feat(metadata): add rate limit retry support to metadata providers

Add RateLimitRetryingProvider and _RateLimitRetryHelper classes to handle rate limiting with exponential backoff retries. Update get_metadata_provider function to automatically wrap providers with rate limit handling. This improves reliability when external APIs return rate limit errors by implementing automatic retries with configurable delays and jitter.

py/services/model_metadata_provider.py

@@ -41,6 +41,55 @@ def _require_aiosqlite() -> Any:
 
 logger = logging.getLogger(__name__)
 
+
+class _RateLimitRetryHelper:
+    """Coordinate exponential backoff retries after rate limiting."""
+
+    def __init__(
+        self,
+        *,
+        retry_limit: int = 3,
+        base_delay: float = 1.5,
+        max_delay: float = 30.0,
+        jitter_ratio: float = 0.2,
+    ) -> None:
+        self._retry_limit = max(1, retry_limit)
+        self._base_delay = base_delay
+        self._max_delay = max_delay
+        self._jitter_ratio = max(0.0, jitter_ratio)
+
+    async def run(self, label: str, func, *args, **kwargs):
+        attempt = 0
+        while True:
+            try:
+                return await func(*args, **kwargs)
+            except RateLimitError as exc:
+                attempt += 1
+                if attempt >= self._retry_limit:
+                    exc.provider = exc.provider or label
+                    raise
+
+                delay = self._calculate_delay(exc.retry_after, attempt)
+                logger.warning(
+                    "Provider %s rate limited request; retrying in %.2fs (attempt %s/%s)",
+                    label,
+                    delay,
+                    attempt,
+                    self._retry_limit,
+                )
+                await asyncio.sleep(delay)
+
+    def _calculate_delay(self, retry_after: Optional[float], attempt: int) -> float:
+        if retry_after is not None:
+            return min(self._max_delay, max(0.0, retry_after))
+
+        base_delay = self._base_delay * (2 ** max(0, attempt - 1))
+        jitter_span = base_delay * self._jitter_ratio
+        if jitter_span > 0:
+            base_delay += random.uniform(-jitter_span, jitter_span)
+
+        return min(self._max_delay, max(0.0, base_delay))
+
 class ModelMetadataProvider(ABC):
     """Base abstract class for all model metadata providers"""
     
@@ -390,6 +439,12 @@ class FallbackMetadataProvider(ModelMetadataProvider):
         self._rate_limit_base_delay = rate_limit_base_delay
         self._rate_limit_max_delay = rate_limit_max_delay
         self._rate_limit_jitter_ratio = max(0.0, rate_limit_jitter_ratio)
+        self._rate_limit_helper = _RateLimitRetryHelper(
+            retry_limit=self._rate_limit_retry_limit,
+            base_delay=self._rate_limit_base_delay,
+            max_delay=self._rate_limit_max_delay,
+            jitter_ratio=self._rate_limit_jitter_ratio,
+        )
 
     async def get_model_by_hash(self, model_hash: str) -> Tuple[Optional[Dict], Optional[str]]:
         for provider, label in self._iter_providers():
@@ -485,44 +540,80 @@ class FallbackMetadataProvider(ModelMetadataProvider):
     def _iter_providers(self):
         return zip(self.providers, self._provider_labels)
 
-    async def _call_with_rate_limit(
+    async def _call_with_rate_limit(self, label: str, func, *args, **kwargs):
+        return await self._rate_limit_helper.run(label, func, *args, **kwargs)
+
+
+class RateLimitRetryingProvider(ModelMetadataProvider):
+    """Adapter that retries individual provider calls after rate limiting."""
+
+    def __init__(
         self,
-        label: str,
-        func,
-        *args,
-        **kwargs,
-    ):
-        attempt = 0
-        while True:
-            try:
-                return await func(*args, **kwargs)
-            except RateLimitError as exc:
-                attempt += 1
-                if attempt >= self._rate_limit_retry_limit:
-                    exc.provider = exc.provider or label
-                    raise exc
-                delay = self._calculate_rate_limit_delay(exc.retry_after, attempt)
-                logger.warning(
-                    "Provider %s rate limited request; retrying in %.2fs (attempt %s/%s)",
-                    label,
-                    delay,
-                    attempt,
-                    self._rate_limit_retry_limit,
-                )
-                await asyncio.sleep(delay)
-            except Exception:
-                raise
+        provider: ModelMetadataProvider,
+        label: Optional[str] = None,
+        *,
+        rate_limit_retry_limit: int = 3,
+        rate_limit_base_delay: float = 1.5,
+        rate_limit_max_delay: float = 30.0,
+        rate_limit_jitter_ratio: float = 0.2,
+    ) -> None:
+        self._provider = provider
+        self._label = label or provider.__class__.__name__
+        self._rate_limit_helper = _RateLimitRetryHelper(
+            retry_limit=rate_limit_retry_limit,
+            base_delay=rate_limit_base_delay,
+            max_delay=rate_limit_max_delay,
+            jitter_ratio=rate_limit_jitter_ratio,
+        )
 
-    def _calculate_rate_limit_delay(self, retry_after: Optional[float], attempt: int) -> float:
-        if retry_after is not None:
-            return min(self._rate_limit_max_delay, max(0.0, retry_after))
+    def __getattr__(self, item):
+        return getattr(self._provider, item)
 
-        base_delay = self._rate_limit_base_delay * (2 ** max(0, attempt - 1))
-        jitter_span = base_delay * self._rate_limit_jitter_ratio
-        if jitter_span > 0:
-            base_delay += random.uniform(-jitter_span, jitter_span)
+    async def get_model_by_hash(self, model_hash: str) -> Tuple[Optional[Dict], Optional[str]]:
+        return await self._rate_limit_helper.run(
+            self._label,
+            self._provider.get_model_by_hash,
+            model_hash,
+        )
 
-        return min(self._rate_limit_max_delay, max(0.0, base_delay))
+    async def get_model_versions(self, model_id: str) -> Optional[Dict]:
+        return await self._rate_limit_helper.run(
+            self._label,
+            self._provider.get_model_versions,
+            model_id,
+        )
+
+    async def get_model_versions_bulk(
+        self,
+        model_ids: Sequence[int],
+    ) -> Optional[Dict[int, Dict]]:
+        return await self._rate_limit_helper.run(
+            self._label,
+            self._provider.get_model_versions_bulk,
+            model_ids,
+        )
+
+    async def get_model_version(self, model_id: int = None, version_id: int = None) -> Optional[Dict]:
+        return await self._rate_limit_helper.run(
+            self._label,
+            self._provider.get_model_version,
+            model_id,
+            version_id,
+        )
+
+    async def get_model_version_info(self, version_id: str) -> Tuple[Optional[Dict], Optional[str]]:
+        return await self._rate_limit_helper.run(
+            self._label,
+            self._provider.get_model_version_info,
+            version_id,
+        )
+
+    async def get_user_models(self, username: str) -> Optional[List[Dict]]:
+        return await self._rate_limit_helper.run(
+            self._label,
+            self._provider.get_user_models,
+            username,
+        )
 
 class ModelMetadataProviderManager:
     """Manager for selecting and using model metadata providers"""