make number of threads configurable per CLI

1 files changed, 11 insertions, 0 deletions

diff --git a/src/main.rs b/src/main.rs
index 77af69f..9c3250e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,6 +4,7 @@ use clap::Parser;
 use color_eyre::eyre::{bail, Result};
 use indicatif::{MultiProgress, ProgressBar, ProgressDrawTarget, ProgressStyle};
 use is_terminal::IsTerminal;
+use rayon::ThreadPoolBuilder;
 
 mod gpx;
 mod layer;
@@ -16,11 +17,17 @@ struct Args {
     #[arg(required = true)]
     files: Vec<PathBuf>,
 
+    /// Minimum zoom level to generate tiles for.
     #[arg(long, default_value_t = 0)]
     min_zoom: u32,
 
+    /// Maximum zoom level to generate tiles for.
     #[arg(long, default_value_t = 19)]
     max_zoom: u32,
+
+    /// Number of threads to use. Set to 0 to use all available CPU cores.
+    #[arg(long, short, default_value_t = 0)]
+    threads: usize,
 }
 
 fn main() -> Result<()> {
@@ -32,6 +39,10 @@ fn main() -> Result<()> {
         bail!("Max zoom cannot be smaller than min zoom!");
     }
 
+    ThreadPoolBuilder::new()
+        .num_threads(args.threads)
+        .build_global()?;
+
     let progress_style =
         ProgressStyle::with_template("[{elapsed}] {prefix:.cyan} {wide_bar} {pos:.green}/{len}")?;
     let zoom_style =