cached 1.0.0

Generic cache implementations and simplified function memoization
Documentation 
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/*
Synchronous on-disk cache: `#[concurrent_cached(disk = true)]` backed by `sled`.
Default cache files live under $system_cache_dir/cached_disk_cache/.

Run:
    cargo run --example disk --features "disk_store,proc_macro"
*/

use cached::macros::concurrent_cached;
use cached::time::Duration;
use std::io;
use std::io::Write;
use thiserror::Error;

#[derive(Error, Debug, PartialEq, Clone)]
enum ExampleError {
    #[error("error with disk cache `{0}`")]
    DiskError(String),
}

// When the macro constructs your DiskCache instance, the default
// cache files will be stored under $system_cache_dir/cached_disk_cache/
#[concurrent_cached(
    disk = true,
    ttl = 30,
    map_error = r##"|e| ExampleError::DiskError(format!("{:?}", e))"##
)]
fn cached_sleep_secs(secs: u64) -> Result<(), ExampleError> {
    std::thread::sleep(Duration::from_secs(secs));
    Ok(())
}

fn main() {
    print!("1. first sync call with a 2 seconds sleep...");
    io::stdout().flush().unwrap();
    cached_sleep_secs(2).unwrap();
    println!("done");
    print!("second sync call with a 2 seconds sleep (it should be fast)...");
    io::stdout().flush().unwrap();
    cached_sleep_secs(2).unwrap();
    println!("done");

    use cached::ConcurrentCached;
    CACHED_SLEEP_SECS.cache_remove(&2).unwrap();
    print!("third sync call with a 2 seconds sleep (slow, after cache-remove)...");
    io::stdout().flush().unwrap();
    cached_sleep_secs(2).unwrap();
    println!("done");
}