From 9ef1967af73f66c0e302cae84576fc78b4826637 Mon Sep 17 00:00:00 2001
From: Baptiste Assmann <bedis9@gmail.com>
Date: Sun, 29 Mar 2020 08:10:16 +0200
Subject: [PATCH] MINOR: ist: add istadv() function

The purpose of istadv() function is to move forward <.ptr> by <nb>
characters. It is very useful when parsing a payload.
---
 include/common/ist.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/common/ist.h b/include/common/ist.h
index 2b5178f8c..2b647a22a 100644
--- a/include/common/ist.h
+++ b/include/common/ist.h
@@ -740,6 +740,17 @@ static inline struct ist iststop(const struct ist ist, char chr)
 	return ist2(ist.ptr, len - 1);
 }
 
+/*
+ * advance <.ptr> by <nb> characters.
+ * If <ist> is too short, (ist.end,0) is returned.
+ */
+static inline struct ist istadv(const struct ist ist, const size_t nb)
+{
+	if (ist.len < nb)
+		return ist2(ist.ptr + ist.len, 0);
+	return ist2(ist.ptr + nb, ist.len - nb);
+}
+
 #ifndef IST_FREESTANDING
 /* This function allocates <size> bytes and returns an `ist` pointing to
  * the allocated area with size `0`.