warunicode.c

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#include "StdAfx.h"
#include "WarUnicode.h"

/* From RFC 2640 */
size_t war_ucs4_to_utf8(const wchar_t *ucs4_buf, 
                     size_t ucs4_len, 
                     unsigned char *utf8_buf)
                     
{
    const wchar_t *ucs4_endbuf = ucs4_buf + ucs4_len;
    size_t utf8_len = 0;        // return value for UTF8 size
    unsigned char *t_utf8_buf = utf8_buf; // Temporary pointer
    // to load UTF8 values
    
    while (ucs4_buf != ucs4_endbuf)
    {
        if ( *ucs4_buf <= 0x7F)    // ASCII chars no conversion needed
        {
            *t_utf8_buf++ = (unsigned char) *ucs4_buf;
            utf8_len++;
            ucs4_buf++;
        }
        else
            if ( *ucs4_buf <= 0x07FF ) // In the 2 byte utf-8 range
            {
                *t_utf8_buf++= (unsigned char) (0xC0 + (*ucs4_buf/0x40));
                *t_utf8_buf++= (unsigned char) (0x80 + (*ucs4_buf%0x40));
                utf8_len+=2;
                ucs4_buf++;
            }
            else
            if ( *ucs4_buf <= 0xFFFF ) /* In the 3 byte utf-8 range. The
                                       values 0x0000FFFE, 0x0000FFFF
                                       and 0x0000D800 - 0x0000DFFF do
                                       not occur in UCS-4 */
            {
                *t_utf8_buf++= (unsigned char) (0xE0 +
                    (*ucs4_buf/0x1000));
                *t_utf8_buf++= (unsigned char) (0x80 +
                    ((*ucs4_buf/0x40)%0x40));
                *t_utf8_buf++= (unsigned char) (0x80 + (*ucs4_buf%0x40));
                utf8_len+=3;
                ucs4_buf++;
            }
            else
                if ( *ucs4_buf <= 0x1FFFFF ) //In the 4 byte utf-8 range
                {
                    *t_utf8_buf++= (unsigned char) (0xF0 +
                        (*ucs4_buf/0x040000));
                    *t_utf8_buf++= (unsigned char) (0x80 +
                        ((*ucs4_buf/0x10000)%0x40));
                    *t_utf8_buf++= (unsigned char) (0x80 +
                        ((*ucs4_buf/0x40)%0x40));
                    *t_utf8_buf++= (unsigned char) (0x80 + (*ucs4_buf%0x40));
                    utf8_len+=4;
                    ucs4_buf++;
                    
                }
                else
                    if ( *ucs4_buf <= 0x03FFFFFF )//In the 5 byte utf-8 range
                    {
                        *t_utf8_buf++= (unsigned char) (0xF8 +
                            (*ucs4_buf/0x01000000));
                        *t_utf8_buf++= (unsigned char) (0x80 +
                            ((*ucs4_buf/0x040000)%0x40));
                        *t_utf8_buf++= (unsigned char) (0x80 +
                            ((*ucs4_buf/0x1000)%0x40));
                        *t_utf8_buf++= (unsigned char) (0x80 +
                            ((*ucs4_buf/0x40)%0x40));
                        *t_utf8_buf++= (unsigned char) (0x80 +
                            (*ucs4_buf%0x40));
                        utf8_len+=5;
                        ucs4_buf++;
                    }
                    else
                        if ( *ucs4_buf <= 0x7FFFFFFF )//In the 6 byte utf-8 range
                        {
                            *t_utf8_buf++= (unsigned char)
                                (0xF8 +(*ucs4_buf/0x40000000));
                            *t_utf8_buf++= (unsigned char) (0x80 +
                                ((*ucs4_buf/0x01000000)%0x40));
                            *t_utf8_buf++= (unsigned char) (0x80 +
                                ((*ucs4_buf/0x040000)%0x40));
                            *t_utf8_buf++= (unsigned char) (0x80 +
                                ((*ucs4_buf/0x1000)%0x40));
                            *t_utf8_buf++= (unsigned char) (0x80 +
                                ((*ucs4_buf/0x40)%0x40));
                            *t_utf8_buf++= (unsigned char) (0x80 +
                                (*ucs4_buf%0x40));
                            utf8_len+=6;
                            ucs4_buf++;
                            
                        }
    }
    return (utf8_len);
}


/* From RFC 2640 */
int war_utf8_to_ucs4(wchar_t *ucs4_buf, 
                 size_t utf8_len,
                 const unsigned char *utf8_buf)
{
    const unsigned char *utf8_endbuf = utf8_buf + utf8_len;
    size_t ucs_len=0;
    while (utf8_buf != utf8_endbuf)
    {
        if ((*utf8_buf & 0x80) == 0x00)  /*ASCII chars no conversion needed */
        {
            *ucs4_buf++ = (wchar_t) *utf8_buf;
            utf8_buf++;
            ucs_len++;
        }
        else if ((*utf8_buf & 0xE0)== 0xC0) //In the 2 byte utf-8 range
        {
            *ucs4_buf++ = (wchar_t) (((*utf8_buf - 0xC0) * 0x40)
                + ( *(utf8_buf+1) - 0x80));
            utf8_buf += 2;
            ucs_len++;
        }
        else if ( (*utf8_buf & 0xF0) == 0xE0 ) /*In the 3 byte utf-8 range */
        {
            *ucs4_buf++ = (wchar_t) (((*utf8_buf - 0xE0) * 0x1000)
                + (( *(utf8_buf+1) -  0x80) * 0x40)
                + ( *(utf8_buf+2) - 0x80));
                utf8_buf+=3;
            ucs_len++;
        }
        else if ((*utf8_buf & 0xF8) == 0xF0) /* In the 4 byte utf-8 range */
        {
            *ucs4_buf++ = (wchar_t)
                (((*utf8_buf - 0xF0) * 0x040000)
                + (( *(utf8_buf+1) -  0x80) * 0x1000)
                + (( *(utf8_buf+2) -  0x80) * 0x40)
                + ( *(utf8_buf+3) - 0x80));
            utf8_buf+=4;
            ucs_len++;
        } else if ((*utf8_buf & 0xFC) == 0xF8) /* In the 5 byte utf-8 range */
        {
            *ucs4_buf++ = (wchar_t)
                (((*utf8_buf - 0xF8) * 0x01000000)
                + ((*(utf8_buf+1) - 0x80) * 0x040000)
                + (( *(utf8_buf+2) -  0x80) * 0x1000)
                + (( *(utf8_buf+3) -  0x80) * 0x40)
                + ( *(utf8_buf+4) - 0x80));
            utf8_buf+=5;
            ucs_len++;
        }
        else if ((*utf8_buf & 0xFE) == 0xFC) /* In the 6 byte utf-8 range */
        {
            *ucs4_buf++ = (wchar_t)
                (((*utf8_buf - 0xFC) * 0x40000000)
                + ((*(utf8_buf+1) - 0x80) * 0x010000000)
                + ((*(utf8_buf+2) - 0x80) * 0x040000)
                + (( *(utf8_buf+3) -  0x80) * 0x1000)
                + (( *(utf8_buf+4) -  0x80) * 0x40)
                + ( *(utf8_buf+5) - 0x80));
            utf8_buf+=6;
            ucs_len++;
        }
    }
    return (ucs_len);
}

/* From RFC 2640 */
int war_utf8_valid(const unsigned char *buf, size_t len)
{
    const unsigned char *endbuf = buf + len;
    unsigned char byte2mask=0x00, c;
    int trailing = 0;  
    
    while (buf != endbuf)
    {
        c = *buf++;
        if (trailing)
        {
            if ((c&0xC0) == 0x80) 
            {
                if (byte2mask)        
                    if (c&byte2mask)     
                        byte2mask=0x00;
                    else
                        return 0;
                    trailing--; 
            }
            else
                return 0;
        }
        else
        {
            if ((c&0x80) == 0x00)  
                continue;      
            else if ((c&0xE0) == 0xC0)   
            {
                if (c&0x1E)                                           
                    trailing =1;
                else
                    return 0;
            }
            else if ((c&0xF0) == 0xE0)           
            {
                if (!(c&0x0F))                                     
                    byte2mask=0x20;                 
                trailing = 2;
            }
            else if ((c&0xF8) == 0xF0)           
            {
                if (!(c&0x07))                
                    byte2mask=0x30;              
                trailing = 3;
            }
            else if ((c&0xFC) == 0xF8)           
            {
                if (!(c&0x03))                                     
                    byte2mask=0x38;              
                trailing = 4;
            }
            else if ((c&0xFE) == 0xFC)           
            {
                if (!(c&0x01))
                    byte2mask=0x3C;
                trailing = 5;}
            else  
                return 0;
        }
    }
    return trailing == 0;
}