fix: Rename SlidingWindowCompactor to LlmEventSummarizer and refine its docstring

The class is now named `LlmEventSummarizer` to better reflect that its primary function is to use an LLM to summarize events. The docstring has been updated to clarify that this class is responsible *only* for the LLM-based summarization of a given set of events, while the logic for determining *when* and *which* events form the sliding window is handled by an external component, such as an ADK Runner.

PiperOrigin-RevId: 815976264

src/google/adk/apps/llm_event_summarizer.py

@@ -27,31 +27,23 @@ from ..models.llm_request import LlmRequest
 from .base_events_compactor import BaseEventsCompactor
 
 
-class SlidingWindowCompactor(BaseEventsCompactor):
-  """A summarizer for Sliding Window Compaction logic in Runner.
+class LlmEventSummarizer(BaseEventsCompactor):
+  """An LLM-based event summarizer for sliding window compaction.
 
-  This compactor works with ADK runner to provide sliding window compaction.
-  The runner uses `compaction_invocation_threshold` and `overlap_size`
-  configured in `EventsCompactionConfig` on the `App` to determine when to
-  trigger compaction and which events to compact. This class performs
-  summarization of events passed by the runner.
+  This class is responsible for summarizing a provided list of events into a
+  single compacted event. It is designed to be used as part of a sliding window
+  compaction process.
 
-  The compaction process is controlled by two parameters read by the Runner from
-  `EventsCompactionConfig`:
-  1.  `compaction_invocation_threshold`: The number of *new* user-initiated
-  invocations that, once fully
-      represented in the session's events, will trigger a compaction.
-  2.  `overlap_size`: The number of preceding invocations to include from the
-  end of the last
-      compacted range. This creates an overlap between consecutive compacted
-      summaries,
-      maintaining context.
+  The actual logic for determining *when* to trigger compaction and *which*
+  events form the sliding window (based on parameters like
+  `compaction_invocation_threshold` and `overlap_size` from
+  `EventsCompactionConfig`) is handled by an external component, such as an ADK
+  "Runner". This compactor focuses solely on generating a summary of the events
+  it receives.
 
-  When `Runner` determines compaction is needed based on
-  `compaction_invocation_threshold`,
-  it selects a range of events based on `overlap_size` and passes them to
-  `maybe_compact_events` for summarization into a `CompactedEvent`.
-  This `CompactedEvent` is then appended to the session by the `Runner`.
+  When `maybe_compact_events` is called with a list of events, this class
+  formats the events, generates a summary using an LLM, and returns a new
+  `Event` containing the summary within an `EventCompaction`.
   """
 
   _DEFAULT_PROMPT_TEMPLATE = (
@@ -68,7 +60,7 @@ class SlidingWindowCompactor(BaseEventsCompactor):
       llm: BaseLlm,
       prompt_template: Optional[str] = None,
   ):
-    """Initializes the SlidingWindowCompactor.
+    """Initializes the LlmEventSummarizer.
 
     Args:
         llm: The LLM used for summarization.

src/google/adk/runners.py

@@ -28,7 +28,6 @@ from typing import Optional
 import warnings
 
 from google.adk.apps.compaction import _run_compaction_for_sliding_window
-from google.adk.apps.sliding_window_compactor import SlidingWindowCompactor
 from google.genai import types
 
 from .agents.active_streaming_tool import ActiveStreamingTool

tests/unittests/apps/test_compaction.py

@@ -20,7 +20,7 @@ from google.adk.agents.base_agent import BaseAgent
 from google.adk.apps.app import App
 from google.adk.apps.app import EventsCompactionConfig
 from google.adk.apps.compaction import _run_compaction_for_sliding_window
-from google.adk.apps.sliding_window_compactor import SlidingWindowCompactor
+from google.adk.apps.llm_event_summarizer import LlmEventSummarizer
 from google.adk.events.event import Event
 from google.adk.events.event_actions import EventActions
 from google.adk.events.event_actions import EventCompaction
@@ -38,7 +38,7 @@ class TestCompaction(unittest.IsolatedAsyncioTestCase):
 
   def setUp(self):
     self.mock_session_service = AsyncMock(spec=BaseSessionService)
-    self.mock_compactor = AsyncMock(spec=SlidingWindowCompactor)
+    self.mock_compactor = AsyncMock(spec=LlmEventSummarizer)
 
   def _create_event(
       self, timestamp: float, invocation_id: str, text: str

tests/unittests/apps/test_llm_event_summarizer.py

@@ -16,7 +16,7 @@ import unittest
 from unittest.mock import AsyncMock
 from unittest.mock import Mock
 
-from google.adk.apps.sliding_window_compactor import SlidingWindowCompactor
+from google.adk.apps.llm_event_summarizer import LlmEventSummarizer
 from google.adk.events.event import Event
 from google.adk.events.event_actions import EventActions
 from google.adk.events.event_actions import EventCompaction
@@ -32,12 +32,12 @@ import pytest
 @pytest.mark.parametrize(
     'env_variables', ['GOOGLE_AI', 'VERTEX'], indirect=True
 )
-class TestSlidingWindowCompactor(unittest.IsolatedAsyncioTestCase):
+class TestLlmEventSummarizer(unittest.IsolatedAsyncioTestCase):
 
   def setUp(self):
     self.mock_llm = AsyncMock(spec=BaseLlm)
     self.mock_llm.model = 'test-model'
-    self.compactor = SlidingWindowCompactor(llm=self.mock_llm)
+    self.compactor = LlmEventSummarizer(llm=self.mock_llm)
 
   def _create_event(
       self, timestamp: float, text: str, author: str = 'user'