refactor(sdk): make FlowLiveUpdater constructor light with a start()

python/cocoindex/cli.py

@@ -137,9 +137,9 @@ def update(flow_name: str | None, live: bool, quiet: bool):
     if flow_name is None:
         return flow.update_all_flows(options)
     else:
-        updater = flow.FlowLiveUpdater(_flow_by_name(flow_name), options)
-        updater.wait()
-        return updater.update_stats()
+        with flow.FlowLiveUpdater(_flow_by_name(flow_name), options) as updater:
+            updater.wait()
+            return updater.update_stats()
 
 @cli.command()
 @click.argument("flow_name", type=str, required=False)

python/cocoindex/flow.py

@@ -383,40 +383,43 @@ class FlowLiveUpdater:
     """
     A live updater for a flow.
     """
-    _engine_live_updater: _engine.FlowLiveUpdater
+    _flow: Flow
+    _options: FlowLiveUpdaterOptions
+    _engine_live_updater: _engine.FlowLiveUpdater | None = None
 
-    def __init__(self, arg: Flow | _engine.FlowLiveUpdater, options: FlowLiveUpdaterOptions | None = None):
-        if isinstance(arg, _engine.FlowLiveUpdater):
-            self._engine_live_updater = arg
-        else:
-            self._engine_live_updater = execution_context.run(_engine.FlowLiveUpdater(
-                arg.internal_flow(), dump_engine_object(options or FlowLiveUpdaterOptions())))
-
-    @staticmethod
-    async def create_async(fl: Flow, options: FlowLiveUpdaterOptions | None = None) -> FlowLiveUpdater:
-        """
-        Create a live updater for a flow.
-        Similar to the constructor, but for async usage.
-        """
-        engine_live_updater = await _engine.FlowLiveUpdater.create(
-            await fl.internal_flow_async(),
-            dump_engine_object(options or FlowLiveUpdaterOptions()))
-        return FlowLiveUpdater(engine_live_updater)
+    def __init__(self, fl: Flow, options: FlowLiveUpdaterOptions | None = None):
+        self._flow = fl
+        self._options = options or FlowLiveUpdaterOptions()
 
     def __enter__(self) -> FlowLiveUpdater:
+        self.start()
         return self
 
     def __exit__(self, exc_type, exc_value, traceback):
         self.abort()
         self.wait()
 
     async def __aenter__(self) -> FlowLiveUpdater:
+        await self.start_async()
         return self
 
     async def __aexit__(self, exc_type, exc_value, traceback):
         self.abort()
         await self.wait_async()
 
+    def start(self) -> None:
+        """
+        Start the live updater.
+        """
+        execution_context.run(self.start_async())
+
+    async def start_async(self) -> None:
+        """
+        Start the live updater.
+        """
+        self._engine_live_updater = await _engine.FlowLiveUpdater.create(
+            await self._flow.internal_flow_async(), dump_engine_object(self._options))
+
     def wait(self) -> None:
         """
         Wait for the live updater to finish.
@@ -427,20 +430,24 @@ async def wait_async(self) -> None:
         """
         Wait for the live updater to finish. Async version.
         """
-        await self._engine_live_updater.wait()
-
+        await self._get_engine_live_updater().wait()
 
     def abort(self) -> None:
         """
         Abort the live updater.
         """
-        self._engine_live_updater.abort()
+        self._get_engine_live_updater().abort()
 
     def update_stats(self) -> _engine.IndexUpdateInfo:
         """
         Get the index update info.
         """
-        return self._engine_live_updater.index_update_info()
+        return self._get_engine_live_updater().index_update_info()
+
+    def _get_engine_live_updater(self) -> _engine.FlowLiveUpdater:
+        if self._engine_live_updater is None:
+            raise RuntimeError("Live updater is not started")
+        return self._engine_live_updater
 
 
 @dataclass
@@ -620,9 +627,9 @@ async def update_all_flows_async(options: FlowLiveUpdaterOptions) -> dict[str, _
     """
     await ensure_all_flows_built_async()
     async def _update_flow(fl: Flow) -> _engine.IndexUpdateInfo:
-        updater = await FlowLiveUpdater.create_async(fl, options)
-        await updater.wait_async()
-        return updater.update_stats()
+        async with FlowLiveUpdater(fl, options) as updater:
+            await updater.wait_async()
+            return updater.update_stats()
     fls = flows()
     all_stats = await asyncio.gather(*(_update_flow(fl) for fl in fls))
     return {fl.name: stats for fl, stats in zip(fls, all_stats)}