Feature request per pod (#1946)

This feature enables routing more than one request to a pod at the same time. This is the first draft of the work and might involve more optimizations later.

pkg/poolcache/poolcache_test.go

@@ -0,0 +1,58 @@
+package poolcache
+
+import (
+	"log"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/api/resource"
+)
+
+func checkErr(err error) {
+	if err != nil {
+		log.Panicf("err: %v", err)
+	}
+}
+
+func TestPoolCache(t *testing.T) {
+	c := NewPoolCache()
+
+	c.SetValue("func", "ip", "value", resource.MustParse("45m"))
+
+	c.SetValue("func2", "ip2", "value2", resource.MustParse("50m"))
+
+	c.SetValue("func2", "ip22", "value22", resource.MustParse("33m"))
+
+	checkErr(c.DeleteValue("func2", "ip2"))
+
+	cc := c.ListAvailableValue()
+	if len(cc) != 0 {
+		log.Panicf("expected 0 available items")
+	}
+
+	c.MarkAvailable("func", "ip")
+
+	_, active, err := c.GetValue("func", 5)
+	if active != 1 {
+		log.Panicln("Expected 1 active, found", active)
+	}
+	checkErr(err)
+
+	checkErr(c.DeleteValue("func", "ip"))
+
+	_, active, err = c.GetValue("func", 5)
+	if err == nil {
+		log.Panicf("found deleted element")
+	}
+
+	c.SetValue("cpulimit", "100", "value", resource.MustParse("3m"))
+	c.SetCPUUtilization("cpulimit", "100", resource.MustParse("4m"))
+
+	_, _, err = c.GetValue("cpulimit", 5)
+
+	if err == nil {
+		log.Panicf("received pod address with higher CPU usage than limit")
+	}
+	c.SetCPUUtilization("cpulimit", "100", resource.MustParse("2m"))
+	_, _, err = c.GetValue("cpulimit", 5)
+	checkErr(err)
+}