Re: Stream_Element_Array

[Alexander Korolev <antonovkablog@gmail.com>]

On Sep 14, 9:29 am, Per Sandberg <per.sandb...@bredband.net> wrote:
> Why not just:
>    Message_Header'Write(Output_Stream,My_Message_Header)
> That would serialize the Data into the stream.
>
> If the target stream is a blocked message why not do
>    Message_Header'Write(Buffer_Stream,My_Message_Header)
>    Buffer_Stream'Write(Output_Stream,Buffer_Stream)
>
> And the Buffer_Stream is a stream of the kind found in:
>    http://sourceforge.net/projects/ada-spread/
>          spread-memory_streams.*
> or
>
> https://github.com/persan/zeromq-Ada
>     zmq-utilities-memory_streams.ad
>
> Which now is part of fedora15
> /Per
>
> On 09/14/2011 05:13 AM, Alexander Korolev wrote:
>
>
>
> > I have a Type
>
> > type Message_Header is
> >      record
> >         -- Components                  --   8 bit
> >         Length    : Unsigned_16;    -- 16 bit  (MSB)
> >         -- other components          --   8 bit
> >      end record;
>
> > How I could split the Lenght component on two subsequent
> > Stream_Element ( 8-bit)?
>
> > Command: Stream_Element_Array (1 .. 64);
>
> > Thanks

Thanks Per

I've just tried with GNAT a similar to your suggestion aproach

In_Memory_Stream:Volatile_Streams.Memory_Resident_Stream (Size =>
128);
Message_Length:Stream_Element_Array(1..2);
Last:Stream_Element_Count;
Msg_Header_Instance:Message_Header;

Begin

Message_Header'Write(In_Memory_Stream, Msg_Header_Instance);
--  writes to meomory
read (In_Memory_Stream,Message_Length,Last);
-- retreives Message_Length wich is Stream_Element_Array -- and the
Last
-- I left only one component in Message_Header - the Lengh, expected
-- the Last = 2, and Message_Length instance filled in after read
(...).
--
End;

Complaints on compilation: "expected access to
Ada.Streams.Root_Stream_Type'Access"