1// Copyright 2019 The Prometheus Authors 2// Licensed under the Apache License, Version 2.0 (the "License"); 3// you may not use this file except in compliance with the License. 4// You may obtain a copy of the License at 5// 6// http://www.apache.org/licenses/LICENSE-2.0 7// 8// Unless required by applicable law or agreed to in writing, software 9// distributed under the License is distributed on an "AS IS" BASIS, 10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 11// See the License for the specific language governing permissions and 12// limitations under the License. 13 14package procfs 15 16import ( 17 "bufio" 18 "bytes" 19 "fmt" 20 "strconv" 21 "strings" 22 23 "github.com/prometheus/procfs/internal/util" 24) 25 26// Swap represents an entry in /proc/swaps. 27type Swap struct { 28 Filename string 29 Type string 30 Size int 31 Used int 32 Priority int 33} 34 35// Swaps returns a slice of all configured swap devices on the system. 36func (fs FS) Swaps() ([]*Swap, error) { 37 data, err := util.ReadFileNoStat(fs.proc.Path("swaps")) 38 if err != nil { 39 return nil, err 40 } 41 return parseSwaps(data) 42} 43 44func parseSwaps(info []byte) ([]*Swap, error) { 45 swaps := []*Swap{} 46 scanner := bufio.NewScanner(bytes.NewReader(info)) 47 scanner.Scan() // ignore header line 48 for scanner.Scan() { 49 swapString := scanner.Text() 50 parsedSwap, err := parseSwapString(swapString) 51 if err != nil { 52 return nil, err 53 } 54 swaps = append(swaps, parsedSwap) 55 } 56 57 err := scanner.Err() 58 return swaps, err 59} 60 61func parseSwapString(swapString string) (*Swap, error) { 62 var err error 63 64 swapFields := strings.Fields(swapString) 65 swapLength := len(swapFields) 66 if swapLength < 5 { 67 return nil, fmt.Errorf("too few fields in swap string: %s", swapString) 68 } 69 70 swap := &Swap{ 71 Filename: swapFields[0], 72 Type: swapFields[1], 73 } 74 75 swap.Size, err = strconv.Atoi(swapFields[2]) 76 if err != nil { 77 return nil, fmt.Errorf("invalid swap size: %s", swapFields[2]) 78 } 79 swap.Used, err = strconv.Atoi(swapFields[3]) 80 if err != nil { 81 return nil, fmt.Errorf("invalid swap used: %s", swapFields[3]) 82 } 83 swap.Priority, err = strconv.Atoi(swapFields[4]) 84 if err != nil { 85 return nil, fmt.Errorf("invalid swap priority: %s", swapFields[4]) 86 } 87 88 return swap, nil 89} 90