Merge pull request #14117 from keylimesoda/fix/image-picker-large-collections

Keep the image picker responsive with large theme collections

bin/omarchy-menu-images

@@ -230,7 +230,7 @@ thumbnail_for() {
       rows_cacheable=false
 
       if [[ $prepare_only != true ]]; then
-        generate_thumbnail "$image" "$thumbnail" >/dev/null 2>&1 &
+        printf '%s\0%s\0' "$image" "$thumbnail" >>"$pending_file"
       fi
 
       printf '%s' "$image"
@@ -247,17 +247,55 @@ thumbnail_for() {
   printf '%s' "$thumbnail"
 }
 
-# Each vips run is single-threaded, so still images can fill every core.
+# Each vips run is single-threaded. Eager preparation can fill every core;
+# lazy preparation leaves CPU and I/O capacity for the interactive shell.
 # ffmpegthumbnailer leaves FFmpeg's automatic threading on, so a full-width fan
 # out of those would put a codec thread pool on every core at once.
 drain_pending_thumbnails() {
-  local video_jobs
+  local video_jobs image_jobs pending_fd queue_file queue_lock_fd worker_lock_fd
 
   export -f generate_thumbnail is_video_path
 
   if [[ -s $pending_file ]]; then
-    xargs -a "$pending_file" -0 -n 2 -P "$(nproc)" \
-      bash -c 'generate_thumbnail "$1" "$2"' _ >/dev/null 2>&1 || true
+    if [[ $lazy_thumbnails == true && $cache_only != true ]]; then
+      image_jobs=$(( $(nproc) / 2 ))
+      (( image_jobs > 0 )) || image_jobs=1
+      (( image_jobs > 2 )) && image_jobs=2
+      # Publish jobs before trying to own the pool. A contended refresh leaves
+      # its jobs for the current owner instead of throwing its queue away.
+      queue_file="$rows_cache_file.thumbnails.pending"
+      exec {queue_lock_fd}>"$rows_cache_file.thumbnails.queue.lock" || return
+      flock "$queue_lock_fd" || return
+      cat "$pending_file" >>"$queue_file"
+      exec {queue_lock_fd}>&-
+      (
+        exec {worker_lock_fd}>"$rows_cache_file.thumbnails.lock"
+        flock -n "$worker_lock_fd" || exit 0
+        exec {queue_lock_fd}>"$rows_cache_file.thumbnails.queue.lock" || exit 1
+        while true; do
+          flock "$queue_lock_fd" || exit 1
+          if [[ ! -s $queue_file ]]; then
+            # Release ownership while publishing is still locked. A producer
+            # arriving after the empty check can then start the next pool.
+            exec {worker_lock_fd}>&-
+            exec {queue_lock_fd}>&-
+            break
+          fi
+          # Unlink the batch under the queue lock, then drain its open fd.
+          # Producers can publish the next batch while conversions run.
+          exec {pending_fd}<"$queue_file" || exit 1
+          rm -f "$queue_file"
+          flock -u "$queue_lock_fd"
+          # Converters must not inherit the publication lock's descriptor.
+          nice -n 10 ionice -c 3 xargs -0 -n 2 -P "$image_jobs" \
+            bash -c 'generate_thumbnail "$1" "$2"' _ <&"$pending_fd" {queue_lock_fd}>&-
+          exec {pending_fd}<&-
+        done
+      ) >/dev/null 2>&1 &
+    else
+      xargs -a "$pending_file" -0 -n 2 -P "$(nproc)" \
+        bash -c 'generate_thumbnail "$1" "$2"' _ >/dev/null 2>&1 || true
+    fi
   fi
 
   if [[ -s $pending_video_file ]]; then