```

### 3.2 Automatic removal of noncurrent versions keeping only most recent ones after noncurrent days

It is possible to configure automatic removal of older noncurrent versions keeping only the most recent `N` using `NewerNoncurrentVersions`.

e.g, To remove noncurrent versions of all objects keeping the most recent 5 noncurrent versions under the prefix `user-uploads/` 30 days after they become noncurrent ,

Contributing
============

Keeping the project small and stable limits our ability to accept new contributors. We are not
seeking new committers at this time, but some small contributions are welcome.

If you've found a security problem, please follow our [bug bounty][security] program.

If you've found a bug, please contribute a failing test case so we can study and fix it.

If you have a new feature idea, please build it in an external library. There are

Contributing
============

Keeping the project small and stable limits our ability to accept new contributors. We are not
seeking new committers at this time, but some small contributions are welcome.

If you've found a security problem, please follow our [bug bounty][security] program.

If you've found a bug, please contribute a failing test case so we can study and fix it.

If you have a new feature idea, please build it in an external library. There are

	recursive    bool       `msg:"rec"`
	dataVersion  uint8      `msg:"v"`
}

func (m *metacache) finished() bool {
	return !m.ended.IsZero()
}

// worthKeeping indicates if the cache by itself is worth keeping.
func (m *metacache) worthKeeping() bool {
	if m == nil {
		return false
	}
	cache := m
	switch {
	case !cache.finished() && time.Since(cache.lastUpdate) > metacacheMaxRunningAge:

  }

  @GwtIncompatible
  @J2ktIncompatible
  /*
   * The mainline copy of ImmutableMapValues doesn't produce this serialized form anymore, though
   * the backport does. For now, we're keeping the class declaration in *both* flavors so that both
   * flavors can read old data or data from the other flavor. However, we strongly discourage

import org.slf4j.LoggerFactory;

import static java.util.Objects.requireNonNull;

/**
 * A {@link TransferListener} implementation that wraps another delegate {@link TransferListener} but makes it run
 * on single thread, keeping the listener logic simple. This listener also blocks on last transfer event to allow
 * output to perform possible cleanup. It spawns a daemon thread to consume queued events that may fall in even
 * concurrently.
 *

    // 3) Caller specified but assuming the visible defaults in MODERN_CIPHER_SUITES are rejigged
    // to match legacy i.e. the platform/provider
    //
    // Opting for 2 here and keeping MODERN_TLS in line with secure browsers.
    cipherSuitesAsString.intersect(socketEnabledCipherSuites, CipherSuite.ORDER_BY_NAME)
  } else {
    socketEnabledCipherSuites
  }

import org.slf4j.LoggerFactory;

import static java.util.Objects.requireNonNull;

/**
 * A {@link TransferListener} implementation that wraps another delegate {@link TransferListener} but makes it run
 * on single thread, keeping the listener logic simple. This listener also blocks on last transfer event to allow
 * output to perform possible cleanup. It spawns a daemon thread to consume queued events that may fall in even
 * concurrently.
 *

	// Test on a copy
	// cleanup is the only one deleting caches.
	caches, _ := b.cloneCaches()

	for id, cache := range caches {
		if !cache.worthKeeping() {
			b.debugf("cache %s not worth keeping", id)
			remove[id] = struct{}{}
			continue
		}
		if cache.id != id {
			logger.Info("cache ID mismatch %s != %s", id, cache.id)
			remove[id] = struct{}{}
			continue
		}

		p.actionsLatency[a].add(duration)
	}
}

type currentPathTracker struct {
	name *unsafe.Pointer // contains atomically accessed *string
}

// currentPathUpdater provides a lightweight update function for keeping track of
// current objects for each disk.
// Returns a function that can be used to update the current object
// and a function to call to when processing finished.