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, 53 insertions, 0 deletions

diff --git a/src/core.hpp b/src/core.hpp
new file mode 100644
index 0000000..fb50646
--- /dev/null
+++ b/src/core.hpp
@@ -0,0 +1,53 @@
+/*
+    Copyright (c) 2012 250bpm s.r.o.
+    Copyright (c) 2012 Other contributors as noted in the AUTHORS file
+
+    This file is part of Crossroads I/O project.
+
+    Crossroads I/O is free software; you can redistribute it and/or modify it
+    under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    Crossroads is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __XS_CORE_HPP_INCLUDED__
+#define __XS_CORE_HPP_INCLUDED__
+
+#include <stddef.h>
+
+namespace xs
+{
+
+    //  This class is not a core of Crossroads. It's rather a callback interface
+    //  for extensions, ie. what's extensions see as Crossroads core.
+
+    class core_t
+    {
+    public:
+
+        core_t ();
+        virtual ~core_t ();
+
+        virtual int filter_subscribed (const unsigned char *data_,
+            size_t size_);
+        virtual int filter_unsubscribed (const unsigned char *data_,
+            size_t size_);
+        virtual int filter_matching (void *subscriber_);
+
+    private:
+
+        core_t (const core_t&);
+        const core_t &operator = (const core_t&);
+    };
+
+}
+
+#endif