From: Willy Tarreau <w@1wt.eu>
Date: Fri, 6 Dec 2013 22:43:17 +0000 (+0100)
Subject: DIET/MINOR: http: reduce the size of struct http_txn by 8 bytes
X-Git-Tag: v1.5-dev20~78
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c8987b3664a703440ed80a2086d262898873d173;p=thirdparty%2Fhaproxy.git

DIET/MINOR: http: reduce the size of struct http_txn by 8 bytes

Here again we had some oversized and misaligned entries. The method
and the status don't need 4 bytes each, and there was a hole after
the status that does not exist anymore. That's 8 additional bytes
saved from http_txn and as much for the session.

Also some fields were slightly moved to present better memory access
patterns resulting in a steady 0.5% performance increase.
---

diff --git a/include/types/proto_http.h b/include/types/proto_http.h
index 5a671b0b90..52c3c70b18 100644
--- a/include/types/proto_http.h
+++ b/include/types/proto_http.h
@@ -217,7 +217,7 @@ enum {
 };
 
 /* Known HTTP methods */
-typedef enum {
+enum http_meth_t {
 	HTTP_METH_NONE = 0,
 	HTTP_METH_OPTIONS,
 	HTTP_METH_GET,
@@ -228,7 +228,7 @@ typedef enum {
 	HTTP_METH_TRACE,
 	HTTP_METH_CONNECT,
 	HTTP_METH_OTHER,
-} http_meth_t;
+} __attribute__((packed));
 
 enum {
 	HTTP_AUTH_WRONG		= -1,		/* missing or unknown */
@@ -405,13 +405,13 @@ struct http_res_rule {
  * response message (which can be empty).
  */
 struct http_txn {
-	struct http_msg req;            /* HTTP request message */
 	struct hdr_idx hdr_idx;         /* array of header indexes (max: global.tune.max_http_hdr) */
-	unsigned int flags;             /* transaction flags */
-	http_meth_t meth;               /* HTTP method */
-
-	int status;                     /* HTTP status from the server, negative if from proxy */
 	struct http_msg rsp;            /* HTTP response message */
+	struct http_msg req;            /* HTTP request message */
+	unsigned int flags;             /* transaction flags */
+	enum http_meth_t meth;          /* HTTP method */
+	/* 1 unused byte here */
+	short status;                   /* HTTP status from the server, negative if from proxy */
 
 	char *uri;                      /* first line if log needed, NULL otherwise */
 	char *cli_cookie;               /* cookie presented by the client, in capture mode */
diff --git a/src/proto_http.c b/src/proto_http.c
index a06b0ec8ec..c8705d4745 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -294,7 +294,7 @@ void init_proto_http()
  * up to 3 entries (2 valid, 1 null).
  */
 struct http_method_desc {
-	http_meth_t meth;
+	enum http_meth_t meth;
 	int len;
 	const char text[8];
 };
@@ -767,7 +767,7 @@ struct chunk *http_error_message(struct session *s, int msgnum)
  * returns HTTP_METH_NONE if there is nothing valid to read (empty or non-text
  * string), HTTP_METH_OTHER for unknown methods, or the identified method.
  */
-static http_meth_t find_http_meth(const char *str, const int len)
+static enum http_meth_t find_http_meth(const char *str, const int len)
 {
 	unsigned char m;
 	const struct http_method_desc *h;