Multithreaded Proxy Server with Cache

A C-based multithreaded HTTP proxy server that handles concurrent client requests and caches responses using an LRU-style strategy.

Features

• Handles multiple client connections using threads (pthread)
• Uses a semaphore to limit active concurrent requests
• Parses HTTP requests with proxy_parse.c/proxy_parse.h
• Forwards GET requests to remote servers
• Stores responses in an in-memory cache and serves cache hits directly
• Sends HTTP error responses for invalid/failed requests

Project Structure

• proxy_server_with_cache.c: Main proxy server implementation with caching
• proxy_parse.c: HTTP request parsing library implementation
• proxy_parse.h: HTTP request parsing library interface
• Makefile: Build rules
• make.bat: Windows wrapper for mingw32-make

Requirements

• Windows + MSYS2 UCRT64 toolchain
• g++, mingw32-make
• WinSock library (ws2_32) for networking (already linked in Makefile)

Build

From the project directory:

.\make.bat

Run

.\proxy 8080

Use any free port instead of 8080 if needed.

Notes

• The proxy currently supports GET requests.
• Cache size and related limits are defined with macros in proxy_server_with_cache.c.
• If make is not recognized in a new terminal, use make.bat from the project folder.