switch {
		case compressed:
			// ... nothing changes for compressed stream.
			// if actualSize is -1 we have no known way to
			// determine what is the actualSize.
		case encrypted:
			decSize, err := sio.DecryptedSize(uint64(n))
			if err == nil {
				actualSize = int64(decSize)
			}
		default:
			actualSize = n
		}
	}

	partInfo := ObjectPartInfo{
		Number:     partID,
		ETag:       md5hex,

		case compressed:
			// ... nothing changes for compressed stream.
			// if actualSize is -1 we have no known way to
			// determine what is the actualSize.
		case encrypted:
			decSize, err := sio.DecryptedSize(uint64(n))
			if err == nil {
				actualSize = int64(decSize)
			}
		default:
			actualSize = n
		}
	}
	// If ServerSideChecksum is wanted for this object, it takes precedence

			targetSize = objInfo.EncryptedSize()
		case !isSourceEncrypted && isTargetEncrypted:
			targetSize = srcInfo.EncryptedSize()
		case isSourceEncrypted && !isTargetEncrypted:
			targetSize, _ = srcInfo.DecryptedSize()
		}

		// Client can request that a different type of checksum is computed server-side for the
		// destination object using the x-amz-checksum-algorithm header.