Have pg_itoa, pg_ltoa and pg_lltoa return the length of the string

Core by no means makes excessive use of these functions, but quite a large
number of those usages do require the caller to call strlen() on the
returned string.  This is quite wasteful since these functions do already
have a good idea of the length of the string, so we might as well just
have them return that.

Reviewed-by: Andrew Gierth
Discussion: https://postgr.es/m/CAApHDvrm2A5x2uHYxsqriO2cUaGcFvND%2BksC9e7Tjep0t2RK_A%40mail.gmail.com

1 files changed, 9 insertions, 2 deletions

diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index abba8f1df0..005f68d853 100644
--- a/src/backend/utils/adt/int8.c
+++ b/src/backend/utils/adt/int8.c
@@ -149,9 +149,16 @@ int8out(PG_FUNCTION_ARGS)
 	int64		val = PG_GETARG_INT64(0);
 	char		buf[MAXINT8LEN + 1];
 	char	   *result;
+	int			len;
 
-	pg_lltoa(val, buf);
-	result = pstrdup(buf);
+	len = pg_lltoa(val, buf) + 1;
+
+	/*
+	 * Since the length is already known, we do a manual palloc() and memcpy()
+	 * to avoid the strlen() call that would otherwise be done in pstrdup().
+	 */
+	result = palloc(len);
+	memcpy(result, buf, len);
 	PG_RETURN_CSTRING(result);
 }