@deftypefun {ssize_t} {gnutls_record_recv_early_data} (gnutls_session_t @var{session}, void * @var{data}, size_t @var{data_size})
@var{session}: is a @code{gnutls_session_t}  type.

@var{data}: the buffer that the data will be read into

@var{data_size}: the number of requested bytes

This function can be used by a searver to retrieve data sent early
in the handshake processes when resuming a session.  This is used
to implement a zero-roundtrip (0-RTT) mode.  It has the same
semantics as @code{gnutls_record_recv()} .

This function can be called either in a handshake hook, or after
the handshake is complete.

@strong{Returns:} The number of bytes received and zero when early data
reading is complete.  A negative error code is returned in case of
an error.  If no early data is received during the handshake, this
function returns @code{GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE} .  The
number of bytes received might be less than the requested
 @code{data_size} .

@strong{Since:} 3.6.5
@end deftypefun