Add pause/resume/stop/restart controls to AssetSeeder

- Add PAUSED state to state machine
- Add pause() method - blocks scan at next checkpoint
- Add resume() method - unblocks paused scan
- Add stop() method - alias for cancel()
- Add restart() method - cancel + wait + start with same/overridden params
- Add _check_pause_and_cancel() helper for checkpoint locations
- Emit assets.seed.paused and assets.seed.resumed WebSocket events
- Update get_object_info to use async seeder instead of blocking seed_assets
- Scan all roots (models, input, output) on object_info, not just models

Amp-Thread-ID: https://ampcode.com/threads/T-019c4f2b-5801-711c-8d47-bd1525808d77
Co-authored-by: Amp <amp@ampcode.com>

app/assets/seeder.py

@@ -30,6 +30,7 @@ class State(Enum):
 
     IDLE = "IDLE"
     RUNNING = "RUNNING"
+    PAUSED = "PAUSED"
     CANCELLING = "CANCELLING"
 
 
@@ -90,6 +91,8 @@ class AssetSeeder:
         self._errors: list[str] = []
         self._thread: threading.Thread | None = None
         self._cancel_event = threading.Event()
+        self._pause_event = threading.Event()
+        self._pause_event.set()  # Start unpaused (set = running, clear = paused)
         self._roots: tuple[RootType, ...] = ()
         self._phase: ScanPhase = ScanPhase.FULL
         self._compute_hashes: bool = False
@@ -127,6 +130,7 @@ class AssetSeeder:
             self._compute_hashes = compute_hashes
             self._progress_callback = progress_callback
             self._cancel_event.clear()
+            self._pause_event.set()  # Ensure unpaused when starting
             self._thread = threading.Thread(
                 target=self._run_scan,
                 name="AssetSeeder",
@@ -187,15 +191,94 @@ class AssetSeeder:
         """Request cancellation of the current scan.
 
         Returns:
-            True if cancellation was requested, False if not running
+            True if cancellation was requested, False if not running or paused
+        """
+        with self._lock:
+            if self._state not in (State.RUNNING, State.PAUSED):
+                return False
+            self._state = State.CANCELLING
+            self._cancel_event.set()
+            self._pause_event.set()  # Unblock if paused so thread can exit
+            return True
+
+    def stop(self) -> bool:
+        """Stop the current scan (alias for cancel).
+
+        Returns:
+            True if stop was requested, False if not running
+        """
+        return self.cancel()
+
+    def pause(self) -> bool:
+        """Pause the current scan.
+
+        The scan will complete its current batch before pausing.
+
+        Returns:
+            True if pause was requested, False if not running
         """
         with self._lock:
             if self._state != State.RUNNING:
                 return False
-            self._state = State.CANCELLING
-            self._cancel_event.set()
+            self._state = State.PAUSED
+            self._pause_event.clear()
             return True
 
+    def resume(self) -> bool:
+        """Resume a paused scan.
+
+        Returns:
+            True if resumed, False if not paused
+        """
+        with self._lock:
+            if self._state != State.PAUSED:
+                return False
+            self._state = State.RUNNING
+            self._pause_event.set()
+            self._emit_event("assets.seed.resumed", {})
+            return True
+
+    def restart(
+        self,
+        roots: tuple[RootType, ...] | None = None,
+        phase: ScanPhase | None = None,
+        progress_callback: ProgressCallback | None = None,
+        prune_first: bool | None = None,
+        compute_hashes: bool | None = None,
+        timeout: float = 5.0,
+    ) -> bool:
+        """Cancel any running scan and start a new one.
+
+        Args:
+            roots: Roots to scan (defaults to previous roots)
+            phase: Scan phase (defaults to previous phase)
+            progress_callback: Progress callback (defaults to previous)
+            prune_first: Prune before scan (defaults to previous)
+            compute_hashes: Compute hashes (defaults to previous)
+            timeout: Max seconds to wait for current scan to stop
+
+        Returns:
+            True if new scan was started, False if failed to stop previous
+        """
+        with self._lock:
+            prev_roots = self._roots
+            prev_phase = self._phase
+            prev_callback = self._progress_callback
+            prev_prune = getattr(self, "_prune_first", False)
+            prev_hashes = self._compute_hashes
+
+        self.cancel()
+        if not self.wait(timeout=timeout):
+            return False
+
+        return self.start(
+            roots=roots if roots is not None else prev_roots,
+            phase=phase if phase is not None else prev_phase,
+            progress_callback=progress_callback if progress_callback is not None else prev_callback,
+            prune_first=prune_first if prune_first is not None else prev_prune,
+            compute_hashes=compute_hashes if compute_hashes is not None else prev_hashes,
+        )
+
     def wait(self, timeout: float | None = None) -> bool:
         """Wait for the current scan to complete.
 
@@ -284,6 +367,21 @@ class AssetSeeder:
         """Check if cancellation has been requested."""
         return self._cancel_event.is_set()
 
+    def _check_pause_and_cancel(self) -> bool:
+        """Block while paused, then check if cancelled.
+
+        Call this at checkpoint locations in scan loops. It will:
+        1. Block indefinitely while paused (until resume or cancel)
+        2. Return True if cancelled, False to continue
+
+        Returns:
+            True if scan should stop, False to continue
+        """
+        if not self._pause_event.is_set():
+            self._emit_event("assets.seed.paused", {})
+        self._pause_event.wait()  # Blocks if paused
+        return self._is_cancelled()
+
     def _emit_event(self, event_type: str, data: dict) -> None:
         """Emit a WebSocket event if server is available."""
         try:
@@ -377,7 +475,7 @@ class AssetSeeder:
                 if marked > 0:
                     logging.info("Marked %d cache states as missing before scan", marked)
 
-            if self._is_cancelled():
+            if self._check_pause_and_cancel():
                 logging.info("Asset scan cancelled after pruning phase")
                 cancelled = True
                 return
@@ -388,7 +486,7 @@ class AssetSeeder:
             if phase in (ScanPhase.FAST, ScanPhase.FULL):
                 total_created, skipped_existing, total_paths = self._run_fast_phase(roots)
 
-                if self._is_cancelled():
+                if self._check_pause_and_cancel():
                     cancelled = True
                     return
 
@@ -404,7 +502,7 @@ class AssetSeeder:
 
             # Phase 2: Enrichment scan (metadata + hashes)
             if phase in (ScanPhase.ENRICH, ScanPhase.FULL):
-                if self._is_cancelled():
+                if self._check_pause_and_cancel():
                     cancelled = True
                     return
 
@@ -469,11 +567,11 @@ class AssetSeeder:
 
         existing_paths: set[str] = set()
         for r in roots:
-            if self._is_cancelled():
+            if self._check_pause_and_cancel():
                 return total_created, skipped_existing, 0
             existing_paths.update(sync_root_safely(r))
 
-        if self._is_cancelled():
+        if self._check_pause_and_cancel():
             return total_created, skipped_existing, 0
 
         paths = collect_paths_for_roots(roots)
@@ -489,7 +587,7 @@ class AssetSeeder:
         specs, tag_pool, skipped_existing = build_stub_specs(paths, existing_paths)
         self._update_progress(skipped=skipped_existing)
 
-        if self._is_cancelled():
+        if self._check_pause_and_cancel():
             return total_created, skipped_existing, total_paths
 
         batch_size = 500
@@ -497,7 +595,7 @@ class AssetSeeder:
         progress_interval = 1.0
 
         for i in range(0, len(specs), batch_size):
-            if self._is_cancelled():
+            if self._check_pause_and_cancel():
                 logging.info(
                     "Fast scan cancelled after %d/%d files (created=%d)",
                     i,
@@ -554,7 +652,7 @@ class AssetSeeder:
         )
 
         while True:
-            if self._is_cancelled():
+            if self._check_pause_and_cancel():
                 logging.info("Enrich scan cancelled after %d assets", total_enriched)
                 break
 

server.py

@@ -33,7 +33,7 @@ import node_helpers
 from comfyui_version import __version__
 from app.frontend_management import FrontendManager, parse_version
 from comfy_api.internal import _ComfyNodeInternal
-from app.assets.scanner import seed_assets
+from app.assets.seeder import asset_seeder
 from app.assets.api.routes import register_assets_system
 
 from app.user_manager import UserManager
@@ -691,10 +691,7 @@ class PromptServer():
 
         @routes.get("/object_info")
         async def get_object_info(request):
-            try:
-                seed_assets(["models"])
-            except Exception as e:
-                logging.error(f"Failed to seed assets: {e}")
+            asset_seeder.start(roots=("models", "input", "output"))
             with folder_paths.cache_helper:
                 out = {}
                 for x in nodes.NODE_CLASS_MAPPINGS:

tests-unit/seeder_test/test_seeder.py

@@ -523,3 +523,261 @@ class TestSeederPhases:
 
             assert len(fast_called) == 1
             assert len(enrich_called) == 1
+
+
+class TestSeederPauseResume:
+    """Test pause/resume behavior."""
+
+    def test_pause_transitions_to_paused(
+        self, fresh_seeder: AssetSeeder, mock_dependencies
+    ):
+        barrier = threading.Event()
+
+        def slow_collect(*args):
+            barrier.wait(timeout=5.0)
+            return []
+
+        with patch(
+            "app.assets.seeder.collect_paths_for_roots", side_effect=slow_collect
+        ):
+            fresh_seeder.start(roots=("models",))
+            time.sleep(0.05)
+
+            paused = fresh_seeder.pause()
+            assert paused is True
+            assert fresh_seeder.get_status().state == State.PAUSED
+
+            barrier.set()
+
+    def test_pause_when_idle_returns_false(self, fresh_seeder: AssetSeeder):
+        paused = fresh_seeder.pause()
+        assert paused is False
+
+    def test_resume_returns_to_running(
+        self, fresh_seeder: AssetSeeder, mock_dependencies
+    ):
+        barrier = threading.Event()
+
+        def slow_collect(*args):
+            barrier.wait(timeout=5.0)
+            return []
+
+        with patch(
+            "app.assets.seeder.collect_paths_for_roots", side_effect=slow_collect
+        ):
+            fresh_seeder.start(roots=("models",))
+            time.sleep(0.05)
+
+            fresh_seeder.pause()
+            assert fresh_seeder.get_status().state == State.PAUSED
+
+            resumed = fresh_seeder.resume()
+            assert resumed is True
+            assert fresh_seeder.get_status().state == State.RUNNING
+
+            barrier.set()
+
+    def test_resume_when_not_paused_returns_false(
+        self, fresh_seeder: AssetSeeder, mock_dependencies
+    ):
+        barrier = threading.Event()
+
+        def slow_collect(*args):
+            barrier.wait(timeout=5.0)
+            return []
+
+        with patch(
+            "app.assets.seeder.collect_paths_for_roots", side_effect=slow_collect
+        ):
+            fresh_seeder.start(roots=("models",))
+            time.sleep(0.05)
+
+            resumed = fresh_seeder.resume()
+            assert resumed is False
+
+            barrier.set()
+
+    def test_cancel_while_paused_works(
+        self, fresh_seeder: AssetSeeder, mock_dependencies
+    ):
+        barrier = threading.Event()
+        reached_checkpoint = threading.Event()
+
+        def slow_collect(*args):
+            reached_checkpoint.set()
+            barrier.wait(timeout=5.0)
+            return []
+
+        with patch(
+            "app.assets.seeder.collect_paths_for_roots", side_effect=slow_collect
+        ):
+            fresh_seeder.start(roots=("models",))
+            reached_checkpoint.wait(timeout=1.0)
+
+            fresh_seeder.pause()
+            time.sleep(0.05)
+
+            cancelled = fresh_seeder.cancel()
+            assert cancelled is True
+
+            barrier.set()
+            fresh_seeder.wait(timeout=5.0)
+            assert fresh_seeder.get_status().state == State.IDLE
+
+    def test_pause_blocks_scan_until_resume(self, fresh_seeder: AssetSeeder):
+        """Verify scan blocks at checkpoint while paused."""
+        batch_count = 0
+        pause_detected = threading.Event()
+        resume_signal = threading.Event()
+
+        def counting_insert(specs, tags):
+            nonlocal batch_count
+            batch_count += 1
+            if batch_count == 1:
+                pause_detected.set()
+                resume_signal.wait(timeout=5.0)
+            return len(specs)
+
+        paths = [f"/path/file{i}.safetensors" for i in range(1000)]
+        specs = [
+            {
+                "abs_path": p,
+                "size_bytes": 100,
+                "mtime_ns": 0,
+                "info_name": f"file{i}",
+                "tags": [],
+                "fname": f"file{i}",
+                "metadata": None,
+                "hash": None,
+                "mime_type": None,
+            }
+            for i, p in enumerate(paths)
+        ]
+
+        with (
+            patch("app.assets.seeder.dependencies_available", return_value=True),
+            patch("app.assets.seeder.sync_root_safely", return_value=set()),
+            patch("app.assets.seeder.collect_paths_for_roots", return_value=paths),
+            patch("app.assets.seeder.build_stub_specs", return_value=(specs, set(), 0)),
+            patch("app.assets.seeder.insert_asset_specs", side_effect=counting_insert),
+            patch("app.assets.seeder.get_unenriched_assets_for_roots", return_value=[]),
+            patch("app.assets.seeder.enrich_assets_batch", return_value=(0, 0)),
+        ):
+            fresh_seeder.start(roots=("models",))
+            pause_detected.wait(timeout=2.0)
+
+            fresh_seeder.pause()
+            count_at_pause = batch_count
+            time.sleep(0.1)
+            assert batch_count == count_at_pause
+
+            fresh_seeder.resume()
+            resume_signal.set()
+            fresh_seeder.wait(timeout=5.0)
+
+            assert batch_count > count_at_pause
+
+
+class TestSeederStopRestart:
+    """Test stop and restart behavior."""
+
+    def test_stop_is_alias_for_cancel(
+        self, fresh_seeder: AssetSeeder, mock_dependencies
+    ):
+        barrier = threading.Event()
+
+        def slow_collect(*args):
+            barrier.wait(timeout=5.0)
+            return []
+
+        with patch(
+            "app.assets.seeder.collect_paths_for_roots", side_effect=slow_collect
+        ):
+            fresh_seeder.start(roots=("models",))
+            time.sleep(0.05)
+
+            stopped = fresh_seeder.stop()
+            assert stopped is True
+            assert fresh_seeder.get_status().state == State.CANCELLING
+
+            barrier.set()
+
+    def test_restart_cancels_and_starts_new_scan(
+        self, fresh_seeder: AssetSeeder, mock_dependencies
+    ):
+        barrier = threading.Event()
+        start_count = 0
+
+        def slow_collect(*args):
+            nonlocal start_count
+            start_count += 1
+            if start_count == 1:
+                barrier.wait(timeout=5.0)
+            return []
+
+        with patch(
+            "app.assets.seeder.collect_paths_for_roots", side_effect=slow_collect
+        ):
+            fresh_seeder.start(roots=("models",))
+            time.sleep(0.05)
+
+            barrier.set()
+            restarted = fresh_seeder.restart()
+            assert restarted is True
+
+            fresh_seeder.wait(timeout=5.0)
+            assert start_count == 2
+
+    def test_restart_preserves_previous_params(self, fresh_seeder: AssetSeeder):
+        """Verify restart uses previous params when not overridden."""
+        collected_roots = []
+
+        def track_collect(roots):
+            collected_roots.append(roots)
+            return []
+
+        with (
+            patch("app.assets.seeder.dependencies_available", return_value=True),
+            patch("app.assets.seeder.sync_root_safely", return_value=set()),
+            patch("app.assets.seeder.collect_paths_for_roots", side_effect=track_collect),
+            patch("app.assets.seeder.build_stub_specs", return_value=([], set(), 0)),
+            patch("app.assets.seeder.insert_asset_specs", return_value=0),
+            patch("app.assets.seeder.get_unenriched_assets_for_roots", return_value=[]),
+            patch("app.assets.seeder.enrich_assets_batch", return_value=(0, 0)),
+        ):
+            fresh_seeder.start(roots=("input", "output"))
+            fresh_seeder.wait(timeout=5.0)
+
+            fresh_seeder.restart()
+            fresh_seeder.wait(timeout=5.0)
+
+            assert len(collected_roots) == 2
+            assert collected_roots[0] == ("input", "output")
+            assert collected_roots[1] == ("input", "output")
+
+    def test_restart_can_override_params(self, fresh_seeder: AssetSeeder):
+        """Verify restart can override previous params."""
+        collected_roots = []
+
+        def track_collect(roots):
+            collected_roots.append(roots)
+            return []
+
+        with (
+            patch("app.assets.seeder.dependencies_available", return_value=True),
+            patch("app.assets.seeder.sync_root_safely", return_value=set()),
+            patch("app.assets.seeder.collect_paths_for_roots", side_effect=track_collect),
+            patch("app.assets.seeder.build_stub_specs", return_value=([], set(), 0)),
+            patch("app.assets.seeder.insert_asset_specs", return_value=0),
+            patch("app.assets.seeder.get_unenriched_assets_for_roots", return_value=[]),
+            patch("app.assets.seeder.enrich_assets_batch", return_value=(0, 0)),
+        ):
+            fresh_seeder.start(roots=("models",))
+            fresh_seeder.wait(timeout=5.0)
+
+            fresh_seeder.restart(roots=("input",))
+            fresh_seeder.wait(timeout=5.0)
+
+            assert len(collected_roots) == 2
+            assert collected_roots[0] == ("models",)
+            assert collected_roots[1] == ("input",)