Add ndpi_hll_reset() API call

Fixes bug in ndpi_data_window_average() with zero points

3 files changed, 13 insertions, 1 deletions

diff --git a/src/include/ndpi_api.h.in b/src/include/ndpi_api.h.in
index 4b36fd3b2..c272d66c8 100644
--- a/src/include/ndpi_api.h.in
+++ b/src/include/ndpi_api.h.in
@@ -1059,7 +1059,8 @@ extern "C" {
   /* Memory lifecycle */
   int ndpi_hll_init(struct ndpi_hll *hll, u_int8_t bits);
   void ndpi_hll_destroy(struct ndpi_hll *hll);
-
+  void ndpi_hll_reset(struct ndpi_hll *hll);
+  
   /* Add values */
   void ndpi_hll_add(struct ndpi_hll *hll, const char *data, size_t data_len);
   void ndpi_hll_add_number(struct ndpi_hll *hll, u_int32_t value) ;
diff --git a/src/lib/ndpi_analyze.c b/src/lib/ndpi_analyze.c
index 79a3dcf59..4b4fbf72b 100644
--- a/src/lib/ndpi_analyze.c
+++ b/src/lib/ndpi_analyze.c
@@ -144,6 +144,9 @@ float ndpi_data_window_average(struct ndpi_analyze_struct *s) {
     float   sum = 0.0;
     u_int16_t i, n = ndpi_min(s->num_data_entries, s->num_values_array_len);
 
+    if(n == 0)
+      return(0);
+    
     for(i=0; i<n; i++)
       sum += s->values[i];
 
@@ -228,6 +231,10 @@ void ndpi_hll_destroy(struct ndpi_hll *hll) {
   hll_destroy(hll);
 }
 
+void ndpi_hll_reset(struct ndpi_hll *hll) {
+  hll_reset(hll);
+}
+
 void ndpi_hll_add(struct ndpi_hll *hll, const char *data, size_t data_len) {
   hll_add(hll, (const void *)data, data_len);
 }
diff --git a/src/lib/third_party/src/hll/hll.c b/src/lib/third_party/src/hll/hll.c
index 07d33f6dd..f8cd817db 100644
--- a/src/lib/third_party/src/hll/hll.c
+++ b/src/lib/third_party/src/hll/hll.c
@@ -67,6 +67,10 @@ void hll_destroy(struct ndpi_hll *hll) {
   hll->registers = NULL;
 }
 
+void hll_reset(struct ndpi_hll *hll) {
+  memset(hll->registers, 0, hll->size);
+}
+
 static __inline void _hll_add_hash(struct ndpi_hll *hll, u_int32_t hash) {
   u_int32_t index = hash >> (32 - hll->bits);
   u_int8_t rank = _hll_rank(hash, hll->bits);