Method Lock

internal/repository/lock.go:46–106

Lock wraps the ctx such that it is cancelled when the repository is unlocked cancelling the original context also stops the lock refresh

(ctx context.Context, r *Repository, exclusive bool, retryLock time.Duration, printRetry func(msg string), logger func(format string, args ...interface{}))

// Lock wraps the ctx such that it is cancelled when the repository is unlocked
// cancelling the original context also stops the lock refresh
func (l *locker) Lock(ctx context.Context, r *Repository, exclusive bool, retryLock time.Duration, printRetry func(msg string), logger func(format string, args ...interface{})) (*Unlocker, context.Context, error) {
	var lock *restic.Lock
	var err error

	retrySleep := minDuration(l.retrySleepStart, retryLock)
	retryMessagePrinted := false
	retryTimeout := time.After(retryLock)

	repo := &internalRepository{r}

retryLoop:
	for {
		lock, err = restic.NewLock(ctx, repo, exclusive)
		if err != nil && restic.IsAlreadyLocked(err) {

			if !retryMessagePrinted {
				printRetry(fmt.Sprintf("repo already locked, waiting up to %s for the lock\n", retryLock))
				retryMessagePrinted = true
			}

			debug.Log("repo already locked, retrying in %v", retrySleep)
			retrySleepCh := time.After(retrySleep)

			select {
			case <-ctx.Done():
				return nil, ctx, ctx.Err()
			case <-retryTimeout:
				debug.Log("repo already locked, timeout expired")
				// Last lock attempt
				lock, err = restic.NewLock(ctx, repo, exclusive)
				break retryLoop
			case <-retrySleepCh:
				retrySleep = minDuration(retrySleep*2, l.retrySleepMax)
			}
		} else {
			// anything else, either a successful lock or another error
			break retryLoop
		}
	}
	if restic.IsInvalidLock(err) {
		return nil, ctx, errors.Fatalf("%v\n\nthe `unlock --remove-all` command can be used to remove invalid locks. Make sure that no other restic process is accessing the repository when running the command", err)
	}
	if err != nil {
		return nil, ctx, fmt.Errorf("unable to create lock in backend: %w", err)
	}
	debug.Log("create lock %p (exclusive %v)", lock, exclusive)

	ctx, cancel := context.WithCancel(ctx)
	lockInfo := &lockContext{
		lock:   lock,
		cancel: cancel,
	}
	lockInfo.refreshWG.Add(2)
	refreshChan := make(chan struct{})
	forceRefreshChan := make(chan refreshLockRequest)

	go l.refreshLocks(ctx, repo.be, lockInfo, refreshChan, forceRefreshChan, logger)
	go l.monitorLockRefresh(ctx, lockInfo, refreshChan, forceRefreshChan, logger)