return r.refs == 0
}

// IncLockRef - is used by called to indicate lock refs.
func (r *RLockedFile) IncLockRef() {
	r.mutex.Lock()
	r.refs++
	r.mutex.Unlock()
}

// Close - this closer implements a special closer
// closes the underlying fd only when the refs
// reach zero.
func (r *RLockedFile) Close() (err error) {
	r.mutex.Lock()
	defer r.mutex.Unlock()

	if r.refs == 0 {
		return os.ErrInvalid
	}

type Reader struct {
	io.Closer
	r *parquetgo.FileReader
}

// NewParquetReader creates a Reader2 from a io.ReadSeekCloser.
func NewParquetReader(rsc io.ReadSeekCloser, _ *ReaderArgs) (r *Reader, err error) {
	fr, err := parquetgo.NewFileReader(rsc)
	if err != nil {
		return nil, errParquetParsingError(err)
	}

	return &Reader{Closer: rsc, r: fr}, nil
}

	deletedBucketsPrefix = ".deleted"

	// ETag (hex encoded md5sum) of empty string.
	emptyETag = "d41d8cd98f00b204e9800998ecf8427e"
)

// Global object layer mutex, used for safely updating object layer.
var globalObjLayerMutex sync.RWMutex

// Global object layer, only accessed by globalObjectAPI.
var globalObjectAPI ObjectLayer

type storageOpts struct {
	cleanUp     bool
	healthCheck bool
}

// Helpers
/////////////////

// limitedReadCloser is like io.LimitedReader, but also implements io.Closer.
type limitedReadCloser struct {
	io.LimitedReader
	io.Closer
}

func newLimitedReadCloser(r io.ReadCloser, n int64) *limitedReadCloser {
	return &limitedReadCloser{
		LimitedReader: io.LimitedReader{R: r, N: n},
		Closer:        r,
	}
}

		for _, mf := range mfs {
			if err := enc.Encode(mf); err != nil {
				// client may disconnect for any reasons
				// we do not have to log this.
				return
			}
		}
		if closer, ok := enc.(expfmt.Closer); ok {
			closer.Close()
		}
	})
}

// NoAuthMiddleware no auth middle ware.
func NoAuthMiddleware(h http.Handler) http.Handler {
	return h
}

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

		for _, mf := range mfs {
			if err := enc.Encode(mf); err != nil {
				// client may disconnect for any reasons
				// we do not have to log this.
				return
			}
		}
		if closer, ok := enc.(expfmt.Closer); ok {
			closer.Close()
		}
	})
}

func metricsBucketHandler() http.Handler {
	return metricsHTTPHandler(bucketCollector, "handler.MetricsBucket")
}