From: Willy Tarreau <w@1wt.eu>
Date: Thu, 23 Feb 2023 08:52:42 +0000 (+0100)
Subject: MINOR: buf: add b_add_ofs() to add a count to an absolute position
X-Git-Tag: v3.0-dev6~52
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=15e47b6a5970ad90f9e4ae53f157863aac0fa23a;p=thirdparty%2Fhaproxy.git

MINOR: buf: add b_add_ofs() to add a count to an absolute position

This function is used to compute a new absolute buffer offset by adding a
length to an existing valid offset. It will check for wrapping.
---

diff --git a/include/haproxy/buf.h b/include/haproxy/buf.h
index 59484684a5..b24ec7902e 100644
--- a/include/haproxy/buf.h
+++ b/include/haproxy/buf.h
@@ -91,6 +91,18 @@ static inline size_t b_full(const struct buffer *b)
 	return !b_room(b);
 }
 
+/* b_add_ofs() : return new offset within buffer after applying wrapping. Only
+ * offsets resulting from initial positions added to counts within buffer size
+ * limits are handled.
+ */
+static inline size_t b_add_ofs(const struct buffer *b, size_t ofs, size_t count)
+{
+	ofs += count;
+	if (ofs >= b->size)
+		ofs -= b->size;
+	return ofs;
+}
+
 
 /* b_stop() : returns the pointer to the byte following the end of the buffer,
  * which may be out of the buffer if the buffer ends on the last byte of the