core: Add the store writer plugin type.

[sysdb.git] / src / include / core / plugin.h

diff --git a/src/include/core/plugin.h b/src/include/core/plugin.h
index f75788ad2359a479c5be92d276366d41bf2fa21b..e09bf0f346c42143948843e4e0ef84326f4ee870 100644 (file)
--- a/src/include/core/plugin.h
+++ b/src/include/core/plugin.h
@@ -30,11 +30,14 @@
 
 #include "sysdb.h"
 #include "core/object.h"
+#include "core/store.h"
 #include "core/time.h"
+#include "core/timeseries.h"
 
 #include "liboconfig/oconfig.h"
 
 #include <stdarg.h>
+#include <stdbool.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -69,7 +72,7 @@ typedef struct {
        int sdb_module_init(sdb_plugin_info_t *info)
 
 typedef struct {
-       _Bool do_loop;
+       bool do_loop;
        sdb_time_t default_interval;
 } sdb_plugin_loop_t;
 #define SDB_PLUGIN_LOOP_INIT { 1, 0 }
@@ -120,6 +123,9 @@ typedef int (*sdb_plugin_shutdown_cb)(sdb_object_t *user_data);
 typedef int (*sdb_plugin_log_cb)(int prio, const char *msg,
                sdb_object_t *user_data);
 
+typedef sdb_timeseries_t *(*sdb_plugin_fetch_ts_cb)(const char *id,
+               sdb_timeseries_opts_t *opts, sdb_object_t *user_data);
+
 /*
  * sdb_plugin_register_config:
  * Register a "config" function. This will be used to pass on the
@@ -233,6 +239,42 @@ int
 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
                sdb_object_t *user_data);
 
+/*
+ * sdb_plugin_register_ts_fetcher:
+ * Register a "time-series fetcher" function to be called whenever retrieving
+ * a time-series from a data-store. The callback will receive an identifier
+ * describing where to retrieve the data from (e.g. a filename or some kind of
+ * URL) and options which further describe the query.
+ *
+ * The name is used literally (without prepending the plugin name) to look up
+ * the appropriate fetcher callback.
+ *
+ * Arguments:
+ *  - user_data: If specified, this will be passed on to each call of the
+ *    callback. The function will take ownership of the object, that is,
+ *    increment the reference count by one. In case the caller does not longer
+ *    use the object for other purposes, it should thus deref it.
+ */
+int
+sdb_plugin_register_ts_fetcher(const char *name,
+               sdb_plugin_fetch_ts_cb callback, sdb_object_t *user_data);
+
+/*
+ * sdb_plugin_register_writer:
+ * Register a "writer" implementation to be used when adding an object to the
+ * store. It is invalid to register an incomplete writer which does not
+ * implement all of the writer interface.
+ *
+ * Arguments:
+ *  - user_data: If specified, this will be passed on to each call of the
+ *    callback. The function will take ownership of the object, that is,
+ *    increment the reference count by one. In case the caller does not longer
+ *    use the object for other purposes, it should thus deref it.
+ */
+int
+sdb_plugin_register_writer(const char *name,
+               sdb_store_writer_t *writer, sdb_object_t *user_data);
+
 /*
  * sdb_plugin_get_ctx, sdb_plugin_set_ctx:
  * The plugin context defines a set of settings that are available whenever a
@@ -349,9 +391,27 @@ sdb_plugin_log(int prio, const char *msg);
  * Log a formatted message. See sdb_plugin_log for more information.
  */
 int
-sdb_plugin_vlogf(int prio, const char *fmt, va_list ap);
+sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
+               __attribute__((format(printf, 2, 0)));
 int
-sdb_plugin_logf(int prio, const char *fmt, ...);
+sdb_plugin_logf(int prio, const char *fmt, ...)
+               __attribute__((format(printf, 2, 3)));
+
+/*
+ * sdb_plugin_fetch_timeseries:
+ * Fetch the time-series identified by 'id' from a backend data-store of the
+ * specified 'type'. The type has to match an existing time-series fetcher
+ * callback's name. The identifier is passed through to the callback which
+ * then needs to make sense of it. The time-series option specify which data
+ * to fetch.
+ *
+ * Returns:
+ *  - a time-series on success
+ *  - NULL else
+ */
+sdb_timeseries_t *
+sdb_plugin_fetch_timeseries(const char *type, const char *id,
+               sdb_timeseries_opts_t *opts);
 
 #ifdef __cplusplus
 } /* extern "C" */