Mbedthis AppWeb Features

The AppWeb product includes the following components:

AppWeb HTTP Server library
AppWeb HTTP Client library
AppWeb HTTP server main program
AppWeb loadable modules for server-side JavaScript, Embedded Server Pages, Embedded Gateway Interface, Common Gateway Interface, and PHP
Secure Sockets Layer (SSL)
Documentation
Samples
Source code

Feature Overview

Dynamic Content

Embedded Server Pages (ESP) -- see below:
Embedded JavaScript
Embedded Gateway Interface (in-memory CGI)
CGI/1.1
PHP (4 and 5)

Embedded Server Pages

Server-side JavaScripting
Integrated session state management
Scripted generation of HTML
Extensible via new functions
Manage client state-data via sessions
Post-back paradigm. Same page for form and post logic

Security

Secure Sockets Layer (SSL)
Basic and Digest Authentication
Directory and URL location based authorization
Sandbox limits
Access and access violation logging

Modularity

Dynamic loading of modules
Extensible URL handlers
Extensible / replaceable authorization, SSL and script

Ease of Use

Apache-style configuration file
Debugging and trace logging
Packaged installations for Linux and Windows
Run as a service / daemon

Other Features

HTTP server and client access program
Named and IP based virtual hosts
Listen on multiple ports
Compile web pages and files into C code for execution from ROM

Standards

HTTP/1.1
CGI/1.1
Apache configuration file compatibility

Performance

Multithreaded with high performance thread pool
Request throughput (> 3,500 requests per second)
Scales on multi-cpu systems
Small memory footprint even under heavy load (from 400K)

Developer Features

HTTP server and client libraries
Shared and static libraries supplied
C and C++ APIs
Operate single-threaded or multithreaded (Compile or run-time selectable)
Easy, intuitive programming model
Integrate with common event mechanism: Windows Messages, Unix select, dedicated thread
Coding minimized as most features can be specified via the configuration file
Cookbook of samples (cut and paste to get going)
SMP safe
Extensive debug trace logging

AppWeb Feature Detail

Server-side JavaScript

JavaScript or ECMAScript (ECMA-262) has typically been implemented in the client. However, it is ideally suited for embedded use on the server. AppWeb supports a subset of ECMAScript that is fast and compact.

Embedded Server Pages (ESP)

Embedded Server Pages are server side JavaScripted HTML pages that allow direct binding between the JavaScript procedures and logic routines in your application.

Alternative methodologies for creating dynamic web pages such as CGI suffer from several deficiencies that make them a poor choice for creating dynamic user interfaces in embedded applications:

You cannot view the page layout at design time
Very slow to generate
Large demand on system resources
Additional programs and interfaces need securing

The Embedded Server Pages technology remedies these shortcomings by allowing you to use page layout programs such as Dreamweaver while still retaining the ability to generate dynamic content within the page via server-side JavaScripting.

Embedded Gateway Interface (EGI)

The Embedded Gateway Interface is a modern replacement for the Common Gateway Interface (CGI) when it is used to process form data. Using CGI for form data suffers from many of the same deficiencies it exhibits when it is used to generate page data. In addition, it provides a very low level interface that does not assist the developer when decoding query or posted data.

The Embedded Gateway Interface remedies these shortcomings by allowing an equivalent of in-process CGI. Form URLs may be bound directly to EGI code routines that will be called when the form is posted. AppWeb further assists by decoding query arguments and providing hashed lookup to all environment data variables.

Open Modular Architecture

AppWeb supports dynamically loadable modules so that new content handlers, scripting engines and page generation environments can be easily added. The existing mechanisms: ESP and EGI have been developed as loadable modules so that they are only loaded if required. Scripting engines such as PHP are also being created as loadable modules.

Common Gateway Interface (CGI)

Should you need to support existing code bases that use CGI, AppWeb provides a high performance CGI implementation.

Debugging Support

The AppWeb HTTP server includes a powerful debug logging facility and is fully instrumented to log trace information. This can be invaluable in debugging ESP code logic or new AppWeb handlers that you may have written.