Reads a 64-bit/8-byte value from this.
In order to get the correct byte order for this read operation, see get_byte_order and set_byte_order.
If cancellable
is not null, then the operation can be cancelled by triggering the
cancellable object from another thread. If the operation was cancelled, the error g_io_error_cancelled
will be returned.
this |
a given DataInputStream. |
cancellable |
optional Cancellable object, null to ignore. |
a signed 64-bit/8-byte value read from this or `0` if an error occurred. |