Validate name checks for CachedContent creation

Change-Id: Ie41602621d99ddff6404c6708c7278e0da790652

Author: mayureshagashe2105

google/generativeai/caching.py

@@ -88,8 +88,10 @@ def _prepare_create_request(
         ttl: Optional[caching_types.ExpirationTypes] = datetime.timedelta(hours=1),
     ) -> glm.CreateCachedContentRequest:
         """Prepares a CreateCachedContentRequest."""
-        if "cachedContents/" not in name:
+        if caching_types.valid_cached_content_name(name):
             name = "cachedContents/" + name
+        else:
+            raise ValueError(caching_types.NAME_ERROR_MESSAGE.format(name=name))
 
         if "/" not in model:
             model = "models/" + model

google/generativeai/types/caching_types.py

@@ -17,10 +17,21 @@
 import datetime
 from typing import Optional, Union
 from typing_extensions import TypedDict
+import re
 
 __all__ = ["TTL"]
 
 
+_VALID_CACHED_CONTENT_NAME = r"([a-z0-9-\.]+)$"
+NAME_ERROR_MESSAGE = (
+    "The `name` must consist of alphanumeric characters (or `-` or `.`). Received: `{name}`"
+)
+
+
+def valid_cached_content_name(name: str) -> bool:
+    return re.match(_VALID_CACHED_CONTENT_NAME, name) is not None
+
+
 class TTL(TypedDict):
     seconds: int