67 lines
1.4 KiB
Go
67 lines
1.4 KiB
Go
package document
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import (
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"bufio"
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"bytes"
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"os"
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"path/filepath"
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"strconv"
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"strings"
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"time"
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)
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const LockFile = ".aego/editor.lock"
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type LockInfo struct {
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PID int
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Host string
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Time time.Time
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}
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func lockPath(root string) string {
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return filepath.Join(root, filepath.FromSlash(LockFile))
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}
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func ReadLock(root string) (*LockInfo, bool) {
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data, err := os.ReadFile(lockPath(root))
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if err != nil {
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return nil, false
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}
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info := &LockInfo{}
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sc := bufio.NewScanner(bytes.NewReader(data))
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for sc.Scan() {
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k, v, ok := strings.Cut(sc.Text(), "=")
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if !ok {
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continue
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}
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switch k {
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case "pid":
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info.PID, _ = strconv.Atoi(v)
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case "host":
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info.Host = v
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case "time":
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info.Time, _ = time.Parse(time.RFC3339Nano, v)
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}
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}
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return info, info.PID != 0
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}
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func AcquireLock(root string) (func(), *LockInfo, error) {
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var other *LockInfo
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if info, ok := ReadLock(root); ok && info.PID != os.Getpid() && time.Since(info.Time) < 7*24*time.Hour {
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other = info
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}
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host, _ := os.Hostname()
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me := LockInfo{PID: os.Getpid(), Host: host, Time: time.Now()}
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data := "pid=" + strconv.Itoa(me.PID) + "\nhost=" + me.Host + "\ntime=" + me.Time.Format(time.RFC3339Nano) + "\n"
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if err := WriteAtomic(lockPath(root), []byte(data)); err != nil {
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return func() {}, other, err
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}
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release := func() {
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if cur, ok := ReadLock(root); ok && cur.PID == me.PID && cur.Host == me.Host {
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os.Remove(lockPath(root))
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}
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}
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return release, other, nil
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}
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