Implement SP wire protocol

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, 32 insertions, 0 deletions

diff --git a/src/xrespondent.cpp b/src/xrespondent.cpp
index c16d900..9d949ce 100644
--- a/src/xrespondent.cpp
+++ b/src/xrespondent.cpp
@@ -35,6 +35,10 @@ xs::xrespondent_t::xrespondent_t (class ctx_t *parent_, uint32_t tid_,
     next_peer_id (generate_random ())
 {
     options.type = XS_XRESPONDENT;
+    options.sp_pattern = SP_SURVEY;
+    options.sp_version = 2;
+    options.sp_role = SP_SURVEY_RESPONDENT;
+    options.sp_complement = SP_SURVEY_SURVEYOR;
 
     //  If the connection disappears it makes no sense to read any more surveys
     //  from it. The responses will be unroutable anyway.
@@ -49,6 +53,34 @@ xs::xrespondent_t::~xrespondent_t ()
     prefetched_msg.close ();
 }
 
+int xs::xrespondent_t::xsetsockopt (int option_, const void *optval_,
+    size_t optvallen_)
+{
+    if (option_ != XS_PATTERN_VERSION) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if (optvallen_ != sizeof (int)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if (!optval_) {
+        errno = EFAULT;
+        return -1;
+    }
+
+    int version = *(int *) optval_;
+    if (version != 1) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    options.sp_version = version;
+    return 0;
+}
+
 void xs::xrespondent_t::xattach_pipe (pipe_t *pipe_, bool icanhasall_)
 {
     xs_assert (pipe_);