XS_PLUGIN and XS_FILTER implementation

This patch introduces following features:
- XS_PLUGIN context option to add plugins to libxs
- XS_FILTER option to switch between different filter types
- Automatic loading of plug-ins is *not* implemented.

From the implementation point of view:
- standard prefix filter is implemented as a pluggable filter
- trie_t and mtrie_t are joined into a single class
- the code for 0MQ/3.1 compatibility is left in in the form of comments
- new test for testing re-subscriptions is added
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/options.cpp b/src/options.cpp
index c9cbaae..fdbffde 100644
--- a/src/options.cpp
+++ b/src/options.cpp
@@ -23,6 +23,8 @@
 #include <string.h>
 #include <limits>
 
+#include "../include/xs.h"
+
 #include "options.hpp"
 #include "err.hpp"
 
@@ -47,6 +49,7 @@ xs::options_t::options_t () :
     ipv4only (1),
     keepalive (0),
     protocol (0),
+    filter_id (XS_FILTER_PREFIX),
     delay_on_close (true),
     delay_on_disconnect (true),
     filter (false),
@@ -248,6 +251,14 @@ int xs::options_t::setsockopt (int option_, const void *optval_,
             return 0;
         }
 
+    case XS_FILTER:
+        if (optvallen_ != sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        filter_id = *((int*) optval_);
+        return 0;
+
     }
 
     errno = EINVAL;
@@ -438,6 +449,15 @@ int xs::options_t::getsockopt (int option_, void *optval_, size_t *optvallen_)
         *optvallen_ = sizeof (int);
         return 0;
 
+    case XS_FILTER:
+        if (*optvallen_ < sizeof (int)) {
+            errno = EINVAL;
+            return -1;
+        }
+        *((int*) optval_) = filter_id;
+        *optvallen_ = sizeof (int);
+        return 0;
+
     }
 
     errno = EINVAL;