android-logd-logger

This logger writes logs to the Android logd, a system service with multiple ring buffers for logs and events. This is normally done via liblog (a native Android library). Instead of using liblog, this crate writes directly to the logd socket with a simple protocol. This logger is written in pure Rust without any need for FFI.

On non Android system the log output is printed to stdout in the default format of logcat.

Usage

Add this to your Cargo.toml

[dependencies]
android-logd-logger = "0.4.3"

Initialize the logger with a fixed tag and the module path included in the log payload.

use log::{debug, error, info, trace, warn};

fn main() {
    android_logd_logger::builder()
        .parse_filters("debug")
        .tag("MyApp")
        .prepend_module(true)
        .init();

    trace!("trace message: is not logged");
    debug!("debug message");
    info!("info message");
    warn!("warn message");
    error!("error message");
}

Runtime Configuration

The logger can be reconfigured at runtime using the returned Logger handle:

use log::LevelFilter;

fn main() {
    let logger = android_logd_logger::builder()
        .tag("MyApp")
        .init();

    // Change settings at runtime
    logger.tag("NewTag");
    logger.filter_level(LevelFilter::Warn);
}

To write Android logd "events" use write_event_now, e.g:

android_logd_logger::write_event_now(1, "test").unwrap();

Configuration

Writing to the logd socket is a single point of synchronization for threads. The android-logd-logger can be configured with the tls feature to maintain one socket per thread or use a single socket for the whole process. Use the features tls if you want less interference between threads but pay for one connection per thread.

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)