From 02938e00d026e78e83cc5e3da52db94825fac697 Mon Sep 17 00:00:00 2001
From: andig <andi@evcc.io>
Date: Tue, 1 Apr 2025 19:40:47 +0200
Subject: [PATCH] chore: log retries - revert me (#20311)

---
 cmd/dumper.go | 16 +++++++++++++++-
 core/site.go  | 15 ++++++++++++++-
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/cmd/dumper.go b/cmd/dumper.go
index 885533b0c..5f1545f06 100644
--- a/cmd/dumper.go
+++ b/cmd/dumper.go
@@ -9,6 +9,7 @@ import (
 	"text/tabwriter"
 	"time"
 
+	"github.com/cenkalti/backoff/v4"
 	"github.com/evcc-io/evcc/api"
 	"github.com/fatih/structs"
 )
@@ -34,6 +35,11 @@ func (d *dumper) DumpWithHeader(name string, device interface{}) {
 	}
 }
 
+// bo returns an exponential backoff for reading meter power quickly
+func bo() *backoff.ExponentialBackOff {
+	return backoff.NewExponentialBackOff(backoff.WithInitialInterval(20*time.Millisecond), backoff.WithMaxElapsedTime(time.Second))
+}
+
 func (d *dumper) Dump(name string, v interface{}) {
 	w := tabwriter.NewWriter(os.Stdout, 0, 0, 1, ' ', 0)
 
@@ -45,7 +51,15 @@ func (d *dumper) Dump(name string, v interface{}) {
 	// meter
 
 	if v, ok := v.(api.Meter); ok {
-		if power, err := v.CurrentPower(); err != nil {
+		power, err := backoff.RetryWithData(func() (float64, error) {
+			f, err := v.CurrentPower()
+			if err != nil {
+				fmt.Println(err)
+			}
+			return f, err
+		}, bo())
+
+		if err != nil {
 			fmt.Fprintf(w, "Power:\t%v\n", err)
 		} else {
 			fmt.Fprintf(w, "Power:\t%.0fW\n", power)
diff --git a/core/site.go b/core/site.go
index 420f4937f..0297c9ff6 100644
--- a/core/site.go
+++ b/core/site.go
@@ -1,6 +1,7 @@
 package core
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"math"
@@ -484,10 +485,22 @@ func (site *Site) collectMeters(key string, meters []config.Device[api.Meter]) [
 		meter := dev.Instance()
 
 		// power
-		power, err := backoff.RetryWithData(meter.CurrentPower, bo())
+		var b bytes.Buffer
+		start := time.Now()
+		power, err := backoff.RetryWithData(func() (float64, error) {
+			f, err := meter.CurrentPower()
+			if err != nil {
+				fmt.Fprintf(&b, "%v !! %v\n", time.Now(), err)
+			}
+			return f, err
+		}, bo())
 		if err == nil {
 			site.log.DEBUG.Printf("%s %d power: %.0fW", key, i+1, power)
 		} else {
+			if b.Len() > 0 {
+				site.log.ERROR.Println(start, "!!")
+				site.log.ERROR.Println(b.String())
+			}
 			site.log.ERROR.Printf("%s %d power: %v", key, i+1, err)
 		}