vendor.github.com.prometheus.procfs.swaps.go Maven / Gradle / Ivy
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// Copyright 2019 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"
"bytes"
"fmt"
"strconv"
"strings"
"github.com/prometheus/procfs/internal/util"
)
// Swap represents an entry in /proc/swaps.
type Swap struct {
Filename string
Type string
Size int
Used int
Priority int
}
// Swaps returns a slice of all configured swap devices on the system.
func (fs FS) Swaps() ([]*Swap, error) {
data, err := util.ReadFileNoStat(fs.proc.Path("swaps"))
if err != nil {
return nil, err
}
return parseSwaps(data)
}
func parseSwaps(info []byte) ([]*Swap, error) {
swaps := []*Swap{}
scanner := bufio.NewScanner(bytes.NewReader(info))
scanner.Scan() // ignore header line
for scanner.Scan() {
swapString := scanner.Text()
parsedSwap, err := parseSwapString(swapString)
if err != nil {
return nil, err
}
swaps = append(swaps, parsedSwap)
}
err := scanner.Err()
return swaps, err
}
func parseSwapString(swapString string) (*Swap, error) {
var err error
swapFields := strings.Fields(swapString)
swapLength := len(swapFields)
if swapLength < 5 {
return nil, fmt.Errorf("%w: too few fields in swap string: %s", ErrFileParse, swapString)
}
swap := &Swap{
Filename: swapFields[0],
Type: swapFields[1],
}
swap.Size, err = strconv.Atoi(swapFields[2])
if err != nil {
return nil, fmt.Errorf("%s: invalid swap size: %s: %w", ErrFileParse, swapFields[2], err)
}
swap.Used, err = strconv.Atoi(swapFields[3])
if err != nil {
return nil, fmt.Errorf("%s: invalid swap used: %s: %w", ErrFileParse, swapFields[3], err)
}
swap.Priority, err = strconv.Atoi(swapFields[4])
if err != nil {
return nil, fmt.Errorf("%s: invalid swap priority: %s: %w", ErrFileParse, swapFields[4], err)
}
return swap, nil
}