From bc1212319191ed1aadd243c7c86db5a62e3c70bd Mon Sep 17 00:00:00 2001
From: Ingo Oppermann <ingo@datarhei.com>
Date: Mon, 14 Oct 2024 15:49:07 +0200
Subject: [PATCH] Add statistics about buffer reuse

---
 mem/pool.go     | 4 ++++
 monitor/self.go | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/mem/pool.go b/mem/pool.go
index 08ae8519..23a7c1d6 100644
--- a/mem/pool.go
+++ b/mem/pool.go
@@ -27,6 +27,7 @@ type BufferPool struct {
 	maxSize     uint64
 
 	alloc   uint64
+	reuse   uint64
 	recycle uint64
 	dump    uint64
 
@@ -35,6 +36,7 @@ type BufferPool struct {
 
 type PoolStats struct {
 	Alloc   uint64
+	Reuse   uint64
 	Recycle uint64
 	Dump    uint64
 
@@ -53,6 +55,7 @@ func NewBufferPool() *BufferPool {
 func (p *BufferPool) Stats() PoolStats {
 	s := PoolStats{
 		Alloc:       atomic.LoadUint64(&p.alloc),
+		Reuse:       atomic.LoadUint64(&p.reuse),
 		Recycle:     atomic.LoadUint64(&p.recycle),
 		Dump:        atomic.LoadUint64(&p.dump),
 		DefaultSize: atomic.LoadUint64(&p.defaultSize),
@@ -65,6 +68,7 @@ func (p *BufferPool) Stats() PoolStats {
 func (p *BufferPool) Get() *Buffer {
 	v := p.pool.Get()
 	if v != nil {
+		atomic.AddUint64(&p.reuse, 1)
 		return v.(*Buffer)
 	}
 
diff --git a/monitor/self.go b/monitor/self.go
index bd564ae5..1964340b 100644
--- a/monitor/self.go
+++ b/monitor/self.go
@@ -9,6 +9,7 @@ import (
 
 type selfCollector struct {
 	bufferAllocDescr       *metric.Description
+	bufferReuseDescr       *metric.Description
 	bufferRecycleDescr     *metric.Description
 	bufferDumpDescr        *metric.Description
 	bufferDefaultSizeDescr *metric.Description
@@ -28,6 +29,7 @@ func NewSelfCollector() metric.Collector {
 	c := &selfCollector{}
 
 	c.bufferAllocDescr = metric.NewDesc("self_bufferpool_alloc", "Number of buffer allocations", nil)
+	c.bufferReuseDescr = metric.NewDesc("self_bufferpool_reuse", "Number of buffer reuses", nil)
 	c.bufferRecycleDescr = metric.NewDesc("self_bufferpool_recycle", "Number of buffer recycles", nil)
 	c.bufferDumpDescr = metric.NewDesc("self_bufferpool_dump", "Number of buffer dumps", nil)
 	c.bufferDefaultSizeDescr = metric.NewDesc("self_bufferpool_default_size", "Default buffer size", nil)
@@ -54,6 +56,7 @@ func (c *selfCollector) Prefix() string {
 func (c *selfCollector) Describe() []*metric.Description {
 	return []*metric.Description{
 		c.bufferAllocDescr,
+		c.bufferReuseDescr,
 		c.bufferRecycleDescr,
 		c.bufferDumpDescr,
 		c.bufferDefaultSizeDescr,
@@ -75,6 +78,7 @@ func (c *selfCollector) Collect() metric.Metrics {
 	metrics := metric.NewMetrics()
 
 	metrics.Add(metric.NewValue(c.bufferAllocDescr, float64(bufferstats.Alloc)))
+	metrics.Add(metric.NewValue(c.bufferReuseDescr, float64(bufferstats.Reuse)))
 	metrics.Add(metric.NewValue(c.bufferRecycleDescr, float64(bufferstats.Recycle)))
 	metrics.Add(metric.NewValue(c.bufferDumpDescr, float64(bufferstats.Dump)))
 	metrics.Add(metric.NewValue(c.bufferDefaultSizeDescr, float64(bufferstats.DefaultSize)))