/* Unescape the buffer pointed to by s 'in-place' using the (un)escape mechanizm
described at http://www.postgresql.org/docs/9.0/static/datatype-binary.html
The new size of s is assigned to r. Returns s. See PostgresqlResultSet_getBlob()
below for usage and further info. See also Postgres' PQunescapeBytea() function
which this function mirrors except it does not allocate a new string.
*/
static inline const void *unescape_bytea(uchar_t *s, int len, int *r) {
assert(s);
register int i, j;
if (s[0] == '\\' && s[1] == 'x') { // bytea hex format
static const uchar_t hex[128] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0,
0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 10, 11, 12, 13, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
for (i = 0, j = 2; j < len; j++) {
/*
According to the doc, whitespace between hex pairs are allowed. Blarg!!
*/
if (isxdigit(s[j])) {
s[i] = hex[s[j]] << 4;
s[i] |= hex[s[j + 1]];
i++;
j++;
}
}
} else { // bytea escaped format
uchar_t byte;
for (i = j = 0; j < len; i++, j++) {
if ((s[i] = s[j]) == '\\') {
if (s[j + 1] == '\\')
j++;
else if ((ISFIRSTOCTDIGIT(s[j + 1]))
&& (ISOCTDIGIT(s[j + 2]))
&& (ISOCTDIGIT(s[j + 3]))) {
byte = OCTVAL(s[j + 1]);
byte = (byte << 3) + OCTVAL(s[j + 2]);
byte = (byte << 3) + OCTVAL(s[j + 3]);
s[i] = byte;
j += 3;
}
}
}
}
*r = i;
if (i < j)
s[i] = 0; // If unescape was performed, terminate the buffer to mirror postgres behavior
return s;
}
int esc( const tchar * * s)
{
/* Map escape sequences into their equivalent symbols. Return
* the equivalent ASCII character. *s is advanced past the
* escape sequence. If no escape sequence is present, the
* current character is returned and the string is advanced by
* one. The following are recognized:
*
* \b backspace
* \f formfeed
* \n newline
* \r carriage return
* \s space
* \t tab
* \e ASCII ESC character ('\033')
* \DDD number formed of 1-3 octal digits
* \xDDD number formed of 1-3 hex digits
* \^C C = any letter. Control code
*/
int rval;
if( **s != _T('\\') )
rval = *( (*s)++ );
else {
++(*s); /* Skip the \ */
switch( toupper(**s) ) {
case _T('\0'): rval = _T('\\'); break;
case _T('B'): rval = _T('\b') ; break;
case _T('F'): rval = _T('\f') ; break;
case _T('N'): rval = _T('\n') ; break;
case _T('R'): rval = _T('\r') ; break;
case _T('S'): rval = _T(' ') ; break;
case _T('T'): rval = _T('\t') ; break;
case _T('E'): rval = _T('\033'); break;
case _T('^'):
rval = *++(*s) ;
rval = _toupper(rval) - _T('@') ;
break;
case _T('X'):
rval = 0;
++(*s);
if( ISHEXDIGIT(**s) ) {
rval = hex2bin( *(*s)++ );
}
if( ISHEXDIGIT(**s) ) {
rval <<= 4;
rval |= hex2bin( *(*s)++ );
}
if( ISHEXDIGIT(**s) ) {
rval <<= 4;
rval |= hex2bin( *(*s)++ );
}
--(*s);
break;
default:
if( !ISOCTDIGIT(**s) )
rval = **s;
else {
++(*s);
rval = oct2bin( *(*s)++ );
if( ISOCTDIGIT(**s) ) {
rval <<= 3;
rval |= oct2bin( *(*s)++ );
}
if( ISOCTDIGIT(**s) ) {
rval <<= 3;
rval |= oct2bin( *(*s)++ );
}
--(*s);
}
break;
}
++(*s);
}
return rval;
}
