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Diffstat (limited to 'vendor/github.com/prometheus/common/model/value.go')
-rw-r--r-- | vendor/github.com/prometheus/common/model/value.go | 416 |
1 files changed, 416 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/common/model/value.go b/vendor/github.com/prometheus/common/model/value.go new file mode 100644 index 000000000..c9ed3ffd8 --- /dev/null +++ b/vendor/github.com/prometheus/common/model/value.go @@ -0,0 +1,416 @@ +// 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" + "sort" + "strconv" + "strings" +) + +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} + + // ZeroSample is the pseudo zero-value of Sample used to signal a + // non-existing sample. It is a Sample with timestamp Earliest, value 0.0, + // and metric nil. Note that the natural zero value of Sample has a timestamp + // of 0, which is possible to appear in a real Sample and thus not suitable + // to signal a non-existing Sample. + ZeroSample = Sample{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 +} + +// MarshalJSON implements json.Marshaler. +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 sematics 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) +} + +// Sample is a sample pair associated with a metric. +type Sample struct { + Metric Metric `json:"metric"` + Value SampleValue `json:"value"` + Timestamp Time `json:"timestamp"` +} + +// Equal compares first the metrics, then the timestamp, then the value. The +// sematics of value equality is defined by SampleValue.Equal. +func (s *Sample) Equal(o *Sample) bool { + if s == o { + return true + } + + if !s.Metric.Equal(o.Metric) { + return false + } + if !s.Timestamp.Equal(o.Timestamp) { + return false + } + + return s.Value.Equal(o.Value) +} + +func (s Sample) String() string { + return fmt.Sprintf("%s => %s", s.Metric, SamplePair{ + Timestamp: s.Timestamp, + Value: s.Value, + }) +} + +// 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, + }, + } + + 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: s.Metric, + Value: SamplePair{ + Timestamp: s.Timestamp, + Value: s.Value, + }, + } + + if err := json.Unmarshal(b, &v); err != nil { + return err + } + + s.Metric = v.Metric + s.Timestamp = v.Value.Timestamp + s.Value = v.Value.Value + + return nil +} + +// Samples is a sortable Sample slice. It implements sort.Interface. +type Samples []*Sample + +func (s Samples) Len() int { + return len(s) +} + +// Less compares first the metrics, then the timestamp. +func (s Samples) Less(i, j int) bool { + switch { + case s[i].Metric.Before(s[j].Metric): + return true + case s[j].Metric.Before(s[i].Metric): + return false + case s[i].Timestamp.Before(s[j].Timestamp): + return true + default: + return false + } +} + +func (s Samples) Swap(i, j int) { + s[i], s[j] = s[j], s[i] +} + +// Equal compares two sets of samples and returns true if they are equal. +func (s Samples) Equal(o Samples) bool { + if len(s) != len(o) { + return false + } + + for i, sample := range s { + if !sample.Equal(o[i]) { + return false + } + } + return true +} + +// SampleStream is a stream of Values belonging to an attached COWMetric. +type SampleStream struct { + Metric Metric `json:"metric"` + Values []SamplePair `json:"values"` +} + +func (ss SampleStream) String() string { + vals := make([]string, len(ss.Values)) + for i, v := range ss.Values { + vals[i] = v.String() + } + return fmt.Sprintf("%s =>\n%s", ss.Metric, strings.Join(vals, "\n")) +} + +// Value is a generic interface for values resulting from a query evaluation. +type Value interface { + Type() ValueType + String() string +} + +func (Matrix) Type() ValueType { return ValMatrix } +func (Vector) Type() ValueType { return ValVector } +func (*Scalar) Type() ValueType { return ValScalar } +func (*String) Type() ValueType { return ValString } + +type ValueType int + +const ( + ValNone ValueType = iota + ValScalar + ValVector + ValMatrix + ValString +) + +// MarshalJSON implements json.Marshaler. +func (et ValueType) MarshalJSON() ([]byte, error) { + return json.Marshal(et.String()) +} + +func (et *ValueType) UnmarshalJSON(b []byte) error { + var s string + if err := json.Unmarshal(b, &s); err != nil { + return err + } + switch s { + case "<ValNone>": + *et = ValNone + case "scalar": + *et = ValScalar + case "vector": + *et = ValVector + case "matrix": + *et = ValMatrix + case "string": + *et = ValString + default: + return fmt.Errorf("unknown value type %q", s) + } + return nil +} + +func (e ValueType) String() string { + switch e { + case ValNone: + return "<ValNone>" + case ValScalar: + return "scalar" + case ValVector: + return "vector" + case ValMatrix: + return "matrix" + case ValString: + return "string" + } + panic("ValueType.String: unhandled value type") +} + +// Scalar is a scalar value evaluated at the set timestamp. +type Scalar struct { + Value SampleValue `json:"value"` + Timestamp Time `json:"timestamp"` +} + +func (s Scalar) String() string { + return fmt.Sprintf("scalar: %v @[%v]", s.Value, s.Timestamp) +} + +// MarshalJSON implements json.Marshaler. +func (s Scalar) MarshalJSON() ([]byte, error) { + v := strconv.FormatFloat(float64(s.Value), 'f', -1, 64) + return json.Marshal([...]interface{}{s.Timestamp, string(v)}) +} + +// UnmarshalJSON implements json.Unmarshaler. +func (s *Scalar) UnmarshalJSON(b []byte) error { + var f string + v := [...]interface{}{&s.Timestamp, &f} + + if err := json.Unmarshal(b, &v); err != nil { + return err + } + + value, err := strconv.ParseFloat(f, 64) + if err != nil { + return fmt.Errorf("error parsing sample value: %s", err) + } + s.Value = SampleValue(value) + return nil +} + +// String is a string value evaluated at the set timestamp. +type String struct { + Value string `json:"value"` + Timestamp Time `json:"timestamp"` +} + +func (s *String) String() string { + return s.Value +} + +// MarshalJSON implements json.Marshaler. +func (s String) MarshalJSON() ([]byte, error) { + return json.Marshal([]interface{}{s.Timestamp, s.Value}) +} + +// UnmarshalJSON implements json.Unmarshaler. +func (s *String) UnmarshalJSON(b []byte) error { + v := [...]interface{}{&s.Timestamp, &s.Value} + return json.Unmarshal(b, &v) +} + +// Vector is basically only an alias for Samples, but the +// contract is that in a Vector, all Samples have the same timestamp. +type Vector []*Sample + +func (vec Vector) String() string { + entries := make([]string, len(vec)) + for i, s := range vec { + entries[i] = s.String() + } + return strings.Join(entries, "\n") +} + +func (vec Vector) Len() int { return len(vec) } +func (vec Vector) Swap(i, j int) { vec[i], vec[j] = vec[j], vec[i] } + +// Less compares first the metrics, then the timestamp. +func (vec Vector) Less(i, j int) bool { + switch { + case vec[i].Metric.Before(vec[j].Metric): + return true + case vec[j].Metric.Before(vec[i].Metric): + return false + case vec[i].Timestamp.Before(vec[j].Timestamp): + return true + default: + return false + } +} + +// Equal compares two sets of samples and returns true if they are equal. +func (vec Vector) Equal(o Vector) bool { + if len(vec) != len(o) { + return false + } + + for i, sample := range vec { + if !sample.Equal(o[i]) { + return false + } + } + return true +} + +// Matrix is a list of time series. +type Matrix []*SampleStream + +func (m Matrix) Len() int { return len(m) } +func (m Matrix) Less(i, j int) bool { return m[i].Metric.Before(m[j].Metric) } +func (m Matrix) Swap(i, j int) { m[i], m[j] = m[j], m[i] } + +func (mat Matrix) String() string { + matCp := make(Matrix, len(mat)) + copy(matCp, mat) + sort.Sort(matCp) + + strs := make([]string, len(matCp)) + + for i, ss := range matCp { + strs[i] = ss.String() + } + + return strings.Join(strs, "\n") +} |