forked from mirror/client_golang
69 lines
2.0 KiB
Go
69 lines
2.0 KiB
Go
// Copyright 2014 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 prometheus_test
|
|
|
|
import (
|
|
"runtime"
|
|
|
|
"code.google.com/p/goprotobuf/proto"
|
|
|
|
dto "github.com/prometheus/client_model/go"
|
|
|
|
"github.com/prometheus/client_golang/prometheus"
|
|
)
|
|
|
|
func NewCallbackMetric(desc *prometheus.Desc, callback func() float64) *CallbackMetric {
|
|
result := &CallbackMetric{desc: desc, callback: callback}
|
|
result.Init(result) // Initialize the SelfCollector.
|
|
return result
|
|
}
|
|
|
|
// TODO: Come up with a better example.
|
|
|
|
// CallbackMetric is an example for a user-defined Metric that exports the
|
|
// result of a function call as a metric of type "untyped" without any
|
|
// labels. It uses SelfCollector to turn the Metric into a Collector so that it
|
|
// can be registered with Prometheus.
|
|
//
|
|
// Note that this example is pretty much academic as the prometheus package
|
|
// already provides an UntypedFunc type.
|
|
type CallbackMetric struct {
|
|
prometheus.SelfCollector
|
|
|
|
desc *prometheus.Desc
|
|
callback func() float64
|
|
}
|
|
|
|
func (cm *CallbackMetric) Desc() *prometheus.Desc {
|
|
return cm.desc
|
|
}
|
|
|
|
func (cm *CallbackMetric) Write(m *dto.Metric) {
|
|
m.Untyped = &dto.Untyped{Value: proto.Float64(cm.callback())}
|
|
}
|
|
|
|
func ExampleSelfCollector() {
|
|
m := NewCallbackMetric(
|
|
prometheus.NewDesc(
|
|
"runtime_goroutines_count",
|
|
"Total number of goroutines that currently exist.",
|
|
nil, nil, // No labels, these must be nil.
|
|
),
|
|
func() float64 {
|
|
return float64(runtime.NumGoroutine())
|
|
},
|
|
)
|
|
prometheus.MustRegister(m)
|
|
}
|