Implement SP wire protocolsp

Implements the SP wire protocol, and infrastructure for legacy wire
protocol support.

Also added an XS_SERVICE_ID socket option to set the service id and renamed
the XS_PROTOCOL option to XS_PATTERN_VERSION.

The following pattern versions are supported:

PAIR:     v3
PUBSUB:   v1 (legacy), v4
REQREP:   v2
PIPELINE: v3
SURVEY:   v2

Note that all existing pattern versions have been bumped by 1 to allow for
use of legacy protocols (otherwise there would be no way to distinguish
between e.g. PUBSUB v3 and PUBSUB v3 using SP).

Signed-off-by: Martin Lucina <martin@lucina.net>

1 files changed, 10 insertions, 2 deletions

diff --git a/src/options.hpp b/src/options.hpp
index 805f793..9070c0f 100644
--- a/src/options.hpp
+++ b/src/options.hpp
@@ -92,8 +92,16 @@ namespace xs
         //  If 1, keepalives are to be sent periodically.
         int keepalive;
 
-        //  Version of wire protocol to use.
-        int protocol;
+        //  If true, the legacy non-SP wire protocol is in use.
+        bool legacy_protocol;
+
+        //  SP protocol service id, pattern, version, role and complementary
+        //  role.
+        int sp_service;
+        int sp_pattern;
+        int sp_version;
+        int sp_role;
+        int sp_complement;
 
         //  Filter ID to be used with subscriptions and unsubscriptions.
         int filter;