Expand description
This is a simple, thread-safe, count-based, progress logger.
This progress logger is intended to be as low-overhead as possible so that it can be used in hot-loops.
Synopsis
proglog hooks into your existing log implementation (i.e. env_logger) and will output a log message every unit number of items it has seen.
There are two primary methods, record() and record_with(...).
record() simply increments the counter and will cause a log message to output when counter % unit == 0.
record_with(Fn() -> impl Display) takes a function that outputs anything implementing display which will be appended to the log message.
Things to Know
If unit is too small, and your loop is too tight, this will output many log messages which will slow your program down in the same way any logging would slow a program down in a hot loop.
If unit is sufficiently large, this should be safe to put in a hot loop as all it does increment update an atomic u64.
If your loop is tight, unit is small, and you are using rayon / updating from multiple threads your log messages may end up out of order.
There is no guaranteed ordering of the submission of the log message to the logger.
So thread A could hit the first unit break, thread B could hit the second point at the same time, but thread B gets to submit its log message first.
Having sufficiently large unit will mitigate this, but you should not be depending on the log output order here.
The tradeoff made is for speed of incrementing so this can be put in hot loops over guaranteed output ordering.
Example
use proglog::ProgLogBuilder;
// Note a `log` backend needs to be globally initialized first
env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info")).init();
let logger = ProgLogBuilder::new().build();
for i in 0..10_000 {
logger.record_with(|| format!("Logged item: {}", i));
}
// The logger will flush when it is dropped, writing a final progress message no mater the count.
// Alternatively you can call .flush() or .flush_with().Features
pretty_counts
The pretty_counts features turns on the ability to format the numbers in the log messages.
Set the [ProgLogBuilder::count_formatter] to one of the [CountFormatterKind]s and numbers will
be formatted accordingly. i.e. 100000000 -> 100_000_000 with [CountFormatterKind::Underscore].
Structs
The builder for ProgLog.