fix: reduce task startup overhead and lazy-load notifications (#3080)

shell/node_path_cache.sh

@@ -65,7 +65,9 @@ ql_read_node_path_cache() {
 # the caller's descriptors. A crashed refresher releases the kernel lock.
 ql_refresh_node_global_path() (
   local cache="$1" key="$2" now result previous_umask
-  local lock="${cache}.lock"
+  # Keep one persistent lock per owner. Removing per-key lock files could
+  # split concurrent waiters across different inodes during cache cleanup.
+  local lock="${dir_tmp}/pnpm-root-${EUID}.lock"
   previous_umask=$(umask)
   umask 077
   if type -P flock &>/dev/null && mkdir -p -- "$dir_tmp" 2>/dev/null; then
@@ -93,6 +95,10 @@ ql_refresh_node_global_path() (
 
   # Private lock creation must not change pnpm's inherited creation mask.
   umask "$previous_umask"
+  # Warm lookups never scan the directory. Retire old environment records on
+  # refresh, while preserving the shared lock and unrelated cache files.
+  find "$dir_tmp" -maxdepth 1 -type f -user "$EUID" \
+    -name "pnpm-root-${EUID}-*.cache" -mmin +60 -delete 2>/dev/null || true
   now=${EPOCHSECONDS:-$(date +%s)}
   result=$(pnpm root -g 9>&- 2>/dev/null) || return $?
   # Never cache failed, empty, multiline or non-absolute answers.
@@ -119,8 +125,10 @@ ql_get_node_global_path() {
   fi
 
   local key cache
-  cache="${dir_tmp}/pnpm-root-${EUID}.cache"
   key=$(ql_node_path_cache_key) || { pnpm root -g 2>/dev/null; return $?; }
+  # Node and crond may have different working directories/configuration.
+  # Preserve both discoveries instead of evicting each other on every run.
+  cache="${dir_tmp}/pnpm-root-${EUID}-${key// /-}.cache"
   if ql_read_node_path_cache "$cache" "$key"; then
     return 0
   fi

shell/preload/sitecustomize.js

@@ -159,9 +159,13 @@ try {
 
   run();
 
-  const { sendNotify } = require('./__ql_notify__.js');
   global.QLAPI = {
-    notify: sendNotify,
+    notify(...args) {
+      // Keep notification dependencies out of ordinary script startup.
+      // require caches the module after the first notification.
+      const { sendNotify } = require('./__ql_notify__.js');
+      return sendNotify.apply(this, args);
+    },
     ...client,
   };
 } catch (error) {

shell/preload/sitecustomize.py

@@ -129,10 +129,12 @@ try:
 
     run()
 
-    from __ql_notify__ import send
-
     class BaseApi(Client):
         def notify(self, *args, **kwargs):
+            # Most scripts never send a notification. Python caches this
+            # module after the first call, including its channel dependencies.
+            from __ql_notify__ import send
+
             return send(*args, **kwargs)
 
     QLAPI = BaseApi()