Handle query result and prepare to forward by API

First draft to be able to read at regular interval the TSDB
InfluxDB. This prepare a JSON object formated to be handled as
an input argument from a regular call to the API verb 'write'
Then it is only needed to call the remote verb to forward all the results

Change-Id: I80076dd9cf00ba43075d37dd4d15180e63e37289
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

3 files changed, 97 insertions, 30 deletions

diff --git a/src/plugins/influxdb-reader.c b/src/plugins/influxdb-reader.c
index 3a6a2b1..b6bef25 100644
--- a/src/plugins/influxdb-reader.c
+++ b/src/plugins/influxdb-reader.c
@@ -15,7 +15,6 @@
  * limitations under the License.
  */
 
-
 #include "influxdb.h"
 
 #include <errno.h>
@@ -27,72 +26,125 @@
 
 #include "../utils/list.h"
 
-void fill_tag_n_fields(void *c, json_object *columnJ)
+struct metrics_list {
+	struct series_t serie;
+	json_object *metricsJ;
+};
+
+static void fill_n_send_values(void *c, json_object *valuesJ)
+{
+	struct list *it = NULL;
+	int length = json_object_get_string_len(valuesJ), i = 0, j = 0;
+	struct metrics_list *m_list = (struct metrics_list *)c;
+	json_object *one_metric = json_object_new_object();
+
+	for (i = 0; i < length; i++) {
+		if(!i)
+			m_list->serie.timestamp = json_object_get_int64(valuesJ);
+		else {
+			if(set_value(m_list->serie.serie_columns.tags, valuesJ, i)) {
+				if(set_value(m_list->serie.serie_columns.fields, valuesJ, j)) {
+					AFB_ERROR("No tags nor fields fits.");
+				}
+				j++;
+			}
+		}
+	}
+
+	/* Build a metric object to add in the JSON array */
+	json_object_object_add(one_metric, "name", json_object_new_string(m_list->serie.name));
+	json_object_object_add(one_metric, "timestamp", json_object_new_int64(m_list->serie.timestamp));
+	for(it = m_list->serie.serie_columns.tags; it != NULL; it = it->next)
+		json_object_object_add(one_metric, m_list->serie.serie_columns.tags->key, m_list->serie.serie_columns.tags->value);
+	for(it = m_list->serie.serie_columns.fields; it != NULL; it = it->next)
+		json_object_object_add(one_metric, m_list->serie.serie_columns.fields->key, m_list->serie.serie_columns.fields->value);
+
+	json_object_array_add(m_list->metricsJ, one_metric);
+}
+
+static void fill_key(void *c, json_object *columnJ)
 {
 	int length = json_object_get_string_len(columnJ);
 	const char *column = json_object_get_string(columnJ);
-	struct series_columns_t *s_col = (struct series_columns_t *)c;
+	struct metrics_list *m_list = (struct metrics_list *)c;
 
-	if(strncasecmp(&column[length-1], "_t", 2) == 0) {
-		add_key(s_col->tags, column);
+	if(strncasecmp(&column[length-2], "_t", 2) == 0) {
+		add_key(&m_list->serie.serie_columns.tags, column);
 	}
-	else if(strncasecmp(&column[length-1], "_f", 2) == 0) {
-		add_key(s_col->fields, column);
+	else if(strncasecmp(&column[length-2], "_f", 2) == 0) {
+		add_key(&m_list->serie.serie_columns.fields, column);
 	}
-	return;
 }
 
-void unpack_metric_from_db(void *series_processed, json_object *metricJ)
+static void unpack_metric_from_db(void *ml, json_object *metricJ)
 {
-	const char *name;
-	int length = 0;
-	struct series_columns_t col = {.tags = NULL, .fields = NULL};
+	struct metrics_list *m_list = (struct metrics_list*)ml;
 	json_object *columnsJ = NULL, *valuesJ = NULL;
 
 	if(wrap_json_unpack(metricJ, "{ss, so, so!}",
-					 "name", &name,
+					 "name", &m_list->serie.name,
 					 "columns", &columnsJ,
 					 "values", &valuesJ)) {
 		AFB_ERROR("Unpacking metric goes wrong");
 		return;
 	 }
 
-	length = json_object_get_string_len(columnsJ);
-	wrap_json_array_for_all(columnsJ, fill_tag_n_fields, &col);
+	wrap_json_array_for_all(columnsJ, fill_key, m_list);
+	wrap_json_array_for_all(valuesJ, fill_n_send_values, m_list);
 
-	/* Increment counter of series well processed */
-	++*((int*)series_processed);
 }
 
-int unpack_series(json_object *seriesJ)
+static json_object *unpack_series(json_object *seriesJ)
 {
-	size_t series_processed = 0;
-	wrap_json_array_for_all(seriesJ, unpack_metric_from_db, (void*)&series_processed);
-
-	return 0;
+	struct metrics_list m_list = {
+		.serie = {
+			.name = NULL,
+			.serie_columns = {
+				.tags = NULL,
+				.fields = NULL
+			},
+			.timestamp = 0
+		},
+		.metricsJ = json_object_new_array()
+	};
+
+	wrap_json_array_for_all(seriesJ, unpack_metric_from_db, (void*)&m_list);
+
+	return m_list.metricsJ;
 }
 
-void forward_to_garner(const char *result, size_t size)
+static void forward_to_garner(const char *result, size_t size)
 {
 	int id = 0;
-
 	json_object *resultsJ = NULL,
 				*seriesJ = NULL,
+				*metrics2send = NULL,
+				*call_resultJ = NULL,
 				*db_dumpJ = json_tokener_parse(result);
+
 	if( wrap_json_unpack(db_dumpJ, "{so!}",
 					 "results", &resultsJ) ||
 		wrap_json_unpack(resultsJ, "[{si,so!}]",
 					 "statement_id", &id,
 					 "series", &seriesJ)) {
-		AFB_ERROR("Unpacking results from influxdb request. Request results was:\n%s", result);
+//		AFB_DEBUG("Unpacking results from influxdb request. Request results was:\n%s", result);
 		return;
 	}
 
-	if(seriesJ)
-		unpack_series(seriesJ);
+	if(seriesJ) {
+		metrics2send = unpack_series(seriesJ);
+		if(json_object_array_length(metrics2send)) {
+			if(afb_service_call_sync("garner", "write", metrics2send, &call_resultJ)) {
+				AFB_ERROR("Metrics were sent but not done, an error happens. Details: %s", json_object_to_json_string(call_resultJ));
+			}
+		}
+	}
+	else {
+		AFB_ERROR("Empty response. Request results was:\n%s", result);
+	}
 }
 
-void influxdb_read_curl_cb(void *closure, int status, CURL *curl, const char *result, size_t size)
+static void influxdb_read_curl_cb(void *closure, int status, CURL *curl, const char *result, size_t size)
 {
 	long rep_code = curl_wrap_response_code_get(curl);
 	switch(rep_code) {
@@ -112,7 +164,7 @@ void influxdb_read_curl_cb(void *closure, int status, CURL *curl, const char *re
 	}
 }
 
-CURL *make_curl_query_get(const char *url)
+static CURL *make_curl_query_get(const char *url)
 {
 	CURL *curl;
 	char *args[5];
@@ -154,7 +206,7 @@ CURL *make_curl_query_get(const char *url)
 	return curl;
 }
 
-int influxdb_read(sd_event_source *s, uint64_t usec, void *userdata)
+static int influxdb_read(sd_event_source *s, uint64_t usec, void *userdata)
 {
 	CURL *curl;
 	struct reader_args *a = NULL;
diff --git a/src/utils/list.c b/src/utils/list.c
index bd7eeac..d47f761 100644
--- a/src/utils/list.c
+++ b/src/utils/list.c
@@ -64,6 +64,20 @@ void add_key(struct list **l, const char *key)
 	}
 }
 
+int set_value(struct list *l, json_object *val, int index)
+{
+	int i;
+
+	for (i = 0; i < index; i++) {
+		l = l->next;
+		if ( l == NULL )
+			return -1;
+	}
+
+	l->value = val;
+	return 0;
+}
+
 struct list *get_elt(struct list *l, int index)
 {
 	int i;
diff --git a/src/utils/list.h b/src/utils/list.h
index 7cacbed..9f93cb6 100644
--- a/src/utils/list.h
+++ b/src/utils/list.h
@@ -29,6 +29,7 @@ struct list {
 void destroy_list(struct list *l);
 void add_elt(struct list **l, const char *key, json_object *value);
 void add_key(struct list **l, const char *key);
+int set_value(struct list *l, json_object *val, int index);
 struct list *get_elt(struct list *l, int index);
 struct list *find_elt_from_key(struct list *l, const char *key);
 json_object *find_key_value(struct list *l, const char *key);