Do config check before ReaderQueryHandler creation

datagateway_api/src/datagateway_api/icat/helpers.py

@@ -4,6 +4,7 @@
 
 from cachetools import cached
 from dateutil.tz import tzlocal
+from datagateway_api.src.common.config import Config
 from icat.exception import (
     ICATInternalError,
     ICATNoObjectError,
@@ -334,6 +335,12 @@ def get_count_with_filters(client, entity_type, filters, client_pool=None):
 def get_data_with_filters(
     client, entity_type, filters, aggregate=None, client_pool=None,
 ):
+    if not is_use_reader_for_performance_enabled():
+        # just execute the query as normal
+        return execute_entity_query(client, entity_type, filters, aggregate=aggregate)
+
+    # otherwise see if this query is eligible to benefit from running
+    # faster using the reader account
     reader_query = ReaderQueryHandler(entity_type, filters)
     if reader_query.is_query_eligible_for_reader_performance():
         log.info("Query is eligible to be passed as reader acount")
@@ -377,6 +384,20 @@ def execute_entity_query(client, entity_type, filters, aggregate=None):
     return query.execute_query(client, True)
 
 
+def is_use_reader_for_performance_enabled():
+    """
+    Returns true is the 'use_reader_for_performance' section is present in the 
+    config file and 'enabled' in that section is set to true
+    """
+    reader_config = Config.config.datagateway_api.use_reader_for_performance
+    if not reader_config:
+        return False
+    if not reader_config.enabled:
+        return False
+
+    return True
+
+
 def get_first_result_with_filters(client, entity_type, filters):
     """
     Using filters in the request, get results of the given entity, but only show the

datagateway_api/src/datagateway_api/icat/reader_query_handler.py

@@ -43,12 +43,6 @@ def create_reader_client(self):
         return ReaderQueryHandler.reader_client
 
     def check_eligibility(self):
-        reader_config = Config.config.datagateway_api.use_reader_for_performance
-        if not reader_config:
-            return False
-        if not reader_config.enabled:
-            return False
-
         log.info("Checking whether query is eligible to go via reader account")
         if self.entity_type in ReaderQueryHandler.entity_filter_check.keys():
             if self.get_where_filter_for_entity_id_check():