ANN: Simple components v.4.3 released

ANN: Simple components v.4.3 released

[Dmitry A. Kazakov]

The current version provides implementations of smart pointers, directed
graphs, sets, maps, B-trees, stacks, tables, string editing, unbounded
arrays, expression analyzers, lock-free data structures, synchronization
primitives (events, race condition free pulse events, arrays of events,
reentrant mutexes, deadlock-free arrays of mutexes), pseudo-random
non-repeating numbers, symmetric encoding and decoding, IEEE 754
representations support, multiple connections server designing tools.

http://www.dmitry-kazakov.de/ada/components.htm

Changes to the previous version:

- Persistent B-tree with keys and values allocated externally

- Persistent tables searchable by multiple keys with multiple values
(columns). This can be used to design a light-weight 100% Ada equivalent of
a relational DB table with several keys.

- WebSockets integrated into the HTTP server. Both half-duplex and
full-duplex operating modes are supported.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de

Re: ANN: Simple components v.4.3 released

[David Botton]

> - WebSockets integrated into the HTTP server. Both half-duplex and
> full-duplex operating modes are supported.

Is half duplex mode part of the Websocket standard or just an implementation method in your code? What would be the advantages or reasons for choosing one mode over the other?

Thanks!
David Botton

Re: ANN: Simple components v.4.3 released

[Dmitry A. Kazakov]

On Sun, 23 Nov 2014 07:39:38 -0800 (PST), David Botton wrote:

>> - WebSockets integrated into the HTTP server. Both half-duplex and
>> full-duplex operating modes are supported.
> 
> Is half duplex mode part of the Websocket standard or just an
> implementation method in your code?

WebSocket is full-duplex in the sense that it allows full-duplex exchange.
AFAIK that was one of the reasons to introduce it, because HTTP is
half-duplex. But it is up to the server and the client to decide if they
actually do.

> What would be the advantages or
> reasons for choosing one mode over the other?

The advantage of a half-duplex exchange is that the server need not to
start an extra task or tasks. Therefore the server need not to protect its
state from concurrent access, since only one task can access it at the
time.

Being half-duplex is a property of the higher-level protocol and ultimately
of the application.

If the application is an echo server, the server only responds to the
client. This can be handled in the half-duplex mode.

If the application is a game when the server sends messages to the client
on real-time events then it must be full-duplex. E.g. a Tetris-game
implementation will use a full-duplex exchange.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de

Re: ANN: Simple components v.4.3 released

[David Botton]

> - WebSockets integrated into the HTTP server

I am happy to announce that the latest version of Gnoga is now using Dmitry's HTTP and WebSockets components instead of AWS. In addition to being a very complete http and websockets implementation it is lightweight and since Ada 95 it should allow Gnoga to compile on much older versions of Gnat as found currently in most distributions.

The Gnoga website http://www.gnoga.com and the snake example http://snake.gnoga.com are both running on Gnoga using the new components.

Thanks!!
David Botton