Fixes and better unit test for histogram

3 files changed, 21 insertions, 15 deletions

diff --git a/src/bp_gtest.cpp b/src/bp_gtest.cpp
index 7bb3da0c..86b7821b 100755
--- a/src/bp_gtest.cpp
+++ b/src/bp_gtest.cpp
@@ -2657,19 +2657,17 @@ public:
 TEST_F(time_histogram, test_average) {
     int i;
     int j;
-    // Latency is calculated by low pass filter, so need to give it time to stabilize
-    for (j=0; j < 13; j++) {
-        for (i=0; i<100; i++) {
-            m_hist.Add(10e-6);
-        }
-        for (i=0; i<100; i++) {
-            m_hist.Add(10e-3);
+    for (j = 0; j < 10; j++) {
+        for (i = 0; i <= 2000; i++) {
+            m_hist.Add(10e-7 * i);
         }
         m_hist.update();
+        // Latency is calculated using low pass filter, with initial value of 0
+        EXPECT_EQ(m_hist.get_average_latency(), 1000.0 - (1000.0 / (2 << j)));
+        EXPECT_EQ(m_hist.get_count(), 2001 * (j+1));
+        EXPECT_EQ(m_hist.get_high_count(), 2001 * (j+1) - (11 * (j+1)));
+        EXPECT_EQ(m_hist.get_max_latency(), 2000);
     }
-
-    EXPECT_GT(m_hist.get_average_latency(), 5004);
-    EXPECT_LT(m_hist.get_average_latency(), 5005);
     
     m_hist.Dump(stdout);
 }
diff --git a/src/time_histogram.cpp b/src/time_histogram.cpp
index dd15c4be..8a92cb6f 100755
--- a/src/time_histogram.cpp
+++ b/src/time_histogram.cpp
@@ -30,6 +30,8 @@ void CTimeHistogram::Reset() {
     m_period_data[0].reset();
     m_period_data[1].reset();
     m_period = 0;
+    m_total_cnt = 0;
+    m_total_cnt_high = 0;
     m_max_dt = 0;
     m_average = 0;
     memset(&m_max_ar[0],0,sizeof(m_max_ar));
@@ -57,6 +59,9 @@ bool CTimeHistogram::Add(dsec_t dt) {
     CTimeHistogramPerPeriodData &period_elem = m_period_data[m_period];
 
     period_elem.inc_cnt();
+    period_elem.update_sum(dt);
+
+    // values smaller then certain threshold do not get into the histogram
     if (dt < m_min_delta) {
         return false;
     }
@@ -87,8 +92,6 @@ bool CTimeHistogram::Add(dsec_t dt) {
         }
     }
 
-    period_elem.update_sum(dt);
-
     return true;
 }
 
@@ -113,6 +116,8 @@ void CTimeHistogram::update() {
         m_win_cnt = 0;
     }
     update_average(period_elem);
+    m_total_cnt += period_elem.get_cnt();
+    m_total_cnt_high += period_elem.get_high_cnt();
 }
 
 void  CTimeHistogram::update_average(CTimeHistogramPerPeriodData &period_elem) {
@@ -181,7 +186,6 @@ void CTimeHistogram::Dump(FILE *fd) {
 */
 
 void CTimeHistogram::dump_json(std::string name,std::string & json ) {
-    CTimeHistogramPerPeriodData &period_elem = m_period_data[get_read_period_index()];
     char buff[200];
     if (name != "")
         sprintf(buff,"\"%s\":{",name.c_str());
@@ -191,8 +195,8 @@ void CTimeHistogram::dump_json(std::string name,std::string & json ) {
 
     json += add_json("min_usec", get_usec(m_min_delta));
     json += add_json("max_usec", get_usec(m_max_dt));
-    json += add_json("high_cnt", period_elem.get_high_cnt());
-    json += add_json("cnt", period_elem.get_cnt());
+    json += add_json("high_cnt", m_total_cnt_high);
+    json += add_json("cnt", m_total_cnt);
     json+=add_json("s_avg", get_average_latency());
     int i;
     int j;
diff --git a/src/time_histogram.h b/src/time_histogram.h
index 9bdf2c93..da70e677 100755
--- a/src/time_histogram.h
+++ b/src/time_histogram.h
@@ -85,6 +85,8 @@ public:
         return period_elem.get_max_usec();
     }
     void  dump_json(std::string name,std::string & json );
+    uint64_t get_count() {return m_total_cnt;}
+    uint64_t get_high_count() {return m_total_cnt_high;}
 
 private:
     uint32_t get_usec(dsec_t d);
@@ -103,6 +105,8 @@ private:
     // Each period we switch between the two
     CTimeHistogramPerPeriodData m_period_data[2];
     uint8_t m_period; // 0 or 1 according to m_period_data element we currently use
+    uint64_t m_total_cnt;
+    uint64_t m_total_cnt_high;
     dsec_t   m_max_dt;  // Total maximum latency
     dsec_t   m_average; /* moving average */
     uint32_t m_win_cnt;