/*********************************************************************//**
Determine how many bytes the first n characters of the given string occupy.
If the string is shorter than n characters, returns the number of bytes
the characters in the string occupy.
@return length of the prefix, in bytes */
UNIV_INTERN
ulint
dtype_get_at_most_n_mbchars(
/*========================*/
ulint prtype, /*!< in: precise type */
ulint mbminmaxlen, /*!< in: minimum and maximum length of
a multi-byte character */
ulint prefix_len, /*!< in: length of the requested
prefix, in characters, multiplied by
dtype_get_mbmaxlen(dtype) */
ulint data_len, /*!< in: length of str (in bytes) */
const char* str) /*!< in: the string whose prefix
length is being determined */
{
ulint mbminlen = DATA_MBMINLEN(mbminmaxlen);
ulint mbmaxlen = DATA_MBMAXLEN(mbminmaxlen);
ut_a(data_len != UNIV_SQL_NULL);
ut_ad(!mbmaxlen || !(prefix_len % mbmaxlen));
if (mbminlen != mbmaxlen) {
ut_a(!(prefix_len % mbmaxlen));
return(innobase_get_at_most_n_mbchars(
dtype_get_charset_coll(prtype),
prefix_len, data_len, str));
}
if (prefix_len < data_len) {
return(prefix_len);
}
return(data_len);
}
ulint
dtype_get_at_most_n_mbchars(
/*========================*/
/* out: length of the prefix,
in bytes */
ulint prtype, /* in: precise type */
ulint mbminlen, /* in: minimum length of a
multi-byte character */
ulint mbmaxlen, /* in: maximum length of a
multi-byte character */
ulint prefix_len, /* in: length of the requested
prefix, in characters, multiplied by
dtype_get_mbmaxlen(dtype) */
ulint data_len, /* in: length of str (in bytes) */
const char* str) /* in: the string whose prefix
length is being determined */
{
#ifndef UNIV_HOTBACKUP
ut_a(data_len != UNIV_SQL_NULL);
ut_ad(!mbmaxlen || !(prefix_len % mbmaxlen));
if (mbminlen != mbmaxlen) {
ut_a(!(prefix_len % mbmaxlen));
return(innobase_get_at_most_n_mbchars(
dtype_get_charset_coll(prtype),
prefix_len, data_len, str));
}
if (prefix_len < data_len) {
return(prefix_len);
}
return(data_len);
#else /* UNIV_HOTBACKUP */
/* This function depends on MySQL code that is not included in
InnoDB Hot Backup builds. Besides, this function should never
be called in InnoDB Hot Backup. */
ut_error;
#endif /* UNIV_HOTBACKUP */
}
