status-go/vendor/github.com/prometheus/procfs/proc_fdinfo.go

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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"
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"bytes"
"regexp"
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"github.com/prometheus/procfs/internal/util"
)
// Regexp variables
var (
rPos = regexp.MustCompile(`^pos:\s+(\d+)$`)
rFlags = regexp.MustCompile(`^flags:\s+(\d+)$`)
rMntID = regexp.MustCompile(`^mnt_id:\s+(\d+)$`)
rInotify = regexp.MustCompile(`^inotify`)
)
// ProcFDInfo contains represents file descriptor information.
type ProcFDInfo struct {
// File descriptor
FD string
// File offset
Pos string
// File access mode and status flags
Flags string
// Mount point ID
MntID string
// List of inotify lines (structed) in the fdinfo file (kernel 3.8+ only)
InotifyInfos []InotifyInfo
}
// FDInfo constructor. On kernels older than 3.8, InotifyInfos will always be empty.
func (p Proc) FDInfo(fd string) (*ProcFDInfo, error) {
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data, err := util.ReadFileNoStat(p.path("fdinfo", fd))
if err != nil {
return nil, err
}
var text, pos, flags, mntid string
var inotify []InotifyInfo
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scanner := bufio.NewScanner(bytes.NewReader(data))
for scanner.Scan() {
text = scanner.Text()
if rPos.MatchString(text) {
pos = rPos.FindStringSubmatch(text)[1]
} else if rFlags.MatchString(text) {
flags = rFlags.FindStringSubmatch(text)[1]
} else if rMntID.MatchString(text) {
mntid = rMntID.FindStringSubmatch(text)[1]
} else if rInotify.MatchString(text) {
newInotify, err := parseInotifyInfo(text)
if err != nil {
return nil, err
}
inotify = append(inotify, *newInotify)
}
}
i := &ProcFDInfo{
FD: fd,
Pos: pos,
Flags: flags,
MntID: mntid,
InotifyInfos: inotify,
}
return i, nil
}
// InotifyInfo represents a single inotify line in the fdinfo file.
type InotifyInfo struct {
// Watch descriptor number
WD string
// Inode number
Ino string
// Device ID
Sdev string
// Mask of events being monitored
Mask string
}
// InotifyInfo constructor. Only available on kernel 3.8+.
func parseInotifyInfo(line string) (*InotifyInfo, error) {
r := regexp.MustCompile(`^inotify\s+wd:([0-9a-f]+)\s+ino:([0-9a-f]+)\s+sdev:([0-9a-f]+)\s+mask:([0-9a-f]+)`)
m := r.FindStringSubmatch(line)
i := &InotifyInfo{
WD: m[1],
Ino: m[2],
Sdev: m[3],
Mask: m[4],
}
return i, nil
}
// ProcFDInfos represents a list of ProcFDInfo structs.
type ProcFDInfos []ProcFDInfo
func (p ProcFDInfos) Len() int { return len(p) }
func (p ProcFDInfos) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
func (p ProcFDInfos) Less(i, j int) bool { return p[i].FD < p[j].FD }
// InotifyWatchLen returns the total number of inotify watches
func (p ProcFDInfos) InotifyWatchLen() (int, error) {
length := 0
for _, f := range p {
length += len(f.InotifyInfos)
}
return length, nil
}