Vendor main dependencies.

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

@@ -0,0 +1,162 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package expfmt
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"sort"
+
+	"github.com/golang/protobuf/proto"
+	dto "github.com/prometheus/client_model/go"
+
+	"github.com/prometheus/common/model"
+)
+
+type json2Decoder struct {
+	dec  *json.Decoder
+	fams []*dto.MetricFamily
+}
+
+func newJSON2Decoder(r io.Reader) Decoder {
+	return &json2Decoder{
+		dec: json.NewDecoder(r),
+	}
+}
+
+type histogram002 struct {
+	Labels model.LabelSet     `json:"labels"`
+	Values map[string]float64 `json:"value"`
+}
+
+type counter002 struct {
+	Labels model.LabelSet `json:"labels"`
+	Value  float64        `json:"value"`
+}
+
+func protoLabelSet(base, ext model.LabelSet) []*dto.LabelPair {
+	labels := base.Clone().Merge(ext)
+	delete(labels, model.MetricNameLabel)
+
+	names := make([]string, 0, len(labels))
+	for ln := range labels {
+		names = append(names, string(ln))
+	}
+	sort.Strings(names)
+
+	pairs := make([]*dto.LabelPair, 0, len(labels))
+
+	for _, ln := range names {
+		lv := labels[model.LabelName(ln)]
+
+		pairs = append(pairs, &dto.LabelPair{
+			Name:  proto.String(ln),
+			Value: proto.String(string(lv)),
+		})
+	}
+
+	return pairs
+}
+
+func (d *json2Decoder) more() error {
+	var entities []struct {
+		BaseLabels model.LabelSet `json:"baseLabels"`
+		Docstring  string         `json:"docstring"`
+		Metric     struct {
+			Type   string          `json:"type"`
+			Values json.RawMessage `json:"value"`
+		} `json:"metric"`
+	}
+
+	if err := d.dec.Decode(&entities); err != nil {
+		return err
+	}
+	for _, e := range entities {
+		f := &dto.MetricFamily{
+			Name:   proto.String(string(e.BaseLabels[model.MetricNameLabel])),
+			Help:   proto.String(e.Docstring),
+			Type:   dto.MetricType_UNTYPED.Enum(),
+			Metric: []*dto.Metric{},
+		}
+
+		d.fams = append(d.fams, f)
+
+		switch e.Metric.Type {
+		case "counter", "gauge":
+			var values []counter002
+
+			if err := json.Unmarshal(e.Metric.Values, &values); err != nil {
+				return fmt.Errorf("could not extract %s value: %s", e.Metric.Type, err)
+			}
+
+			for _, ctr := range values {
+				f.Metric = append(f.Metric, &dto.Metric{
+					Label: protoLabelSet(e.BaseLabels, ctr.Labels),
+					Untyped: &dto.Untyped{
+						Value: proto.Float64(ctr.Value),
+					},
+				})
+			}
+
+		case "histogram":
+			var values []histogram002
+
+			if err := json.Unmarshal(e.Metric.Values, &values); err != nil {
+				return fmt.Errorf("could not extract %s value: %s", e.Metric.Type, err)
+			}
+
+			for _, hist := range values {
+				quants := make([]string, 0, len(values))
+				for q := range hist.Values {
+					quants = append(quants, q)
+				}
+
+				sort.Strings(quants)
+
+				for _, q := range quants {
+					value := hist.Values[q]
+					// The correct label is "quantile" but to not break old expressions
+					// this remains "percentile"
+					hist.Labels["percentile"] = model.LabelValue(q)
+
+					f.Metric = append(f.Metric, &dto.Metric{
+						Label: protoLabelSet(e.BaseLabels, hist.Labels),
+						Untyped: &dto.Untyped{
+							Value: proto.Float64(value),
+						},
+					})
+				}
+			}
+
+		default:
+			return fmt.Errorf("unknown metric type %q", e.Metric.Type)
+		}
+	}
+	return nil
+}
+
+// Decode implements the Decoder interface.
+func (d *json2Decoder) Decode(v *dto.MetricFamily) error {
+	if len(d.fams) == 0 {
+		if err := d.more(); err != nil {
+			return err
+		}
+	}
+
+	*v = *d.fams[0]
+	d.fams = d.fams[1:]
+
+	return nil
+}