RL-ARM User's Guide

SOAP Interface

The SOAP messages in HTTP consist of the POST request, submitted by the client, and a response generated by the Web server. The Embedded Web server handles the SOAP messages different. Instead of processing them internally and notifying the user via user callback functions, the Web server delivers a complete SOAP message to the user via the callback function.

The SOAP messages in general are large. Embedded systems that run the Web server with SOAP, need much more RAM for message buffering and processing. A typical configuration would have:

• a few MBytes of RAM
• an SD Card for deploying web service application, for example the Silverlight.

The following extensions have been added to the Web server:

• the cgi_process_data function has been extended with the code 4 and 5 to allow processing fragmented large POST messages.
• the Content-Type http header for XML-encoded POST requests is buffered. Function http_get_content_type returns a pointer to the Content-Type string, which was received in the XML POST request.
• the Content-Type header for the response can be defined by the user in the cgx_content_type function.
• the http_get_session function is used to identify which Web server session has called a cgi_process_data callback function, if two or more clients have sent XML-POST requests at the same time.
• the HTTP Caching improves the Web server performance a lot when serving large web service applications.