Expand active project wave and serialize refreshes

src/atocore/api/routes.py

@@ -18,6 +18,7 @@ from atocore.context.project_state import (
     set_state,
 )
 from atocore.ingestion.pipeline import (
+    exclusive_ingestion,
     get_ingestion_stats,
     get_source_status,
     ingest_configured_sources,
@@ -153,12 +154,13 @@ def api_ingest(req: IngestRequest) -> IngestResponse:
     """Ingest a markdown file or folder."""
     target = Path(req.path)
     try:
-        if target.is_file():
-            results = [ingest_file(target)]
-        elif target.is_dir():
-            results = ingest_folder(target)
-        else:
-            raise HTTPException(status_code=404, detail=f"Path not found: {req.path}")
+        with exclusive_ingestion():
+            if target.is_file():
+                results = [ingest_file(target)]
+            elif target.is_dir():
+                results = ingest_folder(target)
+            else:
+                raise HTTPException(status_code=404, detail=f"Path not found: {req.path}")
     except HTTPException:
         raise
     except Exception as e:
@@ -171,7 +173,8 @@ def api_ingest(req: IngestRequest) -> IngestResponse:
 def api_ingest_sources() -> IngestSourcesResponse:
     """Ingest enabled configured source directories."""
     try:
-        results = ingest_configured_sources()
+        with exclusive_ingestion():
+            results = ingest_configured_sources()
     except Exception as e:
         log.error("ingest_sources_failed", error=str(e))
         raise HTTPException(status_code=500, detail=f"Configured source ingestion failed: {e}")
@@ -246,7 +249,8 @@ def api_project_update(project_name: str, req: ProjectUpdateRequest) -> dict:
 def api_refresh_project(project_name: str, purge_deleted: bool = False) -> ProjectRefreshResponse:
     """Refresh one registered project from its configured ingest roots."""
     try:
-        result = refresh_registered_project(project_name, purge_deleted=purge_deleted)
+        with exclusive_ingestion():
+            result = refresh_registered_project(project_name, purge_deleted=purge_deleted)
     except ValueError as e:
         raise HTTPException(status_code=404, detail=str(e))
     except Exception as e:

src/atocore/ingestion/pipeline.py

@@ -2,8 +2,10 @@
 
 import hashlib
 import json
+import threading
 import time
 import uuid
+from contextlib import contextmanager
 from pathlib import Path
 
 import atocore.config as _config
@@ -17,6 +19,17 @@ log = get_logger("ingestion")
 
 # Encodings to try when reading markdown files
 _ENCODINGS = ["utf-8", "utf-8-sig", "latin-1", "cp1252"]
+_INGESTION_LOCK = threading.Lock()
+
+
+@contextmanager
+def exclusive_ingestion():
+    """Serialize long-running ingestion operations across API requests."""
+    _INGESTION_LOCK.acquire()
+    try:
+        yield
+    finally:
+        _INGESTION_LOCK.release()
 
 
 def ingest_file(file_path: Path) -> dict: