Need for Custom Logger

• Security and Control: Third-party vulnerabilities can pose significant risks. External libraries, especially widely used logging frameworks, may introduce security flaws. Attackers could exploit these to inject malicious log entries, access sensitive data, or gain elevated privileges. By creating a custom logger, you gain full control over your logging system's security, minimizing exposure to external threats.
• Protocol-specific logging: Protocol-level projects often have unique logging requirements, such as detailed tracing or custom formats. A custom logger can be tailored to your protocol's specific needs, offering greater flexibility and performance.

Logging in Rust

Rust implements logging using the facade pattern, a design concept from the "Gang of Four." Here's how it works:

• You call functions provided by the facade crate (in Rust, this is the "log" crate).
• The facade then calls the actual logic from another crate (such as "log4rs" or "env_logger").

This approach allows for flexibility—you can change the logging crate without altering your main code.

When logging in Rust, you typically import two libraries:

• The facade ("log")
• The specific logging implementation

graph TD
    A["Source Code"] -->|"Uses"| B["log Crate (Facade)"]
    B -->|"Initializes"| C["Logging Implementation Crate"]
    C -->|"Implements"| D["Actual Logging Logic"]
    E["User's Application"] -->|"Calls"| B
    B -->|"Forwards Calls"| C

Custom Logger Implementation

Designing the Facade Log Crate

1. Level Enum

The Level enum represents the logger's verbosity levels, from lowest to highest priority:

#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
pub enum Level {
    Trace,  // Extremely verbose, lowest priority
    Debug,  // Low-priority information
    Info,   // General information
    Warn,   // Potential issues
    Error,  // Serious problems
}

2. LevelFilter Enum