binding: weather: update stats every 15 minutesflounder_5.99.1flounder/5.99.15.99.1

To reduce API calls to OpenWeatherMap only update weather stats every
15 minutes.

Changes that were required:

* add glib-2.0 dependecy
* adding rwlock to url data
* g_timeout_add_seconds schedules an weather update every 15 minutes

Bug-AGL: SPEC-1273
Change-Id: I09b92faf17830f305275dad7f4545cf64ebb43a2
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>

1 files changed, 72 insertions, 22 deletions

diff --git a/binding/afm-weather-binding.c b/binding/afm-weather-binding.c
index 1103722..4c2418d 100644
--- a/binding/afm-weather-binding.c
+++ b/binding/afm-weather-binding.c
@@ -23,6 +23,8 @@
 #include <string.h>
 #include <stdlib.h>
 #include <pthread.h>
+#include <glib.h>
+#include <gio/gio.h>
 #include <curl/curl.h>
 #include <json-c/json.h>
 
@@ -33,16 +35,29 @@
 #define OPENWEATHER_URL         "http://api.openweathermap.org/data/2.5/weather?lat=%.4f&lon=%.4f&units=imperial&APPID=%s"
 
 struct {
-	char *api_key;
-	char url[128];
-	char buffer[1024];
+	gchar *api_key;
+	gchar *url;
+	gchar buffer[1024];
 } data;
 
-static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_rwlock_t rwlock = PTHREAD_RWLOCK_INITIALIZER;
 static struct afb_event weather_event;
 
+// Forward declaration
+gboolean update_weather_data(gpointer ptr);
+
+static void *weather_loop_thread(void *ptr)
+{
+	g_timeout_add_seconds(900, update_weather_data, NULL);
+
+	g_main_loop_run(g_main_loop_new(NULL, FALSE));
+
+	return NULL;
+}
+
 static int init()
 {
+	pthread_t thread_id;
 	json_object *response, *query;
 	int ret;
 
@@ -58,7 +73,7 @@ static int init()
 	ret = afb_service_call_sync("persistence", "read", query, &response);
 
 	if (ret < 0) {
-		data.api_key = strdup(OPENWEATHER_API_KEY);
+		data.api_key = g_strdup(OPENWEATHER_API_KEY);
 		AFB_WARNING("Cannot get OPENWEATHERMAP_API_KEY from persistence storage, defaulting to %s", data.api_key);
 	} else {
 		json_object *jresp = NULL;
@@ -66,7 +81,7 @@ static int init()
 		json_object_object_get_ex(response, "response", &jresp);
 		json_object_object_get_ex(jresp, "value", &jresp);
 
-		data.api_key = strdup(json_object_get_string(jresp));
+		data.api_key = g_strdup(json_object_get_string(jresp));
 
 		AFB_NOTICE("OPENWEATHERMAP_API_KEY retrieved from persistence: %s", data.api_key);
 	}
@@ -92,7 +107,7 @@ static int init()
 
 	weather_event = afb_daemon_make_event("weather");
 
-	return 0;
+	return pthread_create(&thread_id, NULL, weather_loop_thread, NULL);
 }
 
 static size_t weather_cb(char *ptr, size_t size, size_t nmemb, void *usr)
@@ -103,7 +118,7 @@ static size_t weather_cb(char *ptr, size_t size, size_t nmemb, void *usr)
 	if (realsize > (sizeof(data.buffer) - 1))
 		return -ENOMEM;
 
-	pthread_mutex_lock(&mutex);
+	pthread_rwlock_rdlock(&rwlock);
 
 	memcpy(data.buffer, ptr, realsize);
 	data.buffer[realsize] = '\0';
@@ -113,16 +128,45 @@ static size_t weather_cb(char *ptr, size_t size, size_t nmemb, void *usr)
 	if (jresp)
 		json_object_object_add(jresp, "url", json_object_new_string(data.url));
 
-	pthread_mutex_unlock(&mutex);
+	pthread_rwlock_unlock(&rwlock);
+
 	afb_event_push(weather_event, jresp);
 
 	return realsize;
 }
 
+gboolean update_weather_data(gpointer ptr)
+{
+	CURL *ch;
+
+	pthread_rwlock_rdlock(&rwlock);
+
+	if (data.url == NULL) {
+		pthread_rwlock_unlock(&rwlock);
+		return TRUE;
+	}
+
+	ch = curl_easy_init();
+
+	if (ch == NULL) {
+		pthread_rwlock_unlock(&rwlock);
+		return TRUE;
+	}
+
+	curl_easy_setopt(ch, CURLOPT_URL, data.url);
+	curl_easy_setopt(ch, CURLOPT_WRITEFUNCTION, weather_cb);
+
+	(void) curl_easy_perform(ch);
+	curl_easy_cleanup(ch);
+
+	pthread_rwlock_unlock(&rwlock);
+
+	return TRUE;
+}
+
 static void onevent(const char *event, struct json_object *object)
 {
 	json_object *val = NULL;
-	CURL *ch = NULL;
 	double latitude, longitude;
 	int ret;
 
@@ -138,31 +182,37 @@ static void onevent(const char *event, struct json_object *object)
 	if (!ret)
 		return;
 	longitude = json_object_get_double(val);
+	ret = 0;
 
-	sprintf(data.url, OPENWEATHER_URL, latitude, longitude, data.api_key);
+	pthread_rwlock_wrlock(&rwlock);
 
-	ch = curl_easy_init();
-	if (ch == NULL)
-		return;
+	if (data.url != NULL) {
+		g_free(data.url);
+		data.url = NULL;
+		ret = -1;
+	}
 
-	curl_easy_setopt(ch, CURLOPT_URL, data.url);
-	curl_easy_setopt(ch, CURLOPT_WRITEFUNCTION, weather_cb);
+	data.url = g_strdup_printf(OPENWEATHER_URL, latitude, longitude, data.api_key);
 
-	(void) curl_easy_perform(ch);
-	curl_easy_cleanup(ch);
+	pthread_rwlock_unlock(&rwlock);
+
+	// Initial Weather Data
+	if (data.url != NULL && !ret)
+		update_weather_data(NULL);
 }
 
 static void current_weather(struct afb_req request)
 {
 	json_object *jresp = NULL;
 
-	pthread_mutex_lock(&mutex);
+	pthread_rwlock_rdlock(&rwlock);
+
 	jresp = json_tokener_parse(data.buffer);
 
 	if (jresp)
 		json_object_object_add(jresp, "url", json_object_new_string(data.url));
 
-	pthread_mutex_unlock(&mutex);
+	pthread_rwlock_unlock(&rwlock);
 
 	if (jresp == NULL) {
 		afb_req_fail(request, "failed", "No weather data currently");
@@ -211,8 +261,8 @@ static void api_key(struct afb_req request)
 	}
 
 	if (data.api_key != NULL) {
-		free(data.api_key);
-		data.api_key = strdup(value);
+		g_free(data.api_key);
+		data.api_key = g_strdup(value);
 	}
 
 	afb_req_success(request, jresp, NULL);