[datapipe] Make datapipe_t structure opaque

Members of datapipe structures should not be accessed directly, but there
still are some legacy code hacks poking at the internals.

Make datapipe_t structure opaque outside datapipe module.

Add/tweak necessary accessor functions/macros to deal with the change.

Mark architectural sore points with FIXME comments.

Signed-off-by: Simo Piiroinen <simo.piiroinen@jollamobile.com>

datapipe.c

@@ -37,6 +37,24 @@
 #define datapipe_init(datapipe, filtering, caching, datasize, value)\
      datapipe_init_(&(datapipe), #datapipe, filtering, caching, datasize, value)
 
+/* ========================================================================= *
+ * Types
+ * ========================================================================= */
+
+struct datapipe_t
+{
+    const char           *dp_name;             /**< Name of the datapipe */
+    GSList               *dp_filters;          /**< The filters */
+    GSList               *dp_input_triggers;   /**< Triggers called on indata */
+    GSList               *dp_output_triggers;  /**< Triggers called on outdata */
+    gconstpointer         dp_cached_data;      /**< Latest cached data */
+    gsize                 dp_datasize;         /**< Size of data; NULL == automagic */
+    datapipe_filtering_t  dp_read_only;        /**< Datapipe is read only */
+    datapipe_cache_t      dp_cache;
+    guint                 dp_gc_id;
+    guint                 dp_token;
+};
+
 /* ========================================================================= *
  * Prototypes
  * ========================================================================= */
@@ -467,6 +485,26 @@ datapipe_value(const datapipe_t *self)
     return self->dp_cached_data;
 }
 
+/** Set value of datapipe
+ *
+ * Note: Do not use this function.
+ *
+ * This function exists only to facilitate legacy hacks in
+ * the display plugin - no new code should ever call it and
+ * it should be removed as soon as possible.
+ *
+ * The proper way to modify datapipe content is to use
+ * #datapipe_exec_full() function.
+ *
+ * @param self The datapipe
+ * @paran data The value, as void pointer
+ */
+void
+datapipe_set_value(datapipe_t *self, gconstpointer data)
+{
+    self->dp_cached_data = data;
+}
+
 /** Garbage collect stale callback slots
  *
  * While it can be assumed to be extremely rare, filters and triggers can end

datapipe.h

@@ -68,18 +68,7 @@ typedef enum {
  *
  * Only access this struct through the functions
  */
-typedef struct {
-    const char           *dp_name;             /**< Name of the datapipe */
-    GSList               *dp_filters;          /**< The filters */
-    GSList               *dp_input_triggers;   /**< Triggers called on indata */
-    GSList               *dp_output_triggers;  /**< Triggers called on outdata */
-    gconstpointer         dp_cached_data;      /**< Latest cached data */
-    gsize                 dp_datasize;         /**< Size of data; NULL == automagic */
-    datapipe_filtering_t  dp_read_only;        /**< Datapipe is read only */
-    datapipe_cache_t      dp_cache;
-    guint                 dp_gc_id;
-    guint                 dp_token;
-} datapipe_t;
+typedef struct datapipe_t datapipe_t;
 
 typedef struct
 {
@@ -108,6 +97,7 @@ typedef struct
 const char     *datapipe_name     (const datapipe_t *self);
 gconstpointer   datapipe_value    (const datapipe_t *self);
 gconstpointer   datapipe_exec_full(datapipe_t *self, gconstpointer indata);
+void            datapipe_set_value(datapipe_t *self, gconstpointer data);
 
 /* ------------------------------------------------------------------------- *
  * MCE_DATAPIPE
@@ -126,10 +116,10 @@ void  mce_datapipe_generate_inactivity (void);
  * ========================================================================= */
 
 /** Retrieve a gint from a datapipe */
-# define datapipe_get_gint(_datapipe)   (GPOINTER_TO_INT((_datapipe).dp_cached_data))
+# define datapipe_get_gint(_datapipe) ((gint)(void*)datapipe_value(&(_datapipe)))
 
 /** Retrieve a guint from a datapipe */
-# define datapipe_get_guint(_datapipe)  (GPOINTER_TO_UINT((_datapipe).dp_cached_data))
+# define datapipe_get_guint(_datapipe) ((guint)(void*)datapipe_value(&(_datapipe)))
 
 /* Helper for making display state requests
  *

mce.h

@@ -473,7 +473,7 @@ void mce_quit_mainloop(void);
 void mce_signal_handlers_remove(void);
 
 #define display_state_get() ({\
-	gint res = GPOINTER_TO_INT(display_state_curr_pipe.dp_cached_data);\
+	gint res = datapipe_get_gint(display_state_curr_pipe);\
 	mce_log(LL_DEBUG, "display_state_curr=%s",\
 		display_state_repr(res));\
 	res;\

modules/display.c

@@ -7253,7 +7253,9 @@ static void mdy_display_state_enter(display_state_t prev_state,
     }
 
     /* Restore display_state_curr_pipe to valid value */
-    display_state_curr_pipe.dp_cached_data = GINT_TO_POINTER(next_state);
+    // FIXME: datapipe value should not be directly manipulated
+    datapipe_set_value(&display_state_curr_pipe,
+                       GINT_TO_POINTER(next_state));
 
     /* Run display state change triggers */
     mce_log(LL_CRUCIAL, "current display state = %s",
@@ -7347,9 +7349,12 @@ static void mdy_display_state_leave(display_state_t prev_state,
 
         mce_log(LL_CRUCIAL, "current display state = %s",
                 display_state_repr(state));
-        display_state_curr_pipe.dp_cached_data = GINT_TO_POINTER(state);
+
+        // FIXME: datapipe value should not be directly manipulated
+        datapipe_set_value(&display_state_curr_pipe,
+                           GINT_TO_POINTER(state));
         datapipe_exec_full(&display_state_curr_pipe,
-                           display_state_curr_pipe.dp_cached_data);
+                           GINT_TO_POINTER(state));
     }
 }
 

modules/led.c

@@ -3197,8 +3197,8 @@ const gchar *g_module_check_init(GModule *module)
 
 	/* Initialize sw breathing state data */
 	sw_breathing_init();
-	charger_state_trigger(charger_state_pipe.dp_cached_data);
-	battery_level_trigger(battery_level_pipe.dp_cached_data);
+	charger_state_trigger(datapipe_value(&charger_state_pipe));
+	battery_level_trigger(datapipe_value(&battery_level_pipe));
 
 	/* Evaluate initial active pattern state */
 	led_enable();