From dad75eb4a8d5835ecc795d7a7978e7702e4d5912 Mon Sep 17 00:00:00 2001
From: David Rowley <drowley@postgresql.org>
Date: Sat, 13 Jun 2020 12:32:00 +1200
Subject: 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
---
 src/backend/utils/adt/numutils.c | 32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

(limited to 'src/backend/utils/adt/numutils.c')

diff --git a/src/backend/utils/adt/numutils.c b/src/backend/utils/adt/numutils.c
index a9d3fbf758f..412ae361d2c 100644
--- a/src/backend/utils/adt/numutils.c
+++ b/src/backend/utils/adt/numutils.c
@@ -327,16 +327,17 @@ invalid_syntax:
 
 /*
  * pg_itoa: converts a signed 16-bit integer to its string representation
+ * and returns strlen(a).
  *
  * Caller must ensure that 'a' points to enough memory to hold the result
  * (at least 7 bytes, counting a leading sign and trailing NUL).
  *
  * It doesn't seem worth implementing this separately.
  */
-void
+int
 pg_itoa(int16 i, char *a)
 {
-	pg_ltoa((int32) i, a);
+	return pg_ltoa((int32) i, a);
 }
 
 /*
@@ -404,25 +405,27 @@ pg_ultoa_n(uint32 value, char *a)
 }
 
 /*
- * NUL-terminate the output of pg_ultoa_n.
+ * pg_ltoa: converts a signed 32-bit integer to its string representation and
+ * returns strlen(a).
  *
  * It is the caller's responsibility to ensure that a is at least 12 bytes long,
  * which is enough room to hold a minus sign, a maximally long int32, and the
  * above terminating NUL.
  */
-void
+int
 pg_ltoa(int32 value, char *a)
 {
 	uint32		uvalue = (uint32) value;
-	int			len;
+	int			len = 0;
 
 	if (value < 0)
 	{
 		uvalue = (uint32) 0 - uvalue;
-		*a++ = '-';
+		a[len++] = '-';
 	}
-	len = pg_ultoa_n(uvalue, a);
+	len += pg_ultoa_n(uvalue, a + len);
 	a[len] = '\0';
+	return len;
 }
 
 /*
@@ -510,24 +513,27 @@ pg_ulltoa_n(uint64 value, char *a)
 }
 
 /*
- * pg_lltoa: convert a signed 64-bit integer to its string representation
+ * pg_lltoa: converts a signed 64-bit integer to its string representation and
+ * returns strlen(a).
  *
  * Caller must ensure that 'a' points to enough memory to hold the result
  * (at least MAXINT8LEN + 1 bytes, counting a leading sign and trailing NUL).
  */
-void
+int
 pg_lltoa(int64 value, char *a)
 {
-	int			len;
 	uint64		uvalue = value;
+	int			len = 0;
 
 	if (value < 0)
 	{
-		*a++ = '-';
 		uvalue = (uint64) 0 - uvalue;
+		a[len++] = '-';
 	}
-	len = pg_ulltoa_n(uvalue, a);
-	a[len] = 0;
+
+	len += pg_ulltoa_n(uvalue, a + len);
+	a[len] = '\0';
+	return len;
 }
 
 
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