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khenaidooab1f7bd2019-11-14 14:00:27 -05001// Copyright 2017 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 "fmt"
19 "io"
20 "os"
21 "strconv"
22 "strings"
23)
24
25// A BuddyInfo is the details parsed from /proc/buddyinfo.
26// The data is comprised of an array of free fragments of each size.
27// The sizes are 2^n*PAGE_SIZE, where n is the array index.
28type BuddyInfo struct {
29 Node string
30 Zone string
31 Sizes []float64
32}
33
34// NewBuddyInfo reads the buddyinfo statistics from the specified `proc` filesystem.
35func (fs FS) BuddyInfo() ([]BuddyInfo, error) {
36 file, err := os.Open(fs.proc.Path("buddyinfo"))
37 if err != nil {
38 return nil, err
39 }
40 defer file.Close()
41
42 return parseBuddyInfo(file)
43}
44
45func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
46 var (
47 buddyInfo = []BuddyInfo{}
48 scanner = bufio.NewScanner(r)
49 bucketCount = -1
50 )
51
52 for scanner.Scan() {
53 var err error
54 line := scanner.Text()
55 parts := strings.Fields(line)
56
57 if len(parts) < 4 {
58 return nil, fmt.Errorf("invalid number of fields when parsing buddyinfo")
59 }
60
61 node := strings.TrimRight(parts[1], ",")
62 zone := strings.TrimRight(parts[3], ",")
63 arraySize := len(parts[4:])
64
65 if bucketCount == -1 {
66 bucketCount = arraySize
67 } else {
68 if bucketCount != arraySize {
69 return nil, fmt.Errorf("mismatch in number of buddyinfo buckets, previous count %d, new count %d", bucketCount, arraySize)
70 }
71 }
72
73 sizes := make([]float64, arraySize)
74 for i := 0; i < arraySize; i++ {
75 sizes[i], err = strconv.ParseFloat(parts[i+4], 64)
76 if err != nil {
77 return nil, fmt.Errorf("invalid value in buddyinfo: %s", err)
78 }
79 }
80
81 buddyInfo = append(buddyInfo, BuddyInfo{node, zone, sizes})
82 }
83
84 return buddyInfo, scanner.Err()
85}