prometheus/model/metric.go

132 lines
3.0 KiB
Go

// Copyright 2013 Prometheus Team
// 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 (
"bytes"
"fmt"
"sort"
"time"
)
const (
// XXX: Re-evaluate down the road.
reservedDelimiter = `"`
)
// A LabelSet is a collection of LabelName and LabelValue pairs. The LabelSet
// may be fully-qualified down to the point where it may resolve to a single
// Metric in the data store or not. All operations that occur within the realm
// of a LabelSet can emit a vector of Metric entities to which the LabelSet may
// match.
type LabelSet map[LabelName]LabelValue
func (l LabelSet) String() string {
var (
buffer bytes.Buffer
labels LabelNames
labelCount int = len(l)
)
for name := range l {
labels = append(labels, name)
}
sort.Sort(labels)
fmt.Fprintf(&buffer, "{")
for i := 0; i < labelCount; i++ {
var (
label = labels[i]
value = l[label]
)
switch i {
case labelCount - 1:
fmt.Fprintf(&buffer, "%s=%s", label, value)
default:
fmt.Fprintf(&buffer, "%s=%s, ", label, value)
}
}
fmt.Fprintf(&buffer, "}")
return buffer.String()
}
// A Metric is similar to a LabelSet, but the key difference is that a Metric is
// a singleton and refers to one and only one stream of samples.
type Metric map[LabelName]LabelValue
// A SampleValue is a representation of a value for a given sample at a given
// time. It is presently float32 due to that being the representation that
// Protocol Buffers provide of floats in Go. This is a smell and should be
// remedied down the road.
type SampleValue float32
func (v SampleValue) MarshalJSON() ([]byte, error) {
return []byte(fmt.Sprintf("\"%f\"", v)), nil
}
func (s SamplePair) MarshalJSON() ([]byte, error) {
return []byte(fmt.Sprintf("{\"Value\": \"%f\", \"Timestamp\": %d}", s.Value, s.Timestamp.Unix())), nil
}
type SamplePair struct {
Value SampleValue
Timestamp time.Time
}
type Values []SamplePair
func (v Values) Len() int {
return len(v)
}
func (v Values) Less(i, j int) bool {
return v[i].Timestamp.Before(v[j].Timestamp)
}
func (v Values) Swap(i, j int) {
v[i], v[j] = v[j], v[i]
}
// InsideInterval indicates whether a given range of sorted values could contain
// a value for a given time.
func (v Values) InsideInterval(t time.Time) (s bool) {
if v.Len() == 0 {
return
}
if t.Before(v[0].Timestamp) {
return
}
if !v[v.Len()-1].Timestamp.Before(t) {
return
}
return true
}
type SampleSet struct {
Metric Metric
Values Values
}
type Interval struct {
OldestInclusive time.Time
NewestInclusive time.Time
}