h.Write(data)
	raw := h.Sum(nil)
	c := Checksum{Type: t, Encoded: base64.StdEncoding.EncodeToString(raw), Raw: raw}
	if !c.Valid() {
		return nil
	}
	return &c
}

// ReadCheckSums will read checksums from b and return them.
func ReadCheckSums(b []byte, part int) map[string]string {
	res := make(map[string]string, 1)
	for len(b) > 0 {
		t, n := binary.Uvarint(b)
		if n < 0 {
			break
		}

					return nil, err
				}
			case 1, 2:
				v, b, err := msgp.ReadBytesZC(b)
				if err != nil {
					return nil, err
				}
				if _, nbuf, err := msgp.ReadUint32Bytes(b); err == nil {
					// Read metadata CRC (added in v2, ignore if not found)
					b = nbuf
				}

				_, err = msgp.CopyToJSON(buf, bytes.NewReader(v))
				if err != nil {
					return nil, err
				}
				data = b
			case 3:

// the upstream reader after close has been called.
type disconnectReader struct {
	r  io.Reader
	mu sync.Mutex
}

func (d *disconnectReader) Read(p []byte) (n int, err error) {
	d.mu.Lock()
	defer d.mu.Unlock()
	if d.r != nil {
		return d.r.Read(p)
	}
	return 0, errors.New("reader closed")
}

func (d *disconnectReader) Close() error {
	d.mu.Lock()
	d.r = nil
	d.mu.Unlock()
	return nil

	case ObjectAccessedGetRetention:
		return "s3:ObjectAccessed:GetRetention"
	case ObjectAccessedGetLegalHold:
		return "s3:ObjectAccessed:GetLegalHold"
	case ObjectAccessedHead:
		return "s3:ObjectAccessed:Head"
	case ObjectAccessedAttributes:
		return "s3:ObjectAccessed:Attributes"
	case ObjectCreatedAll:
		return "s3:ObjectCreated:*"
	case ObjectCreatedCompleteMultipartUpload:

		writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
		return
	}

	api.getObjectAttributesHandler(ctx, objectAPI, bucket, object, w, r)
}

// HeadObjectHandler - HEAD Object
// -----------
// The HEAD operation retrieves metadata from an object without returning the object itself.
func (api objectAPIHandlers) HeadObjectHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "HeadObject")

	disk       StorageAPI
	volume     string
	filePath   string
	verifier   *BitrotVerifier // Holds the bit-rot info
	tillOffset int64           // Affects the length of data requested in disk.ReadFile depending on Read()'s offset
	buf        []byte          // Holds bit-rot verified data
}

func (b *wholeBitrotReader) ReadAt(buf []byte, offset int64) (n int, err error) {
	if b.buf == nil {
		b.buf = make([]byte, b.tillOffset-offset)

		return "Unknown"
	}
}

// InsufficientReadQuorum storage cannot satisfy quorum for read operation.
type InsufficientReadQuorum struct {
	Bucket string
	Object string
	Err    error
	Type   RQErrType
}

func (e InsufficientReadQuorum) Error() string {
	return "Storage resources are insufficient for the read operation " + e.Bucket + "/" + e.Object
}

// Unwrap the error.

	bucket := "bucket"
	object := "object"

	// Create "bucket"
	err = obj.MakeBucket(ctx, bucket, MakeBucketOptions{})
	if err != nil {
		t.Fatal(err)
	}

	// Test: Upload a small file and read it.
	smallData := []byte{'a'}
	_, err = obj.PutObject(ctx, bucket, object, mustGetPutObjReader(t, bytes.NewReader(smallData), int64(len(smallData)), "", ""), ObjectOptions{})
	if err != nil {
		t.Fatal(err)
	}

	fr, err := parquetgo.NewFileReader(rsc)
	if err != nil {
		return nil, errParquetParsingError(err)
	}

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

func (pr *Reader) Read(dst sql.Record) (rec sql.Record, rerr error) {
	nextRow, err := pr.r.NextRow()
	if err != nil {
		if err == io.EOF {
			return nil, err
		}
		return nil, errParquetParsingError(err)
	}

	kvs := jstream.KVS{}

)

// errOutOfEntropy indicates that the a source of randomness (PRNG) wasn't able
// to produce enough random data. This is fatal error and should cause a panic.