distlock

Overview ¶

Package distlock provides Redis-backed distributed locking with two usage modes: fail-hard and fail-silent.

The locker wraps the bsm/redislock library and ensures locks are always released via defer, even if the handler panics. Lock release failures are logged as warnings but do not cause errors.

Basic usage (fail-hard):

locker := distlock.New(redisClient)
err := locker.WithLock(ctx, "resource:123", 30*time.Second, func() error {
    // Exclusive access to resource:123 for 30 seconds
    return updateResource()
})
if err != nil && errors.Is(err, distlock.ErrLockNotObtained) {
    return fmt.Errorf("failed to acquire lock")
}

For background jobs that should silently skip if the lock is unavailable:

err := locker.TryWithLock(ctx, "job:cleanup", 5*time.Minute, cleanupHandler)
// ErrLockNotObtained is swallowed and logged at debug level

Lock TTL is enforced by Redis; the handler should complete well before the TTL expires.