source: code/trunk/vendor/github.com/prometheus/procfs/netstat.go@ 822

// Copyright 2020 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 procfs

import (
        "bufio"
        "os"
        "path/filepath"
        "strconv"
        "strings"
)

// NetStat contains statistics for all the counters from one file.
type NetStat struct {
        Stats    map[string][]uint64
        Filename string
}

// NetStat retrieves stats from `/proc/net/stat/`.
func (fs FS) NetStat() ([]NetStat, error) {
        statFiles, err := filepath.Glob(fs.proc.Path("net/stat/*"))
        if err != nil {
                return nil, err
        }

        var netStatsTotal []NetStat

        for _, filePath := range statFiles {
                file, err := os.Open(filePath)
                if err != nil {
                        return nil, err
                }

                netStatFile := NetStat{
                        Filename: filepath.Base(filePath),
                        Stats:    make(map[string][]uint64),
                }
                scanner := bufio.NewScanner(file)
                scanner.Scan()
                // First string is always a header for stats
                var headers []string
                headers = append(headers, strings.Fields(scanner.Text())...)

                // Other strings represent per-CPU counters
                for scanner.Scan() {
                        for num, counter := range strings.Fields(scanner.Text()) {
                                value, err := strconv.ParseUint(counter, 16, 64)
                                if err != nil {
                                        return nil, err
                                }
                                netStatFile.Stats[headers[num]] = append(netStatFile.Stats[headers[num]], value)
                        }
                }
                netStatsTotal = append(netStatsTotal, netStatFile)
        }
        return netStatsTotal, nil
}