[Spice-devel] [PATCH spice-protocol 1/2] Add support for a header without sub list.

[Yonit Halperin]

Add SpiceDataHeaderNoSub.
Introduce capability SPICE_COMMON_CAP_HEADER_NO_SUB.
Introduce SPICE_MSG_LIST: the msg body is SpiceSubMessageList.

The advantage of using a header without sub list is to spare the 4 bytes that were sent
for a lot of messages without sublist.
Instead, messages that previously contained sub lists, will be split to two msgs.
The first one will be SPICE_MSG_LIST, holding the sub list, and the second will be the
main msg.
When most of the messages do not contain sub lists, the overhead of the additional 10 bytes
for the header of SPICE_MSG_LIST is negligible.
---
 spice/enums.h    |    1 +
 spice/protocol.h |    9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/spice/enums.h b/spice/enums.h
index a587b00..0314f0b 100644
--- a/spice/enums.h
+++ b/spice/enums.h
@@ -344,6 +344,7 @@ enum {
     SPICE_MSG_WAIT_FOR_CHANNELS,
     SPICE_MSG_DISCONNECTING,
     SPICE_MSG_NOTIFY,
+    SPICE_MSG_LIST,
 };
 
 enum {
diff --git a/spice/protocol.h b/spice/protocol.h
index ddfe84b..cbd8295 100644
--- a/spice/protocol.h
+++ b/spice/protocol.h
@@ -37,7 +37,7 @@
 
 #define SPICE_MAGIC (*(uint32_t*)"REDQ")
 #define SPICE_VERSION_MAJOR 2
-#define SPICE_VERSION_MINOR 1
+#define SPICE_VERSION_MINOR 2
 
 // Encryption & Ticketing Parameters
 #define SPICE_MAX_PASSWORD_LENGTH 60
@@ -55,6 +55,7 @@ enum {
     SPICE_COMMON_CAP_PROTOCOL_AUTH_SELECTION,
     SPICE_COMMON_CAP_AUTH_SPICE,
     SPICE_COMMON_CAP_AUTH_SASL,
+    SPICE_COMMON_CAP_HEADER_NO_SUB,
 };
 
 typedef struct SPICE_ATTR_PACKED SpiceLinkMess {
@@ -89,6 +90,12 @@ typedef struct SPICE_ATTR_PACKED SpiceDataHeader {
     uint32_t sub_list; //offset to SpiceSubMessageList[]
 } SpiceDataHeader;
 
+typedef struct SPICE_ATTR_PACKED SpiceDataHeaderNoSub {
+    uint64_t serial;
+    uint16_t type;
+    uint32_t size;
+} SpiceDataHeaderNoSub;
+
 typedef struct SPICE_ATTR_PACKED SpiceSubMessage {
     uint16_t type;
     uint32_t size;
-- 
1.7.6.4