[shaohuzhang1]

refactor: enhance dynamic model fetching with improved concurrency and error handling

[shaohuzhang1]

Main findings:

1. High priority: cache read key does not match cache write key

   • Write:

     cache_base_model_list(provider, model_type, api_key, api_base, credential, live_list)

   • Read:

     get_cached_base_model_list(provider, model_type, None, credential)

   • The read omits api_key/api_base and passes None for one key component. If the cache is keyed by url + key as the docstring says, this will at best cause cache misses, and at worst return a model list cached for a different API key/base.
   • Fix by using exactly the same cache identity as the write path, for example:

     get_cached_base_model_list(provider, model_type, api_key, api_base, credential)

     Adjust to the actual function signature, but the key fields must match.

2. Fallback does not handle exceptions

   • The intended order is “live → cache → built-in fallback”, but if the live call raises an exception, the cache/built-in paths are never reached.
   • If fallback should happen on network/provider failures, wrap the live call in try/except. Decide explicitly whether auth/validation errors should propagate instead of falling back.

3. _get_model_list is inconsistent about allow_builtin_fallback

   • When allow_builtin_fallback=False, the flag is passed to the provider handler.
   • When True, it is not passed and relies on the handler default.
   • Safer:

     return provider_handler.get_model_list(
         model_type,
         api_key=api_key,
         api_base=api_base,
         credential=credential,
         allow_builtin_fallback=allow_builtin_fallback,
     )

4. if live_list: conflates “empty valid list” with “failure”

   • If a provider legitimately returns [], the code will fall back to cache/built-in models, which may be incorrect.
   • If empty is a valid response, use live_list is not None or a sentinel/structured result to distinguish failure from an empty result.

5. Search normalization is slightly odd

   • _filter_model_list checks if not search before stripping. A whitespace-only search therefore filters to an empty string and returns everything.
   • Cleaner:

     search = str(search or "").strip().lower()
     if not search:
         return model_list

   • Also, this assumes every model entry is a dict; that was true before, but worth keeping consistent.

6. Caching with search is now correct only because filtering was separated

   • The new code caches live_list before applying search, which is good, provided the provider handler returns the full unfiltered list. This part is an improvement over the original “do not cache when search is present” logic.

7. Minor / operational

   • Ensure get_cached_base_model_list is imported/defined; it is newly used here.
   • The walrus operator := requires Python 3.8+.
   • If cache_base_model_list can fail, consider whether a cache-write failure should fail the whole request or just be logged.
   • Update all tests/callers of _get_model_list, since search was removed from its signature.

Overall, the main blocking issue is the cache read/write key mismatch. The rest are robustness and clarity improvements.