A W S - Ada Web Sever
0 . 10
May 24th, 2001.
Dmitriy Anisimkov and I are very happy to announce the availability of the
AWS 0.10 release. This version is close to the 1.0 version. Note that the API
has been changed a lot. This is part of a redesign to have a cleaner API. We
plan to change slightly the API at this stage but it should be mostly stable.
Note that this is definitly a major version.
AWS stand for Ada Web Server. It is not a real Web Server like Apache. It is
an HTTP component to embedded in any applications. It means that you can
communicate with your application using a standard Web browser and this
without the need for a Web Server. AWS is fully developed in Ada with GNAT.
Here are the main changes:
- API redesign.
- Templates_Parser (included) has been almost completly rewritten. It is
something like 8 to 12 times faster than previous version, has lot of nice
new features (like Matrix_Tag). See below for references about
- Fix bug in session handling. The same session ID could have been allocated
to differents client. Generation of Session ID is more secure. And there
is some performance improvement in the way sessions ID are handled.
- New Server interface (more dynamic). HTTP has only one discriminant now,
the other setting are done through the Start procedure.
- Default AWS.OS_Lib is now using the GNAT based implementation instead of
the POSIX one. This should make it easier to build AWS.
- Implement HTTP/1.0 and Keep-Alive connection (Netscape browser ask this
kind of connection). Should fix more server hanging problems.
- Server parameters can be handled with case sensitivity or not.
- Fix possible memory leak in status data.
- Improve again the way slots are aborted, this should fix more browser
- Add Peername to the status data.
- Status page (status.tmplt) use the new Matrix_Tag templates parser
feature and the new filter syntax. Note that this new version of templates
parser is about 8 to 12 times faster than previous version. It has been
- All status page (status.tmplt) vetor tag name have now an _V suffix
(was _L for historical reasons)
- Handle properly all "Cookie:" HTTP messages format.
- Add many configuration options in aws.ini.
- Improve a bit the documentation.
- Hello_World new AWS demo, the famous Hello_World a la AWS. This is
certainly the smallest AWS application.
- As always some minor bugs have been fixed but are not listed here.
NOTE: Since we have switched to the .PNG file format we have found that
Netscape Navigator is not able to display the PNG transparent layer properly!
At this stage we feel that AWS is ready to build small to medium Web
server. AWS has been reported to work under Windows NT, Linux and FreeBSD 4.1.
With this new version you'll need at least version 0.1.11 of the Socket binding
from ENST. It has been tested and works fine with version 0.1.13 too.
You can download AWS and the Sockets binding for Win32 directly from:
An online version of the documentation can be found at
The OpenSSL libraries (optional) distributed are for Windows GNAT 3.13. GNAT
3.12 users must build the libraries from sources or obtain Win32 binaries from
Under UNIX you'll have to build the libraries from sources, it is quite easy
to do so. This has been tested under Linux without trouble.
See documentation for build information.
Templates_Parser module is provided with AWS distribution. Latest version
of this module and the documentation can be found at:
Temlates_Parser is a very useful add-on for AWS. You should have a look at
it if you plan to develop a Web service. Templates_Parser permits to
completly (yes 100%) separate the HTML design from the Ada code.
Some other Templates engine are WebMacro, FreeMarker, PHP, ASP, JSP and
Velocity. All of them are based on explicite iterators (#foreach with a
variable) where Templates_Parser is based on implicit ones (you use a more
intuitive table iterator). Be sure to check the documentation. Only
Velocity project will support complete separation of HTML design and code.
POSIX Binding (optional) :
OpenSSL library (optional) :
Sources for UNIX or Win32:
(we have used and we distribute OpenSSL version 0.9.5a with this AWS
release, we have also tested AWS with OpenSSL 0.9.6a without trouble)
binaries for Win32 with GNAT 3.13 (and later):
Included with the main AWS distribution.
binaries for Win32 with GNAT 3.12:
See OpenSSL license (docs/openssl.license).
Windows Services API (optional):
To build runme demo as a Windows NT/2000 services you must download
the services API made by Ted Dennison for his SETI@Home project.
You can report bugs to:
Dmitriy Anisimkov [log in to unmask]
Pascal Obry [log in to unmask]
It would be nice if you could also sent us a note if you are using AWS just
to know if it is used at all or not :)
- SETI@Home from Ted Dennison. AWS is used as a "plugable" GUI to control the
- DOCWEBSERVER from Wiljan Derks
In our department we keep our documents in a directory tree. These documents
are all project related and have a certain naming convention to be able to
find the right document. In the past I already wrote a program that searches
though this directory and then converts the found documents into fixed html
pages. With AWS I was able to get a much nicer setup. I have now a server
that can do the following:
- browse through the projects in explorer style. The html contains info
about the document like date and title.
- one can check in documents through the web interface
- it shows our download page as I have send you in the example
- we have now all our documentation in small pieces of html as is needed
to build .chm (w2k compiled help) files. For these we use a content
file, that is also stored in the document archive.
The docwebserver gives by reading all this stuff the direct view on this
documentation. On the other hand I can run some tool and automatically
generate the .chm files.
- OESM Server (OESM=Overall Equipment Status Monitoring) from Wiljan Derks
I am working on a project now for our factories. ITEC mainly delivers
equipment for discrete semiconductor assembly. Allmost all of that equipment
is now controlled by a similar Ada 95 based code with having a lot of code in
common. One of the common things, is the way we log errors and state changes
of our equipment.
The OESM Server is an application which copies all this information
continuously to its local pc by opening the proper files on the remote
equipment. That data copied is also stored in local files. The web server
component of the application can then, making use of that data, give reports
that show things like the amount of products produced in a certain period,
error paretos of equipment, mtbf, %time in production and of course many
The cool thing of course is that this information can easily be charted (I
am use kavachart) and it allows simple navigation through different groups
of equipments and different views on the equipment.
- WORM from Pascal Obry
A Web server to share bookmarks, this server was using a standard CGI
design. To keep session information we were using a GLADE partition. With
AWS the design has beeen really simplified, there is no need for a session
partition, there is no need to build all CGI as partitions too. GLADE is now
used only to handle distributed objects. Indeed WORM is a multi-server
system (using RACW) with a register/unregister mechanisme.
Also the server seems to be fastest, there is no more CGI to spawn.
- Internet Currency Trading System at www.actforex.com by Dmitriy Anisimkov
This is a server is used to keep historical data about currency trading to
build charts of currency prices. The charts viewer part is written in Java
and loaded through AWS. This server can be reach on the Internet.
Thanks to all who have reported bugs and have sent us patches.
Dmitriy & Pascal.
--| Pascal Obry Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--| "The best way to travel is by means of imagination"