limit number of local transcoding tasks

3 files changed, 9 insertions, 3 deletions

diff --git a/transcoder/src/image.rs b/transcoder/src/image.rs
index 06a2f80..3cd9986 100644
--- a/transcoder/src/image.rs
+++ b/transcoder/src/image.rs
@@ -1,3 +1,4 @@
+use crate::LOCAL_TRANSCODING_TASKS;
 use anyhow::Context;
 use image::{imageops::FilterType, ImageFormat};
 use jellybase::{cache::async_cache_file, AssetLocationExt};
@@ -22,11 +23,10 @@ pub async fn transcode(
             &format!("{width} {quality} {speed}"),
         ],
         move |mut output| async move {
+            let _permit = LOCAL_TRANSCODING_TASKS.acquire().await?;
+            info!("encoding {asset:?} (speed={speed}, quality={quality}, width={width})");
             let encoded = tokio::task::spawn_blocking(move || {
                 let original_path = asset.path();
-                info!(
-                    "encoding {original_path:?} (speed={speed}, quality={quality}, width={width})"
-                );
                 // TODO shouldn't be neccessary with guessed format.
                 let file = BufReader::new(File::open(&original_path).context("opening source")?);
                 let mut reader = image::io::Reader::new(file);
diff --git a/transcoder/src/lib.rs b/transcoder/src/lib.rs
index 240d37a..673946b 100644
--- a/transcoder/src/lib.rs
+++ b/transcoder/src/lib.rs
@@ -5,5 +5,9 @@
 */
 #![feature(async_closure)]
 #![feature(exit_status_error)]
+
+use tokio::sync::Semaphore;
 pub mod image;
 pub mod snippet;
+
+static LOCAL_TRANSCODING_TASKS: Semaphore = Semaphore::const_new(2);
diff --git a/transcoder/src/snippet.rs b/transcoder/src/snippet.rs
index 42847a0..e9569da 100644
--- a/transcoder/src/snippet.rs
+++ b/transcoder/src/snippet.rs
@@ -4,6 +4,7 @@
     Copyright (C) 2023 metamuffin <metamuffin.org>
 */
 
+use crate::LOCAL_TRANSCODING_TASKS;
 use jellybase::cache::async_cache_file;
 use jellycommon::{jhls::EncodingProfile, AssetLocation};
 use log::info;
@@ -21,6 +22,7 @@ pub async fn transcode(
     Ok(async_cache_file(
         &["snip-tc", key, &format!("{enc:?}")],
         move |mut output| async move {
+            let _permit = LOCAL_TRANSCODING_TASKS.acquire().await?;
             info!("transcoding snippet {key}");
             let args = match enc {
                 EncodingProfile::Video {