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cuberite-2a/squirrel_3_0_1_stable/sqplus/SqPlusUtf8.cpp

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///////////////////////////////////////////////////////////////////////
// Simple conversion routines, to, from UTF8 and full Unicode character
// (using int).
//
// Only when needed
#if !defined(SQPLUS_USE_LATIN1) || SQPLUS_USE_LATIN1==0
static char g_utf8_length[256];
static int g_did_init_length;
void sqplus_init_utf8_lengths() {
// Fill in lengths in array above
for( int lb=0; lb<256; lb++ ){
int l = -1;
if( !(lb&0x80) ) l=1;
else if( (lb&0xE0)==0xC0 ) l=2;
else if( (lb&0xF0)==0xE0 ) l=3;
else if( (lb&0xF8)==0xF0 ) l=4;
else if( (lb&0xFC)==0xF8 ) l=5;
else if( (lb&0xFE)==0xFC ) l=6;
g_utf8_length[lb] = l;
}
g_did_init_length = 1;
}
// Length of a UTF8 encoded Unicode character
int sqplus_utf8_len(int lead_byte){
if( !(lead_byte&0x80) ) return 1; // Special case, make faster
if( !g_did_init_length )
sqplus_init_utf8_lengths();
return g_utf8_length[(unsigned char)lead_byte];
}
int sqplus_utf8_len_first(const char* pc){
int lb = *(unsigned char*)pc;
if( !(lb&0x80) ) return 1; // Special case, make faster
if( !g_did_init_length )
sqplus_init_utf8_lengths();
int l = g_utf8_length[(unsigned char)lb];
if( l>0 ) return l;
// Invalid UTF8 lead byte. Look for next valid character.
const char *pc1 = pc+1;
while( ((*pc1)&0xC0)==0x80 )
pc1++;
return int(pc1 - pc);
}
// Length of a UTF8 encoded Unicode string (number of Unicode characters)
int sqplus_utf8_strlen(const char *str) {
if( !str ) return 0;
int l, tl=0;
while( *str ){
l = sqplus_utf8_len_first(str);
str += l;
tl++;
}
return tl;
}
// Convert one UTF8 encoded character to Unicode point
int sqplus_utf8_to_wchar(int *result, const char *string){
int res=-1;
// Assume argument pointers to be OK
unsigned char ch = *string;
int l = sqplus_utf8_len(ch);
if( l<1 ) return -1;
int wc = l>1 ? (ch&(0x7F>>l)) : ch;
while( l>1 ){
wc = (wc<<6) + (*++string & 0x3F);
l--;
}
*result = wc;
return 0;
}
// Convert one Unicode point to UTF8 encoded version.
// Checks if output fits in 1/4/6 bytes buffer.
int sqplus_wchar_to_utf8(char *s, int wc, int size){
if( size<1 ) return -1;
if( (unsigned int)wc>=0x80000000 ) return -2;
// Single byte case
if( wc<0x80 ){
*s = (char)wc;
//*s = (char)wc&0x7F;
return 1;
}
if( size<4 ) return -3;
// Two or more UTF8 bytes
int p = 1; // Index of last UTF8 byte
if( wc>0x7FF ){ // 11 bits
// Three or more UTF8 bytes
p++; // p>=2
if( wc>0xFFFF ){ // 16 bits
// Four or more UTF8 bytes
p++; // p>=3
if( wc>0x1FFFFF ){ // 21 bits
// Five or more UTF8 bytes
if( size<6 ) return -3;
p++; // p>=4 UTF8 bytes
if( wc>0x3FFFFFF ){ // 26 bits
// Six UTF8 bytes
p++; // p>=5
if( (unsigned int)wc>(unsigned int)0x7FFFFFF ){ // 31 bits
// Would need 7 UTF8 bytes. Not supported.
return -10;
}
s[p-4] = 0x80 | ((wc>>24)&0x3F); // Bit 24..29
}
s[p-3] = 0x80 | ((wc>>18)&0x3F); // Bit 18..23
}
s[p-2] = 0x80 | ((wc>>12)&0x3F); // Bit 12..17
}
s[p-1] = 0x80 | ((wc>>6)&0x3F); // Bit 6..11
}
s[p] = 0x80 | (wc&0x3F); // Bit 0..5
s[0] = (0xFC << (5-p)) | (wc>>(p*6));
return p+1;
}
#endif // #if !defined(SQPLUS_USE_LATIN1) || SQPLUS_USE_LATIN1==0