[BugFix] Fix MultiConnector test after HMA changes (#19291)

Signed-off-by: Nick Hill <nhill@redhat.com>

tests/v1/kv_connector/unit/test_multi_connector.py

@@ -60,7 +60,8 @@ class TestSharedStorageConnector(SharedStorageConnector):
                     if isinstance(arg, int):
                         to_log.append(str(arg))
                     elif isinstance(arg, KVCacheBlocks):
-                        to_log.append(f"num_blocks={len(arg.blocks)}")
+                        to_log.append(
+                            f"num_blocks={[len(b) for b in arg.blocks]}")
 
                 # Log the event as a line to the file
                 try:
@@ -176,7 +177,7 @@ def test_multi_shared_storage_connector_consistency():
     # on each connector in turn.
     assert events["storage1-SCHEDULER"][:3] == [
         'get_num_new_matched_tokens 0',
-        'update_state_after_alloc num_blocks=0 0', 'build_connector_meta'
+        'update_state_after_alloc num_blocks=[0] 0', 'build_connector_meta'
     ]
     assert events["storage1-WORKER"][:5] == [
         'register_kv_caches', 'bind_connector_metadata', 'start_load_kv',
@@ -184,7 +185,7 @@ def test_multi_shared_storage_connector_consistency():
     ]
     assert events["storage2-SCHEDULER"][:3] == [
         'get_num_new_matched_tokens 0',
-        'update_state_after_alloc num_blocks=0 0', 'build_connector_meta'
+        'update_state_after_alloc num_blocks=[0] 0', 'build_connector_meta'
     ]
     assert events["storage2-WORKER"][:5] == [
         'register_kv_caches', 'bind_connector_metadata', 'start_load_kv',
@@ -205,11 +206,11 @@ def test_multi_shared_storage_connector_consistency():
     # chosen).
     assert events["storage1-SCHEDULER"][:3] == [
         'get_num_new_matched_tokens 0',
-        'update_state_after_alloc num_blocks=7 96', 'build_connector_meta'
+        'update_state_after_alloc num_blocks=[7] 96', 'build_connector_meta'
     ]
     assert events["storage2-SCHEDULER"][:3] == [
         'get_num_new_matched_tokens 0',
-        'update_state_after_alloc num_blocks=0 0', 'build_connector_meta'
+        'update_state_after_alloc num_blocks=[0] 0', 'build_connector_meta'
     ]
 
     # Delete storage1 connector state
@@ -229,11 +230,11 @@ def test_multi_shared_storage_connector_consistency():
     # blocks for the second connector.
     assert events["storage1-SCHEDULER"][:3] == [
         'get_num_new_matched_tokens 0',
-        'update_state_after_alloc num_blocks=0 0', 'build_connector_meta'
+        'update_state_after_alloc num_blocks=[0] 0', 'build_connector_meta'
     ]
     assert events["storage2-SCHEDULER"][:3] == [
         'get_num_new_matched_tokens 0',
-        'update_state_after_alloc num_blocks=7 96', 'build_connector_meta'
+        'update_state_after_alloc num_blocks=[7] 96', 'build_connector_meta'
     ]
 
     # Clean up

vllm/distributed/kv_transfer/kv_connector/v1/multi_connector.py

@@ -153,6 +153,7 @@ class MultiConnector(KVConnectorBase_V1):
                                  num_external_tokens: int):
         chosen_connector = self._requests_to_connector.get(
             request.request_id, -1)
+        empty_blocks = blocks.new_empty()
         for i, c in enumerate(self._connectors):
             if i == chosen_connector:
                 # Forward call to the chosen connector (if any).
@@ -160,8 +161,7 @@ class MultiConnector(KVConnectorBase_V1):
                                            num_external_tokens)
             else:
                 # Call with empty blocks for other connectors.
-                c.update_state_after_alloc(request,
-                                           KVCacheBlocks.create_empty(), 0)
+                c.update_state_after_alloc(request, empty_blocks, 0)
 
     def build_connector_meta(
             self,

vllm/v1/core/kv_cache_manager.py

@@ -61,6 +61,10 @@ class KVCacheBlocks:
             if block.block_hash is None
         ]
 
+    def new_empty(self) -> "KVCacheBlocks":
+        """Creates a new KVCacheBlocks instance with no blocks."""
+        return KVCacheBlocks([[] for _ in range(len(self.blocks))])
+
 
 class KVCacheManager: