github.com/aigarnetwork/aigar@v0.0.0-20191115204914-d59a6eb70f8e/metrics/prometheus/prometheus.go (about)

     1  //  Copyright 2018 The go-ethereum Authors
     2  //  Copyright 2019 The go-aigar Authors
     3  //  This file is part of the go-aigar library.
     4  //
     5  //  The go-aigar library is free software: you can redistribute it and/or modify
     6  //  it under the terms of the GNU Lesser General Public License as published by
     7  //  the Free Software Foundation, either version 3 of the License, or
     8  //  (at your option) any later version.
     9  //
    10  //  The go-aigar library is distributed in the hope that it will be useful,
    11  //  but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  //  GNU Lesser General Public License for more details.
    14  //
    15  //  You should have received a copy of the GNU Lesser General Public License
    16  //  along with the go-aigar library. If not, see <http://www.gnu.org/licenses/>.
    17  
    18  // Package prometheus exposes go-metrics into a Prometheus format.
    19  package prometheus
    20  
    21  import (
    22  	"fmt"
    23  	"net/http"
    24  	"sort"
    25  
    26  	"github.com/AigarNetwork/aigar/log"
    27  	"github.com/AigarNetwork/aigar/metrics"
    28  )
    29  
    30  // Handler returns an HTTP handler which dump metrics in Prometheus format.
    31  func Handler(reg metrics.Registry) http.Handler {
    32  	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    33  		// Gather and pre-sort the metrics to avoid random listings
    34  		var names []string
    35  		reg.Each(func(name string, i interface{}) {
    36  			names = append(names, name)
    37  		})
    38  		sort.Strings(names)
    39  
    40  		// Aggregate all the metris into a Prometheus collector
    41  		c := newCollector()
    42  
    43  		for _, name := range names {
    44  			i := reg.Get(name)
    45  
    46  			switch m := i.(type) {
    47  			case metrics.Counter:
    48  				c.addCounter(name, m.Snapshot())
    49  			case metrics.Gauge:
    50  				c.addGauge(name, m.Snapshot())
    51  			case metrics.GaugeFloat64:
    52  				c.addGaugeFloat64(name, m.Snapshot())
    53  			case metrics.Histogram:
    54  				c.addHistogram(name, m.Snapshot())
    55  			case metrics.Meter:
    56  				c.addMeter(name, m.Snapshot())
    57  			case metrics.Timer:
    58  				c.addTimer(name, m.Snapshot())
    59  			case metrics.ResettingTimer:
    60  				c.addResettingTimer(name, m.Snapshot())
    61  			default:
    62  				log.Warn("Unknown Prometheus metric type", "type", fmt.Sprintf("%T", i))
    63  			}
    64  		}
    65  		w.Header().Add("Content-Type", "text/plain")
    66  		w.Header().Add("Content-Length", fmt.Sprint(c.buff.Len()))
    67  		w.Write(c.buff.Bytes())
    68  	})
    69  }