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Source file src/github.com/prometheus/common/model/value_histogram.go

Documentation: github.com/prometheus/common/model

     1  // Copyright 2013 The Prometheus Authors
     2  // Licensed under the Apache License, Version 2.0 (the "License");
     3  // you may not use this file except in compliance with the License.
     4  // You may obtain a copy of the License at
     5  //
     6  // http://www.apache.org/licenses/LICENSE-2.0
     7  //
     8  // Unless required by applicable law or agreed to in writing, software
     9  // distributed under the License is distributed on an "AS IS" BASIS,
    10  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package model
    15  
    16  import (
    17  	"encoding/json"
    18  	"fmt"
    19  	"strconv"
    20  	"strings"
    21  )
    22  
    23  type FloatString float64
    24  
    25  func (v FloatString) String() string {
    26  	return strconv.FormatFloat(float64(v), 'f', -1, 64)
    27  }
    28  
    29  func (v FloatString) MarshalJSON() ([]byte, error) {
    30  	return json.Marshal(v.String())
    31  }
    32  
    33  func (v *FloatString) UnmarshalJSON(b []byte) error {
    34  	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
    35  		return fmt.Errorf("float value must be a quoted string")
    36  	}
    37  	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
    38  	if err != nil {
    39  		return err
    40  	}
    41  	*v = FloatString(f)
    42  	return nil
    43  }
    44  
    45  type HistogramBucket struct {
    46  	Boundaries int32
    47  	Lower      FloatString
    48  	Upper      FloatString
    49  	Count      FloatString
    50  }
    51  
    52  func (s HistogramBucket) MarshalJSON() ([]byte, error) {
    53  	b, err := json.Marshal(s.Boundaries)
    54  	if err != nil {
    55  		return nil, err
    56  	}
    57  	l, err := json.Marshal(s.Lower)
    58  	if err != nil {
    59  		return nil, err
    60  	}
    61  	u, err := json.Marshal(s.Upper)
    62  	if err != nil {
    63  		return nil, err
    64  	}
    65  	c, err := json.Marshal(s.Count)
    66  	if err != nil {
    67  		return nil, err
    68  	}
    69  	return []byte(fmt.Sprintf("[%s,%s,%s,%s]", b, l, u, c)), nil
    70  }
    71  
    72  func (s *HistogramBucket) UnmarshalJSON(buf []byte) error {
    73  	tmp := []interface{}{&s.Boundaries, &s.Lower, &s.Upper, &s.Count}
    74  	wantLen := len(tmp)
    75  	if err := json.Unmarshal(buf, &tmp); err != nil {
    76  		return err
    77  	}
    78  	if gotLen := len(tmp); gotLen != wantLen {
    79  		return fmt.Errorf("wrong number of fields: %d != %d", gotLen, wantLen)
    80  	}
    81  	return nil
    82  }
    83  
    84  func (s *HistogramBucket) Equal(o *HistogramBucket) bool {
    85  	return s == o || (s.Boundaries == o.Boundaries && s.Lower == o.Lower && s.Upper == o.Upper && s.Count == o.Count)
    86  }
    87  
    88  func (b HistogramBucket) String() string {
    89  	var sb strings.Builder
    90  	lowerInclusive := b.Boundaries == 1 || b.Boundaries == 3
    91  	upperInclusive := b.Boundaries == 0 || b.Boundaries == 3
    92  	if lowerInclusive {
    93  		sb.WriteRune('[')
    94  	} else {
    95  		sb.WriteRune('(')
    96  	}
    97  	fmt.Fprintf(&sb, "%g,%g", b.Lower, b.Upper)
    98  	if upperInclusive {
    99  		sb.WriteRune(']')
   100  	} else {
   101  		sb.WriteRune(')')
   102  	}
   103  	fmt.Fprintf(&sb, ":%v", b.Count)
   104  	return sb.String()
   105  }
   106  
   107  type HistogramBuckets []*HistogramBucket
   108  
   109  func (s HistogramBuckets) Equal(o HistogramBuckets) bool {
   110  	if len(s) != len(o) {
   111  		return false
   112  	}
   113  
   114  	for i, bucket := range s {
   115  		if !bucket.Equal(o[i]) {
   116  			return false
   117  		}
   118  	}
   119  	return true
   120  }
   121  
   122  type SampleHistogram struct {
   123  	Count   FloatString      `json:"count"`
   124  	Sum     FloatString      `json:"sum"`
   125  	Buckets HistogramBuckets `json:"buckets"`
   126  }
   127  
   128  func (s SampleHistogram) String() string {
   129  	return fmt.Sprintf("Count: %f, Sum: %f, Buckets: %v", s.Count, s.Sum, s.Buckets)
   130  }
   131  
   132  func (s *SampleHistogram) Equal(o *SampleHistogram) bool {
   133  	return s == o || (s.Count == o.Count && s.Sum == o.Sum && s.Buckets.Equal(o.Buckets))
   134  }
   135  
   136  type SampleHistogramPair struct {
   137  	Timestamp Time
   138  	// Histogram should never be nil, it's only stored as pointer for efficiency.
   139  	Histogram *SampleHistogram
   140  }
   141  
   142  func (s SampleHistogramPair) MarshalJSON() ([]byte, error) {
   143  	if s.Histogram == nil {
   144  		return nil, fmt.Errorf("histogram is nil")
   145  	}
   146  	t, err := json.Marshal(s.Timestamp)
   147  	if err != nil {
   148  		return nil, err
   149  	}
   150  	v, err := json.Marshal(s.Histogram)
   151  	if err != nil {
   152  		return nil, err
   153  	}
   154  	return []byte(fmt.Sprintf("[%s,%s]", t, v)), nil
   155  }
   156  
   157  func (s *SampleHistogramPair) UnmarshalJSON(buf []byte) error {
   158  	tmp := []interface{}{&s.Timestamp, &s.Histogram}
   159  	wantLen := len(tmp)
   160  	if err := json.Unmarshal(buf, &tmp); err != nil {
   161  		return err
   162  	}
   163  	if gotLen := len(tmp); gotLen != wantLen {
   164  		return fmt.Errorf("wrong number of fields: %d != %d", gotLen, wantLen)
   165  	}
   166  	if s.Histogram == nil {
   167  		return fmt.Errorf("histogram is null")
   168  	}
   169  	return nil
   170  }
   171  
   172  func (s SampleHistogramPair) String() string {
   173  	return fmt.Sprintf("%s @[%s]", s.Histogram, s.Timestamp)
   174  }
   175  
   176  func (s *SampleHistogramPair) Equal(o *SampleHistogramPair) bool {
   177  	return s == o || (s.Histogram.Equal(o.Histogram) && s.Timestamp.Equal(o.Timestamp))
   178  }
   179  

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