Replace too long index file name with hash in ANN bench (#2280)

Too long index file name would lead to a crash while calling the index serialization routines. Such long filenames can occur if we try to specialize many parameters for CAGRA ann index. This PR fixes the issue by replacing the long index file name with a hash. Drawback is the filename will not be descriptive.

Authors:
  - Tamas Bela Feher (https://github.com/tfeher)
  - Corey J. Nolet (https://github.com/cjnolet)

Approvers:
  - Corey J. Nolet (https://github.com/cjnolet)

URL: #2280

python/raft-ann-bench/src/raft-ann-bench/run/__main__.py

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2023, NVIDIA CORPORATION.
+# Copyright (c) 2023-2024, NVIDIA CORPORATION.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -553,10 +553,14 @@ def add_algo_group(group_list):
                             index["build_param"], conf_file["dataset"]["dims"]
                         ):
                             continue
-
+                index_filename = (
+                    index_name
+                    if len(index_name) < 128
+                    else str(hash(index_name))
+                )
                 index["name"] = index_name
                 index["file"] = os.path.join(
-                    args.dataset_path, args.dataset, "index", index_name
+                    args.dataset_path, args.dataset, "index", index_filename
                 )
                 index["search_params"] = []
                 all_search_params = itertools.product(*search_param_lists)