ZMQ_FILTER socket option added

This option is a performance tweak. In devices XSUB socket filters
the messages just to send them to XPUB socket which filters them
once more. Setting ZMQ_FILTER option to 0 allows to switch the
filtering in XSUB socket off.

Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/options.cpp b/src/options.cpp
index 271ebdb..29cf023 100644
--- a/src/options.cpp
+++ b/src/options.cpp
@@ -38,6 +38,7 @@ zmq::options_t::options_t () :
     reconnect_ivl_max (0),
     backlog (100),
     maxmsgsize (-1),
+    filter (1),
     immediate_connect (true)
 {
 }
@@ -172,6 +173,15 @@ int zmq::options_t::setsockopt (int option_, const void *optval_,
         multicast_hops = *((int*) optval_);
         return 0;
 
+    case ZMQ_FILTER:
+        if (optvallen_ != sizeof (int) || (*((int*) optval_) != 0 &&
+                *((int*) optval_) != 1)) {
+            errno = EINVAL;
+            return -1;
+        }
+        filter = *((int*) optval_);
+        return 0;
+
     }
 
     errno = EINVAL;
@@ -317,6 +327,15 @@ int zmq::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
         *optvallen_ = sizeof (int);
         return 0;
 
+    case ZMQ_FILTER:
+        if (*optvallen_ < sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        *((int*) optval_) = filter;
+        *optvallen_ = sizeof (int);
+        return 0;
+
     }
 
     errno = EINVAL;