"""Background asset seeder with thread management and cancellation support.""" import logging import os import threading import time from dataclasses import dataclass, field from enum import Enum from typing import Callable from app.assets.scanner import ( ENRICHMENT_METADATA, ENRICHMENT_STUB, RootType, build_asset_specs, collect_paths_for_roots, enrich_assets_batch, get_all_known_prefixes, get_prefixes_for_root, get_unenriched_assets_for_roots, insert_asset_specs, mark_missing_outside_prefixes_safely, sync_root_safely, ) from app.database.db import dependencies_available class ScanInProgressError(Exception): """Raised when an operation cannot proceed because a scan is running.""" class State(Enum): """Seeder state machine states.""" IDLE = "IDLE" RUNNING = "RUNNING" PAUSED = "PAUSED" CANCELLING = "CANCELLING" class ScanPhase(Enum): """Scan phase options.""" FAST = "fast" # Phase 1: filesystem only (stubs) ENRICH = "enrich" # Phase 2: metadata + hash FULL = "full" # Both phases sequentially @dataclass class Progress: """Progress information for a scan operation.""" scanned: int = 0 total: int = 0 created: int = 0 skipped: int = 0 @dataclass class ScanStatus: """Current status of the asset seeder.""" state: State progress: Progress | None errors: list[str] = field(default_factory=list) ProgressCallback = Callable[[Progress], None] class _AssetSeeder: """Background asset scanning manager. Spawns ephemeral daemon threads for scanning. Each scan creates a new thread that exits when complete. Use the module-level ``asset_seeder`` instance. """ def __init__(self) -> None: # RLock is required because _run_scan() drains pending work while # holding _lock and re-enters start() which also acquires _lock. self._lock = threading.RLock() self._state = State.IDLE self._progress: Progress | None = None self._last_progress: Progress | None = None self._errors: list[str] = [] self._thread: threading.Thread | None = None self._cancel_event = threading.Event() self._run_gate = threading.Event() self._run_gate.set() # Start unpaused (set = running, clear = paused) self._roots: tuple[RootType, ...] = () self._phase: ScanPhase = ScanPhase.FULL self._compute_hashes: bool = False self._prune_first: bool = False self._progress_callback: ProgressCallback | None = None self._disabled: bool = False self._pending_enrich: dict | None = None def disable(self) -> None: """Disable the asset seeder, preventing any scans from starting.""" self._disabled = True logging.info("Asset seeder disabled") def is_disabled(self) -> bool: """Check if the asset seeder is disabled.""" return self._disabled def start( self, roots: tuple[RootType, ...] = ("models", "input", "output"), phase: ScanPhase = ScanPhase.FULL, progress_callback: ProgressCallback | None = None, prune_first: bool = False, compute_hashes: bool = False, ) -> bool: """Start a background scan for the given roots. Args: roots: Tuple of root types to scan (models, input, output) phase: Scan phase to run (FAST, ENRICH, or FULL for both) progress_callback: Optional callback called with progress updates prune_first: If True, prune orphaned assets before scanning compute_hashes: If True, compute blake3 hashes (slow) Returns: True if scan was started, False if already running """ if self._disabled: logging.debug("Asset seeder is disabled, skipping start") return False logging.info("Seeder start (roots=%s, phase=%s)", roots, phase.value) with self._lock: if self._state != State.IDLE: logging.info("Asset seeder already running, skipping start") return False self._state = State.RUNNING self._progress = Progress() self._errors = [] self._roots = roots self._phase = phase self._prune_first = prune_first self._compute_hashes = compute_hashes self._progress_callback = progress_callback self._cancel_event.clear() self._run_gate.set() # Ensure unpaused when starting self._thread = threading.Thread( target=self._run_scan, name="_AssetSeeder", daemon=True, ) self._thread.start() return True def start_fast( self, roots: tuple[RootType, ...] = ("models", "input", "output"), progress_callback: ProgressCallback | None = None, prune_first: bool = False, ) -> bool: """Start a fast scan (phase 1 only) - creates stub records. Args: roots: Tuple of root types to scan progress_callback: Optional callback for progress updates prune_first: If True, prune orphaned assets before scanning Returns: True if scan was started, False if already running """ return self.start( roots=roots, phase=ScanPhase.FAST, progress_callback=progress_callback, prune_first=prune_first, compute_hashes=False, ) def start_enrich( self, roots: tuple[RootType, ...] = ("models", "input", "output"), progress_callback: ProgressCallback | None = None, compute_hashes: bool = False, ) -> bool: """Start an enrichment scan (phase 2 only) - extracts metadata and hashes. Args: roots: Tuple of root types to scan progress_callback: Optional callback for progress updates compute_hashes: If True, compute blake3 hashes Returns: True if scan was started, False if already running """ return self.start( roots=roots, phase=ScanPhase.ENRICH, progress_callback=progress_callback, prune_first=False, compute_hashes=compute_hashes, ) def enqueue_enrich( self, roots: tuple[RootType, ...] = ("models", "input", "output"), compute_hashes: bool = False, ) -> bool: """Start an enrichment scan now, or queue it for after the current scan. If the seeder is idle, starts immediately. Otherwise, the enrich request is stored and will run automatically when the current scan finishes. Args: roots: Tuple of root types to scan compute_hashes: If True, compute blake3 hashes Returns: True if started immediately, False if queued for later """ with self._lock: if self.start_enrich(roots=roots, compute_hashes=compute_hashes): return True if self._pending_enrich is not None: existing_roots = set(self._pending_enrich["roots"]) existing_roots.update(roots) self._pending_enrich["roots"] = tuple(existing_roots) self._pending_enrich["compute_hashes"] = ( self._pending_enrich["compute_hashes"] or compute_hashes ) else: self._pending_enrich = { "roots": roots, "compute_hashes": compute_hashes, } logging.info("Enrich scan queued (roots=%s)", self._pending_enrich["roots"]) return False def cancel(self) -> bool: """Request cancellation of the current scan. Returns: 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 logging.info("Asset seeder cancelling (was %s)", self._state.value) self._state = State.CANCELLING self._cancel_event.set() self._run_gate.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 logging.info("Asset seeder pausing") self._state = State.PAUSED self._run_gate.clear() return True def resume(self) -> bool: """Resume a paused scan. This is a noop if the scan is not in the PAUSED state Returns: True if resumed, False if not paused """ with self._lock: if self._state != State.PAUSED: return False logging.info("Asset seeder resuming") self._state = State.RUNNING self._run_gate.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 """ logging.info("Asset seeder restart requested") with self._lock: prev_roots = self._roots prev_phase = self._phase prev_callback = self._progress_callback prev_prune = self._prune_first prev_hashes = self._compute_hashes self.cancel() if not self.wait(timeout=timeout): return False cb = progress_callback if progress_callback is not None else prev_callback 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=cb, 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. Args: timeout: Maximum seconds to wait, or None for no timeout Returns: True if scan completed, False if timeout expired or no scan running """ with self._lock: thread = self._thread if thread is None: return True thread.join(timeout=timeout) return not thread.is_alive() def get_status(self) -> ScanStatus: """Get the current status and progress of the seeder.""" with self._lock: src = self._progress or self._last_progress return ScanStatus( state=self._state, progress=Progress( scanned=src.scanned, total=src.total, created=src.created, skipped=src.skipped, ) if src else None, errors=list(self._errors), ) def shutdown(self, timeout: float = 5.0) -> None: """Gracefully shutdown: cancel any running scan and wait for thread. Args: timeout: Maximum seconds to wait for thread to exit """ self.cancel() self.wait(timeout=timeout) with self._lock: self._thread = None def mark_missing_outside_prefixes(self) -> int: """Mark references as missing when outside all known root prefixes. This is a non-destructive soft-delete operation. Assets and their metadata are preserved, but references are flagged as missing. They can be restored if the file reappears in a future scan. This operation is decoupled from scanning to prevent partial scans from accidentally marking assets belonging to other roots. Should be called explicitly when cleanup is desired, typically after a full scan of all roots or during maintenance. Returns: Number of references marked as missing Raises: ScanInProgressError: If a scan is currently running """ with self._lock: if self._state != State.IDLE: raise ScanInProgressError( "Cannot mark missing assets while scan is running" ) self._state = State.RUNNING try: if not dependencies_available(): logging.warning( "Database dependencies not available, skipping mark missing" ) return 0 all_prefixes = get_all_known_prefixes() marked = mark_missing_outside_prefixes_safely(all_prefixes) if marked > 0: logging.info("Marked %d references as missing", marked) return marked finally: with self._lock: self._reset_to_idle() def _reset_to_idle(self) -> None: """Reset state to IDLE, preserving last progress. Caller must hold _lock.""" self._last_progress = self._progress self._state = State.IDLE self._progress = None def _is_cancelled(self) -> bool: """Check if cancellation has been requested.""" return self._cancel_event.is_set() def _is_paused_or_cancelled(self) -> bool: """Non-blocking check: True if paused or cancelled. Use as interrupt_check for I/O-bound work (e.g. hashing) so that file handles are released immediately on pause rather than held open while blocked. The caller is responsible for blocking on _check_pause_and_cancel() afterward. """ return not self._run_gate.is_set() or 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._run_gate.is_set(): self._emit_event("assets.seed.paused", {}) self._run_gate.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: from server import PromptServer if hasattr(PromptServer, "instance") and PromptServer.instance: PromptServer.instance.send_sync(event_type, data) except Exception: pass def _update_progress( self, scanned: int | None = None, total: int | None = None, created: int | None = None, skipped: int | None = None, ) -> None: """Update progress counters (thread-safe).""" callback: ProgressCallback | None = None progress: Progress | None = None with self._lock: if self._progress is None: return if scanned is not None: self._progress.scanned = scanned if total is not None: self._progress.total = total if created is not None: self._progress.created = created if skipped is not None: self._progress.skipped = skipped if self._progress_callback: callback = self._progress_callback progress = Progress( scanned=self._progress.scanned, total=self._progress.total, created=self._progress.created, skipped=self._progress.skipped, ) if callback and progress: try: callback(progress) except Exception: pass _MAX_ERRORS = 200 def _add_error(self, message: str) -> None: """Add an error message (thread-safe), capped at _MAX_ERRORS.""" with self._lock: if len(self._errors) < self._MAX_ERRORS: self._errors.append(message) def _log_scan_config(self, roots: tuple[RootType, ...]) -> None: """Log the directories that will be scanned.""" import folder_paths for root in roots: if root == "models": logging.info( "Asset scan [models] directory: %s", os.path.abspath(folder_paths.models_dir), ) else: prefixes = get_prefixes_for_root(root) if prefixes: logging.info("Asset scan [%s] directories: %s", root, prefixes) def _run_scan(self) -> None: """Main scan loop running in background thread.""" t_start = time.perf_counter() roots = self._roots phase = self._phase cancelled = False total_created = 0 total_enriched = 0 skipped_existing = 0 total_paths = 0 try: if not dependencies_available(): self._add_error("Database dependencies not available") self._emit_event( "assets.seed.error", {"message": "Database dependencies not available"}, ) return if self._prune_first: all_prefixes = get_all_known_prefixes() marked = mark_missing_outside_prefixes_safely(all_prefixes) if marked > 0: logging.info("Marked %d refs as missing before scan", marked) if self._check_pause_and_cancel(): logging.info("Asset scan cancelled after pruning phase") cancelled = True return self._log_scan_config(roots) # Phase 1: Fast scan (stub records) if phase in (ScanPhase.FAST, ScanPhase.FULL): created, skipped, paths = self._run_fast_phase(roots) total_created, skipped_existing, total_paths = created, skipped, paths if self._check_pause_and_cancel(): cancelled = True return self._emit_event( "assets.seed.fast_complete", { "roots": list(roots), "created": total_created, "skipped": skipped_existing, "total": total_paths, }, ) # Phase 2: Enrichment scan (metadata + hashes) if phase in (ScanPhase.ENRICH, ScanPhase.FULL): if self._check_pause_and_cancel(): cancelled = True return enrich_cancelled, total_enriched = self._run_enrich_phase(roots) if enrich_cancelled: cancelled = True return self._emit_event( "assets.seed.enrich_complete", { "roots": list(roots), "enriched": total_enriched, }, ) elapsed = time.perf_counter() - t_start logging.info( "Scan(%s, %s) done %.3fs: created=%d enriched=%d skipped=%d", roots, phase.value, elapsed, total_created, total_enriched, skipped_existing, ) self._emit_event( "assets.seed.completed", { "phase": phase.value, "total": total_paths, "created": total_created, "enriched": total_enriched, "skipped": skipped_existing, "elapsed": round(elapsed, 3), }, ) except Exception as e: self._add_error(f"Scan failed: {e}") logging.exception("Asset scan failed") self._emit_event("assets.seed.error", {"message": str(e)}) finally: if cancelled: self._emit_event( "assets.seed.cancelled", { "scanned": self._progress.scanned if self._progress else 0, "total": total_paths, "created": total_created, }, ) with self._lock: self._reset_to_idle() pending = self._pending_enrich if pending is not None: self._pending_enrich = None if not self.start_enrich( roots=pending["roots"], compute_hashes=pending["compute_hashes"], ): logging.warning( "Pending enrich scan could not start (roots=%s)", pending["roots"], ) def _run_fast_phase(self, roots: tuple[RootType, ...]) -> tuple[int, int, int]: """Run phase 1: fast scan to create stub records. Returns: Tuple of (total_created, skipped_existing, total_paths) """ t_fast_start = time.perf_counter() total_created = 0 skipped_existing = 0 existing_paths: set[str] = set() t_sync = time.perf_counter() for r in roots: if self._check_pause_and_cancel(): return total_created, skipped_existing, 0 existing_paths.update(sync_root_safely(r)) logging.debug( "Fast scan: sync_root phase took %.3fs (%d existing paths)", time.perf_counter() - t_sync, len(existing_paths), ) if self._check_pause_and_cancel(): return total_created, skipped_existing, 0 t_collect = time.perf_counter() paths = collect_paths_for_roots(roots) logging.debug( "Fast scan: collect_paths took %.3fs (%d paths found)", time.perf_counter() - t_collect, len(paths), ) total_paths = len(paths) self._update_progress(total=total_paths) self._emit_event( "assets.seed.started", {"roots": list(roots), "total": total_paths, "phase": "fast"}, ) # Use stub specs (no metadata extraction, no hashing) t_specs = time.perf_counter() specs, tag_pool, skipped_existing = build_asset_specs( paths, existing_paths, enable_metadata_extraction=False, compute_hashes=False, ) logging.debug( "Fast scan: build_asset_specs took %.3fs (%d specs, %d skipped)", time.perf_counter() - t_specs, len(specs), skipped_existing, ) self._update_progress(skipped=skipped_existing) if self._check_pause_and_cancel(): return total_created, skipped_existing, total_paths batch_size = 500 last_progress_time = time.perf_counter() progress_interval = 1.0 for i in range(0, len(specs), batch_size): if self._check_pause_and_cancel(): logging.info( "Fast scan cancelled after %d/%d files (created=%d)", i, len(specs), total_created, ) return total_created, skipped_existing, total_paths batch = specs[i : i + batch_size] batch_tags = {t for spec in batch for t in spec["tags"]} try: created = insert_asset_specs(batch, batch_tags) total_created += created except Exception as e: self._add_error(f"Batch insert failed at offset {i}: {e}") logging.exception("Batch insert failed at offset %d", i) scanned = i + len(batch) now = time.perf_counter() self._update_progress(scanned=scanned, created=total_created) if now - last_progress_time >= progress_interval: self._emit_event( "assets.seed.progress", { "phase": "fast", "scanned": scanned, "total": len(specs), "created": total_created, }, ) last_progress_time = now self._update_progress(scanned=len(specs), created=total_created) logging.info( "Fast scan complete: %.3fs total (created=%d, skipped=%d, total_paths=%d)", time.perf_counter() - t_fast_start, total_created, skipped_existing, total_paths, ) return total_created, skipped_existing, total_paths def _run_enrich_phase(self, roots: tuple[RootType, ...]) -> tuple[bool, int]: """Run phase 2: enrich existing records with metadata and hashes. Returns: Tuple of (cancelled, total_enriched) """ total_enriched = 0 batch_size = 100 last_progress_time = time.perf_counter() progress_interval = 1.0 # Get the target enrichment level based on compute_hashes if not self._compute_hashes: target_max_level = ENRICHMENT_STUB else: target_max_level = ENRICHMENT_METADATA self._emit_event( "assets.seed.started", {"roots": list(roots), "phase": "enrich"}, ) skip_ids: set[str] = set() consecutive_empty = 0 max_consecutive_empty = 3 # Hash checkpoints survive across batches so interrupted hashes # can be resumed without re-reading the entire file. hash_checkpoints: dict[str, object] = {} while True: if self._check_pause_and_cancel(): logging.info("Enrich scan cancelled after %d assets", total_enriched) return True, total_enriched # Fetch next batch of unenriched assets unenriched = get_unenriched_assets_for_roots( roots, max_level=target_max_level, limit=batch_size, ) # Filter out previously failed references if skip_ids: unenriched = [r for r in unenriched if r.reference_id not in skip_ids] if not unenriched: break enriched, failed_ids = enrich_assets_batch( unenriched, extract_metadata=True, compute_hash=self._compute_hashes, interrupt_check=self._is_paused_or_cancelled, hash_checkpoints=hash_checkpoints, ) total_enriched += enriched skip_ids.update(failed_ids) if enriched == 0: consecutive_empty += 1 if consecutive_empty >= max_consecutive_empty: logging.warning( "Enrich phase stopping: %d consecutive batches with no progress (%d skipped)", consecutive_empty, len(skip_ids), ) break else: consecutive_empty = 0 now = time.perf_counter() if now - last_progress_time >= progress_interval: self._emit_event( "assets.seed.progress", { "phase": "enrich", "enriched": total_enriched, }, ) last_progress_time = now return False, total_enriched asset_seeder = _AssetSeeder()