feat: disk cache

Author: rahulguptajss

cmd/exporters/prometheus/prometheus.go

@@ -23,12 +23,6 @@ package prometheus
 
 import (
 	"bytes"
-	"github.com/netapp/harvest/v2/cmd/poller/exporter"
-	"github.com/netapp/harvest/v2/cmd/poller/plugin/changelog"
-	"github.com/netapp/harvest/v2/pkg/errs"
-	"github.com/netapp/harvest/v2/pkg/matrix"
-	"github.com/netapp/harvest/v2/pkg/set"
-	"github.com/netapp/harvest/v2/pkg/slogx"
 	"log/slog"
 	"path/filepath"
 	"regexp"
@@ -37,6 +31,13 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/netapp/harvest/v2/cmd/poller/exporter"
+	"github.com/netapp/harvest/v2/cmd/poller/plugin/changelog"
+	"github.com/netapp/harvest/v2/pkg/errs"
+	"github.com/netapp/harvest/v2/pkg/matrix"
+	"github.com/netapp/harvest/v2/pkg/set"
+	"github.com/netapp/harvest/v2/pkg/slogx"
 )
 
 // Default parameters
@@ -729,6 +730,10 @@ func (p *Prometheus) render(data *matrix.Matrix) ([][]byte, exporter.Stats) {
 		}
 	}
 
+	// Both memory and disk cache add a newline character after each metric line
+	// when serving via HTTP (see writeMetric() and writeToDisk())
+	renderedBytes += uint64(len(rendered)) // Add 1 byte per line for '\n'
+
 	stats := exporter.Stats{
 		InstancesExported: instancesExported,
 		MetricsExported:   uint64(len(rendered)),