swarm: initial instrumentation (#15969)

* swarm: initial instrumentation with go-metrics

* swarm: initialise metrics collection and add ResettingTimer to HTTP requests

* swarm: update metrics flags names. remove redundant Timer.

* swarm: rename method for periodically updating gauges

* swarm: finalise metrics after feedback

* swarm/network: always init kad metrics containers

* swarm/network: off-by-one index in metrics containers

* swarm, metrics: resolved conflicts

1 files changed, 14 insertions, 0 deletions

diff --git a/swarm/storage/memstore.go b/swarm/storage/memstore.go
index 3cb25ac62..d6be54220 100644
--- a/swarm/storage/memstore.go
+++ b/swarm/storage/memstore.go
@@ -23,6 +23,13 @@ import (
 	"sync"
 
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/metrics"
+)
+
+//metrics variables
+var (
+	memstorePutCounter    = metrics.NewRegisteredCounter("storage.db.memstore.put.count", nil)
+	memstoreRemoveCounter = metrics.NewRegisteredCounter("storage.db.memstore.rm.count", nil)
 )
 
 const (
@@ -130,6 +137,10 @@ func (s *MemStore) setCapacity(c uint) {
 	s.capacity = c
 }
 
+func (s *MemStore) Counter() uint {
+	return s.entryCnt
+}
+
 // entry (not its copy) is going to be in MemStore
 func (s *MemStore) Put(entry *Chunk) {
 	if s.capacity == 0 {
@@ -145,6 +156,8 @@ func (s *MemStore) Put(entry *Chunk) {
 
 	s.accessCnt++
 
+	memstorePutCounter.Inc(1)
+
 	node := s.memtree
 	bitpos := uint(0)
 	for node.entry == nil {
@@ -289,6 +302,7 @@ func (s *MemStore) removeOldest() {
 	}
 
 	if node.entry.SData != nil {
+		memstoreRemoveCounter.Inc(1)
 		node.entry = nil
 		s.entryCnt--
 	}