Add --threads (-t) option to downloading commands (#256)

* Add `single-threaded` option to downloading commands

* Replace `--single-threaded` boolean option with `--threads` optional `usize` option

* Simplify `threads` field unwrapping

* Make `--threads` `usize` with a default value

crunchy-cli-core/src/archive/command.rs

@@ -98,6 +98,10 @@ pub struct Archive {
     #[arg(short, long, default_value_t = false)]
     pub(crate) yes: bool,
 
+    #[arg(help = "The number of threads used to download")]
+    #[arg(short, long, default_value_t = num_cpus::get())]
+    pub(crate) threads: usize,
+
     #[arg(help = "Crunchyroll series url(s)")]
     #[arg(required = true)]
     pub(crate) urls: Vec<String>,
@@ -158,7 +162,8 @@ impl Execute for Archive {
                 .ffmpeg_preset(self.ffmpeg_preset.clone().unwrap_or_default())
                 .output_format(Some("matroska".to_string()))
                 .audio_sort(Some(self.audio.clone()))
-                .subtitle_sort(Some(self.subtitle.clone()));
+                .subtitle_sort(Some(self.subtitle.clone()))
+                .threads(self.threads);
 
             for single_formats in single_format_collection.into_iter() {
                 let (download_formats, mut format) = get_format(&self, &single_formats).await?;

crunchy-cli-core/src/download/command.rs

@@ -80,6 +80,10 @@ pub struct Download {
     #[arg(long, default_value_t = false)]
     pub(crate) force_hardsub: bool,
 
+    #[arg(help = "The number of threads used to download")]
+    #[arg(short, long, default_value_t = num_cpus::get())]
+    pub(crate) threads: usize,
+
     #[arg(help = "Url(s) to Crunchyroll episodes or series")]
     #[arg(required = true)]
     pub(crate) urls: Vec<String>,
@@ -149,7 +153,8 @@ impl Execute for Download {
                 } else {
                     None
                 })
-                .ffmpeg_preset(self.ffmpeg_preset.clone().unwrap_or_default());
+                .ffmpeg_preset(self.ffmpeg_preset.clone().unwrap_or_default())
+                .threads(self.threads);
 
             for mut single_formats in single_format_collection.into_iter() {
                 // the vec contains always only one item

crunchy-cli-core/src/utils/download.rs

@@ -50,6 +50,7 @@ pub struct DownloadBuilder {
     audio_sort: Option<Vec<Locale>>,
     subtitle_sort: Option<Vec<Locale>>,
     force_hardsub: bool,
+    threads: usize,
 }
 
 impl DownloadBuilder {
@@ -61,6 +62,7 @@ impl DownloadBuilder {
             audio_sort: None,
             subtitle_sort: None,
             force_hardsub: false,
+            threads: num_cpus::get(),
         }
     }
 
@@ -73,6 +75,7 @@ impl DownloadBuilder {
             subtitle_sort: self.subtitle_sort,
 
             force_hardsub: self.force_hardsub,
+            threads: self.threads,
 
             formats: vec![],
         }
@@ -99,6 +102,7 @@ pub struct Downloader {
     subtitle_sort: Option<Vec<Locale>>,
 
     force_hardsub: bool,
+    threads: usize,
 
     formats: Vec<DownloadFormat>,
 }
@@ -502,7 +506,8 @@ impl Downloader {
         let tempfile = tempfile(".mp4")?;
         let (mut file, path) = tempfile.into_parts();
 
-        download_segments(ctx, &mut file, message, variant_data).await?;
+        self.download_segments(ctx, &mut file, message, variant_data)
+            .await?;
 
         Ok(path)
     }
@@ -516,7 +521,8 @@ impl Downloader {
         let tempfile = tempfile(".m4a")?;
         let (mut file, path) = tempfile.into_parts();
 
-        download_segments(ctx, &mut file, message, variant_data).await?;
+        self.download_segments(ctx, &mut file, message, variant_data)
+            .await?;
 
         Ok(path)
     }
@@ -537,14 +543,14 @@ impl Downloader {
 
         Ok(path)
     }
-}
 
-pub async fn download_segments(
+    async fn download_segments(
+        &self,
         ctx: &Context,
         writer: &mut impl Write,
         message: String,
         variant_data: &VariantData,
-) -> Result<()> {
+    ) -> Result<()> {
         let segments = variant_data.segments().await?;
         let total_segments = segments.len();
 
@@ -569,7 +575,7 @@ pub async fn download_segments(
             None
         };
 
-    let cpus = num_cpus::get();
+        let cpus = self.threads;
         let mut segs: Vec<Vec<VariantSegment>> = Vec::with_capacity(cpus);
         for _ in 0..cpus {
             segs.push(vec![])
@@ -673,8 +679,8 @@ pub async fn download_segments(
 
             if let Some(p) = &progress {
                 let progress_len = p.length().unwrap();
-            let estimated_segment_len =
-                (variant_data.bandwidth / 8) * segments.get(pos as usize).unwrap().length.as_secs();
+                let estimated_segment_len = (variant_data.bandwidth / 8)
+                    * segments.get(pos as usize).unwrap().length.as_secs();
                 let bytes_len = bytes.len() as u64;
 
                 p.set_length(progress_len - estimated_segment_len + bytes_len);
@@ -719,6 +725,7 @@ pub async fn download_segments(
         }
 
         Ok(())
+    }
 }
 
 fn estimate_variant_file_size(variant_data: &VariantData, segments: &Vec<VariantSegment>) -> u64 {