Webserver

Webserver Overview

A webserver is a software system that responds to HTTP requests from clients (such as browsers, applications, or devices) and delivers web content such as HTML pages, images, and API responses. Webservers form the backbone of web-based communication and are widely used in applications ranging from embedded systems to cloud services. They are responsible for handling multiple client connections simultaneously, processing requests, and sending back appropriate responses over TCP/IP networks.

RAPIDSEA offers a platform-independent webserver that can run on any system with TCP/IP support. The implementation provides all the core web-server functionalities and is optimized for embedded, desktop, and real-time operating systems.

Some of the salient features of RAPIDSEA Webserver are:

  • HTTP/1.0 support for GET, POST, PUT, DELETE requests.

  • Handles multiple simultaneous client connections.

  • Lightweight and highly optimized for MCUs and resource-constrained systems.

  • Configurable buffer sizes and connection timeouts.

  • Platform independent — runs on Linux, Windows, and RTOS-based systems.

  • Easy integration via callback APIs for custom webpages.

The implementation is fully configurable, supports both blocking and non-blocking operation modes, and can be integrated seamlessly into a variety of embedded and desktop applications.

Webserver

RAPIDSEA implements a lightweight, platform-independent webserver that allows multiple clients to connect and interact with the system through standard HTTP interfaces.

Application Interface

The below table captures the function that are to be called from the application logic.

API Functions

Function

Description

rs_webserver_open

To Initialize the socket configuration.

rs_webserver_run

To set the state to be open

rs_webserver_tcp_comm_handler

To be called to handle the socket connection states.

rs_webserver_process

To be called periodically to receive the request and prepare the client response.

The below table contains the RCB calls invoked by the server stack.

callback Functions

Function

Description

rcb_webserver_file_write

Called to write a specified amount of data to a web server file

rcb_webserver_file_read

Called to read a chunk of data from a web server file

rcb_webserver_file_download_open

Called to initialize the file download process by opening the specified file on the web server

rcb_webserver_file_upload_open

Called to start the process of uploading a file to the web server

rcb_webserver_file_close

Called to close the file session on the web server after completing file operations (upload or download)

rcb_webserver_handle_post_req

Called to validate the input post request data and performs respective action

rcb_webserver_get_file_data

Called to get the buffer and length of the file

Only a millisecond timer is sufficient for the stack to run.

Implementation Guide

This section explains how to implement the Webserver stack using the RAPIDSEA stack, the steps to be followed are

  • Initially start the webserver task from the application layer.

  • Then the server task state is in idle condition, until webserver starts.

  • Webserver starts and changes its state from idle to open.

  • In webserver process, process the client request and prepare the response for the client.

The below diagram captures the high level sequence of operations associated with the webserver.

Webserver Sequence Diagram

Error Code

  • Every API’s for the webserver returns some success or failure values. Please refer below section,

Dependency

This stack depends on the below RAPIDSEA interfaces that can be obtained or custom implemented.

Example demo

An example implementation is available along with the release and is described in Webserver Demo.

Webserver Header Details

Documentation from the relevant server header as follows:

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