[libgweather] GWeatherInfo: add API to store the cache explicitly

[Giovanni Campagna <gcampagna src gnome org>]

commit b688d230b3c67bdb3021468c011b3fecb3b18146
Author: Giovanni Campagna <gcampagna src gnome org>
Date:   Sun Mar 17 18:48:13 2013 +0100

    GWeatherInfo: add API to store the cache explicitly
    
    Not all languages can make sure that the GWeatherInfo object is properly
    finalized at shutdown.

 libgweather/gweather-weather.h |    1 +
 libgweather/weather.c          |   31 +++++++++++++++++++++++++++++--
 2 files changed, 30 insertions(+), 2 deletions(-)
---
diff --git a/libgweather/gweather-weather.h b/libgweather/gweather-weather.h
index a597bf7..86c1f29 100644
--- a/libgweather/gweather-weather.h
+++ b/libgweather/gweather-weather.h
@@ -82,6 +82,7 @@ GWeatherInfo *           gweather_info_new_for_world       (GWeatherLocation *wo
                                                            GWeatherForecastType forecast_type);
 void                     gweather_info_update              (GWeatherInfo *info);
 void                    gweather_info_abort               (GWeatherInfo *info);
+void                     gweather_info_store_cache         (void);
 
 GWeatherProvider         gweather_info_get_enabled_providers (GWeatherInfo        *info);
 void                     gweather_info_set_enabled_providers (GWeatherInfo        *info,
diff --git a/libgweather/weather.c b/libgweather/weather.c
index e63fda8..b36534d 100644
--- a/libgweather/weather.c
+++ b/libgweather/weather.c
@@ -447,12 +447,16 @@ dump_and_unref_cache (SoupCache *cache)
     g_object_unref (cache);
 }
 
+static SoupSession *static_session;
+
 static SoupSession *
 ref_session (void)
 {
-    static SoupSession *session;
+    SoupSession *session;
     SoupCache *cache;
 
+    session = static_session;
+
     if (session != NULL)
        return g_object_ref (session);
 
@@ -468,11 +472,34 @@ ref_session (void)
     soup_cache_load (cache);
     g_object_unref (cache);
 
-    g_object_add_weak_pointer (G_OBJECT (session), (void**) &session);
+    static_session = session;
+    g_object_add_weak_pointer (G_OBJECT (session), (void**) &static_session);
 
     return session;
 }
 
+/**
+ * gweather_info_store_cache:
+ *
+ * Ensures that any data cached from the network is stored to disk.
+ * Calling this is not necessary, as the cache will be saved when
+ * the last reference to a #GWeatherInfo will be dropped.
+ * On the other hand, it must be called if there is any chance that
+ * the application will be closed without unreffing all objects, such
+ * as when using a language binding that employs a GC.
+ */
+void
+gweather_info_store_cache (void)
+{
+    SoupCache *cache;
+
+    if (static_session == NULL)
+       return;
+
+    cache = g_object_get_data (G_OBJECT (static_session), "libgweather-cache");
+    soup_cache_dump (cache);
+}
+
 void
 gweather_info_update (GWeatherInfo *info)
 {