fix the engine_cache bug

py/torch_tensorrt/dynamo/_engine_cache.py

@@ -187,12 +187,20 @@ def check(self, hash: str, *args: Any, **kwargs: Any) -> Optional[UnpackedCacheH
         Returns:
             Optional[Tuple[bytes, List[str], List[str], CompilationSettings, Optional[Dict[Any, Any]]]]: The unpacked cache entry if found, None otherwise.
         """
-        packed_cache_info = self.load(hash, *args, **kwargs)
+        if self.exist(hash):
+            packed_cache_info = self.load(hash, *args, **kwargs)
+            if packed_cache_info:
+                return BaseEngineCache.unpack(packed_cache_info)
+        return None
 
-        if packed_cache_info:
-            return BaseEngineCache.unpack(packed_cache_info)
-        else:
-            return None
+    @abstractmethod
+    def exist(self, hash: str) -> bool:
+        """Check if a cache entry exists for the given hash.
+
+        Args:
+            hash (str): hash value of the GraphModule
+        """
+        pass
 
     @abstractmethod
     def save(self, hash: str, blob: bytes, *args: Any, **kwargs: Any) -> None:
@@ -306,6 +314,14 @@ def LRU() -> None:
         else:
             LRU()
 
+    def exist(self, hash: str) -> bool:
+        directory = os.path.join(self.engine_cache_dir, hash)
+        if os.path.exists(directory):
+            blob_path = os.path.join(directory, "blob.bin")
+            if os.path.exists(blob_path):
+                return True
+        return False
+
     def save(self, hash: str, blob: bytes, *args: Any, **kwargs: Any) -> None:
         blob_size = len(blob)
         if blob_size > self.total_engine_cache_size:

py/torch_tensorrt/dynamo/conversion/_conversion.py

@@ -101,18 +101,20 @@ def interpret_module_to_result(
         and engine_cache is not None
     ):
         hash_val = engine_cache.get_hash(module, inputs, settings)
-        engine_cache.insert(
-            hash_val,
-            (
-                serialized_engine,
-                interpreter_result.input_names,
-                interpreter_result.output_names,
-                inputs,
-                settings,
-                interpreter_result.weight_name_map,
-                interpreter_result.requires_output_allocator,
-            ),
-        )
+        # only insert if the cache entry does not exist
+        if not engine_cache.exist(hash_val):
+            engine_cache.insert(
+                hash_val,
+                (
+                    serialized_engine,
+                    interpreter_result.input_names,
+                    interpreter_result.output_names,
+                    inputs,
+                    settings,
+                    interpreter_result.weight_name_map,
+                    interpreter_result.requires_output_allocator,
+                ),
+            )
 
     serialized_interpreter_result = SerializedInterpreterResult(
         serialized_engine=serialized_engine,

tests/py/dynamo/models/test_engine_cache.py

@@ -31,6 +31,9 @@ def __init__(
 
         self.hashes = {}
 
+    def exist(self, hash: str) -> bool:
+        return hash in self.hashes
+
     def save(
         self,
         hash: str,