Improve Rust Protobuf Reader: Error Handling, Performance & Safety Enhancements

[PsychoPunkSage]

Checklist

• Use enum for Actions – Reduce multiple string comparisons by leveraging Rust enums for action handling.
• Robust Error Handling – Improve error-handling mechanisms to prevent unhandled failures.
• Use matches!() for Boolean Logics – Simplify boolean logic conditions by using the matches!() macro.
• Graceful Error Handling with Result<(), Error> – Replace direct panics with structured error handling using Result<(), Error>.
• Use PathBuf Instead of String Paths – Enhance path handling reliability by using PathBuf instead of raw string paths.
• Replace panic!() with Result<()> – Ensure better error propagation by using Result<()> instead of panic!().
• Write a Logging Method – Implement a dedicated logging method to improve debugging and observability.
• Use Struct Instead of JSON Object – Replace loosely typed JSON objects with strongly typed Rust structs for better type safety.
• Replace exit(1) With Proper Error Handling – Ensure graceful application termination by replacing exit(1) with structured error handling.
• Define a Constant for Buffer Size – Set a proper buffer size (const BUFFER_SIZE: usize = 32767 * 4; // 128 KB) and replace magic numbers.
• Dynamically Adjust EPOLL Cap Based on File Requests – Improve scalability by dynamically adjusting the EPOLL capacity based on the number of file requests.
• Use std::fs::canonicalize(images_dir) to Resolve Symlinks Safely – Ensure safe resolution of symlinks using canonicalize() to prevent path traversal vulnerabilities.
• Improve TCP Communication Reliability – Enhance TCP communication by adding timeouts and retry logic for better reliability.