RSI enhancements

3 files changed, 17 insertions, 13 deletions

diff --git a/src/include/ndpi_api.h.in b/src/include/ndpi_api.h.in
index 0d68237a6..d90bcde19 100644
--- a/src/include/ndpi_api.h.in
+++ b/src/include/ndpi_api.h.in
@@ -1370,7 +1370,7 @@ extern "C" {
   /* Data analysis */
   struct ndpi_analyze_struct* ndpi_alloc_data_analysis(u_int16_t _max_series_len);
   void ndpi_init_data_analysis(struct ndpi_analyze_struct *s, u_int16_t _max_series_len);
-  void ndpi_free_data_analysis(struct ndpi_analyze_struct *d);
+  void ndpi_free_data_analysis(struct ndpi_analyze_struct *d, u_int8_t free_pointer);
   void ndpi_reset_data_analysis(struct ndpi_analyze_struct *d);
   void ndpi_data_add_value(struct ndpi_analyze_struct *s, const u_int32_t value);
 
diff --git a/src/include/ndpi_typedefs.h b/src/include/ndpi_typedefs.h
index a3910a7df..859a7f0e4 100644
--- a/src/include/ndpi_typedefs.h
+++ b/src/include/ndpi_typedefs.h
@@ -1545,7 +1545,7 @@ struct ndpi_analyze_struct {
 /* **************************************** */
 
 struct ndpi_rsi_struct {
-  struct ndpi_analyze_struct *gains, *losses;
+  struct ndpi_analyze_struct gains, losses;
   u_int32_t last_value;
 };
 
diff --git a/src/lib/ndpi_analyze.c b/src/lib/ndpi_analyze.c
index 3b1b2557f..32b1a4920 100644
--- a/src/lib/ndpi_analyze.c
+++ b/src/lib/ndpi_analyze.c
@@ -68,9 +68,9 @@ struct ndpi_analyze_struct* ndpi_alloc_data_analysis(u_int16_t _max_series_len)
 
 /* ********************************************************************************* */
 
-void ndpi_free_data_analysis(struct ndpi_analyze_struct *d) {
+void ndpi_free_data_analysis(struct ndpi_analyze_struct *d, u_int8_t free_pointer) {
   if(d->values) ndpi_free(d->values);
-  ndpi_free(d);
+  if(free_pointer) ndpi_free(d);
 }
 
 /* ********************************************************************************* */
@@ -827,29 +827,33 @@ int ndpi_cluster_bins(struct ndpi_bin *bins, u_int16_t num_bins,
 */
 
 void ndpi_init_rsi(struct ndpi_rsi_struct *s, u_int16_t num_learning_values) {
-  s->gains  = ndpi_alloc_data_analysis(num_learning_values);
-  s->losses = ndpi_alloc_data_analysis(num_learning_values);
+  ndpi_init_data_analysis(&s->gains, num_learning_values);
+  ndpi_init_data_analysis(&s->losses, num_learning_values);
   s->last_value = 0;
 }
 
 void ndpi_free_rsi(struct ndpi_rsi_struct *s) {
-  ndpi_free_data_analysis(s->gains), ndpi_free_data_analysis(s->losses);
+  ndpi_free_data_analysis(&s->gains, 0), ndpi_free_data_analysis(&s->losses, 0);
 }
 
+/*
+  This function adds a new value and returns the computed RSI, or -1
+  if there are too many points (< num_learning_values)
+*/
 float ndpi_rsi_add_value(struct ndpi_rsi_struct *s, const u_int32_t value) {
-  if(s->gains->num_data_entries == 0)
-    ndpi_data_add_value(s->gains, 0), ndpi_data_add_value(s->losses, 0);
+  if(s->gains.num_data_entries == 0)
+    ndpi_data_add_value(&s->gains, 0), ndpi_data_add_value(&s->losses, 0);
   else {
     if(value > s->last_value)    
-      ndpi_data_add_value(s->gains, value - s->last_value), ndpi_data_add_value(s->losses, 0);
+      ndpi_data_add_value(&s->gains, value - s->last_value), ndpi_data_add_value(&s->losses, 0);
     else
-      ndpi_data_add_value(s->losses, s->last_value - value), ndpi_data_add_value(s->gains, 0);
+      ndpi_data_add_value(&s->losses, s->last_value - value), ndpi_data_add_value(&s->gains, 0);
   }
   
   s->last_value = value;
 
-  if(s->gains->num_data_entries >= s->gains->num_values_array_len) {
-    float relative_strength = ndpi_data_average(s->gains) / ndpi_data_average(s->losses);
+  if(s->gains.num_data_entries >= s->gains.num_values_array_len) {
+    float relative_strength = ndpi_data_window_average(&s->gains) / ndpi_data_window_average(&s->losses);
 
     /* printf("RSI: %f\n", relative_strength); */
     return(100. - (100. / (1. + relative_strength)));