Lib.rs

Send Rust logs to Logcat

This library is a drop-in replacement for env_logger. Instead, it outputs messages to ohos's logcat.

This only works on Open Harmony and requires linking to hilog.z which is only available under open harmony. With Cargo, it is possible to conditionally require this library:

[target.'cfg(all(target_os = "linux", target_env = "ohos"))'.dependencies]
ohos_hilog = "0.1"

Example of initialization on activity creation, with log configuration:

#[macro_use] extern crate log;
extern crate ohos_hilog;

use log::LevelFilter;
use ohos_hilog::{Config,FilterBuilder};

fn native_activity_create() {
    ohos_hilog::init_once(
        Config::default()
            .with_max_level(LevelFilter::Trace) // limit log level
            .with_tag("mytag") // logs will show under mytag tag
            .with_filter( // configure messages for specific crate
                FilterBuilder::new()
                    .parse("debug,hello::crate=error")
                    .build())
    );

    trace!("this is a verbose {}", "message");
    error!("this is printed by default");
}

To allow all logs, use the default configuration with min level Trace:

#[macro_use] extern crate log;
extern crate ohos_hilog;

use log::LevelFilter;
use ohos_hilog::Config;

fn native_activity_create() {
    ohos_hilog::init_once(
        Config::default().with_max_level(LevelFilter::Trace),
    );
}

There is a caveat that this library can only be initialized once (hence the init_once function name). Therefore this library will only log a warning for subsequent init_once calls.

This library ensures that logged messages do not overflow open harmony hilog log message limits by efficiently splitting messages into chunks.

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)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.