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// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html 
/* 
 ********************************************************************** 
 *   Copyright (C) 2005-2016, International Business Machines 
 *   Corporation and others.  All Rights Reserved. 
 ********************************************************************** 
 */ 
 
#include "unicode/utypes.h" 
 
#if !UCONFIG_NO_CONVERSION 
 
#include "inputext.h" 
 
#include "cmemory.h" 
#include "cstring.h" 
 
#include <string.h> 
 
U_NAMESPACE_BEGIN 
 
#define BUFFER_SIZE 8192 
 
#define NEW_ARRAY(type,count) (type *) uprv_malloc((count) * sizeof(type)) 
#define DELETE_ARRAY(array) uprv_free((void *) (array)) 
 
InputText::InputText(UErrorCode &status) 
    : fInputBytes(NEW_ARRAY(uint8_t, BUFFER_SIZE)), // The text to be checked.  Markup will have been 
                                                 //   removed if appropriate. 
      fByteStats(NEW_ARRAY(int16_t, 256)),       // byte frequency statistics for the input text. 
                                                 //   Value is percent, not absolute. 
      fDeclaredEncoding(0), 
      fRawInput(0), 
      fRawLength(0) 
{ 
    if (fInputBytes == NULL || fByteStats == NULL) { 
        status = U_MEMORY_ALLOCATION_ERROR; 
    } 
} 
 
InputText::~InputText() 
{ 
    DELETE_ARRAY(fDeclaredEncoding); 
    DELETE_ARRAY(fByteStats); 
    DELETE_ARRAY(fInputBytes); 
} 
 
void InputText::setText(const char *in, int32_t len) 
{ 
    fInputLen  = 0; 
    fC1Bytes   = FALSE; 
    fRawInput  = (const uint8_t *) in; 
    fRawLength = len == -1? (int32_t)uprv_strlen(in) : len; 
} 
 
void InputText::setDeclaredEncoding(const char* encoding, int32_t len) 
{ 
    if(encoding) { 
        if (len == -1) { 
            len = (int32_t)uprv_strlen(encoding); 
        } 
 
        len += 1;     // to make place for the \0 at the end. 
        uprv_free(fDeclaredEncoding); 
        fDeclaredEncoding = NEW_ARRAY(char, len); 
        uprv_strncpy(fDeclaredEncoding, encoding, len); 
    } 
} 
 
UBool InputText::isSet() const  
{ 
    return fRawInput != NULL; 
} 
 
/** 
*  MungeInput - after getting a set of raw input data to be analyzed, preprocess 
*               it by removing what appears to be html markup. 
*  
* @internal 
*/ 
void InputText::MungeInput(UBool fStripTags) { 
    int     srci = 0; 
    int     dsti = 0; 
    uint8_t b; 
    bool    inMarkup = FALSE; 
    int32_t openTags = 0; 
    int32_t badTags  = 0; 
 
    // 
    //  html / xml markup stripping. 
    //     quick and dirty, not 100% accurate, but hopefully good enough, statistically. 
    //     discard everything within < brackets > 
    //     Count how many total '<' and illegal (nested) '<' occur, so we can make some 
    //     guess as to whether the input was actually marked up at all. 
    // TODO: Think about how this interacts with EBCDIC charsets that are detected. 
    if (fStripTags) { 
        for (srci = 0; srci < fRawLength && dsti < BUFFER_SIZE; srci += 1) { 
            b = fRawInput[srci]; 
 
            if (b == (uint8_t)0x3C) { /* Check for the ASCII '<' */ 
                if (inMarkup) { 
                    badTags += 1; 
                } 
 
                inMarkup = TRUE; 
                openTags += 1; 
            } 
 
            if (! inMarkup) { 
                fInputBytes[dsti++] = b; 
            } 
 
            if (b == (uint8_t)0x3E) { /* Check for the ASCII '>' */ 
                inMarkup = FALSE; 
            } 
        } 
 
        fInputLen = dsti; 
    } 
 
    // 
    //  If it looks like this input wasn't marked up, or if it looks like it's 
    //    essentially nothing but markup abandon the markup stripping. 
    //    Detection will have to work on the unstripped input. 
    // 
    if (openTags<5 || openTags/5 < badTags ||  
        (fInputLen < 100 && fRawLength>600)) 
    { 
        int32_t limit = fRawLength; 
 
        if (limit > BUFFER_SIZE) { 
            limit = BUFFER_SIZE; 
        } 
 
        for (srci=0; srci<limit; srci++) { 
            fInputBytes[srci] = fRawInput[srci]; 
        } 
 
        fInputLen = srci; 
    } 
 
    // 
    // Tally up the byte occurence statistics. 
    // These are available for use by the various detectors. 
    // 
 
    uprv_memset(fByteStats, 0, (sizeof fByteStats[0]) * 256); 
 
    for (srci = 0; srci < fInputLen; srci += 1) { 
        fByteStats[fInputBytes[srci]] += 1; 
    } 
 
    for (int32_t i = 0x80; i <= 0x9F; i += 1) { 
        if (fByteStats[i] != 0) { 
            fC1Bytes = TRUE; 
            break; 
        } 
    } 
} 
 
U_NAMESPACE_END 
#endif