VILLASnode/lib/nodes/influxdb.c

/** Node-type for InfluxDB.
 *
 * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
 * @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 <http://www.gnu.org/licenses/>.
 *********************************************************************************/

#include <string.h>
#include <inttypes.h>

#include <villas/node.h>
#include <villas/plugin.h>
#include <villas/signal.h>
#include <villas/config.h>
#include <villas/nodes/influxdb.h>
#include <villas/memory.h>

int influxdb_parse(struct node *n, json_t *json)
{
	struct influxdb *i = (struct influxdb *) n->_vd;

	json_error_t err;
	int ret;

	char *tmp, *host, *port;
	const char *server, *key;

	ret = json_unpack_ex(json, &err, 0, "{ s: s, s: s, s?: o }",
		"server", &server,
		"key", &key
	);
	if (ret)
		jerror(&err, "Failed to parse configuration of node %s", node_name(n));

	tmp = strdup(server);

	host = strtok(tmp, ":");
	port = strtok(NULL, "");

	i->key = strdup(key);
	i->host = strdup(host);
	i->port = strdup(port ? port : "8089");

	free(tmp);

	return 0;
}

int influxdb_open(struct node *n)
{
	int ret;
	struct influxdb *i = (struct influxdb *) n->_vd;

	struct addrinfo hints, *servinfo, *p;

	memset(&hints, 0, sizeof hints);
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_DGRAM;

	ret = getaddrinfo(i->host, i->port, &hints, &servinfo);
	if (ret)
	    error("Failed to lookup server: %s", gai_strerror(ret));

	/* Loop through all the results and connect to the first we can */
	for (p = servinfo; p != NULL; p = p->ai_next) {
		i->sd = socket(p->ai_family, p->ai_socktype, p->ai_protocol);
		if (i->sd == -1) {
	        	serror("socket");
			continue;
	    	}

		ret = connect(i->sd, p->ai_addr, p->ai_addrlen);
		if (ret == -1) {
			warn("connect");
	        	close(i->sd);
	        	continue;
		}

		/* If we get here, we must have connected successfully */
		break;
	}

	return p ? 0 : -1;
}

int influxdb_close(struct node *n)
{
	struct influxdb *i = (struct influxdb *) n->_vd;

	close(i->sd);

	if (i->host)
		free(i->host);
	if (i->port)
		free(i->port);
	if (i->key)
		free(i->key);

	return 0;
}

int influxdb_write(struct node *n, struct sample *smps[], unsigned cnt, unsigned *release)
{
	struct influxdb *i = (struct influxdb *) n->_vd;

	char *buf = NULL;
	ssize_t sentlen, buflen;

	for (int k = 0; k < cnt; k++) {
		/* Key */
		strcatf(&buf, "%s", i->key);

		/* Fields */
		for (int j = 0; j < smps[k]->length; j++) {
			strcatf(&buf, "%c", j == 0 ? ' ' : ',');

			if (j < list_length(&n->out.signals)) {
				struct signal *sig = (struct signal *) list_at(&n->out.signals, j);

				strcatf(&buf, "%s=", sig->name);
			}
			else
				strcatf(&buf, "value%d=", j);

			switch (sample_get_data_format(smps[k], j)) {
				case SAMPLE_DATA_FORMAT_FLOAT:	strcatf(&buf, "%f", smps[k]->data[j].f); break;
				case SAMPLE_DATA_FORMAT_INT:	strcatf(&buf, "%" PRIi64, smps[k]->data[j].i); break;
			}
		}

		/* Timestamp */
		strcatf(&buf, " %ld%09ld\n", smps[k]->ts.origin.tv_sec, smps[k]->ts.origin.tv_nsec);
	}

	buflen = strlen(buf) + 1;
	sentlen = send(i->sd, buf, buflen, 0);
	if (sentlen < 0)
		return -1;
	else if (sentlen < buflen)
		warn("Partial sent");

	free(buf);

	return cnt;
}

char * influxdb_print(struct node *n)
{
	struct influxdb *i = (struct influxdb *) n->_vd;
	char *buf = NULL;

	strcatf(&buf, "host=%s, port=%s, key=%s", i->host, i->port, i->key);

	return buf;
}

static struct plugin p = {
	.name = "influxdb",
	.description = "Write results to InfluxDB",
	.type = PLUGIN_TYPE_NODE,
	.node = {
		.vectorize = 0,
		.size	= sizeof(struct influxdb),
		.parse	= influxdb_parse,
		.print	= influxdb_print,
		.start	= influxdb_open,
		.stop	= influxdb_close,
		.write	= influxdb_write,
	}
};

REGISTER_PLUGIN(&p)
LIST_INIT_STATIC(&p.node.instances)