Implement instant_print_lines argument

src/args.rs

@@ -37,6 +37,10 @@ pub struct AppConfig {
     #[clap(short, long, default_value = "1", value_parser = parse_speed_factor)]
     pub speed_factor: f32,
 
+    /// Instantly print this many lines
+    #[clap(short, long = "instant-print-lines", default_value = "0")]
+    pub instant_print_lines: u32,
+
     /// Exit after running for this long (format example: 2h10min)
     #[clap(long, value_parser = humantime::parse_duration)]
     pub exit_after_time: Option<instant::Duration>,
@@ -61,6 +65,9 @@ pub struct AppConfig {
 
     /// Global speed factor
     pub speed_factor: f32,
+
+    /// Instantly print this many lines
+    pub instant_print_lines: u32,
 }
 
 impl AppConfig {
@@ -122,6 +129,11 @@ pub fn parse_args() -> AppConfig {
         .map(|(_, v)| v.parse::<f32>().unwrap_or(1.0))
         .unwrap_or(1.0);
 
+    let instant_print_lines: u32 = pairs
+        .find(|&(ref k, _)| k == "instant-print-lines")
+        .map(|(_, v)| v.parse::<u32>().unwrap_or(0))
+        .unwrap_or(0);
+
     let modules_to_run = if temp_modules.is_empty() {
         ALL_MODULES.keys().map(|m| m.to_string()).collect()
     } else {
@@ -131,5 +143,6 @@ pub fn parse_args() -> AppConfig {
     AppConfig {
         modules: modules_to_run,
         speed_factor,
+        instant_print_lines,
     }
 }

src/io.rs

@@ -6,20 +6,38 @@ use wasm_bindgen::prelude::*;
 #[cfg(not(target_arch = "wasm32"))]
 use std::io::{stdout, Write};
 
-use crate::SPEED_FACTOR;
+use crate::{INSTANT_PRINT_LINES, SPEED_FACTOR};
+
+use std::sync::atomic::{AtomicU32, Ordering};
+static COUNTER: AtomicU32 = AtomicU32::new(0);
 
 #[cfg(not(target_arch = "wasm32"))]
 pub async fn csleep(length: u64) {
     use std::time;
+
     let speed_factor = *SPEED_FACTOR.lock().await;
-    let sleep_length = time::Duration::from_millis((1.0 / speed_factor * length as f32) as u64);
+    let count = COUNTER.fetch_add(1, Ordering::SeqCst);
+    let sleep_length = if count < INSTANT_PRINT_LINES.load(Ordering::SeqCst) {
+        // If user passed `--instant-print-lines`, there should be
+        // no pauses in first `INSTANT_PRINT_LINES` number of lines
+        time::Duration::new(0, 0)
+    } else {
+        time::Duration::from_millis((1.0 / speed_factor * length as f32) as u64)
+    };
     async_std::task::sleep(sleep_length).await;
 }
 
 #[cfg(target_arch = "wasm32")]
 pub async fn csleep(length: u64) {
     let speed_factor = *SPEED_FACTOR.lock().await;
-    let sleep_length = (1.0 / speed_factor * length as f32) as i32;
+    let count = COUNTER.fetch_add(1, Ordering::SeqCst);
+    let sleep_length = if count < INSTANT_PRINT_LINES.load(Ordering::SeqCst) {
+        // If user passed `--instant-print-lines`, there should be
+        // no pauses in first `INSTANT_PRINT_LINES` number of lines
+        0 as i32
+    } else {
+        (1.0 / speed_factor * length as f32) as i32
+    };
 
     let promise = js_sys::Promise::new(&mut move |resolve, _| {
         let window = web_sys::window().expect("should have a Window");

src/lib.rs

@@ -16,6 +16,7 @@ use modules::{Module, ALL_MODULES};
 lazy_static::lazy_static! {
     pub static ref CTRLC_PRESSED: AtomicBool = AtomicBool::new(false);
     pub static ref SPEED_FACTOR: Mutex<f32> = Mutex::new(1.0);
+    pub static ref INSTANT_PRINT_LINES: AtomicU32 = AtomicU32::new(0);
     pub static ref STARTED_AT: Instant = Instant::now();
     pub static ref MODULES_RAN: AtomicU32 = AtomicU32::new(0);
 }

src/main.rs

@@ -2,7 +2,9 @@
 use anyhow::Result;
 
 use genact::args::parse_args;
-use genact::{run, SPEED_FACTOR};
+use genact::{run, INSTANT_PRINT_LINES, SPEED_FACTOR};
+
+use std::sync::atomic::Ordering;
 
 #[cfg(not(target_arch = "wasm32"))]
 use genact::exit_handler;
@@ -32,6 +34,7 @@ async fn main() -> Result<()> {
     }
 
     *SPEED_FACTOR.lock().await = appconfig.speed_factor;
+    INSTANT_PRINT_LINES.store(appconfig.instant_print_lines, Ordering::SeqCst);
 
     if appconfig.list_modules_and_exit {
         println!("Available modules:");
@@ -57,6 +60,7 @@ async fn main() {
 
     let appconfig = parse_args();
     *SPEED_FACTOR.lock().await = appconfig.speed_factor;
+    INSTANT_PRINT_LINES.store(appconfig.instant_print_lines, Ordering::SeqCst);
 
     run(appconfig).await;
 }