Use ThreadPoolExecuter

app.py

@@ -5,6 +5,7 @@
 
 import json
 import threading
+from concurrent.futures import ThreadPoolExecutor
 from os import path
 from typing import Any, Dict, Optional
 
@@ -30,6 +31,9 @@
 from util import get_validated_static_path, log_error
 from vault.vault import vault_bp
 
+# Create a global ThreadPoolExecutor.
+executor = ThreadPoolExecutor(max_workers=2)
+
 app = Flask(__name__, static_folder='assets')
 app.json.sort_keys = False
 

cache_config.py

@@ -3,6 +3,8 @@
 __copyright__ = 'Copyright (c) 2024, Utrecht University'
 __license__   = 'GPLv3, see LICENSE'
 
+import hashlib
+import json
 from typing import List, Optional
 
 from flask import current_app as app, g, request, session
@@ -126,13 +128,25 @@ def clear_api_cache_keys(fn: str) -> None:
                 log_error(f"Error deleting cache keys: {keys_to_delete}", True)
 
 
-def populate_api_cache() -> None:
+def populate_api_cache(user, irods, session_id) -> None:
     """Function to prepopulate the API cache."""
-    for fn in API_CACHE_TIMEOUTS:
-        try:
-            api.call(fn)
-        except Exception as e:
-            log_error(f"Error prepopulating cache {fn}: {e}", True)
+    # Set and session context.
+    g.user = user
+    g.irods = irods
+    session.sid = session_id
+
+    data = {}
+    params = json.dumps(data)
+    encoded_params = hashlib.md5(params.encode('utf-8')).hexdigest()
+
+    if authenticated():
+        for fn in API_CACHE_TIMEOUTS:
+            cache_key = make_key(f"{fn}-{encoded_params}")
+            if cache.get(cache_key) is None:
+                try:
+                    api.call(fn)
+                except Exception as e:
+                    log_error(f"Error prepopulating cache {fn}: {e}", True)
 
 
 # Create a Cache instance.

setup.cfg

@@ -4,7 +4,7 @@ import-order-style=smarkets
 strictness=short
 docstring_style=sphinx
 max-line-length=127
-application-import-names=admin,api,cache_config,connman,errors,fileviewer,general,group_manager,monitor,research,search,open_search,stats,user,vault,deposit,intake,datarequest,util
+application-import-names=admin,api,app,cache_config,connman,errors,fileviewer,general,group_manager,monitor,research,search,open_search,stats,user,vault,deposit,intake,datarequest,util
 exclude=venv
 
 [mypy]

user/user.py

@@ -5,7 +5,6 @@
 
 import json
 import secrets
-import threading
 from datetime import datetime
 from typing import List
 from uuid import uuid4
@@ -14,6 +13,7 @@
 import requests
 from flask import (
     Blueprint,
+    copy_current_request_context,
     flash,
     g,
     redirect,
@@ -34,6 +34,7 @@
 
 import api
 import connman
+from app import executor
 from cache_config import cache, make_key, populate_api_cache
 from util import is_email_in_domains, is_relative_url, log_error
 
@@ -397,11 +398,6 @@ class UserinfoEmailMismatchError(Exception):
         if exception_occurred:
             return redirect(url_for('user_bp.gate'))  # noqa: B012
 
-    # Start the background task to populate API cache.
-    thread = threading.Thread(target=populate_api_cache)
-    thread.daemon = True
-    thread.start()
-
     return redirect(original_destination())
 
 
@@ -498,6 +494,14 @@ def prepare_user() -> None:
                     session['admin'] = response['data']
                 g.admin = session.get('admin')
 
+                @copy_current_request_context
+                def populate_api_cache_thread(user, irods, session_id):
+                    with app.app_context():
+                        populate_api_cache(user, irods, session_id)
+
+                # Submit the task to the global thread executor.
+                executor.submit(populate_api_cache_thread, g.user, g.irods, session.sid)
+
         except PAM_AUTH_PASSWORD_FAILED:
             # Password is not valid any more (probably OIDC access token).
             connman.clean(session.sid)