vendor.github.com.prometheus.procfs.buddyinfo.go Maven / Gradle / Ivy
// Copyright 2017 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"
"fmt"
"io"
"os"
"strconv"
"strings"
)
// A BuddyInfo is the details parsed from /proc/buddyinfo.
// The data is comprised of an array of free fragments of each size.
// The sizes are 2^n*PAGE_SIZE, where n is the array index.
type BuddyInfo struct {
Node string
Zone string
Sizes []float64
}
// BuddyInfo reads the buddyinfo statistics from the specified `proc` filesystem.
func (fs FS) BuddyInfo() ([]BuddyInfo, error) {
file, err := os.Open(fs.proc.Path("buddyinfo"))
if err != nil {
return nil, err
}
defer file.Close()
return parseBuddyInfo(file)
}
func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
var (
buddyInfo = []BuddyInfo{}
scanner = bufio.NewScanner(r)
bucketCount = -1
)
for scanner.Scan() {
var err error
line := scanner.Text()
parts := strings.Fields(line)
if len(parts) < 4 {
return nil, fmt.Errorf("invalid number of fields when parsing buddyinfo")
}
node := strings.TrimRight(parts[1], ",")
zone := strings.TrimRight(parts[3], ",")
arraySize := len(parts[4:])
if bucketCount == -1 {
bucketCount = arraySize
} else {
if bucketCount != arraySize {
return nil, fmt.Errorf("mismatch in number of buddyinfo buckets, previous count %d, new count %d", bucketCount, arraySize)
}
}
sizes := make([]float64, arraySize)
for i := 0; i < arraySize; i++ {
sizes[i], err = strconv.ParseFloat(parts[i+4], 64)
if err != nil {
return nil, fmt.Errorf("invalid value in buddyinfo: %w", err)
}
}
buddyInfo = append(buddyInfo, BuddyInfo{node, zone, sizes})
}
return buddyInfo, scanner.Err()
}