chore: import upstream snapshot with attribution

tests/distributed/test_kv_cache_events.py

@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+import pytest
+
+from vllm.distributed.kv_events import BlockRemoved, BlockStored
+
+# Minimal ExternalBlockHash for testing (bytes are a valid ExternalBlockHash).
+_FAKE_HASH: bytes = b"\xab" * 32
+
+
+def _make_block_stored(
+    group_idx: int | None = None,
+    kv_cache_spec_sliding_window: int | None = None,
+) -> BlockStored:
+    return BlockStored(
+        block_hashes=[_FAKE_HASH],
+        parent_block_hash=None,
+        token_ids=[1, 2, 3, 4],
+        block_size=4,
+        lora_id=None,
+        medium="GPU",
+        lora_name=None,
+        group_idx=group_idx,
+        kv_cache_spec_sliding_window=kv_cache_spec_sliding_window,
+    )
+
+
+def _make_block_removed(
+    group_idx: int | None = None,
+) -> BlockRemoved:
+    return BlockRemoved(
+        block_hashes=[_FAKE_HASH],
+        medium="GPU",
+        group_idx=group_idx,
+    )
+
+
+def test_block_stored_default_group_idx_is_none():
+    """group_idx defaults to None when not provided."""
+    event = _make_block_stored()
+    assert event.group_idx is None
+
+
+def test_block_removed_default_group_idx_is_none():
+    """group_idx defaults to None when not provided."""
+    event = _make_block_removed()
+    assert event.group_idx is None
+
+
+@pytest.mark.parametrize("group_idx", [1, 2, 3])
+def test_block_stored_hash_differs_by_group_idx(group_idx: int):
+    """BlockStored events that differ only in group_idx must hash differently."""
+    other_group_idx = group_idx + 1
+    event_a = _make_block_stored(group_idx=group_idx)
+    event_b = _make_block_stored(group_idx=other_group_idx)
+    assert hash(event_a) != hash(event_b)
+
+
+def test_block_stored_hash_same_for_equal_group_idx():
+    """Two BlockStored events with identical fields produce the same hash."""
+    event_a = _make_block_stored(group_idx=1)
+    event_b = _make_block_stored(group_idx=1)
+    assert hash(event_a) == hash(event_b)
+
+
+@pytest.mark.parametrize("group_idx", [1, 2, 3])
+def test_block_removed_hash_differs_by_group_idx(group_idx: int):
+    """BlockRemoved events that differ only in group_idx must hash differently."""
+    other_group_idx = group_idx + 1
+    event_a = _make_block_removed(group_idx=group_idx)
+    event_b = _make_block_removed(group_idx=other_group_idx)
+    assert hash(event_a) != hash(event_b)
+
+
+def test_block_removed_hash_same_for_equal_group_idx():
+    """Two BlockRemoved events with identical fields produce the same hash."""
+    event_a = _make_block_removed(group_idx=1)
+    event_b = _make_block_removed(group_idx=1)
+    assert hash(event_a) == hash(event_b)
+
+
+def test_block_stored_hash_differs_by_sliding_window():
+    event_a = _make_block_stored(group_idx=1, kv_cache_spec_sliding_window=128)
+    event_b = _make_block_stored(group_idx=1, kv_cache_spec_sliding_window=256)
+    assert hash(event_a) != hash(event_b)