From 9a5d808f7143d16bc5d7800271cfa78f666de111 Mon Sep 17 00:00:00 2001
From: Nathan Straz <nstraz@redhat.com>
Date: Thu, 19 Sep 2013 15:06:55 -0400
Subject: Reduce size of some fields sent on the wire

We don't need 32bits for packet type or remote fd.
Keeping the field small also helps with reading traces.
---
 qarsh_packet.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/qarsh_packet.c b/qarsh_packet.c
index 24f4661..2ca3f13 100644
--- a/qarsh_packet.c
+++ b/qarsh_packet.c
@@ -203,6 +203,20 @@ qp_packet_type(enum qa_packet_type t)
  * Packet parsing functions
  */
 
+char *
+fetch_uint8(char *buf, int *buflen, int *out)
+{
+	uint8_t i;
+	if (*buflen < sizeof i) {
+		lprintf(0, "Not enough data to unpack a uint8_t, %d\n", *buflen);
+		return buf;
+	}
+	memcpy(&i, buf, sizeof i);
+	*out = i;
+	*buflen -= sizeof i;
+	return buf + sizeof i;
+}
+
 char *
 fetch_int(char *buf, int *buflen, int *out)
 {
@@ -338,7 +352,7 @@ parse_qp_rstat(char *buf, int *buflen, struct qa_packet *qp)
 void
 parse_qp_data(char *buf, int *buflen, struct qa_packet *qp)
 {
-	buf = fetch_int(buf, buflen, (int *)&(qp->qp_data.qp_remfd));
+	buf = fetch_uint8(buf, buflen, (int *)&(qp->qp_data.qp_remfd));
 	buf = fetch_off_t(buf, buflen, &(qp->qp_data.qp_offset));
 	buf = fetch_int(buf, buflen, (int *)&(qp->qp_data.qp_count));
 	if (qp->qp_data.qp_count > *buflen) {
@@ -355,7 +369,7 @@ parse_qp_data(char *buf, int *buflen, struct qa_packet *qp)
 void
 parse_qp_data_allow(char *buf, int *buflen, struct qa_packet *qp)
 {
-	buf = fetch_int(buf, buflen, (int *)&(qp->qp_dallow.qp_remfd));
+	buf = fetch_uint8(buf, buflen, (int *)&(qp->qp_dallow.qp_remfd));
 	buf = fetch_int(buf, buflen, (int *)&(qp->qp_dallow.qp_count));
 }
 
@@ -369,7 +383,7 @@ parse_packet(char *buf, int buflen)
 	memset(qp, 0, sizeof *qp);
 
 	buf = fetch_int(buf, &buflen, &(qp->qp_seq));
-	buf = fetch_int(buf, &buflen, (int *)&(qp->qp_type));
+	buf = fetch_uint8(buf, &buflen, (int *)&(qp->qp_type));
 
 	if (qa_pi[qp->qp_type].pi_parse)
 		qa_pi[qp->qp_type].pi_parse(buf, &buflen, qp);
@@ -386,6 +400,14 @@ parse_packet(char *buf, int buflen)
  * Packet serialization functions
  *
  */
+static char *
+store_uint8(char *buf, int i)
+{
+	uint8_t a = i;
+	memcpy(buf, &a, sizeof a);
+	return buf + sizeof a;
+}
+
 static char *
 store_int(char *buf, int i)
 {
@@ -504,7 +526,7 @@ store_qp_rstat(char *buf, struct qa_packet *qp)
 char *
 store_qp_data(char *buf, struct qa_packet *qp)
 {
-	buf = store_int(buf, qp->qp_data.qp_remfd);
+	buf = store_uint8(buf, qp->qp_data.qp_remfd);
 	buf = store_off_t(buf, qp->qp_data.qp_offset);
 	buf = store_void(buf, qp->qp_data.qp_count, qp->qp_data.qp_blob);
 	return buf;
@@ -513,7 +535,7 @@ store_qp_data(char *buf, struct qa_packet *qp)
 char *
 store_qp_data_allow(char *buf, struct qa_packet *qp)
 {
-	buf = store_int(buf, qp->qp_dallow.qp_remfd);
+	buf = store_uint8(buf, qp->qp_dallow.qp_remfd);
 	buf = store_int(buf, qp->qp_dallow.qp_count);
 	return buf;
 }
@@ -528,7 +550,7 @@ qptostr(struct qa_packet *qp, char *qpstr, int maxsize)
 	cp = qpstr;
 
 	cp = store_int(cp, qp->qp_seq);
-	cp = store_int(cp, qp->qp_type);
+	cp = store_uint8(cp, qp->qp_type);
 
 	if (qa_pi[qp->qp_type].pi_store) {
 		cp = qa_pi[qp->qp_type].pi_store(cp, qp);
-- 
cgit