Modernize invertergui: MQTT write support, HA integration, UI updates

vendor/github.com/prometheus/common/expfmt/decode.go

@@ -45,7 +45,7 @@ func ResponseFormat(h http.Header) Format {
 
 	mediatype, params, err := mime.ParseMediaType(ct)
 	if err != nil {
-		return fmtUnknown
+		return FmtUnknown
 	}
 
 	const textType = "text/plain"
@@ -53,36 +53,51 @@ func ResponseFormat(h http.Header) Format {
 	switch mediatype {
 	case ProtoType:
 		if p, ok := params["proto"]; ok && p != ProtoProtocol {
-			return fmtUnknown
+			return FmtUnknown
 		}
 		if e, ok := params["encoding"]; ok && e != "delimited" {
-			return fmtUnknown
+			return FmtUnknown
 		}
-		return fmtProtoDelim
+		return FmtProtoDelim
 
 	case textType:
 		if v, ok := params["version"]; ok && v != TextVersion {
-			return fmtUnknown
+			return FmtUnknown
 		}
-		return fmtText
+		return FmtText
 	}
 
-	return fmtUnknown
+	return FmtUnknown
 }
 
-// NewDecoder returns a new decoder based on the given input format.
-// If the input format does not imply otherwise, a text format decoder is returned.
+// NewDecoder returns a new decoder based on the given input format. Metric
+// names are validated based on the provided Format -- if the format requires
+// escaping, raditional Prometheues validity checking is used. Otherwise, names
+// are checked for UTF-8 validity. Supported formats include delimited protobuf
+// and Prometheus text format.  For historical reasons, this decoder fallbacks
+// to classic text decoding for any other format. This decoder does not fully
+// support OpenMetrics although it may often succeed due to the similarities
+// between the formats. This decoder may not support the latest features of
+// Prometheus text format and is not intended for high-performance applications.
+// See: https://github.com/prometheus/common/issues/812
 func NewDecoder(r io.Reader, format Format) Decoder {
+	scheme := model.LegacyValidation
+	if format.ToEscapingScheme() == model.NoEscaping {
+		scheme = model.UTF8Validation
+	}
 	switch format.FormatType() {
 	case TypeProtoDelim:
-		return &protoDecoder{r: r}
+		return &protoDecoder{r: bufio.NewReader(r), s: scheme}
+	case TypeProtoText, TypeProtoCompact:
+		return &errDecoder{err: fmt.Errorf("format %s not supported for decoding", format)}
 	}
-	return &textDecoder{r: r}
+	return &textDecoder{r: r, s: scheme}
 }
 
 // protoDecoder implements the Decoder interface for protocol buffers.
 type protoDecoder struct {
-	r io.Reader
+	r protodelim.Reader
+	s model.ValidationScheme
 }
 
 // Decode implements the Decoder interface.
@@ -90,10 +105,10 @@ func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 	opts := protodelim.UnmarshalOptions{
 		MaxSize: -1,
 	}
-	if err := opts.UnmarshalFrom(bufio.NewReader(d.r), v); err != nil {
+	if err := opts.UnmarshalFrom(d.r, v); err != nil {
 		return err
 	}
-	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {
+	if !d.s.IsValidMetricName(v.GetName()) {
 		return fmt.Errorf("invalid metric name %q", v.GetName())
 	}
 	for _, m := range v.GetMetric() {
@@ -107,7 +122,7 @@ func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 			if !model.LabelValue(l.GetValue()).IsValid() {
 				return fmt.Errorf("invalid label value %q", l.GetValue())
 			}
-			if !model.LabelName(l.GetName()).IsValid() {
+			if !d.s.IsValidLabelName(l.GetName()) {
 				return fmt.Errorf("invalid label name %q", l.GetName())
 			}
 		}
@@ -115,10 +130,20 @@ func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 	return nil
 }
 
+// errDecoder is an error-state decoder that always returns the same error.
+type errDecoder struct {
+	err error
+}
+
+func (d *errDecoder) Decode(*dto.MetricFamily) error {
+	return d.err
+}
+
 // textDecoder implements the Decoder interface for the text protocol.
 type textDecoder struct {
 	r    io.Reader
 	fams map[string]*dto.MetricFamily
+	s    model.ValidationScheme
 	err  error
 }
 
@@ -126,7 +151,7 @@ type textDecoder struct {
 func (d *textDecoder) Decode(v *dto.MetricFamily) error {
 	if d.err == nil {
 		// Read all metrics in one shot.
-		var p TextParser
+		p := NewTextParser(d.s)
 		d.fams, d.err = p.TextToMetricFamilies(d.r)
 		// If we don't get an error, store io.EOF for the end.
 		if d.err == nil {
@@ -195,7 +220,7 @@ func extractSamples(f *dto.MetricFamily, o *DecodeOptions) (model.Vector, error)
 		return extractSummary(o, f), nil
 	case dto.MetricType_UNTYPED:
 		return extractUntyped(o, f), nil
-	case dto.MetricType_HISTOGRAM:
+	case dto.MetricType_HISTOGRAM, dto.MetricType_GAUGE_HISTOGRAM:
 		return extractHistogram(o, f), nil
 	}
 	return nil, fmt.Errorf("expfmt.extractSamples: unknown metric family type %v", f.GetType())
@@ -378,9 +403,13 @@ func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 				infSeen = true
 			}
 
+			v := q.GetCumulativeCountFloat()
+			if v <= 0 {
+				v = float64(q.GetCumulativeCount())
+			}
 			samples = append(samples, &model.Sample{
 				Metric:    model.Metric(lset),
-				Value:     model.SampleValue(q.GetCumulativeCount()),
+				Value:     model.SampleValue(v),
 				Timestamp: timestamp,
 			})
 		}
@@ -403,9 +432,13 @@ func extractHistogram(o *DecodeOptions, f *dto.MetricFamily) model.Vector {
 		}
 		lset[model.MetricNameLabel] = model.LabelValue(f.GetName() + "_count")
 
+		v := m.Histogram.GetSampleCountFloat()
+		if v <= 0 {
+			v = float64(m.Histogram.GetSampleCount())
+		}
 		count := &model.Sample{
 			Metric:    model.Metric(lset),
-			Value:     model.SampleValue(m.Histogram.GetSampleCount()),
+			Value:     model.SampleValue(v),
 			Timestamp: timestamp,
 		}
 		samples = append(samples, count)