lib: loadable versioned modules (api subject to change)

1 files changed, 63 insertions, 0 deletions

diff --git a/lib/module.h b/lib/module.h
new file mode 100644
index 00000000..6a65d8f7
--- /dev/null
+++ b/lib/module.h
@@ -0,0 +1,63 @@
+/*  Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <libknot/processing/layer.h>
+
+/*
+ * Forward decls
+ */
+struct kr_module;
+
+/*
+ * API definition.
+ */
+#define KR_MODULE_API 0x20150401 /*!< API version */
+typedef uint32_t (module_api_cb)(void);
+typedef int (module_init_cb)(struct kr_module *);
+typedef int (module_deinit_cb)(struct kr_module *);
+typedef int (module_config_cb)(struct kr_module *, void *);
+typedef const knot_layer_api_t* (module_layer_cb)(void);
+
+/*! Loaded module representation. */ 
+struct kr_module {
+    module_init_cb   *init;   /*!< Constructor */
+    module_deinit_cb *deinit; /*!< Destructor */
+    module_config_cb *config; /*!< Configuration */
+    module_layer_cb  *layer;  /*!< Layer getter */
+    void *lib;                /*!< Shared library handle or RTLD_DEFAULT */
+    void *data;               /*!< Custom data context. */
+};
+
+/*! Load module instance into memory.
+ * @param module module structure
+ * @param name module name
+ * @param path module search path
+ * @return 0 or an error
+ */
+int kr_module_load(struct kr_module *module, const char *name,  const char *path);
+
+/*! Unload module instance.
+ * @param module module structure
+ */
+void kr_module_unload(struct kr_module *module);
+
+/*! Export module API version (place this at the end of your module).
+ * @param module module name (f.e. hints)
+ */
+#define KR_MODULE_EXPORT(module) \
+    uint32_t module ## _api() { return KR_MODULE_API; }
\ No newline at end of file