[dpdk-dev] [PATCH v3 07/12] telemetry: format json response when sending stats

[Kevin Laatz <kevin.laatz@intel.com>]

From: Ciara Power <ciara.power@intel.com>

This patch adds functionality to create a JSON message in
order to send it to a client socket.

When stats are requested by a client, they are retrieved from
the metrics library and encoded in JSON format.

Signed-off-by: Ciara Power <ciara.power@intel.com>
Signed-off-by: Brian Archbold <brian.archbold@intel.com>
Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
---
 lib/librte_telemetry/rte_telemetry.c | 309 ++++++++++++++++++++++++++++++++++-
 1 file changed, 307 insertions(+), 2 deletions(-)

diff --git a/lib/librte_telemetry/rte_telemetry.c b/lib/librte_telemetry/rte_telemetry.c
index 700798f..18b8102 100644
--- a/lib/librte_telemetry/rte_telemetry.c
+++ b/lib/librte_telemetry/rte_telemetry.c
@@ -187,7 +187,7 @@ rte_telemetry_send_error_response(struct telemetry_impl *telemetry,
 		return -EPERM;
 	}
 
-	json_buffer = json_dumps(root, JSON_INDENT(2));
+	json_buffer = json_dumps(root, 0);
 	json_decref(root);
 
 	ret = rte_telemetry_write_to_socket(telemetry, json_buffer);
@@ -199,6 +199,304 @@ rte_telemetry_send_error_response(struct telemetry_impl *telemetry,
 	return 0;
 }
 
+static int
+rte_telemetry_get_metrics(struct telemetry_impl *telemetry, uint32_t port_id,
+	struct rte_metric_value *metrics, struct rte_metric_name *names,
+	int num_metrics)
+{
+	int ret, num_values;
+
+	if (num_metrics < 0) {
+		TELEMETRY_LOG_ERR("Invalid metrics count");
+		goto einval_fail;
+	} else if (num_metrics == 0) {
+		TELEMETRY_LOG_ERR("No metrics to display (none have been registered)");
+		goto eperm_fail;
+	}
+
+	if (metrics == NULL) {
+		TELEMETRY_LOG_ERR("Metrics must be initialised.");
+		goto einval_fail;
+	}
+
+	if (names == NULL) {
+		TELEMETRY_LOG_ERR("Names must be initialised.");
+		goto einval_fail;
+	}
+
+	ret = rte_metrics_get_names(names, num_metrics);
+	if (ret < 0 || ret > num_metrics) {
+		TELEMETRY_LOG_ERR("Cannot get metrics names");
+		goto eperm_fail;
+	}
+
+	num_values = rte_metrics_get_values(port_id, NULL, 0);
+	ret = rte_metrics_get_values(port_id, metrics, num_values);
+	if (ret < 0 || ret > num_values) {
+		TELEMETRY_LOG_ERR("Cannot get metrics values");
+		goto eperm_fail;
+	}
+
+	return 0;
+
+eperm_fail:
+	ret = rte_telemetry_send_error_response(telemetry, -EPERM);
+	if (ret < 0)
+		TELEMETRY_LOG_ERR("Could not send error");
+	return -1;
+
+einval_fail:
+	ret = rte_telemetry_send_error_response(telemetry, -EINVAL);
+	if (ret < 0)
+		TELEMETRY_LOG_ERR("Could not send error");
+	return -1;
+
+}
+
+static int32_t
+rte_telemetry_json_format_stat(struct telemetry_impl *telemetry, json_t *stats,
+	const char *metric_name, uint64_t metric_value)
+{
+	int ret;
+	json_t *stat = json_object();
+
+	if (stat == NULL) {
+		TELEMETRY_LOG_ERR("Could not create stat JSON object");
+		goto eperm_fail;
+	}
+
+	ret = json_object_set_new(stat, "name", json_string(metric_name));
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Stat Name field cannot be set");
+		goto eperm_fail;
+	}
+
+	ret = json_object_set_new(stat, "value", json_integer(metric_value));
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Stat Value field cannot be set");
+		goto eperm_fail;
+	}
+
+	ret = json_array_append_new(stats, stat);
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Stat cannot be added to stats json array");
+		goto eperm_fail;
+	}
+
+	return 0;
+
+eperm_fail:
+	ret = rte_telemetry_send_error_response(telemetry, -EPERM);
+	if (ret < 0)
+		TELEMETRY_LOG_ERR("Could not send error");
+	return -1;
+
+}
+
+static int32_t
+rte_telemetry_json_format_port(struct telemetry_impl *telemetry,
+	uint32_t port_id, json_t *ports, uint32_t *metric_ids,
+	uint32_t num_metric_ids)
+{
+	struct rte_metric_value *metrics = 0;
+	struct rte_metric_name *names = 0;
+	int num_metrics, ret, err_ret;
+	json_t *port, *stats;
+	uint32_t i;
+
+	num_metrics = rte_metrics_get_names(NULL, 0);
+	if (num_metrics < 0) {
+		TELEMETRY_LOG_ERR("Cannot get metrics count");
+		goto einval_fail;
+	} else if (num_metrics == 0) {
+		TELEMETRY_LOG_ERR("No metrics to display (none have been registered)");
+		goto eperm_fail;
+	}
+
+	metrics = malloc(sizeof(struct rte_metric_value) * num_metrics);
+	names = malloc(sizeof(struct rte_metric_name) * num_metrics);
+	if (metrics == NULL || names == NULL) {
+		TELEMETRY_LOG_ERR("Cannot allocate memory");
+		free(metrics);
+		free(names);
+
+		err_ret = rte_telemetry_send_error_response(telemetry, -ENOMEM);
+		if (err_ret < 0)
+			TELEMETRY_LOG_ERR("Could not send error");
+		return -1;
+	}
+
+	ret  = rte_telemetry_get_metrics(telemetry, port_id, metrics, names,
+		num_metrics);
+	if (ret < 0) {
+		free(metrics);
+		free(names);
+		TELEMETRY_LOG_ERR("rte_telemetry_get_metrics failed");
+		return -1;
+	}
+
+	port = json_object();
+	stats = json_array();
+	if (port == NULL || stats == NULL) {
+		TELEMETRY_LOG_ERR("Could not create port/stats JSON objects");
+		goto eperm_fail;
+	}
+
+	ret = json_object_set_new(port, "port", json_integer(port_id));
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Port field cannot be set");
+		goto eperm_fail;
+	}
+
+	for (i = 0; i < num_metric_ids; i++) {
+		int metric_id = metric_ids[i];
+		int metric_index = -1;
+		int metric_name_key = -1;
+		int32_t j;
+		uint64_t metric_value;
+
+		if (metric_id >= num_metrics) {
+			TELEMETRY_LOG_ERR("Metric_id: %d is not valid",
+					metric_id);
+			goto einval_fail;
+		}
+
+		for (j = 0; j < num_metrics; j++) {
+			if (metrics[j].key == metric_id) {
+				metric_name_key = metrics[j].key;
+				metric_index = j;
+				break;
+			}
+		}
+
+		const char *metric_name = names[metric_name_key].name;
+		metric_value = metrics[metric_index].value;
+
+		if (metric_name_key < 0 || metric_index < 0) {
+			TELEMETRY_LOG_ERR("Could not get metric name/index");
+			goto eperm_fail;
+		}
+
+		ret = rte_telemetry_json_format_stat(telemetry, stats,
+			metric_name, metric_value);
+		if (ret < 0) {
+			TELEMETRY_LOG_ERR("Format stat with id: %u failed",
+					metric_id);
+			free(metrics);
+			free(names);
+			return -1;
+		}
+	}
+
+	if (json_array_size(stats) == 0)
+		ret = json_object_set_new(port, "stats", json_null());
+	else
+		ret = json_object_set_new(port, "stats", stats);
+
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Stats object cannot be set");
+		goto eperm_fail;
+	}
+
+	ret = json_array_append_new(ports, port);
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Port object cannot be added to ports array");
+		goto eperm_fail;
+	}
+
+	free(metrics);
+	free(names);
+	return 0;
+
+eperm_fail:
+	free(metrics);
+	free(names);
+	ret = rte_telemetry_send_error_response(telemetry, -EPERM);
+	if (ret < 0)
+		TELEMETRY_LOG_ERR("Could not send error");
+	return -1;
+
+einval_fail:
+	free(metrics);
+	free(names);
+	ret = rte_telemetry_send_error_response(telemetry, -EINVAL);
+	if (ret < 0)
+		TELEMETRY_LOG_ERR("Could not send error");
+	return -1;
+}
+
+static int32_t
+rte_telemetry_encode_json_format(struct telemetry_impl *telemetry,
+	uint32_t *port_ids, uint32_t num_port_ids, uint32_t *metric_ids,
+	uint32_t num_metric_ids, char **json_buffer)
+{
+	int ret;
+	json_t *root, *ports;
+	uint32_t i;
+
+	if (num_port_ids <= 0 || num_metric_ids <= 0) {
+		TELEMETRY_LOG_ERR("Please provide port and metric ids to query");
+		goto einval_fail;
+	}
+
+	ports = json_array();
+	if (ports == NULL) {
+		TELEMETRY_LOG_ERR("Could not create ports JSON array");
+		goto eperm_fail;
+	}
+
+	for (i = 0; i < num_port_ids; i++) {
+		if (!rte_eth_dev_is_valid_port(port_ids[i])) {
+			TELEMETRY_LOG_ERR("Port: %d invalid", port_ids[i]);
+			goto einval_fail;
+		}
+	}
+
+	for (i = 0; i < num_port_ids; i++) {
+		ret = rte_telemetry_json_format_port(telemetry, port_ids[i],
+			ports, metric_ids, num_metric_ids);
+		if (ret < 0) {
+			TELEMETRY_LOG_ERR("Format port in JSON failed");
+			return -1;
+		}
+	}
+
+	root = json_object();
+	if (root == NULL) {
+		TELEMETRY_LOG_ERR("Could not create root JSON object");
+		goto eperm_fail;
+	}
+
+	ret = json_object_set_new(root, "status_code",
+		json_string("Status OK: 200"));
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Status code field cannot be set");
+		goto eperm_fail;
+	}
+
+	ret = json_object_set_new(root, "data", ports);
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("Data field cannot be set");
+		goto eperm_fail;
+	}
+
+	*json_buffer = json_dumps(root, JSON_INDENT(2));
+	json_decref(root);
+	return 0;
+
+eperm_fail:
+	ret = rte_telemetry_send_error_response(telemetry, -EPERM);
+	if (ret < 0)
+		TELEMETRY_LOG_ERR("Could not send error");
+	return -1;
+
+einval_fail:
+	ret = rte_telemetry_send_error_response(telemetry, -EINVAL);
+	if (ret < 0)
+		TELEMETRY_LOG_ERR("Could not send error");
+	return -1;
+}
+
 int32_t
 rte_telemetry_send_ports_stats_values(uint32_t *metric_ids, int num_metric_ids,
 	uint32_t *port_ids, int num_port_ids, struct telemetry_impl *telemetry)
@@ -238,13 +536,20 @@ rte_telemetry_send_ports_stats_values(uint32_t *metric_ids, int num_metric_ids,
 		}
 
 		ret = rte_telemetry_update_metrics_ethdev(telemetry,
-			port_ids[i], telemetry->reg_index);
+				port_ids[i], telemetry->reg_index);
 		if (ret < 0) {
 			TELEMETRY_LOG_ERR("Failed to update ethdev metrics");
 			return -1;
 		}
 	}
 
+	ret = rte_telemetry_encode_json_format(telemetry, port_ids,
+		num_port_ids, metric_ids, num_metric_ids, &json_buffer);
+	if (ret < 0) {
+		TELEMETRY_LOG_ERR("JSON encode function failed");
+		return -1;
+	}
+
 	ret = rte_telemetry_write_to_socket(telemetry, json_buffer);
 	if (ret < 0) {
 		TELEMETRY_LOG_ERR("Could not write to socket");
-- 
2.9.5