Add histogram vectors to model

Signed-off-by: Jeanette Tan <[email protected]>

model/value.go

@@ -111,9 +111,10 @@ func (s SamplePair) String() string {
 
 // Sample is a sample pair associated with a metric.
 type Sample struct {
-	Metric    Metric      `json:"metric"`
-	Value     SampleValue `json:"value"`
-	Timestamp Time        `json:"timestamp"`
+	Metric    Metric          `json:"metric"`
+	Value     SampleValue     `json:"value"`
+	Timestamp Time            `json:"timestamp"`
+	Histogram SampleHistogram `json:"histogram"`
 }
 
 // Equal compares first the metrics, then the timestamp, then the value. The
@@ -129,8 +130,11 @@ func (s *Sample) Equal(o *Sample) bool {
 	if !s.Timestamp.Equal(o.Timestamp) {
 		return false
 	}
+	if !s.Value.Equal(o.Value) {
+		return false
+	}
 
-	return s.Value.Equal(o.Value)
+	return s.Histogram.Equal(&o.Histogram)
 }
 
 func (s Sample) String() string {
@@ -142,40 +146,63 @@ func (s Sample) String() string {
 
 // MarshalJSON implements json.Marshaler.
 func (s Sample) MarshalJSON() ([]byte, error) {
-	v := struct {
-		Metric Metric     `json:"metric"`
-		Value  SamplePair `json:"value"`
-	}{
-		Metric: s.Metric,
-		Value: SamplePair{
-			Timestamp: s.Timestamp,
-			Value:     s.Value,
-		},
+	if s.Histogram.Count != 0 {
+		v := struct {
+			Metric    Metric              `json:"metric"`
+			Histogram SampleHistogramPair `json:"histogram"`
+		}{
+			Metric: s.Metric,
+			Histogram: SampleHistogramPair{
+				Timestamp: s.Timestamp,
+				Histogram: s.Histogram,
+			},
+		}
+		return json.Marshal(&v)
+	} else {
+		v := struct {
+			Metric Metric     `json:"metric"`
+			Value  SamplePair `json:"value"`
+		}{
+			Metric: s.Metric,
+			Value: SamplePair{
+				Timestamp: s.Timestamp,
+				Value:     s.Value,
+			},
+		}
+		return json.Marshal(&v)
 	}
-
-	return json.Marshal(&v)
 }
 
 // UnmarshalJSON implements json.Unmarshaler.
 func (s *Sample) UnmarshalJSON(b []byte) error {
 	v := struct {
-		Metric Metric     `json:"metric"`
-		Value  SamplePair `json:"value"`
+		Metric    Metric              `json:"metric"`
+		Value     SamplePair          `json:"value"`
+		Histogram SampleHistogramPair `json:"histogram"`
 	}{
 		Metric: s.Metric,
 		Value: SamplePair{
 			Timestamp: s.Timestamp,
 			Value:     s.Value,
 		},
+		Histogram: SampleHistogramPair{
+			Timestamp: s.Timestamp,
+			Histogram: s.Histogram,
+		},
 	}
 
 	if err := json.Unmarshal(b, &v); err != nil {
 		return err
 	}
 
 	s.Metric = v.Metric
-	s.Timestamp = v.Value.Timestamp
-	s.Value = v.Value.Value
+	if v.Histogram.Timestamp != 0 {
+		s.Timestamp = v.Histogram.Timestamp
+		s.Histogram = v.Histogram.Histogram
+	} else {
+		s.Timestamp = v.Value.Timestamp
+		s.Value = v.Value.Value
+	}
 
 	return nil
 }

model/value_histogram.go

@@ -0,0 +1,173 @@
+// Copyright 2013 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 model
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+)
+
+type IntString int64
+
+func (v IntString) String() string {
+	return fmt.Sprintf("%d", v)
+}
+
+func (v IntString) MarshalJSON() ([]byte, error) {
+	return json.Marshal(v.String())
+}
+
+func (v *IntString) UnmarshalJSON(b []byte) error {
+	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
+		return fmt.Errorf("int value must be a quoted string")
+	}
+	i, err := strconv.ParseInt(string(b[1:len(b)-1]), 10, 64)
+	if err != nil {
+		return err
+	}
+	*v = IntString(i)
+	return nil
+}
+
+func (v IntString) Equal(o IntString) bool {
+	return v == o
+}
+
+type FloatString float64
+
+func (v FloatString) String() string {
+	return strconv.FormatFloat(float64(v), 'f', -1, 64)
+}
+
+func (v FloatString) MarshalJSON() ([]byte, error) {
+	return json.Marshal(v.String())
+}
+
+func (v *FloatString) UnmarshalJSON(b []byte) error {
+	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
+		return fmt.Errorf("float value must be a quoted string")
+	}
+	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
+	if err != nil {
+		return err
+	}
+	*v = FloatString(f)
+	return nil
+}
+
+func (v FloatString) Equal(o FloatString) bool {
+	return v == o
+}
+
+type HistogramBucket struct {
+	Boundaries int
+	Lower      FloatString
+	Upper      FloatString
+	Count      IntString
+}
+
+func (s HistogramBucket) MarshalJSON() ([]byte, error) {
+	b, err := json.Marshal(s.Boundaries)
+	if err != nil {
+		return nil, err
+	}
+	l, err := json.Marshal(s.Lower)
+	if err != nil {
+		return nil, err
+	}
+	u, err := json.Marshal(s.Upper)
+	if err != nil {
+		return nil, err
+	}
+	c, err := json.Marshal(s.Count)
+	if err != nil {
+		return nil, err
+	}
+	return []byte(fmt.Sprintf("[%s,%s,%s,%s]", b, l, u, c)), nil
+}
+
+func (s *HistogramBucket) UnmarshalJSON(buf []byte) error {
+	tmp := []interface{}{&s.Boundaries, &s.Lower, &s.Upper, &s.Count}
+	wantLen := len(tmp)
+	if err := json.Unmarshal(buf, &tmp); err != nil {
+		return err
+	}
+	if g, e := len(tmp), wantLen; g != e {
+		return fmt.Errorf("wrong number of fields: %d != %d", g, e)
+	}
+	return nil
+}
+
+func (s *HistogramBucket) Equal(o *HistogramBucket) bool {
+	return s == o || (s.Boundaries == o.Boundaries && s.Lower.Equal(o.Lower) && s.Upper.Equal(o.Upper) && s.Count.Equal(o.Count))
+}
+
+type HistogramBuckets []*HistogramBucket
+
+func (s HistogramBuckets) Equal(o HistogramBuckets) bool {
+	if len(s) != len(o) {
+		return false
+	}
+
+	for i, bucket := range s {
+		if !bucket.Equal(o[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+type SampleHistogram struct {
+	Count   IntString        `json:"count"`
+	Sum     FloatString      `json:"sum"`
+	Buckets HistogramBuckets `json:"buckets"`
+}
+
+func (s *SampleHistogram) Equal(o *SampleHistogram) bool {
+	return s == o || (s.Count.Equal(o.Count) && s.Sum.Equal(o.Sum) && s.Buckets.Equal(o.Buckets))
+}
+
+type SampleHistogramPair struct {
+	Timestamp Time
+	Histogram SampleHistogram
+}
+
+func (s SampleHistogramPair) MarshalJSON() ([]byte, error) {
+	t, err := json.Marshal(s.Timestamp)
+	if err != nil {
+		return nil, err
+	}
+	v, err := json.Marshal(s.Histogram)
+	if err != nil {
+		return nil, err
+	}
+	return []byte(fmt.Sprintf("[%s,%s]", t, v)), nil
+}
+
+func (s *SampleHistogramPair) UnmarshalJSON(buf []byte) error {
+	tmp := []interface{}{&s.Timestamp, &s.Histogram}
+	wantLen := len(tmp)
+	if err := json.Unmarshal(buf, &tmp); err != nil {
+		return err
+	}
+	if g, e := len(tmp), wantLen; g != e {
+		return fmt.Errorf("wrong number of fields: %d != %d", g, e)
+	}
+	return nil
+}
+
+func (s *SampleHistogramPair) Equal(o *SampleHistogramPair) bool {
+	return s == o || (s.Histogram.Equal(&o.Histogram) && s.Timestamp.Equal(o.Timestamp))
+}