101 lines
3.0 KiB
Go
101 lines
3.0 KiB
Go
// 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"
|
|
"math"
|
|
"strconv"
|
|
)
|
|
|
|
var (
|
|
// ZeroSamplePair is the pseudo zero-value of SamplePair used to signal a
|
|
// non-existing sample pair. It is a SamplePair with timestamp Earliest and
|
|
// value 0.0. Note that the natural zero value of SamplePair has a timestamp
|
|
// of 0, which is possible to appear in a real SamplePair and thus not
|
|
// suitable to signal a non-existing SamplePair.
|
|
ZeroSamplePair = SamplePair{Timestamp: Earliest}
|
|
)
|
|
|
|
// A SampleValue is a representation of a value for a given sample at a given
|
|
// time.
|
|
type SampleValue float64
|
|
|
|
// MarshalJSON implements json.Marshaler.
|
|
func (v SampleValue) MarshalJSON() ([]byte, error) {
|
|
return json.Marshal(v.String())
|
|
}
|
|
|
|
// UnmarshalJSON implements json.Unmarshaler.
|
|
func (v *SampleValue) UnmarshalJSON(b []byte) error {
|
|
if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
|
|
return fmt.Errorf("sample value must be a quoted string")
|
|
}
|
|
f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
*v = SampleValue(f)
|
|
return nil
|
|
}
|
|
|
|
// Equal returns true if the value of v and o is equal or if both are NaN. Note
|
|
// that v==o is false if both are NaN. If you want the conventional float
|
|
// behavior, use == to compare two SampleValues.
|
|
func (v SampleValue) Equal(o SampleValue) bool {
|
|
if v == o {
|
|
return true
|
|
}
|
|
return math.IsNaN(float64(v)) && math.IsNaN(float64(o))
|
|
}
|
|
|
|
func (v SampleValue) String() string {
|
|
return strconv.FormatFloat(float64(v), 'f', -1, 64)
|
|
}
|
|
|
|
// SamplePair pairs a SampleValue with a Timestamp.
|
|
type SamplePair struct {
|
|
Timestamp Time
|
|
Value SampleValue
|
|
}
|
|
|
|
func (s SamplePair) MarshalJSON() ([]byte, error) {
|
|
t, err := json.Marshal(s.Timestamp)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
v, err := json.Marshal(s.Value)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return []byte(fmt.Sprintf("[%s,%s]", t, v)), nil
|
|
}
|
|
|
|
// UnmarshalJSON implements json.Unmarshaler.
|
|
func (s *SamplePair) UnmarshalJSON(b []byte) error {
|
|
v := [...]json.Unmarshaler{&s.Timestamp, &s.Value}
|
|
return json.Unmarshal(b, &v)
|
|
}
|
|
|
|
// Equal returns true if this SamplePair and o have equal Values and equal
|
|
// Timestamps. The semantics of Value equality is defined by SampleValue.Equal.
|
|
func (s *SamplePair) Equal(o *SamplePair) bool {
|
|
return s == o || (s.Value.Equal(o.Value) && s.Timestamp.Equal(o.Timestamp))
|
|
}
|
|
|
|
func (s SamplePair) String() string {
|
|
return fmt.Sprintf("%s @[%s]", s.Value, s.Timestamp)
|
|
}
|