Codecrafters HTTP Server (C++)

This project is a custom HTTP server implemented in C++. Below is an overview of the program's structure and key components, including the router, threading for concurrent requests, GZIP implementation, and post-processors.

Project Structure

codecrafters-http-server-cpp/
├── src/
│   ├── request_handler.cpp         # Router implementation
│   ├── server.cpp                  # Core server logic
│   ├── settings.cpp                # For flags
│   └── routes
│     └── register.cpp              # Routes and Postprocessors
└── README.md                       # Project documentation

Router Implementation

The router is responsible for mapping HTTP requests to specific handlers based on the request's method and path. It uses a map to store routes and their corresponding handler functions. The router supports dynamic route parameters (e.g., /users/:id) and resolves them at runtime.

Key Features:

• Route Registration: Routes are registered with their HTTP method and path.
• Dynamic Parameters: Extracts parameters from the URL and passes them to the handler.

Example:

router.addRoute("GET", "/users/:id", [](request_t &req, response_t &res) {
   res.body = "User ID: " + req.params["id"];
});

Threading for Concurrent Requests

The server uses threads to handle multiple client requests concurrently.

GZIP Implementation

The server supports GZIP compression to reduce the size of HTTP responses. The register.cpp file registers a compression post-processor to compress response data using the zlib library.

Key Features:

• Compression on Demand: Responses are compressed if the client supports GZIP (via the Accept-Encoding header).
• Efficient Compression: Uses zlib's deflate algorithm for optimal performance.
• Transparent Integration: Compression is applied automatically in the response pipeline.

Post-Processors

Post-processors are middleware functions that modify the response before it is sent to the client. They can be used for tasks like logging, adding headers, or transforming response data.

Key Features:

• Chaining: Multiple post-processors can be applied in sequence.
• Custom Logic: Developers can define custom post-processors for specific use cases.
• Integration: Post-processors are invoked after the main handler generates the response.

Conclusion

This HTTP server demonstrates a modular and efficient design, supporting routing, concurrency, compression, and response post-processing. Each component is designed to be reusable and extensible, making it a robust foundation for building web applications.