I think I just solved a longstanding bug in the rrd_update routine

[rrdtool.git] / src / rrd_update.c

diff --git a/src/rrd_update.c b/src/rrd_update.c
index ec1e5fd..83ef706 100644 (file)
--- a/src/rrd_update.c
+++ b/src/rrd_update.c
@@ -212,7 +212,6 @@ static void initialize_cdp_val(
     unival *scratch,
     int current_cf,
     rrd_value_t pdp_temp_val,
-    unsigned long elapsed_pdp_st,
     unsigned long start_pdp_offset,
     unsigned long pdp_cnt);
 
@@ -227,8 +226,9 @@ static void reset_cdp(
     int cdp_idx,
     enum cf_en current_cf);
 
-static rrd_value_t initialize_average_carry_over(
+static rrd_value_t initialize_carry_over(
     rrd_value_t pdp_temp_val,
+    int         current_cf,
     unsigned long elapsed_pdp_st,
     unsigned long start_pdp_offset,
     unsigned long pdp_cnt);
@@ -1593,18 +1593,15 @@ static void update_cdp(
 
         if (*cdp_unkn_pdp_cnt > pdp_cnt * xff) {
             *cdp_primary_val = DNAN;
-            if (current_cf == CF_AVERAGE) {
-                *cdp_val =
-                    initialize_average_carry_over(pdp_temp_val,
-                                                  elapsed_pdp_st,
-                                                  start_pdp_offset, pdp_cnt);
-            } else {
-                *cdp_val = pdp_temp_val;
-            }
         } else {
             initialize_cdp_val(scratch, current_cf, pdp_temp_val,
-                               elapsed_pdp_st, start_pdp_offset, pdp_cnt);
-        }               /* endif meets xff value requirement for a valid value */
+                               start_pdp_offset, pdp_cnt);
+        }
+        *cdp_val =
+            initialize_carry_over(pdp_temp_val,current_cf,
+                                  elapsed_pdp_st,
+                                  start_pdp_offset, pdp_cnt);
+               /* endif meets xff value requirement for a valid value */
         /* initialize carry over CDP_unkn_pdp_cnt, this must after CDP_primary_val
          * is set because CDP_unkn_pdp_cnt is required to compute that value. */
         if (isnan(pdp_temp_val))
@@ -1640,7 +1637,6 @@ static void initialize_cdp_val(
     unival *scratch,
     int current_cf,
     rrd_value_t pdp_temp_val,
-    unsigned long elapsed_pdp_st,
     unsigned long start_pdp_offset,
     unsigned long pdp_cnt)
 {
@@ -1653,13 +1649,11 @@ static void initialize_cdp_val(
         scratch[CDP_primary_val].u_val =
             (cum_val + cur_val * start_pdp_offset) /
             (pdp_cnt - scratch[CDP_unkn_pdp_cnt].u_cnt);
-        scratch[CDP_val].u_val =
-            initialize_average_carry_over(pdp_temp_val, elapsed_pdp_st,
-                                          start_pdp_offset, pdp_cnt);
         break;
-    case CF_MAXIMUM:
+    case CF_MAXIMUM: 
         cum_val = IFDNAN(scratch[CDP_val].u_val, -DINF);
         cur_val = IFDNAN(pdp_temp_val, -DINF);
+
 #if 0
 #ifdef DEBUG
         if (isnan(scratch[CDP_val].u_val) && isnan(pdp_temp)) {
@@ -1674,8 +1668,6 @@ static void initialize_cdp_val(
             scratch[CDP_primary_val].u_val = cur_val;
         else
             scratch[CDP_primary_val].u_val = cum_val;
-        /* initialize carry over value */
-        scratch[CDP_val].u_val = pdp_temp_val;
         break;
     case CF_MINIMUM:
         cum_val = IFDNAN(scratch[CDP_val].u_val, DINF);
@@ -1694,14 +1686,10 @@ static void initialize_cdp_val(
             scratch[CDP_primary_val].u_val = cur_val;
         else
             scratch[CDP_primary_val].u_val = cum_val;
-        /* initialize carry over value */
-        scratch[CDP_val].u_val = pdp_temp_val;
         break;
     case CF_LAST:
     default:
         scratch[CDP_primary_val].u_val = pdp_temp_val;
-        /* initialize carry over value */
-        scratch[CDP_val].u_val = pdp_temp_val;
         break;
     }
 }
@@ -1763,17 +1751,34 @@ static void reset_cdp(
     }
 }
 
-static rrd_value_t initialize_average_carry_over(
+static rrd_value_t initialize_carry_over(
     rrd_value_t pdp_temp_val,
+    int current_cf,
     unsigned long elapsed_pdp_st,
     unsigned long start_pdp_offset,
     unsigned long pdp_cnt)
 {
-    /* initialize carry over value */
-    if (isnan(pdp_temp_val)) {
-        return DNAN;
-    }
-    return pdp_temp_val * ((elapsed_pdp_st - start_pdp_offset) % pdp_cnt);
+    unsigned long pdp_into_cdp_cnt = ((elapsed_pdp_st - start_pdp_offset) % pdp_cnt);
+    if ( pdp_into_cdp_cnt == 0 || isnan(pdp_temp_val)){
+        switch (current_cf) {
+        case CF_MAXIMUM:
+            return -DINF;
+        case CF_MINIMUM:
+            return DINF;
+        case CF_AVERAGE:
+            return 0;
+        default:
+            return DNAN;
+        }        
+    } 
+    else {
+        switch (current_cf) {
+        case CF_AVERAGE:
+            return pdp_temp_val *  pdp_into_cdp_cnt ;
+        default:
+            return pdp_temp_val;
+        }        
+    }        
 }
 
 /*