index 3db5ca9b6cf1d296ca0e6f128cba353e55ab145f..c9d61de41808fcafde3bf566ad3afa924e5eb396 100644 (file)
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/regexp.c,v 1.62 2006年03月05日 15:58:43 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/regexp.c,v 1.63 2006年04月13日 18:01:31 tgl Exp $
*
* Alistair Crooks added the code for the regex caching
* agc - cached the regular expressions used - there's a good chance
errhint("Escape string must be empty or one character.")));
}
- /* We need room for ^, ,ドル and up to 2 output bytes per input byte */
- result = (text *) palloc(VARHDRSZ + 2 + 2 * plen);
+ /*----------
+ * We surround the transformed input string with
+ * ***:^(?: ... )$
+ * which is bizarre enough to require some explanation. "***:" is a
+ * director prefix to force the regex to be treated as an ARE regardless
+ * of the current regex_flavor setting. We need "^" and "$" to force
+ * the pattern to match the entire input string as per SQL99 spec. The
+ * "(?:" and ")" are a non-capturing set of parens; we have to have
+ * parens in case the string contains "|", else the "^" and "$" will
+ * be bound into the first and last alternatives which is not what we
+ * want, and the parens must be non capturing because we don't want them
+ * to count when selecting output for SUBSTRING.
+ *----------
+ */
+
+ /*
+ * We need room for the prefix/postfix plus as many as 2 output bytes per
+ * input byte
+ */
+ result = (text *) palloc(VARHDRSZ + 10 + 2 * plen);
r = VARDATA(result);
+ *r++ = '*';
+ *r++ = '*';
+ *r++ = '*';
+ *r++ = ':';
*r++ = '^';
+ *r++ = '(';
+ *r++ = '?';
+ *r++ = ':';
while (plen > 0)
{
p++, plen--;
}
+ *r++ = ')';
*r++ = '$';
VARATT_SIZEP(result) = r - ((char *) result);