/** Hook funktions * * Every path can register a hook function which is called for every received * message. This can be used to debug the data flow, get statistics * or alter the message. * * This file includes some examples. * * @file * @author Steffen Vogel * @copyright 2017, Institute for Automation of Complex Power Systems, EONERC * @license GNU General Public License (version 3) * * VILLASnode * * 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 * 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 . */ /** * @addtogroup hooks User-defined hook functions * @ingroup path * @{ *********************************************************************************/ #pragma once #include #include #ifdef __cplusplus extern "C" { #endif /* Forward declarations */ struct path; struct sample; struct list; /** Descriptor for user defined hooks. See hooks[]. */ struct hook { enum state state; struct path *path; struct node *node; struct hook_type *_vt; /**< C++ like Vtable pointer. */ void *_vd; /**< Private data for this hook. This pointer can be used to pass data between consecutive calls of the callback. */ int priority; /**< A priority to change the order of execution within one type of hook. */ json_t *cfg; /**< A JSON object containing the configuration of the hook. */ }; int hook_init(struct hook *h, struct hook_type *vt, struct path *p, struct node *n); int hook_parse(struct hook *h, json_t *cfg); int hook_parse_cli(struct hook *h, int argc, char *argv[]); int hook_destroy(struct hook *h); int hook_start(struct hook *h); int hook_stop(struct hook *h); int hook_periodic(struct hook *h); int hook_restart(struct hook *h); int hook_read(struct hook *h, struct sample *smps[], unsigned *cnt); int hook_process(struct hook *h, struct sample *smps[], unsigned *cnt); int hook_write(struct hook *h, struct sample *smps[], unsigned *cnt); int hook_read_list(struct list *hs, struct sample *smps[], unsigned cnt); int hook_process_list(struct list *hs, struct sample *smps[], unsigned cnt); int hook_write_list(struct list *hs, struct sample *smps[], unsigned cnt); /** Compare two hook functions with their priority. Used by list_sort() */ int hook_cmp_priority(const void *a, const void *b); /** Parses an object of hooks * * Example: * * { * stats = { * output = "stdout" * }, * skip_first = { * seconds = 10 * }, * hooks = [ "print" ] * } */ int hook_parse_list(struct list *list, json_t *cfg, struct path *p, struct node *n); #ifdef __cplusplus } #endif