From: Christopher Faulet <cfaulet@haproxy.com>
Date: Fri, 17 Nov 2023 09:52:36 +0000 (+0100)
Subject: MINOR: htx: Use a macro for overhead induced by HTX
X-Git-Tag: v2.9-dev10~45
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=7393bf7e424d4cd2e0927bf4dc95eb799ec67dd4;p=thirdparty%2Fhaproxy.git

MINOR: htx: Use a macro for overhead induced by HTX

The overhead induced by the HTX format was set to the HTX structure itself
and two HTX blocks. It was set this way to optimize zero-copy during
transfers. This value may (and will) be used at different places. Thus we
now use a macro, called HTX_BUF_OVERHEAD.
---

diff --git a/include/haproxy/htx-t.h b/include/haproxy/htx-t.h
index 687e403c7b..2ea6bc8b2b 100644
--- a/include/haproxy/htx-t.h
+++ b/include/haproxy/htx-t.h
@@ -164,6 +164,12 @@ static forceinline char *hsl_show_flags(char *buf, size_t len, const char *delim
 #undef _
 }
 
+/* Overhead induced by HTX on buffers during transfers. In addition to the size
+ * of the HTX structure itself, and meta data for one block, another block is
+ * accounted to favored zero-copy xfer.
+ */
+#define HTX_BUF_OVERHEAD     (sizeof(struct htx) + 2 * sizeof(struct htx_blk))
+
 /* HTX flags.
  * Please also update the htx_show_flags() function below in case of changes.
  */
diff --git a/include/haproxy/htx.h b/include/haproxy/htx.h
index 59e885a670..c991c81e5c 100644
--- a/include/haproxy/htx.h
+++ b/include/haproxy/htx.h
@@ -673,10 +673,10 @@ static inline size_t buf_room_for_htx_data(const struct buffer *buf)
 	size_t room;
 
 	room = b_room(buf);
-	if (room <= sizeof(struct htx) + 2 * sizeof(struct htx_blk))
+	if (room <= HTX_BUF_OVERHEAD)
 		room = 0;
 	else
-		room -= sizeof(struct htx) + 2 * sizeof(struct htx_blk);
+		room -= HTX_BUF_OVERHEAD;
 
 	return room;
 }