[#88] netmap: use bool, fix hrw_sort tests

Signed-off-by: Andrew Danilin <andnilin@gmail.com>

netmap/aggregator.go

@@ -23,7 +23,8 @@ type (
 	}
 
 	minAgg struct {
-		min *float64
+		min      float64
+		minFound bool
 	}
 
 	meanIQRAgg struct {
@@ -102,17 +103,19 @@ func (a *meanAgg) Compute() float64 {
 }
 
 func (a *minAgg) Add(n float64) {
-	if a.min == nil || n < *a.min {
-		a.min = &n
+	if !a.minFound {
+		a.min = n
+		a.minFound = true
+		return
+	}
+
+	if n < a.min {
+		a.min = n
 	}
 }
 
 func (a *minAgg) Compute() float64 {
-	if a.min == nil {
-		return 0
-	}
-
-	return *a.min
+	return a.min
 }
 
 func (a *meanIQRAgg) Add(n float64) {

netmap/json_tests/hrw_sort.json

@@ -146,19 +146,19 @@
     "select 3 nodes in 3 distinct countries, same placement": {
       "policy": {"replicas":[{"count":1,"selector":"Main"}],"containerBackupFactor":1,"selectors":[{"name":"Main","count":3,"clause":"DISTINCT","attribute":"Country","filter":"*"}],"filters":[]},
       "pivot": "Y29udGFpbmVySUQ=",
-      "result": [[4, 0, 7]],
+      "result": [[0, 2, 3]],
       "placement": {
         "pivot": "b2JqZWN0SUQ=",
-        "result": [[4, 0, 7]]
+        "result": [[0, 2, 3]]
       }
     },
     "select 6 nodes in 3 distinct countries, different placement": {
       "policy": {"replicas":[{"count":1,"selector":"Main"}],"containerBackupFactor":2,"selectors":[{"name":"Main","count":3,"clause":"DISTINCT","attribute":"Country","filter":"*"}],"filters":[]},
       "pivot": "Y29udGFpbmVySUQ=",
-      "result": [[4, 3, 0, 1, 7, 2]],
+      "result": [[0, 1, 2, 6, 3, 4]],
       "placement": {
         "pivot": "b2JqZWN0SUQ=",
-        "result": [[4, 3, 0, 7, 2, 1]]
+        "result": [[0, 1, 2, 6, 3, 4]]
       }
     }
   }