Move testfilter, router etc to examples

Also changed Plugin devel manual to match. Modified roundrobinrouter
to use static_cast due to the change in router api definitions.

examples/testroute.c

@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2016 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2019-07-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+#include <stdio.h>
+#include <maxscale/alloc.h>
+#include <maxscale/router.h>
+#include <maxscale/modinfo.h>
+
+static MXS_ROUTER *createInstance(SERVICE *service, char **options);
+static MXS_ROUTER_SESSION *newSession(MXS_ROUTER *instance, MXS_SESSION *session);
+static void closeSession(MXS_ROUTER *instance, MXS_ROUTER_SESSION *session);
+static void freeSession(MXS_ROUTER *instance, MXS_ROUTER_SESSION *session);
+static int routeQuery(MXS_ROUTER *instance, MXS_ROUTER_SESSION *session, GWBUF *queue);
+static void clientReply(MXS_ROUTER *instance, MXS_ROUTER_SESSION *session, GWBUF *queue, DCB*);
+static void diagnostic(MXS_ROUTER *instance, DCB *dcb);
+static uint64_t getCapabilities(MXS_ROUTER* instance);
+static void handleError(MXS_ROUTER *instance,
+                        MXS_ROUTER_SESSION *router_session,
+                        GWBUF *errbuf,
+                        DCB *backend_dcb,
+                        mxs_error_action_t action,
+                        bool *succp);
+
+typedef struct
+{
+} TESTROUTER;
+
+typedef struct
+{
+} TESTSESSION;
+
+/**
+ * The module entry point routine. It is this routine that
+ * must populate the structure that is referred to as the
+ * "module object", this is a structure with the set of
+ * external entry points for this module.
+ *
+ * @return The module object
+ */
+MXS_MODULE* MXS_CREATE_MODULE()
+{
+    static MXS_ROUTER_OBJECT MyObject =
+    {
+        createInstance,
+        newSession,
+        closeSession,
+        freeSession,
+        routeQuery,
+        diagnostic,
+        clientReply,
+        handleError,
+        getCapabilities,
+        NULL
+    };
+
+    static MXS_MODULE info =
+    {
+        MXS_MODULE_API_ROUTER,
+        MXS_MODULE_IN_DEVELOPMENT,
+        MXS_ROUTER_VERSION,
+        "A test router - not for use in real systems",
+        "V1.0.0",
+        &MyObject,
+        NULL, /* Process init. */
+        NULL, /* Process finish. */
+        NULL, /* Thread init. */
+        NULL, /* Thread finish. */
+        {
+            {MXS_END_MODULE_PARAMS}
+        }
+    };
+
+    return &info;
+}
+
+/**
+ * Create an instance of the router for a particular service
+ * within the gateway.
+ *
+ * @param service   The service this router is being create for
+ * @param options   The options for this query router
+ *
+ * @return The instance data for this new instance
+ */
+static  MXS_ROUTER  *
+createInstance(SERVICE *service, char **options)
+{
+    return (MXS_ROUTER*)MXS_MALLOC(sizeof(TESTROUTER));
+}
+
+/**
+ * Associate a new session with this instance of the router.
+ *
+ * @param instance  The router instance data
+ * @param session   The session itself
+ * @return Session specific data for this session
+ */
+static MXS_ROUTER_SESSION *
+newSession(MXS_ROUTER *instance, MXS_SESSION *session)
+{
+    return (MXS_ROUTER_SESSION*)MXS_MALLOC(sizeof(TESTSESSION));
+}
+
+/**
+ * Close a session with the router, this is the mechanism
+ * by which a router may cleanup data structure etc.
+ *
+ * @param instance  The router instance data
+ * @param session   The session being closed
+ */
+static  void
+closeSession(MXS_ROUTER *instance, MXS_ROUTER_SESSION *session)
+{
+}
+
+static void freeSession(MXS_ROUTER* router_instance,
+                        MXS_ROUTER_SESSION* router_client_session)
+{
+    MXS_FREE(router_client_session);
+}
+
+static  int
+routeQuery(MXS_ROUTER *instance, MXS_ROUTER_SESSION *session, GWBUF *queue)
+{
+    return 0;
+}
+
+void clientReply(MXS_ROUTER* instance, MXS_ROUTER_SESSION* session, GWBUF* queue, DCB* dcb)
+{
+}
+
+/**
+ * Diagnostics routine
+ *
+ * @param   instance    The router instance
+ * @param   dcb     The DCB for diagnostic output
+ */
+static  void
+diagnostic(MXS_ROUTER *instance, DCB *dcb)
+{
+}
+
+static uint64_t getCapabilities(MXS_ROUTER* instance)
+{
+    return 0;
+}
+
+
+static void handleError(MXS_ROUTER *instance,
+                        MXS_ROUTER_SESSION *router_session,
+                        GWBUF *errbuf,
+                        DCB *backend_dcb,
+                        mxs_error_action_t action,
+                        bool *succp)
+{
+}