tiny_logger/
lib.rs

1//! The `logger` module configures `env_logger`
2
3use {
4    lazy_static::lazy_static,
5    std::sync::{Arc, RwLock},
6};
7
8lazy_static! {
9    static ref LOGGER: Arc<RwLock<env_logger::Logger>> =
10        Arc::new(RwLock::new(env_logger::Logger::from_default_env()));
11}
12pub mod logs {
13    pub use log::*;
14}
15struct LoggerShim {}
16
17impl log::Log for LoggerShim {
18    fn enabled(&self, metadata: &log::Metadata) -> bool {
19        LOGGER.read().unwrap().enabled(metadata)
20    }
21
22    fn log(&self, record: &log::Record) {
23        LOGGER.read().unwrap().log(record);
24    }
25
26    fn flush(&self) {}
27}
28
29fn replace_logger(logger: env_logger::Logger) {
30    log::set_max_level(logger.filter());
31    *LOGGER.write().unwrap() = logger;
32    let _ = log::set_boxed_logger(Box::new(LoggerShim {}));
33}
34
35// Configures logging with a specific filter overriding RUST_LOG.  _RUST_LOG is used instead
36// so if set it takes precedence.
37// May be called at any time to re-configure the log filter
38pub fn setup_with(filter: &str) {
39    let logger =
40        env_logger::Builder::from_env(env_logger::Env::new().filter_or("_RUST_LOG", filter))
41            .format_timestamp_nanos()
42            .build();
43    replace_logger(logger);
44}
45
46// Configures logging with a default filter if RUST_LOG is not set
47pub fn setup_with_default(filter: &str) {
48    let logger = env_logger::Builder::from_env(env_logger::Env::new().default_filter_or(filter))
49        .format_timestamp_nanos()
50        .build();
51    replace_logger(logger);
52}
53
54// Configures logging with the default filter "error" if RUST_LOG is not set
55pub fn setup() {
56    setup_with_default("error");
57}
58
59// Configures file logging with a default filter if RUST_LOG is not set
60pub fn setup_file_with_default(logfile: &str, filter: &str) {
61    use std::fs::OpenOptions;
62    let file = OpenOptions::new()
63        .write(true)
64        .create(true)
65        .append(true)
66        .open(logfile)
67        .unwrap();
68    let logger = env_logger::Builder::from_env(env_logger::Env::new().default_filter_or(filter))
69        .format_timestamp_nanos()
70        .target(env_logger::Target::Pipe(Box::new(file)))
71        .build();
72    replace_logger(logger);
73}
tiny_logger/lib.rs

tiny_logger/
lib.rs
