export: add DTOMetricFamily, TextParser, NewPrometheusRegistry; fix HistogramVec to implement Collector

AGENTS.md

@@ -0,0 +1 @@
+LLM.md

CLAUDE.md

@@ -0,0 +1 @@
+LLM.md

GEMINI.md

@@ -0,0 +1 @@
+LLM.md

QWEN.md

@@ -0,0 +1 @@
+LLM.md

export.go

@@ -9,6 +9,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/prometheus/common/expfmt"
 	dto "github.com/prometheus/client_model/go"
 )
 
@@ -41,6 +42,15 @@ type HTTPHandlerOpts = promhttp.HandlerOpts
 // MetricFamilies is a slice of metric families
 type MetricFamilies = []*dto.MetricFamily
 
+// DTOMetricFamily is an alias for dto.MetricFamily for backward compatibility
+type DTOMetricFamily = dto.MetricFamily
+
+// TextParser is an alias for expfmt.TextParser
+type TextParser = expfmt.TextParser
+
+// NewPrometheusRegistry is an alias for NewRegistry for backward compatibility
+var NewPrometheusRegistry = NewRegistry
+
 // WrapPrometheusRegistry wraps a prometheus registry in our Registry interface
 func WrapPrometheusRegistry(promReg *prometheus.Registry) Registry {
 	return promReg

metric.go

@@ -135,6 +135,7 @@ type GaugeVec interface {
 
 // HistogramVec is a vector of histograms
 type HistogramVec interface {
+	prometheus.Collector
 	// With returns a histogram with the given label values
 	With(Labels) Histogram
 	// WithLabelValues returns a histogram with the given label values
@@ -227,10 +228,13 @@ func NewGaugeVec(opts GaugeOpts, labelNames []string) GaugeVec {
 	return WrapPrometheusGaugeVec(prometheus.NewGaugeVec(opts, labelNames))
 }
 
+func NewHistogramVec(opts HistogramOpts, labelNames []string) HistogramVec {
+	return WrapPrometheusHistogramVec(prometheus.NewHistogramVec(opts, labelNames))
+}
+
 // Keep these as direct aliases since they don't need wrapping
 var (
 	NewHistogram       = prometheus.NewHistogram
-	NewHistogramVec    = prometheus.NewHistogramVec
 	NewSummary         = prometheus.NewSummary
 	NewSummaryVec      = prometheus.NewSummaryVec
 	NewRegistry        = prometheus.NewRegistry

noop.go

@@ -67,6 +67,8 @@ type noopHistogramVec struct{}
 
 func (n *noopHistogramVec) With(Labels) Histogram               { return &noopHistogram{} }
 func (n *noopHistogramVec) WithLabelValues(...string) Histogram { return &noopHistogram{} }
+func (n *noopHistogramVec) Describe(ch chan<- *prometheus.Desc)       {}
+func (n *noopHistogramVec) Collect(ch chan<- prometheus.Metric)        {}
 
 // noopSummaryVec is a summary vector that does nothing
 type noopSummaryVec struct{}

prometheus.go

@@ -105,6 +105,10 @@ func (p *prometheusHistogramVec) WithLabelValues(labelValues ...string) Histogra
 	return &prometheusHistogram{histogram: p.vec.WithLabelValues(labelValues...).(prometheus.Histogram)}
 }
 
+// Implement prometheus.Collector interface
+func (p *prometheusHistogramVec) Describe(ch chan<- *prometheus.Desc) { p.vec.Describe(ch) }
+func (p *prometheusHistogramVec) Collect(ch chan<- prometheus.Metric)  { p.vec.Collect(ch) }
+
 // prometheusSummaryVec wraps prometheus.SummaryVec
 type prometheusSummaryVec struct {
 	vec *prometheus.SummaryVec

wrappers.go

@@ -22,11 +22,16 @@ func WrapPrometheusCounterVec(cv *prometheus.CounterVec) CounterVec {
 	return &prometheusCounterVec{vec: cv}
 }
 
-// WrapPrometheusGaugeVec wraps a prometheus.GaugeVec to implement our GaugeVec interface  
+// WrapPrometheusGaugeVec wraps a prometheus.GaugeVec to implement our GaugeVec interface
 func WrapPrometheusGaugeVec(gv *prometheus.GaugeVec) GaugeVec {
 	return &prometheusGaugeVec{vec: gv}
 }
 
+// WrapPrometheusHistogramVec wraps a prometheus.HistogramVec to implement our HistogramVec interface
+func WrapPrometheusHistogramVec(hv *prometheus.HistogramVec) HistogramVec {
+	return &prometheusHistogramVec{vec: hv}
+}
+
 // NewCounterWithOpts creates a wrapped counter from options
 func NewCounterWithOpts(opts prometheus.CounterOpts) Counter {
 	return WrapPrometheusCounter(prometheus.NewCounter(opts))