diff options
Diffstat (limited to 'vendor/github.com/prometheus/common/model/value_float.go')
-rw-r--r-- | vendor/github.com/prometheus/common/model/value_float.go | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/common/model/value_float.go b/vendor/github.com/prometheus/common/model/value_float.go new file mode 100644 index 000000000..0f615a705 --- /dev/null +++ b/vendor/github.com/prometheus/common/model/value_float.go @@ -0,0 +1,100 @@ +// 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) +} |