCUT_THRESHOLD (float)0.95 +#define MINIMUM_THRESHOLD (float)0.20 + +nsresult nsUniversalDetector::HandleData(const char* aBuf, PRUint32 aLen) +{ + if(mDone) + return NS_OK; + + if (aLen > 0) + mGotData = PR_TRUE; + + //If the data starts with BOM, we know it is UTF + if (mStart) + { + mStart = PR_FALSE; + if (aLen > 2) + switch (aBuf[0]) + { + case '\xEF': + if (('\xBB' == aBuf[1]) && ('\xBF' == aBuf[2])) + // EF BB BF UTF-8 encoded BOM + mDetectedCharset = "UTF-8"; + break; + case '\xFE': + if ('\xFF' == aBuf[1]) + // FE FF UTF-16, big endian BOM + mDetectedCharset = "UTF-16"; + break; + case '\xFF': + if ('\xFE' == aBuf[1]) + // FF FE UTF-16, little endian BOM + mDetectedCharset = "UTF-16"; + break; + } // switch + + if (mDetectedCharset) + { + mDone = PR_TRUE; + return NS_OK; + } + } + + PRUint32 i; + for (i = 0; i < aLen; i++) + { + //other than 0xa0, if every othe character is ascii, the page is ascii + if ((aBuf[i] & '\x80') && aBuf[i] != '\xA0') //Since many Ascii only page contains NBSP + { + //we got a non-ascii byte (high-byte) + if (mInputState != eHighbyte) + { + //adjust state + mInputState = eHighbyte; + + //kill mEscCharSetProber if it is active + if (mEscCharSetProber) { + delete mEscCharSetProber; + mEscCharSetProber = nsnull; + } + + //start multibyte and singlebyte charset prober + if (nsnull == mCharSetProbers[0]) + { + mCharSetProbers[0] = new nsMBCSGroupProber(mLanguageFilter); + if (nsnull == mCharSetProbers[0]) + return NS_ERROR_OUT_OF_MEMORY; + } + if (nsnull == mCharSetProbers[1] && + (mLanguageFilter & NS_FILTER_NON_CJK)) + { + mCharSetProbers[1] = new nsSBCSGroupProber; + if (nsnull == mCharSetProbers[1]) + return NS_ERROR_OUT_OF_MEMORY; + } + if (nsnull == mCharSetProbers[2]) + { + mCharSetProbers[2] = new nsLatin1Prober; + if (nsnull == mCharSetProbers[2]) + return NS_ERROR_OUT_OF_MEMORY; + } + } + } + else + { + //ok, just pure ascii so far + if ( ePureAscii == mInputState && + (aBuf[i] == '\033' || (aBuf[i] == '{' && mLastChar == '~')) ) + { + //found escape character or HZ "~{" + mInputState = eEscAscii; + } + mLastChar = aBuf[i]; + } + } + + nsProbingState st; + switch (mInputState) + { + case eEscAscii: + if (nsnull == mEscCharSetProber) { + mEscCharSetProber = new nsEscCharSetProber(mLanguageFilter); + if (nsnull == mEscCharSetProber) + return NS_ERROR_OUT_OF_MEMORY; + } + st = mEscCharSetProber->HandleData(aBuf, aLen); + if (st == eFoundIt) + { + mDone = PR_TRUE; + mDetectedCharset = mEscCharSetProber->GetCharSetName(); + } + break; + case eHighbyte: + for (i = 0; i < NUM_OF_CHARSET_PROBERS; i++) + { + if (mCharSetProbers[i]) + { + st = mCharSetProbers[i]->HandleData(aBuf, aLen); + if (st == eFoundIt) + { + mDone = PR_TRUE; + mDetectedCharset = mCharSetProbers[i]->GetCharSetName(); + return NS_OK; + } + } + } + break; + + default: //pure ascii + ;//do nothing here + } + return NS_OK; +} + +//--------------------------------------------------------------------- +void nsUniversalDetector::DataEnd() +{ + if (!mGotData) + { + // we haven't got any data yet, return immediately + // caller program sometimes call DataEnd before anything has been sent to detector + return; + } + + if (mDetectedCharset) + { + mDone = PR_TRUE; + Report(mDetectedCharset); + return; + } + + switch (mInputState) + { + case eHighbyte: + { + float proberConfidence; + float maxProberConfidence = (float)0.0; + PRInt32 maxProber = 0; + + for (PRInt32 i = 0; i < NUM_OF_CHARSET_PROBERS; i++) + { + if (mCharSetProbers[i]) + { + proberConfidence = mCharSetProbers[i]->GetConfidence(); + if (proberConfidence > maxProberConfidence) + { + maxProberConfidence = proberConfidence; + maxProber = i; + } + } + } + //do not report anything because we are not confident of it, that's in fact a negative answer + if (maxProberConfidence > MINIMUM_THRESHOLD) + Report(mCharSetProbers[maxProber]->GetCharSetName()); + } + break; + case eEscAscii: + break; + default: + ; + } + return; +} + +///* +void nsUniversalDetector::DataEnd2(float *confidence) +{ + if (!mGotData) + { + // we haven't got any data yet, return immediately + // caller program sometimes call DataEnd before anything has been sent to detector + return; + } + + if (mDetectedCharset) + { + mDone = PR_TRUE; + Report(mDetectedCharset); + // no confidence + *confidence = (float)0.99; + return; + } + + switch (mInputState) + { + case eHighbyte: + { + float proberConfidence; + float maxProberConfidence = (float)0.0; + PRInt32 maxProber = 0; + + for (PRInt32 i = 0; i < NUM_OF_CHARSET_PROBERS; i++) + { + if (mCharSetProbers[i]) + { + proberConfidence = mCharSetProbers[i]->GetConfidence(); + if (proberConfidence > maxProberConfidence) + { + maxProberConfidence = proberConfidence; + maxProber = i; + } + } + } + //do not report anything because we are not confident of it, that's in fact a negative answer + if (maxProberConfidence > MINIMUM_THRESHOLD){ + Report(mCharSetProbers[maxProber]->GetCharSetName()); + *confidence = maxProberConfidence; + } + } + break; + case eEscAscii: + break; + default: + ; + } + return; +} +//*/
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