From a53f4765858285f520b8a2645da80aed2b1487b1 Mon Sep 17 00:00:00 2001
From: Luca Deri <deri@ntop.org>
Date: Wed, 17 Aug 2022 16:25:10 +0200
Subject: [PATCH] Modified definition of hll_add

---
 src/include/ndpi_api.h.in         |  4 ++--
 src/lib/ndpi_analyze.c            |  9 +++++----
 src/lib/third_party/include/hll.h |  8 ++++----
 src/lib/third_party/src/hll/hll.c | 16 +++++++++++-----
 4 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/src/include/ndpi_api.h.in b/src/include/ndpi_api.h.in
index 9064ac6272b..2e869020361 100644
--- a/src/include/ndpi_api.h.in
+++ b/src/include/ndpi_api.h.in
@@ -1692,8 +1692,8 @@ extern "C" {
   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) ;
+  int ndpi_hll_add(struct ndpi_hll *hll, const char *data, size_t data_len);
+  int ndpi_hll_add_number(struct ndpi_hll *hll, u_int32_t value) ;
 
   /* Get cardinality estimation */
   double ndpi_hll_count(struct ndpi_hll *hll);
diff --git a/src/lib/ndpi_analyze.c b/src/lib/ndpi_analyze.c
index a3c51805147..2b5d46a90bc 100644
--- a/src/lib/ndpi_analyze.c
+++ b/src/lib/ndpi_analyze.c
@@ -290,12 +290,13 @@ 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);
+int ndpi_hll_add(struct ndpi_hll *hll, const char *data, size_t data_len) {
+  return(hll_add(hll, (const void *)data, data_len));
 }
 
-void ndpi_hll_add_number(struct ndpi_hll *hll, u_int32_t value) {
-  hll_add(hll, (const void *)&value, sizeof(value));
+/* 1 = rank changed, 0 = no changes in rank */
+int ndpi_hll_add_number(struct ndpi_hll *hll, u_int32_t value) {
+  return(hll_add(hll, (const void *)&value, sizeof(value)));
 }
 
 double ndpi_hll_count(struct ndpi_hll *hll) {
diff --git a/src/lib/third_party/include/hll.h b/src/lib/third_party/include/hll.h
index 00975ec36ef..4b094a63e9b 100644
--- a/src/lib/third_party/include/hll.h
+++ b/src/lib/third_party/include/hll.h
@@ -21,7 +21,7 @@
  */
 
 
-extern int      hll_init(struct ndpi_hll *hll, u_int8_t bits);
-extern void     hll_destroy(struct ndpi_hll *hll);
-extern void     hll_add(struct ndpi_hll *hll, const void *buf, size_t size);
-extern double   hll_count(const struct ndpi_hll *hll);
+extern int    hll_init(struct ndpi_hll *hll, u_int8_t bits);
+extern void   hll_destroy(struct ndpi_hll *hll);
+extern int    hll_add(struct ndpi_hll *hll, const void *buf, size_t size);
+extern double hll_count(const struct ndpi_hll *hll);
diff --git a/src/lib/third_party/src/hll/hll.c b/src/lib/third_party/src/hll/hll.c
index c526c6af0e4..ad7284411b8 100644
--- a/src/lib/third_party/src/hll/hll.c
+++ b/src/lib/third_party/src/hll/hll.c
@@ -97,20 +97,26 @@ 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) {
+/* Return: 0 = nothing changed, 1 = ranking changed */
+static __inline int _hll_add_hash(struct ndpi_hll *hll, u_int32_t hash) {
   if(hll->registers) {
     u_int32_t index = hash >> (32 - hll->bits);   /* Use the first 'hll->bits' bits as bucket index */
     u_int8_t rank   = _hll_rank(hash, hll->bits); /* Count the number of leading 0 */
     
-    if(rank > hll->registers[index])
-      hll->registers[index] = rank; /* Store the largest number of lesding zeros for the bucket */    
+    if(rank > hll->registers[index]) {
+      hll->registers[index] = rank; /* Store the largest number of lesding zeros for the bucket */
+      return(1);
+    }
   }
+  
+  return(0);
 }
 
-void hll_add(struct ndpi_hll *hll, const void *buf, size_t size) {
+/* Return: 0 = nothing changed, 1 = ranking changed */
+int hll_add(struct ndpi_hll *hll, const void *buf, size_t size) {
   u_int32_t hash = MurmurHash3_x86_32((const char *)buf, (u_int32_t)size, 0x5f61767a);
 
-  _hll_add_hash(hll, hash);
+  return(_hll_add_hash(hll, hash));
 }
 
 double hll_count(const struct ndpi_hll *hll) {