extern crate flame;

use std::fs::File;

fn main() {
    // Manual `start` and `end`
    flame::start("read file");
    let x = read_a_file();
    flame::end("read file");

    // Time the execution of a closure.  (the result of the closure is returned)
    let y = flame::span_of("database query", || query_database());

    // Time the execution of a block by creating a guard.
    let z = {
        let _guard = flame::start_guard("cpu-heavy calculation");
        cpu_heavy_operations_1();
        // Notes can be used to annotate a particular instant in time.
        flame::note("something interesting happened", None);
        cpu_heavy_operations_2()
    };

    // Dump the report to disk
    flame::dump_html(&mut File::create("flame-graph.html").unwrap()).unwrap();
    
    // Or read and process the data yourself!
    let spans = flame::spans();
    
    println!("{} {} {}", x, y, z);
}

use std::fs::File;

use flame;

fn make_vec(size: usize) -> Vec<u32> {
    // start_guard needs to drop to calculate duration.
    let _fg = ::flame::start_guard("make_vec");

    let mut res = flame::span_of("vec init", || vec![0_u32; size]);
    for x in 0..size {
        res[x] = ((x + 10)/3) as u32;
    }
    let mut waste_time = 0;
    for i in 0..size*10 {
        waste_time += i
    }
    res
}

fn more_computing(i: usize) {
    let _fg = ::flame::start_guard("more_computation");

    for x in 0..(i * 100) {
        let mut v = make_vec(x);
        let x = Vec::from(&v[..]);
        for i in 0..v.len() {
            let flip = (v.len() - 1) - i as usize;
            v[i] = x[flip];
        }
    }
}

fn some_computation() {
    let _fg = ::flame::start_guard("some_computation");

    for i in 0..15 {
        more_computing(i);
    }
}


fn main() {
    let _fg = ::flame::start_guard("main");
    
    some_computation();
    // in order to create the flamegraph you must call one of the
    // flame::dump_* functions.
    flame::dump_html(File::create("flamegraph.html").unwrap()).unwrap();
}

#[flame]
fn this_function_is_profiled() {
    ...
}